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Everything you need to know about Computed Tomography (CT) & CT Scanning

May 2020 Imaging Pearls - Educational Tools | CT Scanning | CT Imaging | CT Scan Protocols - CTisus
Imaging Pearls ❯ May 2020

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3D and Workflow

  • Purpose: Cinematic rendering (CR), a recently launched, FDA-approved rendering technique converts CT image datasets into nearly photorealistic 3D reconstructions by using a unique lighting model. The purpose of this study was to compare CR to volume rendering technique (VRT) images in the preoperative visualization of multifragmentary intraarticular lower extremity fractures.
    Conclusions: CR reconstructions are superior to VRT due to higher image quality and higher anatomical accuracy. Traumatologists find CR reconstructions to improve visualization of lower extremity fractures which should thus be used for fracture demonstration during interdisciplinary conferences.
    Is CT-based cinematic rendering superior to volume rendering technique in T the preoperative evaluation of multifragmentary intraarticular lower extremity fractures?
    Lena M. Wollschlaegera et al.
    European Journal of Radiology 126 (2020) 108911
  • "CR uses a unique lighting model which is far more complex than the ray casting methods used in VR [5]. In CR, the algorithm is based on the global illumination model. This model incorporates information of billions of photons traveling through the volumetric dataset, and the interactions of these rays of light with a joining voxels. Complex lighting effects such as refraction, absorption, depth of field, soft shadows and ambient occlusion can be created.”
    Is CT-based cinematic rendering superior to volume rendering technique in T the preoperative evaluation of multifragmentary intraarticular lower extremity fractures?
    Lena M. Wollschlaegera et al.
    European Journal of Radiology 126 (2020) 108911
  • "Recently, Dappa et al. published a review comparing the potential value of CR to conventional VRT images and illustrated potential clinical applications of CR such as preoperative treatment planning. In their experience, CR is especially striking for visualizing structures with high density and high contrast such as bones. Further- more, they highlighted the high quality of CR images and their ability for the perception of depth and the photorealistic representation of human anatomy.”
    Is CT-based cinematic rendering superior to volume rendering technique in T the preoperative evaluation of multifragmentary intraarticular lower extremity fractures?
    Lena M. Wollschlaegera et al.
    European Journal of Radiology 126 (2020) 108911
  • “CR provides a more detailed visualization of multifragmentary intraarticular lower extremity fractures with improved image quality and higher anatomical accuracy compared to VRT, thus facilitating the understanding of fracture morphology in multifragmentary intraarticular fractures. Therefore, CR improves traumatological pre-operative fracture visualization in patients with multifragmentary in- traarticular lower extremity fractures and thus can be recommended for fracture demonstration during interdisciplinary conferences.”
    Is CT-based cinematic rendering superior to volume rendering technique in T the preoperative evaluation of multifragmentary intraarticular lower extremity fractures?
    Lena M. Wollschlaegera et al.
    European Journal of Radiology 126 (2020) 108911
Chest


  • The Role of Chest Imaging in Patient Management during the COVID-19 Pandemic: A Multinational Consensus Statement from the Fleischner Society.
    Rubin GD et al. Radiology. 2020 Apr 7:201365. doi: 10.1148/radiol.2020201365. [Epub ahead of print]

  • The Role of Chest Imaging in Patient Management during the COVID-19 Pandemic: A Multinational Consensus Statement from the Fleischner Society.
    Rubin GD et al. Radiology. 2020 Apr 7:201365. doi: 10.1148/radiol.2020201365. [Epub ahead of print]

  • The Role of Chest Imaging in Patient Management during the COVID-19 Pandemic: A Multinational Consensus Statement from the Fleischner Society.
    Rubin GD et al. Radiology. 2020 Apr 7:201365. doi: 10.1148/radiol.2020201365. [Epub ahead of print]

  • The Role of Chest Imaging in Patient Management during the COVID-19 Pandemic: A Multinational Consensus Statement from the Fleischner Society.
    Rubin GD et al. Radiology. 2020 Apr 7:201365. doi: 10.1148/radiol.2020201365. [Epub ahead of print]
  • “Thoracic imaging with chest radiography (CXR) and computed tomography (CT) are key tools for pulmonary disease diagnosis and management, but their role in the management of COVID-19 has not been considered within the multivariable context of the severity of respiratory disease, pre-test probability, risk factors for disease progression, and critical resource constraints. To address this deficit, a multidisciplinary panel comprised principally of radiologists and pulmonologists from 10 countries with experience managing COVID-19 patients across a spectrum of healthcare environments evaluated the utility of imaging within three scenarios representing varying risk factors, community conditions, and resource constraints. Fourteen key questions, corresponding to 11 decision points within the three scenarios and three additional clinical situations, were rated by the panel based upon the anticipated value of the information that thoracic imaging would be expected to provide. The results were aggregated, resulting in five main and three additional recommendations intended to guide medical practitioners in the use of CXR and CT in the management of COVID-19.”
    The Role of Chest Imaging in Patient Management during the COVID-19 Pandemic: A Multinational Consensus Statement from the Fleischner Society.
    Rubin GD et al.
    Radiology. 2020 Apr 7:201365. doi: 10.1148/radiol.2020201365. [Epub ahead of print]
  • "Risk factors for poor outcomes in patients with COVID-19 infection are considered separately from pre-test probability, with common risk factors including age > 65 years, cardiovascular disease, diabetes, chronic respiratory disease, hypertension, and immune-compromised. Identifying a patient as being at high risk for COVID-19 progression is not necessarily a feature of any single risk factor, but is rather a clinical judgement based on the combination of underlying comorbidities and general health status that suggests a higher level of clinical concern. Where appropriate, management variations based upon risk factors for disease progression are called out explicitly, as in Scenario 1. All clinical scenarios begin by characterizing COVID-19 status based upon the availability of laboratory test results.”
    The Role of Chest Imaging in Patient Management during the COVID-19 Pandemic: A Multinational Consensus Statement from the Fleischner Society.
    Rubin GD et al.
    Radiology. 2020 Apr 7:201365. doi: 10.1148/radiol.2020201365. [Epub ahead of print]
  • "For COVID-19 negative patients or any patient for whom testing is not performed, imaging may reveal an alternative diagnosis to explain the patient’s clinical features, which should direct patient care as per existing clinical guidelines or standard clinical practice. If an alternative diagnosis is not revealed or images demonstrate features of COVID-19 infection, then subsequent clinical evaluation would depend upon the pre-test probability of COVID-19 infection and COVID-19 test availability. Falsely negative COVID-19 testing is more prevalent in high pre-test probability circumstances and repeat COVID-19 testing is therefore advised if available. Depending upon the imaging findings, other clinical investigations may be pursued.”
    The Role of Chest Imaging in Patient Management during the COVID-19 Pandemic: A Multinational Consensus Statement from the Fleischner Society.
    Rubin GD et al.
    Radiology. 2020 Apr 7:201365. doi: 10.1148/radiol.2020201365. [Epub ahead of print]
  • “Imaging is advised to support more rapid triage of patients in a resource-constrained setting when PoC COVID-19 testing is not available or negative . Imaging may reveal features of COVID-19, which within this scenario may be taken as a presumptive diagnosis of COVID-19 for medical triage and associated decisions regarding disposition, infection control, and clinical management. In this high pre-test probability environment, and as described for Scenario 2, the possibility of falsely negative COVID-19 testing creates a circumstance where a COVID-19 diagnosis may be presumed when imaging findings are strongly suggestive of COVID-19 despite negative COVID-19 testing. This guidance represents a variance from other published recommendations which advise against the use of imaging for the initial diagnosis of COVID-19 and was supported by direct experience amongst panelists providing care within the conditions described for this scenario. The relationship between disease severity and triage may need to be fluid depending upon resources and case load. When imaging reveals an alternative diagnosis to COVID-19, management is based upon established guidelines or standard clinical practice.”
    The Role of Chest Imaging in Patient Management during the COVID-19 Pandemic: A Multinational Consensus Statement from the Fleischner Society.
    Rubin GD et al.
    Radiology. 2020 Apr 7:201365. doi: 10.1148/radiol.2020201365. [Epub ahead of print]
Colon

  • Purpose The purpose of this study was to determine whether the measured size of active gastrointestinal hemorrhage was useful in predicting subsequent positive findings at catheter angiography.
    Materials and methods. Each CTA was reviewed, with axial measurements of the anterior–posterior and transverse dimensions of the largest foci of hemorrhage recorded. Volumetric analysis was used to measure the volume of hemorrhage. These measurements were performed for both the arterial and portal venous phases. Additionally, the interval growth between the arterial and portal venous phase was also calculated.
    CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
    Hsu M et al.
    Abdominal Radiology (2020) 45:615–622
  • Results There was a statistically significant difference in the absolute size of the maximum transverse dimension on portal venous phase imaging (mean = 19.8 mm, p < 0.001), as well as an interval increase in transverse (mean = 8.5 mm, p < 0.001) and anteriorposterior (mean = 5.4 mm, p = 0.027) size between arterial and portal venous phases in patients with positive catheter angiography versus negative catheter angiography. There was a statistically significant difference in the volume of hemorrhage on arterial (mean = 1.72 cm3, p = 0.020) and portal venous phases (mean = 5.89 cm3, p = 0.016), as well as an interval change in the size of hemorrhage between the two phases (mean = 4.17 cm3, p = 0.020) in patients with positive catheter angiography versus patients in the negative catheter angiography group.
    Conclusions The absolute axial size and volume of hemorrhage, as well as the interval change between the arterial and portal venous phases of CTA imaging is predictive of subsequent positive catheter angiography.
    CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
    Hsu M et al.
    Abdominal Radiology (2020) 45:615–622
  • Results There was a statistically significant difference in the volume of hemorrhage on arterial (mean = 1.72 cm3, p = 0.020) and portal venous phases (mean = 5.89 cm3, p = 0.016), as well as an interval change in the size of hemorrhage between the two phases (mean = 4.17 cm3, p = 0.020) in patients with positive catheter angiography versus patients in the negative catheter angiography group.
    Conclusions The absolute axial size and volume of hemorrhage, as well as the interval change between the arterial and portal venous phases of CTA imaging is predictive of subsequent positive catheter angiography.
    CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
    Hsu M et al.
    Abdominal Radiology (2020) 45:615–622
  • “The average maximum anterior–posterior size of hem- orrhage on the portal venous phase was 14.0 mm (range 2–64 mm) for the positive catheter angiography group as compared to 8.0 mm (range 1–34 mm) for the negative catheter angiography group. These were not statistically significantly different (p = 0.057). The average increase in maximum transverse size of hemorrhage between the arterial and portal venous phases was 8.5 mm (range 0–24 mm) for the positive catheter angiography group as compared to 1.2 mm (range 0–9 mm) for the negative angiography group. This was statistically significantly different (p < 0.001).”
    CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
    Hsu M et al.
    Abdominal Radiology (2020) 45:615–622

  • CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
    Hsu M et al.
    Abdominal Radiology (2020) 45:615–622
  • "The absolute axial size and volume of hemorrhage, as well as the interval change between the arterial and portal venous phases of CTA imaging is predictive of subsequent positive catheter angiography.”
    CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
    Hsu M et al.
    Abdominal Radiology (2020) 45:615–622
Deep Learning

  • Rationale and Objectives: Generative adversarial networks (GANs) are deep learning models aimed at generating fake realistic looking images. These novel models made a great impact on the computer vision field. Our study aims to review the literature on GANs applications in radiology.
    Conclusion: GANs are increasingly studied for various radiology applications. They enable the creation of new data, which can be used to improve clinical care, education and research.”
    Creating Artificial Images for Radiology Applications Using Generative Adversarial Networks (GANs) – A Systematic Review
    Vera Sorin et al.
    Acad Radiol 2020 (in press)
  • “Generative adversarial networks (GANs) are a more recent deep learning development, invented by Ian Goodfellow and colleagues. GAN is a type of deep learning model that is aimed at generating new images. GANs are now at the center of public attention due to “deepfake” digital media manipulations. This technique uses GANs to generate artificial images of humans. As an example, this webpage uses GAN to create random fake pictures of non-existent people.”
    Creating Artificial Images for Radiology Applications Using Generative Adversarial Networks (GANs) – A Systematic Review
    Vera Sorin et al.
    Acad Radiol 2020 (in press)
  • "Deep learning can improve diagnostic imaging tasks in radiology enabling segmentation of images, improvement of image quality, classification of images, detection of findings, and prioritization of examinations according to urgent diagnoses. Successful training of deep learning algorithms requires large-scale data sets. However, the difficulty of obtaining sufficient data limits the development and implementation of deep learning algorithms in radiology. GANs can help to overcome this obstacle. As dem- onstrated in this review, several studies have successfully trained deep learning algorithms using augmented data generated by GANs. Data augmentation with generated images significantly improved the performance of CNN algorithms. Furthermore, using GANs can reduce the amount of clinical data needed for training. The increasing research focus on GANs can therefore impact successful automatic image analysis in radiology.”
    Creating Artificial Images for Radiology Applications Using Generative Adversarial Networks (GANs) – A Systematic Review
    Vera Sorin et al.
    Acad Radiol 2020 (in press)
  • "Some risks are involved with the development of GANs. In a recent publication Mirski et al. warn against hacking of imaging examinations, artificially adding or removing medical conditions from patient scans. Also, using generated images in clinical practice should be done with caution, as the algorithms are not without limitations. For example, in image reconstruction details can get lost at translation, while fake inexistent details can suddenly appear.”
    Creating Artificial Images for Radiology Applications Using Generative Adversarial Networks (GANs) – A Systematic Review
    Vera Sorin et al.
    Acad Radiol 2020 (in press)
  • Use of AI in Radiology beyond Reading Scans
    - IMAGE PRODUCTION AND QUALITY CONTROL
    - IMPROVING RADIOLOGY WORKFLOW
    - BUSINESS APPLICATIONS
    - BILLING AND COLLECTIONS
    - RESEARCH APPLICATIONS
  • “The ultimate goal of AI in medical imaging is to improve patient outcomes. In this review, we have summarized some of the many ways in which noninterpretive AI is relevant to radiologists and their patients. At this time, only a few of these techniques are ready to translate into clinical practice. Regardless of which of these techniques are ultimately adopted, we hope that this review will provoke thought in the wider community of academic radiologists, and to help lead us to even newer and more intriguing applications.”
    Noninterpretive Uses of Artificial Intelligence in Radiology
    Michael L. Richardson et al.
    Acad Radiol 2020 (in press)
  • “Deep learning approaches can also assist radiologists by assigning higher priorities to cases on the worklist that may contain emergent abnormalities. Such prioritization has been proposed in the setting of triage or screening systems to detect abnormalities on chest radiographs, abdominal CT, or head CT. In these paradigms, there is an image interpretation component to the AI’s tasks, but the role of the AI is not to primarily render an interpretation but to alert radiologists to potential critical findings and improve turnaround time for reporting of potentially actionable abnormalities.”
    Noninterpretive Uses of Artificial Intelligence in Radiology
    Michael L. Richardson et al.
    Acad Radiol 2020 (in press)
  • "AI models have been used to successfully localize and annotate organs such as the kidney, segmental anatomy such as lobes of the liver or lung, and automated detection and labeling of vertebral bodies. This is extremely useful when volumetric assessment of a lesion or organ is needed. Examples include automated estimate of renal volume in a potential donor, liver volumes in patients with potential seg- mental or lobar resection and volumetric assessment in tumor treatment response.”
    Noninterpretive Uses of Artificial Intelligence in Radiology
    Michael L. Richardson et al.
    Acad Radiol 2020 (in press)
  • “In radiology, image-based search engines can provide valuable opportunities for education as well as research. Large volumes of medical imaging are accumulating in shared and public databases, and image-based search engines connected to these databases may allow easy discovery and comparison of visually similar cases. As opposed to text searches, which are likely to find cases with similar diagnoses, image searches may also find visually similar cases with different diagnoses. Correlation of visual and textual features of images found using image-based search engines may also provide interesting research opportunities.”
    Noninterpretive Uses of Artificial Intelligence in Radiology
    Michael L. Richardson et al.
    Acad Radiol 2020 (in press)
  • “With rapidly advancing progress in the development of algorithms for detecting and classifying imaging findings, more attention has turned towards limitations of these algorithms and particularly to vulnerabilities in these algorithms. To date, adversarial algorithms have been developed that can systematically deceive a trained AI model or a human radiologist. Notable examples include one algorithm that tricked an AI model into misclassifying pneumothorax on chest radio- graphs and another that misled human radiologists by adding fake pulmonary nodules and removing real pulmonary nodules from chest CT exams.”
    Noninterpretive Uses of Artificial Intelligence in Radiology
    Michael L. Richardson et al.
    Acad Radiol 2020 (in press)
  • “AI tools might also help in tracking radiology resident performance and evaluate competency. AI tools are being devel- oped and implemented across medical specialties to evaluate physician competence, and radiology training should be particularly amenable given the highly digitized nature of radiology practice. Metrics used for evaluation of resident competency, such as the ACGME/American Board of Radiology milestone project, could incorporate AI-based assessments in the future.”
    Noninterpretive Uses of Artificial Intelligence in Radiology
    Michael L. Richardson et al.
    Acad Radiol 2020 (in press)
  • “The ultimate goal of AI in medical imaging is to improve patient outcomes. In this review, we have summarized some of the many ways in which noninterpretive AI is relevant to radiologists and their patients. At this time, only a few of these techniques are ready to translate into clinical practice. Regardless of which of these techniques are ultimately adopted, we hope that this review will provoke thought in the wider community of academic radiologists, and to help lead us to even newer and more intriguing applications.”
    Noninterpretive Uses of Artificial Intelligence in Radiology
    Michael L. Richardson et al.
    Acad Radiol 2020 (in press)
  • “The U.S. health care industry is structured on the historically necessary model of in-person interactions between patients and their clinicians. Clinical workflows and economic incentives have largely been developed to support and reinforce a face-to-face model of care, resulting in the congregation of patients in emergency departments and waiting areas during this crisis. This care structure contributes to the spread of the virus to uninfected patients who are seeking evaluation.”
    Covid-19 and Health Care’s Digital Revolution
    Sirina KeeIsara, Andrea Jonas,Kevin Schulman
    N Engl J Med. 2020 Apr 2. doi: 10.1056/NEJMp2005835.
  • “Specifically, the authors propose that all individuals and entities with access to clinical data become data stewards, with fiduciary (or trust) responsibilities to patients to carefully safeguard patient privacy, and to the public to ensure that the data are made widely available for the development of knowledge and tools to benefit future patients. According to this framework, the authors maintain that it is unethical for providers to “sell” clinical data to other parties by granting access to clinical data, especially under exclusive arrangements, in exchange for monetary or in-kind payments that exceed costs. The authors also propose that patient consent is not required before the data are used for secondary purposes when obtaining such consent is prohibitively costly or burdensome, as long as mechanisms are in place to ensure that ethical standards are strictly followed.”
    Ethics of Using and Sharing Clinical Imaging Data for Artificial Intelligence: A Proposed Framework
    David B.Larson et al.
    Radiology 2020; 00:1–8
  • "The authors also propose that patient consent is not required before the data are used for secondary purposes when obtaining such consent is prohibitively costly or burdensome, as long as mechanisms are in place to ensure that ethical standards are strictly fol- lowed. Rather than debate whether patients or provider organizations “own” the data, the authors propose that clinical data are not owned at all in the traditional sense, but rather that all who interact with or control the data have an obligation to ensure that the data are used for the benefit of future patients and society.”
    Ethics of Using and Sharing Clinical Imaging Data for Artificial Intelligence: A Proposed Framework
    David B.Larson et al.
    Radiology 2020; 00:1–8
  • Objective — To systematically examine the design, reporting standards, risk of bias, and claims of studies comparing the performance of diagnostic deep learning algorithms for medical imaging with that of expert clinicians.
    Conclusions — Few prospective deep learning studies and randomised trials exist in medical imaging. Most non-randomised trials are not prospective, are at high risk of bias, and deviate from existing reporting standards. Data and code availability are lacking in most studies, and human comparator groups are often small. Future studies should diminish risk of bias, enhance real world clinical relevance, improve reporting and transparency, and appropriately temper conclusions.
    Artificial intelligence versus clinicians: systematic review of design, reporting standards, and claims of deep learning studies
    Myura Nagendran et al.
    BMJ 2020;368:m689 doi: 10.1136/bmj.m689 (Published 25 March 2020)
  • “Deep learning AI is an innovative and fast moving field with the potential to improve clinical outcomes. Financial investment is pouring in, global media coverage is widespread, and in some cases algorithms are already at marketing and public adoption stage. However, at present, many arguably exaggerated claims exist about equivalence with or superiority over clinicians, which presents a risk for patient safety and population health at the societal level, with AI algorithms applied in some cases to millions of patients.”
    Artificial intelligence versus clinicians: systematic review of design, reporting standards, and claims of deep learning studies
    Myura Nagendran et al.
    BMJ 2020;368:m689 doi: 10.1136/bmj.m689 (Published 25 March 2020)
  • "Overpromising language could mean that some studies might inadvertently mislead the media and the public, and potentially lead to the provision of inappropriate care that does not align with patients’ best interests. The development of a higher quality and more transparently reported evidence base moving forward will help to avoid hype, diminish research waste, and protect patients.”
    Artificial intelligence versus clinicians: systematic review of design, reporting standards, and claims of deep learning studies
    Myura Nagendran et al.
    BMJ 2020;368:m689 doi: 10.1136/bmj.m689 (Published 25 March 2020)
  • “Specifically, the authors propose that all individuals and entities with access to clinical data become data stewards, with fiduciary (or trust) responsibilities to patients to carefully safeguard patient privacy, and to the public to ensure that the data are made widely available for the development of knowledge and tools to benefit future patients. According to this framework, the authors maintain that it is unethical for providers to “sell” clinical data to other parties by granting access to clinical data, especially under exclusive arrangements, in exchange for monetary or in-kind payments that exceed costs. The authors also propose that patient consent is not required before the data are used for secondary purposes when obtaining such consent is prohibitively costly or burdensome, as long as mechanisms are in place to ensure that ethical standards are strictly followed.”
    Ethics of Using and Sharing Clinical Imaging Data for Artificial Intelligence: A Proposed Framework
    David B.Larson et al.
    Radiology 2020; 00:1–8
  • "The authors also propose that patient consent is not required before the data are used for secondary purposes when obtaining such consent is prohibitively costly or burdensome, as long as mechanisms are in place to ensure that ethical standards are strictly fol- lowed. Rather than debate whether patients or provider organizations “own” the data, the authors propose that clinical data are not owned at all in the traditional sense, but rather that all who interact with or control the data have an obligation to ensure that the data are used for the benefit of future patients and society.”
    Ethics of Using and Sharing Clinical Imaging Data for Artificial Intelligence: A Proposed Framework
    David B.Larson et al.
    Radiology 2020; 00:1–8
  • Objective — To systematically examine the design, reporting standards, risk of bias, and claims of studies comparing the performance of diagnostic deep learning algorithms for medical imaging with that of expert clinicians.
    Conclusions — Few prospective deep learning studies and randomised trials exist in medical imaging. Most non-randomised trials are not prospective, are at high risk of bias, and deviate from existing reporting standards. Data and code availability are lacking in most studies, and human comparator groups are often small. Future studies should diminish risk of bias, enhance real world clinical relevance, improve reporting and transparency, and appropriately temper conclusions.
    Artificial intelligence versus clinicians: systematic review of design, reporting standards, and claims of deep learning studies
    Myura Nagendran et al.
    BMJ 2020;368:m689 doi: 10.1136/bmj.m689 (Published 25 March 2020)
  • “Deep learning AI is an innovative and fast moving field with the potential to improve clinical outcomes. Financial investment is pouring in, global media coverage is widespread, and in some cases algorithms are already at marketing and public adoption stage. However, at present, many arguably exaggerated claims exist about equivalence with or superiority over clinicians, which presents a risk for patient safety and population health at the societal level, with AI algorithms applied in some cases to millions of patients.”
    Artificial intelligence versus clinicians: systematic review of design, reporting standards, and claims of deep learning studies
    Myura Nagendran et al.
    BMJ 2020;368:m689 doi: 10.1136/bmj.m689 (Published 25 March 2020)
  • "Overpromising language could mean that some studies might inadvertently mislead the media and the public, and potentially lead to the provision of inappropriate care that does not align with patients’ best interests. The development of a higher quality and more transparently reported evidence base moving forward will help to avoid hype, diminish research waste, and protect patients.”
    Artificial intelligence versus clinicians: systematic review of design, reporting standards, and claims of deep learning studies
    Myura Nagendran et al.
    BMJ 2020;368:m689 doi: 10.1136/bmj.m689 (Published 25 March 2020)
Kidney

  • “Rhabdomyolysis, a clinical syndrome caused by damage to skeletal muscle and release of its breakdown products into the circulation, can be followed by acute kidney injury (AKI) as a severe complication. The belief that the AKI is triggered by myoglobin as the toxin responsible appears to be oversimplified. Better knowledge of the pathophysiology of rhabdomyolysis and following AKI could widen treatment options, leading to preservation of the kidney: the decision to initiate renal replacement therapy in clinical practice should not be made on the basis of the myoglobin or creatine phosphokinase serum concentrations.”
    Acute kidney injury due to rhabdomyolysis and renal replacement therapy: a critical review.
    Petejova N, Martinek A.
    Crit Care. 2014 May 28;18(3):224
  • “Rhabdomyolysis is a syndrome characterized by the breakdown of skeletal muscle and leakage of intracellular myocyte contents, such as creatine phosphokinase (CPK) and myoglobin, into the interstitial space and plasma resulting in acute kidney injury (AKI). Elevated CPK of at least 5 times the upper limit of normal is an important diagnostic marker of Rhabdomyolysis.”
    Rhabdomyolysis-Associated Acute Kidney Injury With Normal Creatine Phosphokinase.
    Kamal F, Snook L, Saikumar JH.
    Am J Med Sci. 2018 Jan;355(1):84-87. 
  • Renal Medullary Carcinoma: Facts
    - Highly aggressive renal neoplasm that has association with sickle cell trait or rarely hemoglobin SC disease (unknown mechanism).
    - Some considered this be a variant of collecting duct carcinoma.
    - Usually encountered in young patients, male > female (2:1), mostly African-American and with sickle cell hemoglobinopathies.
  • Renal Medullary Carcinoma: Facts
    - Patients with RMC tend to be young with a median age of 19-22 years.
    - Patients are almost always of black race (although RMC has been reported in Hispanics/Brazilians and a few Caucasians).5 Nearly all RMC patients have sickle cell trait or, rarely, sickle cell disease.
  • Renal Medullary Carcinoma: Facts
    - The right kidney is the affected kidney in more than 75% of cases. Metastasis at presentation is extremely common. The most common sites of metastases are the regional lymph nodes, adrenal glands, lung, liver, inferior vena cava, and peritoneum
    - RMC is a highly aggressive cancer with an extremely poor prognosis. Mean survival time of less than 1 year is seen in most cases.
  • “Renal medullary carcinoma (RMC) is an aggressive form of non–clear cell kidney cancer that typically affects young adults and is almost exclusively associated with sickle cell trait. Typical RMC patients tend to be young black males (2:1 male to female predominance) with sickle cell trait who present with pain and hematuria and are found to have metastatic disease at diagnosis. Prognosis is extremely poor, with a mean survival of less than a year in most cases.”
    Renal Medullary Carcinoma: A Case Report and Brief Review of the Literature
    Aditya Shetty, Marc R. Matrana, Ochsner J.
    2014 Summer; 14(2): 270–275
  • "One type of non–clear cell RCC that has been more recently recognized is renal medullary carcinoma (RMC). RMC is an aggressive form of kidney cancer first described by Davis et al in 1995.The disease almost always affects young patients with sickle cell trait and has been described as the seventh sickle cell nephropathy (the other sickle cell nephropathies are gross hematuria, papillary necrosis, nephrotic syndrome, renal infarction, inability to concentrate urine, and pyelonephritis).”
    Renal Medullary Carcinoma: A Case Report and Brief Review of the Literature
    Aditya Shetty, Marc R. Matrana, Ochsner J.
    2014 Summer; 14(2): 270–275
  • The tumors in the current study presented a mean diameter of 7.48±3.25 cm, and were observed to be solitary and heterogeneous with necrotic components. The majority of the tumors did not contain calcifications (5/6); displayed an ill-defined margin (4/6); were centered in the medulla; extended into the renal pelvis or peripelvic tissues (6/6); and did not exhibit a fibrous capsule. Localized caliectasis was observed in 3 of the 6 cases. The attenuation of the solid region of the RMC on unenhanced CT was equal to that of the renal cortex or medulla (42.3±2.7 vs. 40.7±3.6 and 41.2±3.9 Hounsfield units, respectively; P>0.05) while, on enhanced CT, the enhancement of the tumor was lower than that of the normal renal cortex and medulla during all phases (cortical phase, 52.6±4.8 vs. l99.5±9.7 and 72.7±6.4; medullary phase, 58.6±5.7 vs. 184.6±10.8 and 93.5±7.8; delayed phase, 56.8±6.1 vs. 175.7±8.5 and 96.5±7.9, respectively; P<0.05). 
  • "In conclusion, RMC tends to be an infiltrative, ill-defined heterogeneous mass with intratumoral necrosis, which arises from the renal medulla, and displays lower enhancement than the renal cortex and medulla during all phases on enhanced CT. Despite its rarity in adults, RMC should be included in a differential diagnosis when CT imaging reveals these features."
    Clinical and computed tomography imaging features of renal medullary carcinoma: A report of six cases.
    Shi Z1, Zhuang Q2, You R1, Li Y1, Li J1, Cao D
    Oncol Lett. 2016 Jan;11(1):261-266. Epub 2015 Nov 9
  • “Primary renal lymphoma without systemic extension is a rare clinical occurrence and it accounts for less than 1% of extranodal lymphomas. As the renal parenchyma does not normally contain lymphoid tissue, the development of primary renal lymphomas is thought to originate from lymphatic-rich renal capsule or perirenal fat with subsequent extension into the renal parenchyma. Secondary renal lymphomas may commonly occur in patients with advanced stage disease. Autopsy series of patients with lymphoma showed renal involvement in 30%–60% of the cases. Renal lymphomas are usually B cell non-Hodgkin type lymphomas. Secondary lymphomatous involvement of the kidneys is usually clinically silent, however, in a small percentage of patients flank pain, hematuria, and rarely renal failure may be observed.”
    Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies.
    Gumeler E et al.
    Abdom Radiol (NY). 2018 Sep;43(9):2400-2411
  • “Renal involvement typically presents as solid solitary or multiple lesions within the renal parenchyma. Perirenal or diffuse parenchymal involvement may also be seen some patients. Isolated renal sinus involvement is rare and peripelvic involvement occurs secondary to tumoral extension from the conglomerated retroperitoneal lymph nodes. Ureteral obstruction may be frequently observed in patients with periureteral extension. Renal vascular occlusion or thrombosis is rare despite extensive encasement of these structures, owing to the soft and pliable nature of the lymphoma .”
    Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies.
    Gumeler E et al.
    Abdom Radiol (NY). 2018 Sep;43(9):2400-2411
  • “CT demonstrates low attenuated lymphomatous infiltration along renal sinus and ureteral wall while this infiltration typically manifests as hypointense on both T1W and T2W images on MRI scans. This infiltrative growth pattern is reminiscent of transitional cell carcinomas (TCCs) and other inflammatory processes such as XGP. Based on these similarities, both TCC and XGP should be considered in the differential diagnosis. Mild and homogeneous post-contrast enhancement may be a helpful imaging hint to differentiate peripelvic and periureteral lymphoma from these disorders.”
    Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies.
    Gumeler E et al.
    Abdom Radiol (NY). 2018 Sep;43(9):2400-2411
  • “Erdheim-Chester disease is a non–Langerhans cell histiocytosis characterized by the infiltration of foamy histiocytes with fibrosis that can affect many organs, most commonly long bones.Renal involvement commonly manifests in this disease as a histiocytic infiltration into the perirenal fat. Histopathologic findings from biopsy of the right retroperitoneal region included fragments of fibroadipose tissue displaying a lymphohistiocytic infiltrate.”
    The Hairy Kidney of Erdheim-Chester Disease
    Scolaro JC, Peiris AN
    Mayo Clin Proceed May 2018Volume 93, Issue 5, Page 671
  • “Peripelvic and periureteric areas are frequently overlooked in the imaging evaluations of the urinary system on computed tomography and magnetic resonance imaging. Several neoplastic and non-neoplastic disorders and diseases including lipomatosis, angiomyolipoma and angiolipomatous proliferation, vascular lesions, lymphangiomatosis, Rosai-Dorfman disease, Erdheim-Chester disease, extramedullary hematopoiesis, IgG4-related disease, lymphoma, mesenchymal tumors, trauma, and Antopol-Goldman lesion may involve these areas. Differentiation of these benign or malignant pathologies among themselves and from primary renal pathologies is of utmost importance to expedite the triage of patients for correct treatment approach.”
    Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies.
    Gumeler E et al.
    Abdom Radiol (NY). 2018 Sep;43(9):2400-2411
  • “Erdheim–Chester disease (ECD) is first described by Jacob Erdheim and William Chester in 1930 and is also referred to as lipogranulomatosis. ECD is a systemic inflammatory disorder with a poor prognosis. Skeletal system is the most commonly involved body part, however, around 50% of the cases may have extraskeletal involvement. Symmetrical diaphyseal and metaphyseal osteosclerosis of the long bones is the typical skeletal finding. Among the extraskeletal sites that are involved central nervous system, pulmonary and cardiovascular systems, orbital cavity and cutaneous system may be counted in addition to the kidneys and the retroperitoneum.”
    Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies.
    Gumeler E et al.
    Abdom Radiol (NY). 2018 Sep;43(9):2400-2411
  • "Urological manifestations of ECD may include, but not limited to, ureteral obstruction secondary to retroperitoneal involvement, primary adrenal and kidney involvement. Adrenal and renal failure may occur in some of the affected patients. Perirenal soft tissue infiltration is reported as the most frequently observed form of retroperitoneal involvement.”
    Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies.
    Gumeler E et al.
    Abdom Radiol (NY). 2018 Sep;43(9):2400-2411
  • “For genitourinary system evaluation in patients with ECD, CT may be utilized as the first modality of choice. The so called “hairy kidney appearance,” due to perirenal involvement, is typically characterized by hypoattenuating, irregularly shaped soft tissue masses with minimal enhancement after contrast injection. This finding is very frequent in cases with renal ECD, with a reported rate of 68% of all patients with genitourinary involvement. Infiltrative extension towards the kidney periphery into the renal sinus may be observed.”
    Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies.
    Gumeler E et al.
    Abdom Radiol (NY). 2018 Sep;43(9):2400-2411
  • “Erdheim–Chester disease (ECD) is a rare xanthogranulomatous histiocytosis of non-Langerhans cells most common in male adults between the fourth and seventh decades of life. It was first described by Erdheim and Chester in 1930 and is characterized by multifocal osteosclerotic lesions of the long bones.Although there is a speculation that ECD and other histiocytic disorders may represent an aberrant response to infection, no infectious etiology has been identified. It remains controversial if ECD is a reactive polyclonal histiocyte proliferation or a monoclonal neoplastic process.”
    Spectrum of abdominal imaging findings in histiocytic disorders. 
    de Souza Maciel Rocha Horvat, N., Coelho, C.R., Roza, L.C. et al. 
    Abdom Imaging 40, 2738–2746 (2015). https://doi.org/10.1007/s00261-015-0449-1
  • "Infiltration of the perirenal fat appears as an irregular renal border producing a “hairy kidney” appearance on CT and MRI. On CT, this manifests as a hypodense and homogeneous band with spiculated contours and mild contrast enhancement. On MRI, it is isointense to muscle on T1- and T2-weighted sequences, with a slight and homogeneous enhancement after contrast injection. Perirenal infiltration may progress to the renal sinuses and produce a post renal obstruction. The ureteral segments which are most commonly affected by fibrosis are the middle and distal segments. The renal arteries may also be involved by tissue infiltration and fibrosis.”
    Spectrum of abdominal imaging findings in histiocytic disorders.
    de Souza Maciel Rocha Horvat, N., Coelho, C.R., Roza, L.C. et al.
    Abdom Imaging 40, 2738–2746 (2015). https://doi.org/10.1007/s00261-015-0449-1
  • "Retroperitoneal involvement with ECD can manifest as a mass-like infiltrative surrounding the abdominal aorta with the same characteristics of the perirenal lesions. This can lead to acute or slowly progressive renal insufficiency. Retroperitoneal involvement frequently includes a bilateral, symmetric, and diffuse thickening of the adrenal glands associated with infiltration of the adjacent fat.”
    Spectrum of abdominal imaging findings in histiocytic disorders.
    de Souza Maciel Rocha Horvat, N., Coelho, C.R., Roza, L.C. et al.
    Abdom Imaging 40, 2738–2746 (2015). https://doi.org/10.1007/s00261-015-0449-1
  • Erdheim Chester Disease: Renal Changes
    - Perirenal fat effaced or infiltrated by soft tissue
    - Usually bilateral and symmetric
    - Infiltration of para-aortic regions is also common
  • Erdheim Chester Disease: Vascular Changes
    - Periaortic infiltration which is usually circumferential and nonocclusive
    - May involve aorta from root thru iliac vessels
  • Perinephric Masses on CT: Differential Diagnosis
    - Lymphoma
    - Metastases (especially melanoma)
    - Myeloma
    - Urinomas
    - Hemmorrhage
    - Infection
    - Extramedullary hematopoiesis
    - Retroperitoneal fibrosis
    - Erdheim Chester disease
  • Perirenal Space Pathology
    - Solitary soft tissue masses (RCC, lymphangioma,hemangioma)
    Rindlike soft tissue lesions (lymphoma, retroperitoneal fibrosis, Erdheim Chester disease)
    - Multifocal soft tissue masses (metastases)
    - Masses containing macroscopic fat (AML, extramedullary hematopoiesis)
    Neoplastic and Nonneoplastic Proliferative Disorders of the Perirenal Space: Cross-sectional Imaging Findings
    Surabhi VR et al
    RadioGraphics 2008; 28:1005-1017
Musculoskeletal

  • Purpose: Cinematic rendering (CR), a recently launched, FDA-approved rendering technique converts CT image datasets into nearly photorealistic 3D reconstructions by using a unique lighting model. The purpose of this study was to compare CR to volume rendering technique (VRT) images in the preoperative visualization of multifragmentary intraarticular lower extremity fractures.
    Conclusions: CR reconstructions are superior to VRT due to higher image quality and higher anatomical accuracy. Traumatologists find CR reconstructions to improve visualization of lower extremity fractures which should thus be used for fracture demonstration during interdisciplinary conferences.
    Is CT-based cinematic rendering superior to volume rendering technique in T the preoperative evaluation of multifragmentary intraarticular lower extremity fractures?
    Lena M. Wollschlaegera et al.
    European Journal of Radiology 126 (2020) 108911
  • "CR uses a unique lighting model which is far more complex than the ray casting methods used in VR [5]. In CR, the algorithm is based on the global illumination model. This model incorporates information of billions of photons traveling through the volumetric dataset, and the interactions of these rays of light with a joining voxels. Complex lighting effects such as refraction, absorption, depth of field, soft shadows and ambient occlusion can be created.”
    Is CT-based cinematic rendering superior to volume rendering technique in T the preoperative evaluation of multifragmentary intraarticular lower extremity fractures?
    Lena M. Wollschlaegera et al.
    European Journal of Radiology 126 (2020) 108911
  • “Recently, Dappa et al. published a review comparing the potential value of CR to conventional VRT images and illustrated potential clinical applications of CR such as preoperative treatment planning. In their experience, CR is especially striking for visualizing structures with high density and high contrast such as bones. Further- more, they highlighted the high quality of CR images and their ability for the perception of depth and the photorealistic representation of human anatomy.”
    Is CT-based cinematic rendering superior to volume rendering technique in T the preoperative evaluation of multifragmentary intraarticular lower extremity fractures?
    Lena M. Wollschlaegera et al.
    European Journal of Radiology 126 (2020) 108911
  • “CR provides a more detailed visualization of multifragmentary intraarticular lower extremity fractures with improved image quality and higher anatomical accuracy compared to VRT, thus facilitating the understanding of fracture morphology in multifragmentary intraarticular fractures. Therefore, CR improves traumatological pre-operative fracture visualization in patients with multifragmentary in- traarticular lower extremity fractures and thus can be recommended for fracture demonstration during interdisciplinary conferences.”
    Is CT-based cinematic rendering superior to volume rendering technique in T the preoperative evaluation of multifragmentary intraarticular lower extremity fractures?
    Lena M. Wollschlaegera et al.
    European Journal of Radiology 126 (2020) 108911
Pancreas

  • “CT-texture analysis (CTTA) is an emerging field of investigation capable to identify specific tissue features meant to more accurately characterize tumors and other tissue types (e.g., inflammatory disorders) by using image data quantification. Results of CTTA can be further tested for correlations with other non-image-based patient data (laboratory, genetic, etc.) in order to allow for a more individualized approach of these patients and their diseases, to provide valuable information capable of stratifying prognosis, and search for the most appropriate therapy.”
    Complementary role of computed tomography texture analysis for differentiation of pancreatic ductal adenocarcinoma from pancreatic neuroendocrine tumors in the portal‐venous enhancement phase
    Christian Philipp Reinert et al.
    Abdominal Radiology (2020) 45:750–758
  • "In conclusion, our data indicate that CT-texture analysis is a feasible tool for differentiation of PNEN from PDAC and also of G1 from G2/3 PNEN in the portal-venous phase. Most textural features reflect lower tissue attenuation and uniformity in PDAC as compared to PNEN. Notably, CTTA seems to outmatch the results of both visual assessment and tumor attenuation quantification.”
    Complementary role of computed tomography texture analysis for differentiation of pancreatic ductal adenocarcinoma from pancreatic neuroendocrine tumors in the portal‐venous enhancement phase
    Christian Philipp Reinert et al.
    Abdominal Radiology (2020) 45:750–758
  • “Incidentally detected pancreatic adenocarcinomas in the pancreas body/tail were characterized by an earlier tumor stage than in cases of symptomatically detected pancreatic adenocarcinoma. Several CT findings prior to the detection of a tumor may be useful for the early detection of pancreatic adenocarcinoma during the follow-up for other diseases.”
    Incidentally detected pancreatic adenocarcinomas on computed tomography obtained during the follow‐up for other diseases
    Higashi M et al.
    Abdominal Radiology (2020) 45:774–781
  • “In this study, incidentally detected pancreatic adenocarcinomas were more likely to localize in the body or tail of the pancreas than the head (body/tail, 64.3% vs. head, 35.7%), although the distribution of tumor location showed no statistically significant differences between the incidental group and non-incidental group. This fact suggests that tumor-induced symptoms may be less likely to occur in the body or tail of the pancreas than the head.”
    Incidentally detected pancreatic adenocarcinomas on computed tomography obtained during the follow‐up for other diseases
    Higashi M et al.
    Abdominal Radiology (2020) 45:774–781
  • “Loss of fatty marbling, which has been reported as an imaging finding suggestive of the presence of pancreatic cancer, may reflect intrapancreatic or extrapancreatic neural invasion by pancreatic cancers or associated pancreatitis. Preserved lobulation may reflect tumors being less likely to spread and destroy normal pan- creatic parenchyma.”
    Incidentally detected pancreatic adenocarcinomas on computed tomography obtained during the follow‐up for other diseases
    Higashi M et al.
    Abdominal Radiology (2020) 45:774–781
  • "As we mentioned, incidentally detected pancreatic adenocarcinomas in the body/tail of the pancreas tend to be characterized by preserved lobulation and fatty marbling, indicating limited morphologic changes in the pancreatic parenchyma. Therefore, physicians must pay close attention to the presence of hypoattenuated lesions with delayed enhancement for the early detection of incidental pancreatic adenocarcinoma during follow-up CT for other diseases.”
    Incidentally detected pancreatic adenocarcinomas on computed tomography obtained during the follow‐up for other diseases
    Higashi M et al.
    Abdominal Radiology (2020) 45:774–781
  • “In conclusion, incidentally detected pancreatic adenocarcinomas in the body or tail of the pancreas were characterized by an earlier tumor stage than symptomatically detected pancreatic adenocarcinomas. Being alert for several CT findings prior to the detection of a tumor may contribute to the early detection of pancreatic adenocarcinomas during the follow-up for other diseases.”
    Incidentally detected pancreatic adenocarcinomas on computed tomography obtained during the follow‐up for other diseases
    Higashi M et al.
    Abdominal Radiology (2020) 45:774–781
  • Purpose To assess the role of CT-texture analysis (CTTA) for differentiation of pancreatic ductal adenocarcinoma (PDAC) from pancreatic neuroendocrine neoplasm (PNEN) in the portal-venous phase as compared with visual assessment and tumor-to-pancreas attenuation ratios
    Conclusions Our data indicate that CTTA is a feasible tool for differentiation of PNEN from PDAC and also of G1 from G2/3 PNEN in the portal-venous phase. Visual assessment and tumor-to-parenchyma ratios were not useful for discrimination.
    Complementary role of computed tomography texture analysis for differentiation of pancreatic ductal adenocarcinoma from pancreatic neuroendocrine tumors in the portal‐venous enhancement phase
    Christian Philipp Reinert et al.
    Abdominal Radiology (2020) 45:750–758
  • “The most current guidelines from the NCCN place patients with PDAC into one of three broad groups: resectable, borderline resectable, and unresectable disease based pre- dominantly on imaging findings. The NCCN’s clinical practice guidelines for PDAC are a consensus statement to aid diagnosis and treatment. The guidelines are reviewed and updated on a continu- ing basis to ensure that the recommendations consider the most current evidence. This section provides an overview of the most recent version of the NCCN guidelines for PDAC (version 2.2019—April 9, 2019).”
    White paper on pancreatic ductal adenocarcinoma from society of abdominal radiology’s disease‐focused panel for pancreatic ductal adenocarcinoma: Part I, AJCC staging system, NCCN guidelines, and borderline resectable disease
    Kulkarni NM et al.
    Abdominal Radiology (2020) 45:716–728

  • White paper on pancreatic ductal adenocarcinoma from society of abdominal radiology’s disease‐focused panel for pancreatic ductal adenocarcinoma: Part I, AJCC staging system, NCCN guidelines, and borderline resectable disease
    Kulkarni NM et al.
    Abdominal Radiology (2020) 45:716–728
  • "CT is recommended as the preferred technique owing to its wide availability, superior spatial resolution, and rapid acquisition. In addition, clinicians from various specialties (e.g., surgeons, radiation oncologists etc.) have better familiarity with CT than MRI. MRI is therefore recommended as an adjunct tool when CT findings are indeterminate (small pancreatic tumors or liver lesions), or when contrast-enhanced CT is not possible due to a life-threatening allergy to iodinated contrast agent.”
    White paper on pancreatic ductal adenocarcinoma from society of abdominal radiology’s disease‐focused panel for pancreatic ductal adenocarcinoma: Part I, AJCC staging system, NCCN guidelines, and borderline resectable disease
    Kulkarni NM et al.
    Abdominal Radiology (2020) 45:716–728
  • "The NCCN suggests that PET/CT be considered following a dedicated pancreatic protocol CT in those patients who are at high risk for distant/disseminated disease (such as large primary tumors or large regional lymph nodes, borderline resectable disease, markedly elevated CA19-9, excessive weight loss and/or marked symptomatology such as severe abdominal pain).”
    White paper on pancreatic ductal adenocarcinoma from society of abdominal radiology’s disease‐focused panel for pancreatic ductal adenocarcinoma: Part I, AJCC staging system, NCCN guidelines, and borderline resectable disease
    Kulkarni NM et al.
    Abdominal Radiology (2020) 45:716–728
  • “In addition to the above measures, serum CA 19-9 level (drawn following biliary decompression and with confirmation that serum bilirubin levels have normalized) and baseline standard laboratory studies are also recommended. Not all patients with PDAC have tumors that express CA 19-9, a sialylated Lewis A blood group antigen. CA 19-9 can be a good diagnostic and prognostic marker in those tumors that express it. Preoperative CA 19-9 levels have shown correlation with resectability and can provide additional information for staging. The NCCN recommends measurement of serum CA 19-9 levels before and after neoadjuvant treatment, before surgery, immediately prior to adjuvant treatment, and for the purposes of surveillance.”
    White paper on pancreatic ductal adenocarcinoma from society of abdominal radiology’s disease‐focused panel for pancreatic ductal adenocarcinoma: Part I, AJCC staging system, NCCN guidelines, and borderline resectable disease
    Kulkarni NM et al.
    Abdominal Radiology (2020) 45:716–728
  • "Surgical resection is currently the only potentially curative option for PDAC. The median survival of resected patients after adjuvant therapy ranges from 20.1 to 28.0 months even in optimal clinical trial conditions. Patient selection should be based on the probability of achieving an R0 resection; R0 means a negative resection margin based on assessment with microscopy. Small tumor size, R0 margin, and N0 (node-negative) status are the strongest predictors of long- term patient survival. The guidelines advise that patient performance status, symptom burden, and comorbidity profile also be utilized to identify those patients who can undergo major surgery.”
    White paper on pancreatic ductal adenocarcinoma from society of abdominal radiology’s disease‐focused panel for pancreatic ductal adenocarcinoma: Part I, AJCC staging system, NCCN guidelines, and borderline resectable disease
    Kulkarni NM et al.
    Abdominal Radiology (2020) 45:716–728
  • “Unlike patients with clearly resectable disease, patients with borderline resectable disease are at high risk for a positive surgical margin and recurrence in the setting of upfront surgery. For patients with borderline resectable disease, the aim of neoadjuvant therapy is to sufficiently treat the tumor so that a negative resection margin can be achieved even though such a change may not be apparent at imaging.”
    White paper on pancreatic ductal adenocarcinoma from society of abdominal radiology’s disease‐focused panel for pancreatic ductal adenocarcinoma: Part I, AJCC staging system, NCCN guidelines, and borderline resectable disease
    Kulkarni NM et al.
    Abdominal Radiology (2020) 45:716–728
  • “The current NCCN criteria for borderline resectable disease are based on cross-sectional imaging features for arterial involvement. Borderline resectable disease is defined as solid tumor contact with the common hepatic artery (CHA) without extension to the celiac axis (CA) or hepatic artery (HA) bifurcation, (2) ≤ 180° involvement of the SMA and/or celiac axis (CA), and solid tumor contact with variant arterial anatomy .The NCCN makes an exception for greater than 180° involvement of the CA if the aorta and gastroduodenal artery (GDA) are uninvolved, and the surgeons are able to perform an arterial anastomosis (modified Appleby procedure).”
    White paper on pancreatic ductal adenocarcinoma from society of abdominal radiology’s disease‐focused panel for pancreatic ductal adenocarcinoma: Part I, AJCC staging system, NCCN guidelines, and borderline resectable disease
    Kulkarni NM et al.
    Abdominal Radiology (2020) 45:716–728
  • "Surgical resection with R0 margin is the only potentially curative option for PDAC. Unfortunately, only a small subset of patients present at an early enough stage that a potentially curative resection can be considered. Determining resectability and predicting prognosis for PDAC are dependent on accurate staging of the disease. The primary goal of the most recent revision of the AJCC staging system is to aid in the determination of a given patient’s prognosis. In contrast, clinical management guidelines based on clinical and radiographic examinations have been developed by several societies; one of the most notable and comprehensive being those of the NCCN.”
    White paper on pancreatic ductal adenocarcinoma from society of abdominal radiology’s disease‐focused panel for pancreatic ductal adenocarcinoma: Part I, AJCC staging system, NCCN guidelines, and borderline resectable disease
    Kulkarni NM et al.
    Abdominal Radiology (2020) 45:716–728
Quotes

Small Bowel

  • “Schwannomas are benign nerve sheath tumors with significant Schwann cell differentiation. They similarly affect both genders and are atypically discovered in patients in their 3th and 5th decades of life. Schwannomas most commonly involve peripheral, motor, sympathetic, or cranial nerves of the head and neck region and upper and lower extremities. Schwannomas have been found at almost every location of the body including in extremities, head, neck, retroperitoneum, mediastinum, pelvis, and rectum. Visceral locations, however, are very rare and preoperative diagnosis is challenging, as schwannomas are often confused with other neoplasms. We review the imaging findings of abdominal schwannomas focusing on pancreatic, gastrointestinal, and retroperitoneal/adrenal schwannomas.”
    Abdominal schwannomas: review of imaging findings and pathology. 
    Lee, N.J., Hruban, R.H. & Fishman, E.K.
    Abdom Radiol 42, 1864–1870 (2017). https://doi.org/10.1007/s00261-017-1088-5
  • “The most common locations of cellular schwannomas are the paravertebral areas in pelvis, retroperitoneum, and mediastinum. On imaging, the more vascular Antoni A areas are usually enhancing solid components, whereas Antoni B areas are frequently nonenhancing cystic or multiseptated components. Immunohistochemical labeling is a usually required for accurate diagnosis. S-100 protein positivity is an important marker in the diagnosis of schwannoma, as the neoplastic cells strongly label with antibodies to S-100.”
    Abdominal schwannomas: review of imaging findings and pathology. 
    Lee, N.J., Hruban, R.H. & Fishman, E.K.
    Abdom Radiol 42, 1864–1870 (2017). https://doi.org/10.1007/s00261-017-1088-5
  • “On computed tomography (CT) or magnetic resonance imaging (MRI), schwannomas in various anatomic locations are typically a well-demarcated round or oval masses. Calcification and cystic changes may be seen in larger tumors. After contrast enhancement, homogeneous to heterogeneous contrast enhancement may be seen due to variable degree of internal cystic and hemorrhagic changes. Most schwannomas appear as inhomogeneous low-density masses on CT scan images, isointense with muscle on T1-weighted images, and high intensity on T2-weighted images on MRI.”
    Abdominal schwannomas: review of imaging findings and pathology. 
    Lee, N.J., Hruban, R.H. & Fishman, E.K.
    Abdom Radiol 42, 1864–1870 (2017). https://doi.org/10.1007/s00261-017-1088-5
  • “Schwannomas rarely arise in the gastrointestinal tract. When they do, they are most often seen in the stomach followed by in small intestine and in colon or the rectum. In addition to the typical histological features of schwannomas, schwannomas of the gastrointestinal tract often have a peripheral cuff of lymphoid cells. Additionally, distinct Antoni A (Verocay bodies) and B areas are usually not present. Schwannomas of the gastrointestinal tract are usually submucosal and richly vascular. The lesions typically protrude into the lumen of the bowel and can be associated with small mucosal erosions, which can be appreciated at endoscopic examination. Because they are submucosal, superficial biopsies may be negative. Most schwannomas of the gastrointestinal tract grow contralateral to the mesenteric attachment. They are usually clinically indolent but can erode the overlying mucosa, causing complications such as bleeding or bowel obstruction.”
    Abdominal schwannomas: review of imaging findings and pathology. 
    Lee, N.J., Hruban, R.H. & Fishman, E.K.
    Abdom Radiol 42, 1864–1870 (2017). https://doi.org/10.1007/s00261-017-1088-5
  • "Gastrointestinal schwannomas are similar to gastrointestinal stromal tumors (GISTs) on CT or MRI. However, it has been suggested that compared to GISTs, schwannomas tend to be more homogeneously enhancing, more often exophytic or mixed (both endoluminal and exophytic), and slower growing. Homogeneous attenuation may be due to small tumor size and lack of hemorrhage, necrotic, or cystic degeneration. Immunohistochemical labeling is often necessary to confirm the diagnosis. Virtually all GISTs express c-Kit and DOG1, whereas schwannomas are negative for c-Kit and DOG1, and strongly express S100.”
    Abdominal schwannomas: review of imaging findings and pathology.
    Lee, N.J., Hruban, R.H. & Fishman, E.K.
    Abdom Radiol 42, 1864–1870 (2017). https://doi.org/10.1007/s00261-017-1088-5
  • "Abdominal Schwannoma is rare and preoperative diagnosis is challenging because of the lack of definitive non-histological diagnostic modalities, as imaging findings are not specific even with developed advanced imaging techniques. Surgical excision is required for treatment and to provide a definitive diagnosis made by histological and immunohistochemical evaluations. Understanding the image findings of abdominal schwannomas will help with considering schwannoma in differential diagnosis appropriately to guide treatment plan and to avoid an unnecessary radical resection.”
    Abdominal schwannomas: review of imaging findings and pathology.
    Lee, N.J., Hruban, R.H. & Fishman, E.K.
    Abdom Radiol 42, 1864–1870 (2017). https://doi.org/10.1007/s00261-017-1088-5 
  • Purpose The purpose of this study was to determine whether the measured size of active gastrointestinal hemorrhage was useful in predicting subsequent positive findings at catheter angiography.
    Materials and methods. Each CTA was reviewed, with axial measurements of the anterior–posterior and transverse dimensions of the largest foci of hemorrhage recorded. Volumetric analysis was used to measure the volume of hemorrhage. These measurements were performed for both the arterial and portal venous phases. Additionally, the interval growth between the arterial and portal venous phase was also calculated.
    CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
    Hsu M et al.
    Abdominal Radiology (2020) 45:615–622
  • Results There was a statistically significant difference in the absolute size of the maximum transverse dimension on portal venous phase imaging (mean = 19.8 mm, p < 0.001), as well as an interval increase in transverse (mean = 8.5 mm, p < 0.001) and anteriorposterior (mean = 5.4 mm, p = 0.027) size between arterial and portal venous phases in patients with positive catheter angiography versus negative catheter angiography. There was a statistically significant difference in the volume of hemorrhage on arterial (mean = 1.72 cm3, p = 0.020) and portal venous phases (mean = 5.89 cm3, p = 0.016), as well as an interval change in the size of hemorrhage between the two phases (mean = 4.17 cm3, p = 0.020) in patients with positive catheter angiography versus patients in the negative catheter angiography group.
    Conclusions The absolute axial size and volume of hemorrhage, as well as the interval change between the arterial and portal venous phases of CTA imaging is predictive of subsequent positive catheter angiography.
    CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
    Hsu M et al.
    Abdominal Radiology (2020) 45:615–622
  • Results There was a statistically significant difference in the volume of hemorrhage on arterial (mean = 1.72 cm3, p = 0.020) and portal venous phases (mean = 5.89 cm3, p = 0.016), as well as an interval change in the size of hemorrhage between the two phases (mean = 4.17 cm3, p = 0.020) in patients with positive catheter angiography versus patients in the negative catheter angiography group.
    Conclusions The absolute axial size and volume of hemorrhage, as well as the interval change between the arterial and portal venous phases of CTA imaging is predictive of subsequent positive catheter angiography.
    CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
    Hsu M et al.
    Abdominal Radiology (2020) 45:615–622
  • “The average maximum anterior–posterior size of hem- orrhage on the portal venous phase was 14.0 mm (range 2–64 mm) for the positive catheter angiography group as compared to 8.0 mm (range 1–34 mm) for the negative catheter angiography group. These were not statistically significantly different (p = 0.057). The average increase in maximum transverse size of hemorrhage between the arterial and portal venous phases was 8.5 mm (range 0–24 mm) for the positive catheter angiography group as compared to 1.2 mm (range 0–9 mm) for the negative angiography group. This was statistically significantly different (p < 0.001).”
    CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
    Hsu M et al.
    Abdominal Radiology (2020) 45:615–622

  • CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
    Hsu M et al.
    Abdominal Radiology (2020) 45:615–622
  • "The absolute axial size and volume of hemorrhage, as well as the interval change between the arterial and portal venous phases of CTA imaging is predictive of subsequent positive catheter angiography.”
    CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
    Hsu M et al.
    Abdominal Radiology (2020) 45:615–622
Spleen

  • "Exposure to thorium dioxide (Thorotrast) is the most common iatrogenic cause of hepatic angiosarcoma and it can also cause splenic angiosarcoma. Thorotrast is a highly radioactive contrast agent used until the 1950s. Because Thorotrast has a half- life of 22 years, it has great radioactive potential, leading to fibrosis and carcinogenesis, and may eventually lead to malignancy in patients up to 65 years after injection, especially in the liver and spleen because of the biodistribution and clearance. In some cases, patients may present with concurrent spontaneous hemoperitoneum resulting from rupture of the highly vascular tumor.”
    Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
    Consul N et al.
    AJR 2020; 214:1083–1091
  • "Surface nodular metastases are most commonly a result of mucinous neoplasm that disseminates throughout the peritoneal cavity, studding the splenic hilum with hypoattenuating cystic lesions that may have faint, linear, or coarse calcifications. Ovarian mucinous neoplasm in particular may involve psammomatous calcifications that invade the splenic parenchyma. Associated findings with ovarian cancer or other metastatic cancers may include malignant ascites, peritoneal carcinomatosis, and omental cake.”
    Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
    Consul N et al.
    AJR 2020; 214:1083–1091
  • “Angiosarcoma is the most common prima- ry malignant splenic solid tumor, but it is very rare overall. It presents in adults 40–79 years old and is not related to chemical exposures (unlike hepatic angiosarcoma). This malignancy arises from highly mitotic splenic sinus endothelial cells along disorganized, anastomosing vascular channels. There is a high 1-year mortality rate associated with this malignancy.”
    Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
    Consul N et al.
    AJR 2020; 214:1083–1091
  • "Incidental splenic calcifications have a broad differential diagnosis; however, they can be readily categorized into a clinically useful shortened list according to the imaging patterns and clinical context. This article proposes an algorithmic approach to diagnosing splenic lesions with calcifications that should be used in conjunction with the patient’s history and other imaging findings. In general, splenic lesions are managed conservatively even when the patient is showing symptoms of disease. Additional treatment is best determined after diagnosing the underlying abnormality.”
    Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
    Consul N et al.
    AJR 2020; 214:1083–1091
  • OBJECTIVE. Incidental splenic lesions, often found on CT images of the abdomen, may often be ignored or mischaracterized. Calcified splenic lesions are often presumed to be granulomas; however, understanding the broader differential diagnostic considerations can be useful.
    CONCLUSION. Determining the cause of splenic lesions is essential to guide appropriate management; the pattern of calcification together with other imaging and clinical findings can aid with differentiation.
    Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
    Consul N et al.
    AJR 2020; 214:1083–1091
  • “In cases in which splenic lesions on CT may not have a characteristic pattern of attenuation or enhancement, the morphologic features and pattern of calcifications can help the differential diagnosis. Using the imaging characteristics of a splenic mass, radiologists can recommend further imaging, surveillance, or more invasive management. Whereas most calci- fied splenic lesions are presumed to be sequelae of prior granulomatous infection, there is a broader differential diagnosis for these lesions. An algorithmic approach to splenic lesions according to their characteristic calcification patterns can therefore narrow the differential diagnosis and help guide management.”
    Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
    Consul N et al.
    AJR 2020; 214:1083–1091
  • "The calcifications within hemangiomas can appear as central punctate, curvilinear, or speckled in areas of thrombosis. Multiphase CT of a splenic hemangioma will typically show a hypoattenuating lesion on unenhanced CT, sometimes with early peripheral discontinuous enhancement with uniform delayed enhancement mirroring the blood pool, although this pattern can be obscured because of background parenchyma enhancement. Smaller lesions may show flash-filling enhancement, especially among the capillary subtype, and larger lesions will often show centripetal progression of enhancement with a persistently enhancing central fibrous scar.”
    Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
    Consul N et al.
    AJR 2020; 214:1083–1091
  • “Some cysts may have internal septations that enhance with contrast administration. Up to 14% of true epithelial cysts can have thin curvilinear wall calcifications, but calcifications can also be seen within septations. When compared with pseudocysts, which are the primary differential diagnostic consideration for these lesions, true epithelial cysts are more likely to have internal enhancing septations but are less likely to have wall calcifications.”
    Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
    Consul N et al.
    AJR 2020; 214:1083–1091
  • "Calcified splenic granulomas are a common incidental finding, most commonly resulting from tuberculosis or histoplasmosis and less commonly from Pneumocystis carinii pneumonia or brucellosis .A risk factor for many of these infections is HIV infection. In all cases, the granulomas are preceded by multiple splenic microabscesses that are hypoattenuating lesions less than 2 cm in diameter. When the microabscesses heal, they may calcify with or without preceding regression. Those that calcify after regression, in cases of histoplasmosis or tuberculosis, may appear as stippled, diffuse calcifications in an otherwise normal spleen.”
    Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
    Consul N et al.
    AJR 2020; 214:1083–1091
  • "Cysts typically measure up to 8–16 cm in diameter. On CT, these hydatid cysts are typically well-marginated with internal fluid attenuation and occasional air-fluid levels. At all stages, hydatid cysts may have curvilinear, ringlike peripheral calcifications of the pericyst in up to 20–30% of cases.”
    Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
    Consul N et al.
    AJR 2020; 214:1083–1091

  • Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
    Consul N et al.
    AJR 2020; 214:1083–1091
  • Littoral Cell Splenic Angioma: Facts
    - It is a primary vascular tumor arising from the cells lining the splenic red pulp venous sinuses, hence the name littoral cells. 
    - LCA is a rare splenic vascular tumor discovered either as an incidental finding or patients may present with abdominal pain. 
    - The gross appearance of the spleen can be slight to moderately enlarged size and weight, with a cross-section showing widened splenic trabeculae and more commonly multifocal than a solitary nodule.
  • Littoral Cell Splenic Angioma: Facts
    The LCA can present as an incidental finding in an asymptomatic patient or as abdominal pain. The physical exam can reveal the presence of splenomegaly in some cases. Other less common clinical features include the presence of anemia, thrombocytopenia, hepatitis, cirrhosis, and portal hypertension.
  • Littoral Cell Splenic Angioma: Facts
    The radiological imaging studies like magnetic resonance imaging (MRI) and computed tomography scan (CT scan) have not proven to be adequate in diagnosing littoral cell angioma, given that it is difficult to differentiate from other splenic neoplasms like angiosarcomas, lymphomas, metastatic tumors on imaging. Owing to the hemosiderin deposits in the tumor cells, hypodense lesions are visible on T1 and T2 weighted MRI images. Sonography evaluation is not helpful because of the variable findings of heterogeneous echotexture and no definite lesions.
  • Littoral Cell Splenic Angioma: Facts
    Currently, splenectomy followed by long term follow up is the recommended treatment for LCA given its malignant potential. Since LCA can be associated with splenomegaly, performing a laparoscopic splenectomy (LS) can be a challenging task. It should only be performed by an experienced surgeon with particular attention to prevent splenic capsule rupture and, consequently, any tumor cell dissemination.
  • Littoral Cell Splenic Angioma: Facts
    The differential diagnosis includes other vascular neoplasms of the spleen, including splenic hemangioma, lymphangioma, hamartoma, angiosarcoma. The LCA can be differentiated from these lesions based on the histopathological and immunophenotyping findings, as detailed above. Imaging studies (MRI, CT scan, ultrasound) have not demonstrated usefulness in differentiating between these.
  • Littoral Cell Splenic Angioma: Facts
    The complications of littoral cell angioma could be secondary to hypersplenism leading to anemia, thrombocytopenia, abdominal pain, and weight loss. Additionally, the patient can develop early postoperative complications of splenectomy performed for treatment of LCA like bleeding, incision site infection, hernia, atelectasis, pulmonary and abdominal sepsis, pancreatitis, pulmonary embolism.
Stomach

  • Carney-Stratakis Syndrome
    - Familial paraganglioma and GIST
    --- Autosomal dominant
    - Germline mutations in succinate dehydrogenase genes SDHB, SDHC or SDHD
    --- No germline or somatic CKIT or PDGFRA mutations
    - Mean age 23
    --- Males and females affected
    - Nearly all stomach
    --- Frequently multiple and multinodular
    - GIST may metastasize to lymph nodes
    --- Usually protracted, indolent course (e.g. 15 years) in most cases even with metastasis or recurrence
  • Carney-Stratakis Syndrome
    A diverse group of researchers has found the genetic defects that cause a rare type of familial GIST called “Carney-Stratakis syndrome”. This syndrome has some similarities to Carney’s Triad but it is a distinct entity. This discovery may one day lead to better treatments for the affected patients and may give researchers new insights into Carney’s Triad and possibly into pediatric GIST in general.
  • GIST Syndromes
    - Primary familial GIST syndrome
    - Neurofibromatosis type 1 (von Recklinghausen disease)
    - Carney-Stratakis syndrome
  • Primary Familial GIST Syndrome
    - This is a rare, inherited condition that leads to an increased risk of developing GISTs. People with this syndrome tend to develop GISTs at a younger age than when they usually occur. They are also more likely to have more than one GIST.
    - Most often, this syndrome is caused by an abnormal KIT gene that is passed from parent to child. This is the same gene that is mutated (changed) in most sporadic GISTs.
  • Neurofibromatosis type 1 (von Recklinghausen disease)
    - This condition is caused by a defect in the NF1 gene. This gene change may be inherited from a parent, but in some cases the change occurs before birth, without being inherited.
    - People affected by this syndrome often have many benign (non-cancerous) nerve tumors, called neurofibromas, starting when they are young. These tumors form under the skin and in other parts of the body. These people also typically have tan or brown spots on the skin (called café au lait spots).
    - People with NF1 have a higher risk of GISTs (most often in the small intestine), as well as some other types of cancer.
  • Carney-Stratakis Syndrome
    - People with this rare inherited condition have an increased risk of GISTs (most often in the stomach), as well as nerve tumors called paragangliomas. GISTs often develop when these people are in their teens or 20s. They are also more likely to have more than one GIST.
    - This syndrome is caused by a change in one of the SDH (succinate dehydrogenase) genes, which is passed from parent to child.
Syndromes in CT

  • “Erdheim-Chester disease is a non–Langerhans cell histiocytosis characterized by the infiltration of foamy histiocytes with fibrosis that can affect many organs, most commonly long bones.Renal involvement commonly manifests in this disease as a histiocytic infiltration into the perirenal fat. Histopathologic findings from biopsy of the right retroperitoneal region included fragments of fibroadipose tissue displaying a lymphohistiocytic infiltrate.”
    The Hairy Kidney of Erdheim-Chester Disease
    Scolaro JC, Peiris AN
    Mayo Clin Proceed May 2018 Volume 93, Issue 5, Page 671
  • “Peripelvic and periureteric areas are frequently overlooked in the imaging evaluations of the urinary system on computed tomography and magnetic resonance imaging. Several neoplastic and non-neoplastic disorders and diseases including lipomatosis, angiomyolipoma and angiolipomatous proliferation, vascular lesions, lymphangiomatosis, Rosai-Dorfman disease, Erdheim-Chester disease, extramedullary hematopoiesis, IgG4-related disease, lymphoma, mesenchymal tumors, trauma, and Antopol-Goldman lesion may involve these areas. Differentiation of these benign or malignant pathologies among themselves and from primary renal pathologies is of utmost importance to expedite the triage of patients for correct treatment approach.”
    Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies.
    Gumeler E et al.
    Abdom Radiol (NY). 2018 Sep;43(9):2400-2411
  • “Erdheim–Chester disease (ECD) is first described by Jacob Erdheim and William Chester in 1930 and is also referred to as lipogranulomatosis. ECD is a systemic inflammatory disorder with a poor prognosis. Skeletal system is the most commonly involved body part, however, around 50% of the cases may have extraskeletal involvement. Symmetrical diaphyseal and metaphyseal osteosclerosis of the long bones is the typical skeletal finding. Among the extraskeletal sites that are involved central nervous system, pulmonary and cardiovascular systems, orbital cavity and cutaneous system may be counted in addition to the kidneys and the retroperitoneum.”
    Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies.
    Gumeler E et al.
    Abdom Radiol (NY). 2018 Sep;43(9):2400-2411
  • "Urological manifestations of ECD may include, but not limited to, ureteral obstruction secondary to retroperitoneal involvement, primary adrenal and kidney involvement. Adrenal and renal failure may occur in some of the affected patients. Perirenal soft tissue infiltration is reported as the most frequently observed form of retroperitoneal involvement.”
    Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies.
    Gumeler E et al.
    Abdom Radiol (NY). 2018 Sep;43(9):2400-2411
  • “For genitourinary system evaluation in patients with ECD, CT may be utilized as the first modality of choice. The so called “hairy kidney appearance,” due to perirenal involvement, is typically characterized by hypoattenuating, irregularly shaped soft tissue masses with minimal enhancement after contrast injection. This finding is very frequent in cases with renal ECD, with a reported rate of 68% of all patients with genitourinary involvement. Infiltrative extension towards the kidney periphery into the renal sinus may be observed.”
    Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies.
    Gumeler E et al.
    Abdom Radiol (NY). 2018 Sep;43(9):2400-2411
  • “Primary renal lymphoma without systemic extension is a rare clinical occurrence and it accounts for less than 1% of extranodal lymphomas. As the renal parenchyma does not normally contain lymphoid tissue, the development of primary renal lymphomas is thought to originate from lymphatic-rich renal capsule or perirenal fat with subsequent extension into the renal parenchyma. Secondary renal lymphomas may commonly occur in patients with advanced stage disease. Autopsy series of patients with lymphoma showed renal involvement in 30%–60% of the cases. Renal lymphomas are usually B cell non-Hodgkin type lymphomas. Secondary lymphomatous involvement of the kidneys is usually clinically silent, however, in a small percentage of patients flank pain, hematuria, and rarely renal failure may be observed.”
    Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies.
    Gumeler E et al.
    Abdom Radiol (NY). 2018 Sep;43(9):2400-2411
  • “Renal involvement typically presents as solid solitary or multiple lesions within the renal parenchyma. Perirenal or diffuse parenchymal involvement may also be seen some patients. Isolated renal sinus involvement is rare and peripelvic involvement occurs secondary to tumoral extension from the conglomerated retroperitoneal lymph nodes. Ureteral obstruction may be frequently observed in patients with periureteral extension. Renal vascular occlusion or thrombosis is rare despite extensive encasement of these structures, owing to the soft and pliable nature of the lymphoma .”
    Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies.
    Gumeler E et al.
    Abdom Radiol (NY). 2018 Sep;43(9):2400-2411
  • “CT demonstrates low attenuated lymphomatous infiltration along renal sinus and ureteral wall while this infiltration typically manifests as hypointense on both T1W and T2W images on MRI scans. This infiltrative growth pattern is reminiscent of transitional cell carcinomas (TCCs) and other inflammatory processes such as XGP. Based on these similarities, both TCC and XGP should be considered in the differential diagnosis. Mild and homogeneous post-contrast enhancement may be a helpful imaging hint to differentiate peripelvic and periureteral lymphoma from these disorders.”
    Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies.
    Gumeler E et al.
    Abdom Radiol (NY). 2018 Sep;43(9):2400-2411
  • “Erdheim–Chester disease (ECD) is a rare xanthogranulomatous histiocytosis of non-Langerhans cells most common in male adults between the fourth and seventh decades of life. It was first described by Erdheim and Chester in 1930 and is characterized by multifocal osteosclerotic lesions of the long bones.Although there is a speculation that ECD and other histiocytic disorders may represent an aberrant response to infection, no infectious etiology has been identified. It remains controversial if ECD is a reactive polyclonal histiocyte proliferation or a monoclonal neoplastic process.”
    Spectrum of abdominal imaging findings in histiocytic disorders. 
    de Souza Maciel Rocha Horvat, N., Coelho, C.R., Roza, L.C. et al. 
    Abdom Imaging 40, 2738–2746 (2015). https://doi.org/10.1007/s00261-015-0449-1
  • "Infiltration of the perirenal fat appears as an irregular renal border producing a “hairy kidney” appearance on CT and MRI. On CT, this manifests as a hypodense and homogeneous band with spiculated contours and mild contrast enhancement. On MRI, it is isointense to muscle on T1- and T2-weighted sequences, with a slight and homogeneous enhancement after contrast injection. Perirenal infiltration may progress to the renal sinuses and produce a post renal obstruction. The ureteral segments which are most commonly affected by fibrosis are the middle and distal segments. The renal arteries may also be involved by tissue infiltration and fibrosis.”
    Spectrum of abdominal imaging findings in histiocytic disorders.
    de Souza Maciel Rocha Horvat, N., Coelho, C.R., Roza, L.C. et al.
    Abdom Imaging 40, 2738–2746 (2015). https://doi.org/10.1007/s00261-015-0449-1
  • "Retroperitoneal involvement with ECD can manifest as a mass-like infiltrative surrounding the abdominal aorta with the same characteristics of the perirenal lesions. This can lead to acute or slowly progressive renal insufficiency. Retroperitoneal involvement frequently includes a bilateral, symmetric, and diffuse thickening of the adrenal glands associated with infiltration of the adjacent fat.”
    Spectrum of abdominal imaging findings in histiocytic disorders.
    de Souza Maciel Rocha Horvat, N., Coelho, C.R., Roza, L.C. et al.
    Abdom Imaging 40, 2738–2746 (2015). https://doi.org/10.1007/s00261-015-0449-1
  • Erdheim Chester Disease: Renal Changes
    - Perirenal fat effaced or infiltrated by soft tissue
    - Usually bilateral and symmetric
    - Infiltration of para-aortic regions is also common
  • Erdheim Chester Disease: Vascular Changes
    - Periaortic infiltration which is usually circumferential and nonocclusive
    - May involve aorta from root thru iliac vessels
  • Perinephric Masses on CT: Differential Diagnosis
    - Lymphoma
    - Metastases (especially melanoma)
    - Myeloma
    - Urinomas
    - Hemmorrhage
    - Infection
    - Extramedullary hematopoiesis
    - Retroperitoneal fibrosis
    - Erdheim Chester disease
  • Perirenal Space Pathology
    - Solitary soft tissue masses (RCC, lymphangioma,hemangioma)
    - Rindlike soft tissue lesions (lymphoma, retroperitoneal fibrosis, Erdheim Chester disease)
    - Multifocal soft tissue masses (metastases)
    - Masses containing macroscopic fat (AML, extramedullary hematopoiesis)
    Neoplastic and Nonneoplastic Proliferative Disorders of the Perirenal Space: Cross-sectional Imaging Findings
    Surabhi VR et al
    RadioGraphics 2008; 28:1005-1017
  • Carney-Stratakis Syndrome
    - Familial paraganglioma and GIST
    --- Autosomal dominant
    - Germline mutations in succinate dehydrogenase genes SDHB, SDHC or SDHD
    --- No germline or somatic CKIT or PDGFRA mutations
    - Mean age 23
    --- Males and females affected
    - Nearly all stomach
    --- Frequently multiple and multinodular
    - GIST may metastasize to lymph nodes
    --- Usually protracted, indolent course (e.g. 15 years) in most cases even with metastasis or recurrence
  • Carney-Stratakis Syndrome
    A diverse group of researchers has found the genetic defects that cause a rare type of familial GIST called “Carney-Stratakis syndrome”. This syndrome has some similarities to Carney’s Triad but it is a distinct entity. This discovery may one day lead to better treatments for the affected patients and may give researchers new insights into Carney’s Triad and possibly into pediatric GIST in general.
  • GIST Syndromes
    - Primary familial GIST syndrome
    - Neurofibromatosis type 1 (von Recklinghausen disease)
    - Carney-Stratakis syndrome
  • Primary Familial GIST Syndrome
    - This is a rare, inherited condition that leads to an increased risk of developing GISTs. People with this syndrome tend to develop GISTs at a younger age than when they usually occur. They are also more likely to have more than one GIST.
    - Most often, this syndrome is caused by an abnormal KIT gene that is passed from parent to child. This is the same gene that is mutated (changed) in most sporadic GISTs.
  • Neurofibromatosis type 1 (von Recklinghausen disease)
    - This condition is caused by a defect in the NF1 gene. This gene change may be inherited from a parent, but in some cases the change occurs before birth, without being inherited.
    - People affected by this syndrome often have many benign (non-cancerous) nerve tumors, called neurofibromas, starting when they are young. These tumors form under the skin and in other parts of the body. These people also typically have tan or brown spots on the skin (called café au lait spots).
    - People with NF1 have a higher risk of GISTs (most often in the small intestine), as well as some other types of cancer.
  • Carney-Stratakis Syndrome
    - People with this rare inherited condition have an increased risk of GISTs (most often in the stomach), as well as nerve tumors called paragangliomas. GISTs often develop when these people are in their teens or 20s. They are also more likely to have more than one GIST.
    - This syndrome is caused by a change in one of the SDH (succinate dehydrogenase) genes, which is passed from parent to child.
Trauma

  • Purpose: Cinematic rendering (CR), a recently launched, FDA-approved rendering technique converts CT image datasets into nearly photorealistic 3D reconstructions by using a unique lighting model. The purpose of this study was to compare CR to volume rendering technique (VRT) images in the preoperative visualization of multifragmentary intraarticular lower extremity fractures.
    Conclusions: CR reconstructions are superior to VRT due to higher image quality and higher anatomical accuracy. Traumatologists find CR reconstructions to improve visualization of lower extremity fractures which should thus be used for fracture demonstration during interdisciplinary conferences.
    Is CT-based cinematic rendering superior to volume rendering technique in T the preoperative evaluation of multifragmentary intraarticular lower extremity fractures?
    Lena M. Wollschlaegera et al.
    European Journal of Radiology 126 (2020) 108911
  • "CR uses a unique lighting model which is far more complex than the ray casting methods used in VR [5]. In CR, the algorithm is based on the global illumination model. This model incorporates information of billions of photons traveling through the volumetric dataset, and the interactions of these rays of light with a joining voxels. Complex lighting effects such as refraction, absorption, depth of field, soft shadows and ambient occlusion can be created.”
    Is CT-based cinematic rendering superior to volume rendering technique in T the preoperative evaluation of multifragmentary intraarticular lower extremity fractures?
    Lena M. Wollschlaegera et al.
    European Journal of Radiology 126 (2020) 108911
  • "Recently, Dappa et al. published a review comparing the potential value of CR to conventional VRT images and illustrated potential clinical applications of CR such as preoperative treatment planning. In their experience, CR is especially striking for visualizing structures with high density and high contrast such as bones. Further- more, they highlighted the high quality of CR images and their ability for the perception of depth and the photorealistic representation of human anatomy.”
    Is CT-based cinematic rendering superior to volume rendering technique in T the preoperative evaluation of multifragmentary intraarticular lower extremity fractures?
    Lena M. Wollschlaegera et al.
    European Journal of Radiology 126 (2020) 108911
  • “CR provides a more detailed visualization of multifragmentary intraarticular lower extremity fractures with improved image quality and higher anatomical accuracy compared to VRT, thus facilitating the understanding of fracture morphology in multifragmentary intraarticular fractures. Therefore, CR improves traumatological pre-operative fracture visualization in patients with multifragmentary in- traarticular lower extremity fractures and thus can be recommended for fracture demonstration during interdisciplinary conferences.”
    Is CT-based cinematic rendering superior to volume rendering technique in T the preoperative evaluation of multifragmentary intraarticular lower extremity fractures?
    Lena M. Wollschlaegera et al.
    European Journal of Radiology 126 (2020) 108911
© 1999-2020 Elliot K. Fishman, MD, FACR. All rights reserved.