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

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

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3D and Workflow

  • “The visualization with CR allowed a more correct and faster comprehension of the surgical anatomy compared with conventional CT imaging, independent of level of surgeon experience. Therefore, CR may assist general surgeons with preoperative preparation and intraoperative guidance.”
    Comparison of Cinematic Rendering and Computed Tomography for Speed and Comprehension of Surgical Anatomy.
    Elshafei M et al.
    JAMA Surg. 2019 Aug; 154(8): 738–744.
  • “In many fields of general surgery (eg, hepatopancreatobiliary surgery), accurate knowledge and understanding of the patient’s anatomy with all details (eg, vasculature) is the key requirement in surgical decision making. The interpretation of complex anatomy based on conventional cross-sectional imaging is difficult and susceptible to errors because it requires advanced spatial reasoning abilities. Misinterpretation of imaging data corrupts preoperative decision making and the designated surgical approach, which, in turn, may jeopardize patient outcomes. Virtual 3-dimensional (3-D) reconstruction techniques have been developed to overcome this subjective limitation, ultimately facilitating comprehension of patient anatomy. However, conventional volume-rendering techniques provide images of limited quality that do not allow an adequate evaluation of complex intra-abdominal structures, such as the liver. In this regard, a more photorealistic visualization may facilitate image interpretation and improve the comprehension of the surgical anatomy.”
    Comparison of Cinematic Rendering and Computed Tomography for Speed and Comprehension of Surgical Anatomy.
    Elshafei M et al.
    JAMA Surg. 2019 Aug; 154(8): 738–744.
  • “Misinterpretation of imaging data corrupts preoperative decision making and the designated surgical approach, which, in turn, may jeopardize patient outcomes. Virtual 3-dimensional (3-D) reconstruction techniques have been developed to overcome this subjective limitation, ultimately facilitating comprehension of patient anatomy. However, conventional volume-rendering techniques provide images of limited quality that do not allow an adequate evaluation of complex intra-abdominal structures, such as the liver. In this regard, a more photorealistic visualization may facilitate image interpretation and improve the comprehension of the surgical anatomy.”
    Comparison of Cinematic Rendering and Computed Tomography for Speed and Comprehension of Surgical Anatomy.
    Elshafei M et al.
    JAMA Surg. 2019 Aug; 154(8): 738–744.
  • “Cinematic rendering is a physically based volume-rendering technique. This crossover study used a Monte Carlo path-tracing method to compute the interaction of photons with the scanned patient data. This path-tracing method was first deployed in computer animation programs by the entertainment industry. This rendering method works with data retrieved from conventional CT or magnetic resonance scans. Hence, the image quality is determined by the original resolution and increases with the number of light paths that are traced. The use of high-dynamic-range–rendering light maps for illumination and the real-time computation of complex lighting effects produce a photorealistic depiction of the image data.”
    Comparison of Cinematic Rendering and Computed Tomography for Speed and Comprehension of Surgical Anatomy.
    Elshafei M et al.
    JAMA Surg. 2019 Aug; 154(8): 738–744.
  • “Third, because this is a nonclinical study, we can only speculate about the potential influence that CR imaging may have on surgeons owing to an improved comprehension of the patient anatomy. Thus, it remains to be determined whether the routine clinical use of CR may improve surgical decision making, ultimately leading to a reduction of intraoperative mistakes and an improvement in patient outcome.”
    Comparison of Cinematic Rendering and Computed Tomography for Speed and Comprehension of Surgical Anatomy.
    Elshafei M et al.
    JAMA Surg. 2019 Aug; 154(8): 738–744.
Chest

  • Background: Deep learning has the potential to augment the use of chest radiography in clinical radiology, but challenges include poor generalizability, spectrum bias, and difficulty comparing across studies.
    Purpose: To develop and evaluate deep learning models for chest radiograph interpretation by using radiologist-adjudicated reference standards.
    Conclusion: Expert-level models for detecting clinically relevant chest radiograph findings were developed for this study by using adjudicated reference standards and with population-level performance estimation. Radiologist-adjudicated labels for 2412 ChestX- ray14 validation set images and 1962 test set images are provided.
    Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293
  • Materials and Methods: Deep learning models were developed to detect four findings (pneumothorax, opacity, nodule or mass, and fracture) on frontal chest radiographs. This retrospective study used two data sets. Data set 1 (DS1) consisted of 759 611 images from a multicity hospital network and ChestX-ray14 is a publicly available data set with 112 120 images. Natural language process- ing and expert review of a subset of images provided labels for 657 954 training images. Test sets consisted of 1818 and 1962 images from DS1 and ChestX-ray14, respectively. Reference standards were defined by radiologist-adjudicated image review. Performance was evaluated by area under the receiver operating characteristic curve analysis, sensitivity, specificity, and positive predictive value. Four radiologists reviewed test set images for performance comparison. Inverse probability weighting was applied to DS1 to ac- count for positive radiograph enrichment and estimate population-level performance.
    Results: In DS1, population-adjusted areas under the receiver operating characteristic curve for pneumothorax, nodule or mass, airspace opacity, and fracture were, respectively, 0.95 (95% confidence interval [CI]: 0.91, 0.99), 0.72 (95% CI: 0.66, 0.77), 0.91 (95% CI: 0.88, 0.93), and 0.86 (95% CI: 0.79, 0.92). With ChestX-ray14, areas under the receiver operating characteristic curve were 0.94 (95% CI: 0.93, 0.96), 0.91 (95% CI: 0.89, 0.93), 0.94 (95% CI: 0.93, 0.95), and 0.81 (95% CI: 0.75, 0.86), respectively.
    Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293
  • Materials and Methods: Deep learning models were developed to detect four findings (pneumothorax, opacity, nodule or mass, and fracture) on frontal chest radiographs. This retrospective study used two data sets. Data set 1 (DS1) consisted of 759 611 images from a multicity hospital network and ChestX-ray14 is a publicly available data set with 112 120 images. Natural language process- ing and expert review of a subset of images provided labels for 657 954 training images. Test sets consisted of 1818 and 1962 images from DS1 and ChestX-ray14, respectively. Reference standards were defined by radiologist-adjudicated image review. Performance was evaluated by area under the receiver operating characteristic curve analysis, sensitivity, specificity, and positive predictive value. Four radiologists reviewed test set images for performance comparison. Inverse probability weighting was applied to DS1 to ac- count for positive radiograph enrichment and estimate population-level performance.
    Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293
  • “Deep learning models achieved parity to chest radiography interpretations from board-certified radiologists for the detection of pneumothorax, nodule or mass, airspace opacity, and fracture on a diverse multicenter chest radiography data set (areas under the receiver operative characteristic curve, 0.95, 0.72, 0.91, and 0.86 respectively)."
    Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293

  • Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293
  • “In conclusion, we developed and evaluated clinically relevant artificial intelligence models for chest radiograph interpretation that performed similar to radiologists by using a diverse set of images. The population-adjusted performance analyses reported here along with the release of adjudicated labels for the publicly available ChestX-ray14 images can provide a useful resource to facilitate the continued development of clinically useful artificial intelligence models for chest radiographs.”
    Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293 
  • Background: Deep learning has the potential to augment the use of chest radiography in clinical radiology, but challenges include poor generalizability, spectrum bias, and difficulty comparing across studies.
    Purpose: To develop and evaluate deep learning models for chest radiograph interpretation by using radiologist-adjudicated reference standards.
    Conclusion: Expert-level models for detecting clinically relevant chest radiograph findings were developed for this study by using adjudicated reference standards and with population-level performance estimation. Radiologist-adjudicated labels for 2412 ChestX- ray14 validation set images and 1962 test set images are provided.
    Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293
  • Materials and Methods: Deep learning models were developed to detect four findings (pneumothorax, opacity, nodule or mass, and fracture) on frontal chest radiographs. This retrospective study used two data sets. Data set 1 (DS1) consisted of 759 611 images from a multicity hospital network and ChestX-ray14 is a publicly available data set with 112 120 images. Natural language process- ing and expert review of a subset of images provided labels for 657 954 training images. Test sets consisted of 1818 and 1962 images from DS1 and ChestX-ray14, respectively. Reference standards were defined by radiologist-adjudicated image review. Performance was evaluated by area under the receiver operating characteristic curve analysis, sensitivity, specificity, and positive predictive value. Four radiologists reviewed test set images for performance comparison. Inverse probability weighting was applied to DS1 to ac- count for positive radiograph enrichment and estimate population-level performance.
    Results: In DS1, population-adjusted areas under the receiver operating characteristic curve for pneumothorax, nodule or mass, airspace opacity, and fracture were, respectively, 0.95 (95% confidence interval [CI]: 0.91, 0.99), 0.72 (95% CI: 0.66, 0.77), 0.91 (95% CI: 0.88, 0.93), and 0.86 (95% CI: 0.79, 0.92). With ChestX-ray14, areas under the receiver operating characteristic curve were 0.94 (95% CI: 0.93, 0.96), 0.91 (95% CI: 0.89, 0.93), 0.94 (95% CI: 0.93, 0.95), and 0.81 (95% CI: 0.75, 0.86), respectively.
    Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293
  • Materials and Methods: Deep learning models were developed to detect four findings (pneumothorax, opacity, nodule or mass, and fracture) on frontal chest radiographs. This retrospective study used two data sets. Data set 1 (DS1) consisted of 759 611 images from a multicity hospital network and ChestX-ray14 is a publicly available data set with 112 120 images. Natural language process- ing and expert review of a subset of images provided labels for 657 954 training images. Test sets consisted of 1818 and 1962 images from DS1 and ChestX-ray14, respectively. Reference standards were defined by radiologist-adjudicated image review. Performance was evaluated by area under the receiver operating characteristic curve analysis, sensitivity, specificity, and positive predictive value. Four radiologists reviewed test set images for performance comparison. Inverse probability weighting was applied to DS1 to ac- count for positive radiograph enrichment and estimate population-level performance.
    Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293
  • “Deep learning models achieved parity to chest radiography interpretations from board-certified radiologists for the detection of pneumothorax, nodule or mass, airspace opacity, and fracture on a diverse multicenter chest radiography data set (areas under the receiver operative characteristic curve, 0.95, 0.72, 0.91, and 0.86 respectively)."
    Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293

  • Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293
  • “In conclusion, we developed and evaluated clinically relevant artificial intelligence models for chest radiograph interpretation that performed similar to radiologists by using a diverse set of images. The population-adjusted performance analyses reported here along with the release of adjudicated labels for the publicly available ChestX-ray14 images can provide a useful resource to facilitate the continued development of clinically useful artificial intelligence models for chest radiographs.”
    Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293 
Deep Learning

  • “Radiologists show a rather positive attitude towards AI to become more efficient and precise, but it does not seem to make them extremely confident about their own future. Medical students also advocate the use of AI in radiology but seem to be far more pessimistic regarding danger AI represents to the profession of the diagnostic radiologist.”
    A survey on the future of radiology among radiologists, medical students T and surgeons: Students and surgeons tend to be more skeptical about artificial intelligence and radiologists may fear that other disciplines take over
    Jasper van Hoek et al.
    European Journal of Radiology 121 (2019) 108742
  • “The diagnostic radiologist. This is also reflected in the fact that a large proportion of students answered that AI is a reason not to choose radiology as a specialty. This supposed fear might originate from a lack of information and knowledge. Following the assessment of most radiological publications – in our review of them – AI will not be a threat but rather a welcome addition to the radiological workflow. One must say that the results from our study might be worrisome. Students, and especially the best students, might not choose to go into radiology.”
    A survey on the future of radiology among radiologists, medical students T and surgeons: Students and surgeons tend to be more skeptical about artificial intelligence and radiologists may fear that other disciplines take over
    Jasper van Hoek et al.
    European Journal of Radiology 121 (2019) 108742
  • AI and Surgical Decision Making
  • Observations  Surgical decision-making is dominated by hypothetical-deductive reasoning, individual judgment, and heuristics. These factors can lead to bias, error, and preventable harm. Traditional predictive analytics and clinical decision-support systems are intended to augment surgical decision-making, but their clinical utility is compromised by time-consuming manual data management and suboptimal accuracy. These challenges can be overcome by automated artificial intelligence models fed by livestreaming electronic health record data with mobile device outputs. This approach would require data standardization, advances in model interpretability, careful implementation and monitoring, attention to ethical challenges involving algorithm bias and accountability for errors, and preservation of bedside assessment and human intuition in the decision-making process.
    Conclusions and Relevance  Integration of artificial intelligence with surgical decision-making has the potential to transform care by augmenting the decision to operate, informed consent process, identification and mitigation of modifiable risk factors, decisions regarding postoperative management, and shared decisions regarding resource use.
    Artificial Intelligence and Surgical Decision-Making
    Tyler J. Loftus, MD1; Patrick J. Tighe, MD, MS2; Amanda C. Filiberto, MD1; et al
    JAMA Surg. Published online December 11, 2019. doi:https://doi.org/10.1001/jamasurg.2019.4917
  • Conclusions and Relevance  Integration of artificial intelligence with surgical decision-making has the potential to transform care by augmenting the decision to operate, informed consent process, identification and mitigation of modifiable risk factors, decisions regarding postoperative management, and shared decisions regarding resource use.
    Artificial Intelligence and Surgical Decision-Making
    Tyler J. Loftus, MD1; Patrick J. Tighe, MD, MS2; Amanda C. Filiberto, MD1; et al
    JAMA Surg. Published online December 11, 2019. doi:https://doi.org/10.1001/jamasurg.2019.4917
  • PURPOSE: The purpose of this study was to evaluate the impact of artificial intelligence (AI)-based noise reduction algorithm on aorta computed tomography angiography (CTA) image quality (IQ) at 80 kVp tube voltage and 40 mL contrast medium (CM).
    CONCLUSIONS: The AI-based noise reduction could improve the IQ of aorta CTA with low kV and reduced CM, which achieved the potential of radiation dose and contrast media reduction compared with conventional aorta CTA protocol.
    Application of Artificial Intelligence-based Image Optimization for Computed Tomography Angiography of the Aorta With Low Tube Voltage and Reduced Contrast Medium Volume.
    Wang Y et al.
    J Thorac Imaging. 2019 Nov;34(6):393-399.
  • “Computerized Tomography Angiography (CTA) based follow-up of Abdominal Aortic Aneurysms (AAA) treated with Endovascular Aneurysm Repair (EVAR) is essential to evaluate the progress of the patient and detect complications. In this context, accurate quantification of post-operative thrombus volume is required. However, a proper evaluation is hindered by the lack of automatic, robust and reproducible thrombus segmentation algorithms. We propose a new fully automatic approach based on Deep Convolutional Neural Networks (DCNN) for robust and reproducible thrombus region of interest detection and subsequent fine thrombus segmentation.”
    Fully automatic detection and segmentation of abdominal aortic thrombus in post-operative CT images using Deep Convolutional Neural Networks.
    López-Linares K et al.
    Med Image Anal. 2018 May;46:202-214. 
  • "The DetecNet detection network is adapted to perform region of interest extraction from a complete CTA and a new segmentation network architecture, based on Fully Convolutional Networks and a Holistically-Nested Edge Detection Network, is presented. These networks are trained, validated and tested in 13 post-operative CTA volumes of different patients using a 4-fold cross-validation approach to provide more robustness to the results. Our pipeline achieves a Dice score of more than 82% for post-operative thrombus segmentation and provides a mean relative volume difference between ground truth and automatic segmentation that lays within the experienced human observer variance without the need of human intervention in most common cases."
    Fully automatic detection and segmentation of abdominal aortic thrombus in post-operative CT images using Deep Convolutional Neural Networks.
    López-Linares K et al.
    Med Image Anal. 2018 May;46:202-214. 
  • Purpose: To evaluate the opinion and assessment of radiologists, surgeons and medical students on a number of important topics regarding the future of radiology, such as artificial intelligence (AI), turf battles, teleradiology and 3D-printing.
    Conclusions: With regard to AI, radiologists expect their workflow to become more efficient and tend to support the use of AI, whereas medical students and surgeons tend to be more skeptical towards this technology. Medical students see AI as a potential threat to diagnostic radiologists, while radiologists themselves are rather afraid of turf losses.
    A survey on the future of radiology among radiologists, medical students T and surgeons: Students and surgeons tend to be more skeptical about artificial intelligence and radiologists may fear that other disciplines take over
    Jasper van Hoek et al.
    European Journal of Radiology 121 (2019) 108742
  • Background: Deep learning has the potential to augment the use of chest radiography in clinical radiology, but challenges include poor generalizability, spectrum bias, and difficulty comparing across studies.
    Purpose: To develop and evaluate deep learning models for chest radiograph interpretation by using radiologist-adjudicated reference standards.
    Conclusion: Expert-level models for detecting clinically relevant chest radiograph findings were developed for this study by using adjudicated reference standards and with population-level performance estimation. Radiologist-adjudicated labels for 2412 ChestX- ray14 validation set images and 1962 test set images are provided.
    Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293
  • Materials and Methods: Deep learning models were developed to detect four findings (pneumothorax, opacity, nodule or mass, and fracture) on frontal chest radiographs. This retrospective study used two data sets. Data set 1 (DS1) consisted of 759 611 images from a multicity hospital network and ChestX-ray14 is a publicly available data set with 112 120 images. Natural language process- ing and expert review of a subset of images provided labels for 657 954 training images. Test sets consisted of 1818 and 1962 images from DS1 and ChestX-ray14, respectively. Reference standards were defined by radiologist-adjudicated image review. Performance was evaluated by area under the receiver operating characteristic curve analysis, sensitivity, specificity, and positive predictive value. Four radiologists reviewed test set images for performance comparison. Inverse probability weighting was applied to DS1 to ac- count for positive radiograph enrichment and estimate population-level performance.
    Results: In DS1, population-adjusted areas under the receiver operating characteristic curve for pneumothorax, nodule or mass, airspace opacity, and fracture were, respectively, 0.95 (95% confidence interval [CI]: 0.91, 0.99), 0.72 (95% CI: 0.66, 0.77), 0.91 (95% CI: 0.88, 0.93), and 0.86 (95% CI: 0.79, 0.92). With ChestX-ray14, areas under the receiver operating characteristic curve were 0.94 (95% CI: 0.93, 0.96), 0.91 (95% CI: 0.89, 0.93), 0.94 (95% CI: 0.93, 0.95), and 0.81 (95% CI: 0.75, 0.86), respectively.
    Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293
  • Materials and Methods: Deep learning models were developed to detect four findings (pneumothorax, opacity, nodule or mass, and fracture) on frontal chest radiographs. This retrospective study used two data sets. Data set 1 (DS1) consisted of 759 611 images from a multicity hospital network and ChestX-ray14 is a publicly available data set with 112 120 images. Natural language process- ing and expert review of a subset of images provided labels for 657 954 training images. Test sets consisted of 1818 and 1962 images from DS1 and ChestX-ray14, respectively. Reference standards were defined by radiologist-adjudicated image review. Performance was evaluated by area under the receiver operating characteristic curve analysis, sensitivity, specificity, and positive predictive value. Four radiologists reviewed test set images for performance comparison. Inverse probability weighting was applied to DS1 to ac- count for positive radiograph enrichment and estimate population-level performance.
    Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293
  • “Deep learning models achieved parity to chest radiography interpretations from board-certified radiologists for the detection of pneumothorax, nodule or mass, airspace opacity, and fracture on a diverse multicenter chest radiography data set (areas under the receiver operative characteristic curve, 0.95, 0.72, 0.91, and 0.86 respectively)."
    Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293

  • Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293
  • “In conclusion, we developed and evaluated clinically relevant artificial intelligence models for chest radiograph interpretation that performed similar to radiologists by using a diverse set of images. The population-adjusted performance analyses reported here along with the release of adjudicated labels for the publicly available ChestX-ray14 images can provide a useful resource to facilitate the continued development of clinically useful artificial intelligence models for chest radiographs.”
    Chest Radiograph Interpretation with Deep Learning Models: Assessment with Radiologist-adjudicated Reference Standards and Population-adjusted Evaluation
    Anna Majkowska et al.
    Radiology 2019; 00:1–11 • https://doi.org/10.1148/radiol.2019191293 
Kidney

  • “The utility of 3D CT has been well described for the imaging of a number of renal pathologies. Recently, a new 3D visualization technique known as cinematic rendering(CR) has become available and provides photorealistic images derived from standard CT acquisitions by use of a complex global lighting model. Herein, we describe a number of normal variant and pathologic conditions of the kidney visualized with CR. We provide comparisons of findings with CR to traditional methods of 3D imaging and comment on the potential applications of this new method of 3D CT rendering.”
    3D CT of renal pathology: initial experience with cinematic rendering.
    Rowe SP1, Meyer AR, Gorin MA, Johnson PT, Fishman EK
    Abdom Radiol (NY). 2018 Dec;43(12):3445-3455. 
Liver

  • “Hepatic adenomatosis is a benign disease defined as the presence of multiple adenomas in a normal liver. It is an uncommon condition and there are less than a hundred reported cases in the literature. The etiology is unknown, although it has been associated with the use of oral contraceptives, anabolic steroids, certain storage diseases and some genetic mutations linked to maturity onset diabetes of the young. The coexistence of hepatic adenomatosis and nonalcoholic steatohepatitis has been recently described in two patients suffering from metabolic syndrome. This association is particularly interesting due to the growing prevalence of nonalcoholic fatty liver disease in developed countries and the possibility of a common causal pathway.”
    Nonalcoholic steatohepatitis and hepatic adenomatosis: casual or causal relationship?
    Pérez-Carreras M et al.
    Rev Esp Enferm Dig. 2018 Mar;110(3):204-206
  • OBJECTIVE. The objective of our study was to investigate the relationship between hepatic adenoma and liver steatosis.
    RESULTS. Hepatic steatosis was present in 14 of 24 patients (58%) with hepatic adenoma versus seven of 24 patients (29%) with hemangioma (p = 0.042). Steatosis was more common in patients with multiple hepatic adenomas (9/11, 82%) than in those with a single hepatic adenoma (5/13, 38%) (p = 0.047).
    CONCLUSION. Hepatic adenomas occur in patients with hepatic steatosis.
    Multiple Hepatic Adenomas Associated with Liver Steatosis at CT and MRI: A Case-Control Study
    Furlan A, Federle MP et al.
    AJR 2008; 191:1430–1435
  • “The goal of our study was to investigate the association between hepatic adenoma and liver steatosis. According to our results, the presence of liver fat deposition at CT and MRI was more frequently detected among the study group of patients with hepatic adenoma than in the control group of patients with hepatic hemangioma. In addition, in the study group, patients with multiple adenomas more fre- quently had signs of a fatty liver than patients with a single adenoma. These results suggest that liver steatosis may play a role in the development of multiple hepatic adenomas.”
    Multiple Hepatic Adenomas Associated with Liver Steatosis at CT and MRI: A Case-Control Study
    Furlan A, Federle MP et al.
    AJR 2008; 191:1430–1435
  • “Investigators have reported that, in patients with diabetes, the accumulation of glycogen within the cells, related to the defect in hepatic catabolism, can play a role in the hyperplastic reaction leading to the genesis of hepatic adenomas. The obesity epidemic has paralleled the rapid increase in the prevalence of type 2 diabetes. In our study, there was a significant increased incidence of diabetes in the adenoma group versus the control group; however, no difference could be found between patients with a single adenoma and those with multiple adenomas.”
    Multiple Hepatic Adenomas Associated with Liver Steatosis at CT and MRI: A Case-Control Study
    Furlan A, Federle MP et al.
    AJR 2008; 191:1430–1435
  • “In conclusion, the results of our study show the association of liver steatosis and hepatic adenoma in a case-control setting, which is a suitable study design for uncommon condi- tions such as hepatic adenoma. Multiple ade- nomas were especially correlated with ste- atosis. In view of the increasing incidence of hepatic steatosis and obesity, this group of he- patic adenoma patients might be of growing importance and needs special attention.”
    Multiple Hepatic Adenomas Associated with Liver Steatosis at CT and MRI: A Case-Control Study
    Furlan A, Federle MP et al.
    AJR 2008; 191:1430–1435
  • “Hepatic adenomatosis is a benign disease defined as the presence of multiple adenomas in a normal liver. It is an uncommon condition and there are less than a hundred reported cases in the literature. The etiology is unknown, although it has been associated with the use of oral contraceptives, anabolic steroids, certain storage diseases and some genetic mutations linked to maturity onset diabetes of the young. The coexistence of hepatic adenomatosis and nonalcoholic steatohepatitis has been recently described in two patients suffering from metabolic syndrome. This association is particularly interesting due to the growing prevalence of nonalcoholic fatty liver disease in developed countries and the possibility of a common causal pathway.”
    Nonalcoholic steatohepatitis and hepatic adenomatosis: casual or causal relationship?
    Pérez-Carreras M et al.
    Rev Esp Enferm Dig. 2018 Mar;110(3):204-206
  • OBJECTIVE. The objective of our study was to investigate the relationship between hepatic adenoma and liver steatosis.
    RESULTS. Hepatic steatosis was present in 14 of 24 patients (58%) with hepatic adenoma versus seven of 24 patients (29%) with hemangioma (p = 0.042). Steatosis was more common in patients with multiple hepatic adenomas (9/11, 82%) than in those with a single hepatic adenoma (5/13, 38%) (p = 0.047).
    CONCLUSION. Hepatic adenomas occur in patients with hepatic steatosis.
    Multiple Hepatic Adenomas Associated with Liver Steatosis at CT and MRI: A Case-Control Study
    Furlan A, Federle MP et al.
    AJR 2008; 191:1430–1435
  • “The goal of our study was to investigate the association between hepatic adenoma and liver steatosis. According to our results, the presence of liver fat deposition at CT and MRI was more frequently detected among the study group of patients with hepatic adenoma than in the control group of patients with hepatic hemangioma. In addition, in the study group, patients with multiple adenomas more fre- quently had signs of a fatty liver than patients with a single adenoma. These results suggest that liver steatosis may play a role in the development of multiple hepatic adenomas.”
    Multiple Hepatic Adenomas Associated with Liver Steatosis at CT and MRI: A Case-Control Study
    Furlan A, Federle MP et al.
    AJR 2008; 191:1430–1435
  • “Investigators have reported that, in patients with diabetes, the accumulation of glycogen within the cells, related to the defect in hepatic catabolism, can play a role in the hyperplastic reaction leading to the genesis of hepatic adenomas. The obesity epidemic has paralleled the rapid increase in the prevalence of type 2 diabetes. In our study, there was a significant increased incidence of diabetes in the adenoma group versus the control group; however, no difference could be found between patients with a single adenoma and those with multiple adenomas.”
    Multiple Hepatic Adenomas Associated with Liver Steatosis at CT and MRI: A Case-Control Study
    Furlan A, Federle MP et al.
    AJR 2008; 191:1430–1435
  • “In conclusion, the results of our study show the association of liver steatosis and hepatic adenoma in a case-control setting, which is a suitable study design for uncommon condi- tions such as hepatic adenoma. Multiple ade- nomas were especially correlated with ste- atosis. In view of the increasing incidence of hepatic steatosis and obesity, this group of he- patic adenoma patients might be of growing importance and needs special attention.”
    Multiple Hepatic Adenomas Associated with Liver Steatosis at CT and MRI: A Case-Control Study
    Furlan A, Federle MP et al.
    AJR 2008; 191:1430–1435
  • "Chronic Budd-Chiari syndrome is also characterized by the development of multiple regenerative nodules, which can be viewed as a response to a focal loss of portal perfusion and hyperarterialization in areas with pre- served hepatic venous outflow. These nodules are usually multiple and have a typical diameter of 0.5–4.0 cm. On multiphasic helical CT, regenerative nodules are markedly and homogeneously hyperattenuating on arte- rial phase images and remain slightly hyperattenuating on portal venous phase images, allowing differential diagnosis from hepatocellular carcinoma."
    Hepatic morphology abnormalities: beyond cirrhosis.
    Mamone G, Cortis K, Sarah A, Caruso S, Miraglia R
    Abdom Radiol (NY). 2018 Jul;43(7):1612-1626
  • “The diagnosis of cirrhosis can be reached on the basis of established hepatic morphological changes. However, some other conditions can mimic cirrhosis. The aim of this pictorial essay is to review the CT and MRI appearances of hepatic morphology abnormalities in the cirrhotic liver and other diseases, describing pathologic conditions that can mimic cirrhosis, with useful tips for the differential diagnosis. Mimickers of cirrhosis include congenital hepatic fibrosis, Caroli disease, Budd-Chiari Syndrome, hepatoportal sclerosis, cavernous transformation of the portal vein, pseudocirrhosis from metastatic disease, acute liver failure, post-therapeutic morphologic changes in the liver, and infective conditions including schistosomiasis and oriental cholangiohepatitis. Recognizing the hepatic morphological changes in images can help radiologists to diagnose cirrhosis and other diseases in early stages.”
    Hepatic morphology abnormalities: beyond cirrhosis.
    Mamone G, Cortis K, Sarah A, Caruso S, Miraglia R
    Abdom Radiol (NY). 2018 Jul;43(7):1612-1626
  • “In subacute or chronic Budd-Chiari syn- drome, the morphologic changes in the liver are the result of the type of venous involve- ment, and portosystemic and intrahepatic collateral vessels are often found. Contrast-enhanced CT is useful for depicting regions of hypoperfused liver parenchyma.”
    Hepatic morphology abnormalities: beyond cirrhosis.
    Mamone G, Cortis K, Sarah A, Caruso S, Miraglia R
    Abdom Radiol (NY). 2018 Jul;43(7):1612-1626
  • “In acute Budd-Chiari syndrome, the morphologic features of the liver usually are normal, and occlusion of the hepatic veins with severe ascites is the typical finding. The liver exhibits patchy, decreased peripheral enhancement caused by portal and sinusoidal stasis and stronger enhancement of the central portion of the liver parenchyma. The thrombosed hepatic veins are hypoattenuating, and the inferior vena cava is compressed by the enlarged caudate lobe. Ascites and splenomegaly are usually present.”
    Budd-Chiari Syndrome: Spectrum of Imaging Findings
    Brancatelli G, Vilgrain V, Federle MP et al.
    AJR 2007; 188:W168–W176
  • “The liver exhibits patchy, decreased peripheral enhancement caused by portal and sinusoidal stasis and stronger enhancement of the central portion of the liver parenchyma. The thrombosed hepatic veins are hypoattenuating, and the inferior vena cava is compressed by the enlarged caudate lobe. Ascites and splenomegaly are usually present.”
    Budd-Chiari Syndrome: Spectrum of Imaging Findings
    Brancatelli G, Vilgrain V, Federle MP
    AJR 2007; 188:W168–W176
  • "In subacute or chronic Budd-Chiari syn- drome, the morphologic changes in the liver are the result of the type of venous involve- ment, and portosystemic and intrahepatic col- lateral vessels are often found. Contrast-enhanced CT is useful for depicting regions of hypoperfused liver parenchyma."
    Budd-Chiari Syndrome: Spectrum of Imaging Findings
    Brancatelli G, Vilgrain V, Federle MP
    AJR 2007; 188:W168–W176
  • “Common causes of BCS include inherited and acquired hypercoagulable states. Inherited hypercoagulable states such as factor V Leiden mutation, protein C deficiency, protein S deficiency, the prothrombin G20210A mutation, and antithrombin III deficiency are common causes of hepatic vein thrombosis resulting in BCS. Acquired prothrombotic states such as myeloproliferative disorders (e.g., polycythemia vera, paroxysmal nocturnal hemoglobinuria, essential thrombocytosis, agnogenic myeloid metaplasia, and myelofibrosis) account for more than 50% of BCS cases. Other prothrombotic conditions, such as antiphospholipid syndrome, have also been mentioned. Other conditions have been proposed as risk factors for the development of BCS, including Behçet disease, hypereosinophilic syndrome, and ulcerative colitis and pregnancy, malnutrition, and the use of oral contraceptives. “
    Budd-Chiari Syndrome
    Hector Ferral, George Behrens, Jorge Lopera
    AJR 2012; 199:737–745
  • Budd Chiari Syndrome: Causes
    - Inherited and acquired hypercoagulability states (i.e. factor V Leiden mutation)
    - Myeloproliferative disorders (polycythemia vera, PNH, myelofibrosis)
    - Pregnancy
    - Malnutrition
    - Use of oral contraceptives
  • Budd Chiari Syndrome: Facts
    - Clinical presentation of BCS may be fulminant (5%), acute (20%), and subacute or chronic (60%) [13]. BCS may be asymptomatic in approximately 15–20% of cases.
    - Approximately 75–80% of patients with BCS will have clinical manifestations; the most common include fever, abdominal pain, abdominal distention, ascites, liver failure, lower extremity edema, gastrointestinal bleeding, and encephalopathy
  • Budd Chiari Syndrome: Facts
    - Fulminant Budd Chiari Syndrome
    - Acute Budd-Chiari Syndrome
    - Subacute Budd-Chiari Syndrome
    - Chronic Budd-Chiari Syndrome
  • "CT findings in acute BCS may include nor- mal liver morphology, patchy enhancement, an enlarged caudate lobe, a compressed IVC, the absence of hepatic veins, and ascites. The patchy enhancement seen on CT scans of patients with BCS is related to the stasis in the sinusoids and portal vein and is associated with increased en- hancement of the central portion of the liver parenchyma."
    Budd-Chiari Syndrome
    Hector Ferral, George Behrens, Jorge Lopera
    AJR 2012; 199:737–745
  • “Chronic BCS is associated with an alteration in the morphology of the liver and regenerative nodule formation. These nodules typically show hyperattenuation in the arterial phase and remain hyperattenuating in the portal phase; patchy enhancement may also be seen in this stage of the disease.”
    Budd-Chiari Syndrome
    Hector Ferral, George Behrens, Jorge Lopera
    AJR 2012; 199:737–745
Practice Management

  • “The incorporation of AI into radiology imaging modalities has already begun and can be envisioned to eventually impact all facets of image creation including pre-acquisition (patient positioning and protocol optimization), acquisition (iterative reconstruction, dose modulation, and automatic view detection), and post-acquisition (disease detection, lesion classification, organ and lesion segmentation, quantification of numerous parameters, and voice recognition). Although the post-acquisition aspects of AI incorporation into radiology will take the longest to find widespread clinical application, these are also potentially the most transformative.”
    What Health Care Can Learn From Self-Driving Vehicles.
    Powell K, Fishman EK, Horton KM, Johnson PT, Rowe SP.
    J Am Coll Radiol. 2019 Feb;16(2):261-263.
  • "Furthermore, AI can be the foundation for intelligent hospitals and workflows. Indeed, over the next 5 years, AI will play an increasingly pervasive role in improving efficiency and workflow throughout health care. Of note, there are more than 200 AI startups in the health care industry, an almost overwhelming number working on numerous different applications. Methods of deploying this tremendous number of evolving AI tools are needed, and we may see the emergence of AI application stores where hospital systems can select the plat- forms that would be most beneficial to them."
    What Health Care Can Learn From Self-Driving Vehicles.
    Powell K, Fishman EK, Horton KM, Johnson PT, Rowe SP.
    J Am Coll Radiol. 2019 Feb;16(2):261-263.
  • "Machine learning and AI are already beginning to be integrated into a number of facets of radiology. This includes the implementation of “intelligent instruments” such as CT scanners that can use integrated cameras to detect whether patient position is adequate for the study indication. In the near future, those same scanners will begin to choose and execute an optimized protocol including contrast bolus timing, contrast phases, and dose modulation, and then allow for advanced reconstruction and visualization such as automatic organ and lesion contouring, textural analysis, and cinematic rendering."
    What Health Care Can Learn From Self-Driving Vehicles.
    Powell K, Fishman EK, Horton KM, Johnson PT, Rowe SP.
    J Am Coll Radiol. 2019 Feb;16(2):261-263.
  • “Although it is difficult to predict how health care will evolve through AI, we should not fear the influence of this rapidly evolving technology. Instead of thinking about AI replacing our abilities, we should instead view AI as allowing us to “level up” what we can accomplish. In radiology, having AI perform the mundane tasks that humans may struggle with or find interminable, such as pulmonary nodule detection or organ segmentation, as well as the tasks that are simply impossible for humans, such as extracting lesion textural features across multiple contrast phases or sequences, frees us to interact with the images in ways that can push the boundaries of diagnostic science. By using AI, we can add depth to our readings that can produce tangible benefits to patient care.”
    What Health Care Can Learn From Self-Driving Vehicles.
    Powell K, Fishman EK, Horton KM, Johnson PT, Rowe SP.
    J Am Coll Radiol. 2019 Feb;16(2):261-263.
  • “In April 2016, Facebook launched a live broadcast tool, which CTisus started using in March 2017 as a new way to engage users. Once a week at the same time, CTisus hosts a brief live discussion on a topic related to radiology. Users have the ability to post questions in the live interface, and CTisus can answer in real time via text or voice. Based on positive engagement and user feedback from Facebook users, CTisus began broadcasting the same live discussion on Instagram in October 2017.”
    Social Media for Global Education: Pearls and Pitfalls of Using Facebook, Twitter, and Instagram.
    Thomas RB, Johnson PT, Fishman EK.
    J Am Coll Radiol. 2018 Oct;15(10):1513-1516
  • "Facebook also enables scheduling of posts, which is extremely helpful to manage CTisus’ high post volume strategy. CTisus posts about 15 to 20 times a day to Facebook with a wide range of content: CT case studies, medical illustrations, pearls relevant to radiology, management tips, and current articles relating to health and medicine. In addition to the medical posts, CTisus also posts nonmedical content: music, pop culture, business, and politics, to name a few."
    Social Media for Global Education: Pearls and Pitfalls of Using Facebook, Twitter, and Instagram.
    Thomas RB, Johnson PT, Fishman EK.
    J Am Coll Radiol. 2018 Oct;15(10):1513-1516
  • “In 2016, CTisus joined Insta- gram because of its popularity in the social media space, particularly among medical students. In just under a year, the CTisus Instagram account outperformed Twitter with over 2,100 followers. The Instagram app is an infinite scroll of images with a small text caption beneath; this model works well with the image-heavy field of radi- ology. Instagram posts are limited to square images, 2,200 characters, video lengths of less than 1 min, and no links, and you can only post from a mobile device.”
    Social Media for Global Education: Pearls and Pitfalls of Using Facebook, Twitter, and Instagram.
    Thomas RB, Johnson PT, Fishman EK.
    J Am Coll Radiol. 2018 Oct;15(10):1513-1516
  • "For CTisus, social media has proven invaluable in expanding outreach to achieve our mission of worldwide content distribution. Regular review of use patterns through analytics is important to understand what users want and to drive quality improvement. Students and trainees, who represent the future of the medical profession, are heavily dependent on these platforms. Medical educators interested in global outreach should master these tools to easily provide free medical education dissemination on an international scale."
    Social Media for Global Education: Pearls and Pitfalls of Using Facebook, Twitter, and Instagram.
    Thomas RB, Johnson PT, Fishman EK.
    J Am Coll Radiol. 2018 Oct;15(10):1513-1516

  • Social Media for Global Education: Pearls and Pitfalls of Using Facebook, Twitter, and Instagram.
    Thomas RB, Johnson PT, Fishman EK.
    J Am Coll Radiol. 2018 Oct;15(10):1513-1516
Small Bowel

  • “Initial presentation of ileal carcinoid tumor, even with mesenteric involvement, is often missed prospectively at abdominal CT, leading to delay in diagnosis until bowel or mesenteric findings become more obvious, or hepatic metastatic disease manifests. Radiologists should make a concerted effort to evaluate the bowel and mesentery in patients with long- standing vague abdominal symptoms.”
    CT detection of primary and metastatic ileal carcinoid tumor: rates of missed findings and associated delay in clinical diagnosis
    Akshya Gupta1 · Meghan G. Lubner1 · Robert M. Wertz1 · Eugene Foley2 · Agnes Loeffler3 · Perry J. Pickhardt1,4
    Abdominal Radiology https://doi.org/10.1007/s00261-019-01945-0
  • “Primary ileal tumors were prospectively missed on at least one CT scan in 64% (32/50) of patients with retrospectively identifiable disease. CT findings of mesenteric spread were missed at least once in 46% (25/54) of cases where present in retrospect. By the final pre-operative CT, hepatic metastases and bowel wall thickening were present in 55% (35/64) and 52% (33/64) of cases, respectively. In patients with missed ileal and/or mesenteric findings resulting in diagnostic delay, mean delay was 40 months (range 4–98 months).”
    CT detection of primary and metastatic ileal carcinoid tumor: rates of missed findings and associated delay in clinical diagnosis
    Akshya Gupta1 · Meghan G. Lubner1 · Robert M. Wertz1 · Eugene Foley2 · Agnes Loeffler3 · Perry J. Pickhardt1,4
    Abdominal Radiology https://doi.org/10.1007/s00261-019-01945-0
  • "Despite the presence of calcification and the relatively large size of these missed mesenteric lesions, the lack of oral or intravenous contrast may further increase the difficulty in distinguishing adjacent loops of small bowel with mesenteric pathology. In some cases, even the presence of oral contrast may obscure detection of calcified mesen- teric lesions. The non-specific patient presentation and the absence of localizing symptomatology can also make interpretation more challenging."
    CT detection of primary and metastatic ileal carcinoid tumor: rates of missed findings and associated delay in clinical diagnosis
    Akshya Gupta1 · Meghan G. Lubner1 · Robert M. Wertz1 · Eugene Foley2 · Agnes Loeffler3 · Perry J. Pickhardt1,4
    Abdominal Radiology https://doi.org/10.1007/s00261-019-01945-0
  • "Overall, missed CT findings of primary and metastatic ileal carcinoid tumor result in a clear delay in diagnosis that averaged over 3 years (40 months). To our knowledge, this is the first study to attempt to quantify rates of missed findings and their associated impact on radiologic disease progression. This is significant despite the relatively indolent nature of ileal carcinoid tumor, as patients will have continued symptoms, may present with later stage disease, and may have a worse prognosis."
    CT detection of primary and metastatic ileal carcinoid tumor: rates of missed findings and associated delay in clinical diagnosis
    Akshya Gupta · Meghan G. Lubner · Robert M. Wertz · Eugene Foley · Agnes Loeffler · Perry J. Pickhardt
    Abdominal Radiology https://doi.org/10.1007/s00261-019-01945-0
  • "In summary, our findings highlight the need for radi- ologists to pay close attention to both the mesentery and the small bowel as part of their routine CT search pattern, especially for patients with subacute or chronic non-specific abdominal complaints. Given the ease with which these subtle findings can be missed, patients with non-specific abdominal symptoms including pain, nausea, and diarrhea should have their imaging studies closely protocolled and evaluated."
    CT detection of primary and metastatic ileal carcinoid tumor: rates of missed findings and associated delay in clinical diagnosis
    Akshya Gupta · Meghan G. Lubner · Robert M. Wertz · Eugene Foley · Agnes Loeffler · Perry J. Pickhardt
    Abdominal Radiology https://doi.org/10.1007/s00261-019-01945-0
Stomach

  • “The most frequent and sensitive CT findings of volvulus with high positive likelihood ratios were stenosis at the hernia neck (reader 1, sensitivity = 80%, positive likelihood ratio = 26.66; reader 2, sensitivity = 77%, pos- itive likelihood ratio = 12.83) and transition point at the pylorus (reader 1, sensitivity = 80%, positive likelihood ratio = 17; reader 2, sensitivity = 70%, positive likelihood ratio = 15). The presence of perigastric fluid or a pleural effusion were significantly more frequent in patients with ischemia at surgical pathology (p < 0.05 in all comparisons, both radiologists).”
    CT of Gastric Volvulus: Interobserver Reliability, Radiologists’ Accuracy, and Imaging Findings
    Mazaheri P et al.
    AJR 2019; 212:103–108
  • OBJECTIVE. The objective of this study was to identify CT findings and determine interobserver reliability of surgically proven gastric volvulus.
    CONCLUSION. In our series, CT showed substantial interobserver agreement and fair accuracy in identifying the presence of gastric volvulus.
    CT of Gastric Volvulus: Interobserver Reliability, Radiologists’ Accuracy, and Imaging Findings
    Mazaheri P et al.
    AJR 2019; 212:103–108
  • “Gastric volvulus refers to at least 180°rotation of the stomach and leads to gastric outlet obstruction, impairment of vascularity, eventually ischemia. It is a rare condition with unknown exact incidence or prevalence. Although 70% of patients present with the Borchardt triad, a combination of severe epigastric pain, retching, and inability to pass a nasogastric tube, the clinical presentation may not be classic.”
    CT of Gastric Volvulus: Interobserver Reliability, Radiologists’ Accuracy, and Imaging Findings
    Mazaheri P et al.
    AJR 2019; 212:103–108
  • “Because of its rarity and the overlap in appearance with large hiatal hernias, gastric volvulus remains a challenging condition to diagnose with CT. Acute gastric volvulus may lead to gangrene in 5–28% of patients, so missing or delaying an appropriate diagnosis can have grave consequences.”
    CT of Gastric Volvulus: Interobserver Reliability, Radiologists’ Accuracy, and Imaging Findings
    Mazaheri P et al.
    AJR 2019; 212:103–108
  • “Acute gastric volvulus is a surgical emergency with high morbidity and mortality. The diagnosis of gastric volvulus is difficult to make clinically because symptoms are nonspecific, so imaging is performed to aid in diagnosis. For this reason, radiologists must be familiar with diagnostically useful CT findings of gastric volvulus to enable early detection and reduce morbidity and mortality in this patient population.”
    CT of Gastric Volvulus: Interobserver Reliability, Radiologists’ Accuracy, and Imaging Findings
    Mazaheri P et al.
    AJR 2019; 212:103–108
  • “CT findings of overt ischemia including gastric wall edema, poor gastric wall enhancement, perigastric fluid, pneumatosis, pleural effusion, and pneumoperitoneum were uncommonly seen in our study and, though insensitive, were highly specific for volvulus with near complete agreement. Among these findings of ischemia, perigastric fluid and pleural effusion had the highest sensitivities (30–47% and 27–37%, respectively) for gastric volvulus.”
    CT of Gastric Volvulus: Interobserver Reliability, Radiologists’ Accuracy, and Imaging Findings
    Mazaheri P et al.
    AJR 2019; 212:103–108
  • “Competitive eaters are known to be able to accommodate large quantities of food particles within their flaccid stomach sac conditioned by repeated rapid distension of the gastric wall during their gobbling episodes. These individuals are at risk of gastroparesis, aspiration pneumonia, gastric perforation, Mallory-Weiss tear, Boerhaave syndrome, and morbid obesity. Rapid and gross gastric distension owing to the consumption of food items that are not chewed results in large chunks of solid food particles accumulating in the stomach, preventing food from entering the duodenum.”
    The Perils of Competitive Speed Eating!
    Lim TZ1, Rajaguru K1, Lee CL1.
    Gastroenterology. 2018 Jun;154(8):2030-2032
  • “Despite the health consequences illustrated, many of these competitors seek the fame and glory associated with accomplishing such incredible feats and continue to test the limits of human health.”
    The Perils of Competitive Speed Eating!
    Lim TZ1, Rajaguru K1, Lee CL1.
    Gastroenterology. 2018 Jun;154(8):2030-2032
Vascular

  • “The goal of abdominal aortic aneurysm (AAA) detection is to identify asymptomatic AAA before rupture, as the mortality rate associated with a ruptured aneurysm may exceed 80%, while the mortality rate of an elective repair is 0.5% to 4% in most contemporary studies. The US Preventive Services Task Force (USPSTF) has recommend 1-time screening for patients at risk of AAA since 2005, and AAA screening has been a covered benefit under Centers for Medicare & Medicaid Services since 2007. The 2019 update by USPSTF1,2 has incorporated new evidence since its last update in 2014 and continues to recommend 1-time screening for certain patients.”
    Screening for Abdominal Aortic Aneurysm—A Call to Arms?
    Matthew Mell
    JAMA Network Open. 2019;2(12):e1917168.
  • "The 2019 recommendations are complicated. Specifically, the 2019 USPSTF statement recommends 1-time screening for AAA with ultrasonography for men aged 65 to 75 years who have ever smoked (Grade B recommendation) and selective screening for men aged 65 to 75 years who have never smoked (Grade C recommendation). For women aged 65 to 75 years who have ever smoked or have a family history of AAA, the USPSTF indicates that “the current evidence is insufficient to assess the balance of benefits and harms of screening for AAA”2 (Grade I statement), and the USPSTF recommends against routine screening for women who have never smoked and have no family history of AAA (Grade D recommendation)."
    Screening for Abdominal Aortic Aneurysm—A Call to Arms?
    Matthew Mell
    JAMA Network Open. 2019;2(12):e1917168.
  • “The most effective way to prevent death from ruptured AAA is to prevent rupture. More research is needed to optimize diffusion of current recommendations and to identify other patient cohorts with a high pretest probability of AAA and who benefit from repair and therefore screening.”
    Screening for Abdominal Aortic Aneurysm—A Call to Arms?
    Matthew Mell
    JAMA Network Open. 2019;2(12):e1917168.
  • “Abdominal aortic aneurysms (AAAs) are often asymptomatic, with slow expansion until rupture. AAA screening to identify and treat aneurysms before rupture can potentially prevent a fatal outcome. To prevent rupture, AAA, defined as an aneurysm 3.0 cm in diameter or larger, is most commonly surgically repaired via open repair or endovascular aneurysm repair (EVAR) when it reaches a diameter of 5.5 cm. The role of pharmacotherapy to slow aneurysm expansion has been uncertain. Reported AAA prevalence rates in persons 60 years or older have declined from 3.9% to 7.2% in the 1990s to more contemporary estimates that range from 1.2% to 3.3%.The most important risk factors for the development of AAA include advanced age, male sex, smoking, and family history of AAA.”
    Primary Care Screening for Abdominal Aortic Aneurysm Updated Evidence Report and Systematic Review for the US Preventive Services Task Force
    Janelle M. Guirguis-Blake, MD1,2; Tracy L. Beil, MS2; Caitlyn A. Senger, MPH2; et al
    JAMA. 2019;322(22):2219-2238
  • “Conclusions and Relevance  One-time AAA screening in men 65 years or older was associated with decreased AAA-related mortality and rupture rates but was not associated with all-cause mortality benefit. Higher rates of elective surgery but no long-term differences in quality of life resulted from screening.”
    Primary Care Screening for Abdominal Aortic Aneurysm Updated Evidence Report and Systematic Review for the US Preventive Services Task Force
    Janelle M. Guirguis-Blake, MD1,2; Tracy L. Beil, MS2; Caitlyn A. Senger, MPH2; et al
    JAMA. 2019;322(22):2219-2238
  • Smoking is the strongest predictor of AAA prevalence, growth, and rupture rates. Even with substantial declines since 1995-2002 when the screening trials were conducted, AAA prevalence in male smokers aged 65 to 75 years matches that of the population-based screening trials. Family history is associated with an increased risk of developing AAA (OR, 2.2 [95% CI, 1.6-3.2]).  At this time, however, there is a lack of evidence to determine whether individuals with family histories exhibit differences in natural history or surgical success rates to alter the net screening benefits. Overall, because there is no direct trial evidence evaluating screening effectiveness in subpopulations and no externally validated risk assessment tools, decision analysis models populated with meta-analytic estimates of prevalence, yield, and surgical complication rates would be considered the best available evidence to date.”
    Primary Care Screening for Abdominal Aortic Aneurysm Updated Evidence Report and Systematic Review for the US Preventive Services Task Force
    Janelle M. Guirguis-Blake, MD1,2; Tracy L. Beil, MS2; Caitlyn A. Senger, MPH2; et al
    JAMA. 2019;322(22):2219-2238
  • “Smoking is the strongest predictor of AAA prevalence, growth, and rupture rates. Even with substantial declines since 1995-2002 when the screening trials were conducted, AAA prevalence in male smokers aged 65 to 75 years matches that of the population-based screening trials. Family history is associated with an increased risk of developing AAA (OR, 2.2 [95% CI, 1.6-3.2]).  At this time, however, there is a lack of evidence to determine whether individuals with family histories exhibit differences in natural history or surgical success rates to alter the net screening benefits.”
    Primary Care Screening for Abdominal Aortic Aneurysm Updated Evidence Report and Systematic Review for the US Preventive Services Task Force
    Janelle M. Guirguis-Blake, MD1,2; Tracy L. Beil, MS2; Caitlyn A. Senger, MPH2; et al
    JAMA. 2019;322(22):2219-2238
  • “The goal of abdominal aortic aneurysm (AAA) detection is to identify asymptomatic AAA before rupture, as the mortality rate associated with a ruptured aneurysm may exceed 80%, while the mortality rate of an elective repair is 0.5% to 4% in most contemporary studies. The US Preventive Services Task Force (USPSTF) has recommend 1-time screening for patients at risk of AAA since 2005, and AAA screening has been a covered benefit under Centers for Medicare & Medicaid Services since 2007. The 2019 update by USPSTF1,2 has incorporated new evidence since its last update in 2014 and continues to recommend 1-time screening for certain patients.”
    Screening for Abdominal Aortic Aneurysm—A Call to Arms?
    Matthew Mell
    JAMA Network Open. 2019;2(12):e1917168.
  • "The 2019 recommendations are complicated. Specifically, the 2019 USPSTF statement recommends 1-time screening for AAA with ultrasonography for men aged 65 to 75 years who have ever smoked (Grade B recommendation) and selective screening for men aged 65 to 75 years who have never smoked (Grade C recommendation). For women aged 65 to 75 years who have ever smoked or have a family history of AAA, the USPSTF indicates that “the current evidence is insufficient to assess the balance of benefits and harms of screening for AAA”2 (Grade I statement), and the USPSTF recommends against routine screening for women who have never smoked and have no family history of AAA (Grade D recommendation)."
    Screening for Abdominal Aortic Aneurysm—A Call to Arms?
    Matthew Mell
    JAMA Network Open. 2019;2(12):e1917168.
  • “The most effective way to prevent death from ruptured AAA is to prevent rupture. More research is needed to optimize diffusion of current recommendations and to identify other patient cohorts with a high pretest probability of AAA and who benefit from repair and therefore screening.”
    Screening for Abdominal Aortic Aneurysm—A Call to Arms?
    Matthew Mell
    JAMA Network Open. 2019;2(12):e1917168.
  • “Abdominal aortic aneurysms (AAAs) are often asymptomatic, with slow expansion until rupture. AAA screening to identify and treat aneurysms before rupture can potentially prevent a fatal outcome. To prevent rupture, AAA, defined as an aneurysm 3.0 cm in diameter or larger, is most commonly surgically repaired via open repair or endovascular aneurysm repair (EVAR) when it reaches a diameter of 5.5 cm. The role of pharmacotherapy to slow aneurysm expansion has been uncertain. Reported AAA prevalence rates in persons 60 years or older have declined from 3.9% to 7.2% in the 1990s to more contemporary estimates that range from 1.2% to 3.3%.The most important risk factors for the development of AAA include advanced age, male sex, smoking, and family history of AAA.”
    Primary Care Screening for Abdominal Aortic Aneurysm Updated Evidence Report and Systematic Review for the US Preventive Services Task Force
    Janelle M. Guirguis-Blake, MD1,2; Tracy L. Beil, MS2; Caitlyn A. Senger, MPH2; et al
    JAMA. 2019;322(22):2219-2238
  • “Conclusions and Relevance  One-time AAA screening in men 65 years or older was associated with decreased AAA-related mortality and rupture rates but was not associated with all-cause mortality benefit. Higher rates of elective surgery but no long-term differences in quality of life resulted from screening.”
    Primary Care Screening for Abdominal Aortic Aneurysm Updated Evidence Report and Systematic Review for the US Preventive Services Task Force
    Janelle M. Guirguis-Blake, MD1,2; Tracy L. Beil, MS2; Caitlyn A. Senger, MPH2; et al
    JAMA. 2019;322(22):2219-2238
  • Smoking is the strongest predictor of AAA prevalence, growth, and rupture rates. Even with substantial declines since 1995-2002 when the screening trials were conducted, AAA prevalence in male smokers aged 65 to 75 years matches that of the population-based screening trials. Family history is associated with an increased risk of developing AAA (OR, 2.2 [95% CI, 1.6-3.2]).  At this time, however, there is a lack of evidence to determine whether individuals with family histories exhibit differences in natural history or surgical success rates to alter the net screening benefits. Overall, because there is no direct trial evidence evaluating screening effectiveness in subpopulations and no externally validated risk assessment tools, decision analysis models populated with meta-analytic estimates of prevalence, yield, and surgical complication rates would be considered the best available evidence to date.”
    Primary Care Screening for Abdominal Aortic Aneurysm Updated Evidence Report and Systematic Review for the US Preventive Services Task Force
    Janelle M. Guirguis-Blake, MD1,2; Tracy L. Beil, MS2; Caitlyn A. Senger, MPH2; et al
    JAMA. 2019;322(22):2219-2238
  • “Smoking is the strongest predictor of AAA prevalence, growth, and rupture rates. Even with substantial declines since 1995-2002 when the screening trials were conducted, AAA prevalence in male smokers aged 65 to 75 years matches that of the population-based screening trials. Family history is associated with an increased risk of developing AAA (OR, 2.2 [95% CI, 1.6-3.2]).  At this time, however, there is a lack of evidence to determine whether individuals with family histories exhibit differences in natural history or surgical success rates to alter the net screening benefits.”
    Primary Care Screening for Abdominal Aortic Aneurysm Updated Evidence Report and Systematic Review for the US Preventive Services Task Force
    Janelle M. Guirguis-Blake, MD1,2; Tracy L. Beil, MS2; Caitlyn A. Senger, MPH2; et al
    JAMA. 2019;322(22):2219-2238
  • PURPOSE: The purpose of this study was to evaluate the impact of artificial intelligence (AI)-based noise reduction algorithm on aorta computed tomography angiography (CTA) image quality (IQ) at 80 kVp tube voltage and 40 mL contrast medium (CM).
    CONCLUSIONS: The AI-based noise reduction could improve the IQ of aorta CTA with low kV and reduced CM, which achieved the potential of radiation dose and contrast media reduction compared with conventional aorta CTA protocol.
    Application of Artificial Intelligence-based Image Optimization for Computed Tomography Angiography of the Aorta With Low Tube Voltage and Reduced Contrast Medium Volume.
    Wang Y et al.
    J Thorac Imaging. 2019 Nov;34(6):393-399.
  • “Computerized Tomography Angiography (CTA) based follow-up of Abdominal Aortic Aneurysms (AAA) treated with Endovascular Aneurysm Repair (EVAR) is essential to evaluate the progress of the patient and detect complications. In this context, accurate quantification of post-operative thrombus volume is required. However, a proper evaluation is hindered by the lack of automatic, robust and reproducible thrombus segmentation algorithms. We propose a new fully automatic approach based on Deep Convolutional Neural Networks (DCNN) for robust and reproducible thrombus region of interest detection and subsequent fine thrombus segmentation.”
    Fully automatic detection and segmentation of abdominal aortic thrombus in post-operative CT images using Deep Convolutional Neural Networks.
    López-Linares K et al.
    Med Image Anal. 2018 May;46:202-214. 
  • "The DetecNet detection network is adapted to perform region of interest extraction from a complete CTA and a new segmentation network architecture, based on Fully Convolutional Networks and a Holistically-Nested Edge Detection Network, is presented. These networks are trained, validated and tested in 13 post-operative CTA volumes of different patients using a 4-fold cross-validation approach to provide more robustness to the results. Our pipeline achieves a Dice score of more than 82% for post-operative thrombus segmentation and provides a mean relative volume difference between ground truth and automatic segmentation that lays within the experienced human observer variance without the need of human intervention in most common cases."
    Fully automatic detection and segmentation of abdominal aortic thrombus in post-operative CT images using Deep Convolutional Neural Networks.
    López-Linares K et al.
    Med Image Anal. 2018 May;46:202-214. 

  • CT Angiography in the Lower Extremity Peripheral Artery Disease Feasibility of an Ultra-Low Volume Contrast Media Protocol
    Barbora Horehledova et al.
    Cardiovasc Intervent Radiol (2018) 41:1751–1764
  • PURPOSE: The purpose of this study was to evaluate the impact of artificial intelligence (AI)-based noise reduction algorithm on aorta computed tomography angiography (CTA) image quality (IQ) at 80 kVp tube voltage and 40 mL contrast medium (CM).
    CONCLUSIONS: The AI-based noise reduction could improve the IQ of aorta CTA with low kV and reduced CM, which achieved the potential of radiation dose and contrast media reduction compared with conventional aorta CTA protocol.
    Application of Artificial Intelligence-based Image Optimization for Computed Tomography Angiography of the Aorta With Low Tube Voltage and Reduced Contrast Medium Volume.
    Wang Y et al.
    J Thorac Imaging. 2019 Nov;34(6):393-399.
  • “Computerized Tomography Angiography (CTA) based follow-up of Abdominal Aortic Aneurysms (AAA) treated with Endovascular Aneurysm Repair (EVAR) is essential to evaluate the progress of the patient and detect complications. In this context, accurate quantification of post-operative thrombus volume is required. However, a proper evaluation is hindered by the lack of automatic, robust and reproducible thrombus segmentation algorithms. We propose a new fully automatic approach based on Deep Convolutional Neural Networks (DCNN) for robust and reproducible thrombus region of interest detection and subsequent fine thrombus segmentation.”
    Fully automatic detection and segmentation of abdominal aortic thrombus in post-operative CT images using Deep Convolutional Neural Networks.
    López-Linares K et al.
    Med Image Anal. 2018 May;46:202-214. 
  • "The DetecNet detection network is adapted to perform region of interest extraction from a complete CTA and a new segmentation network architecture, based on Fully Convolutional Networks and a Holistically-Nested Edge Detection Network, is presented. These networks are trained, validated and tested in 13 post-operative CTA volumes of different patients using a 4-fold cross-validation approach to provide more robustness to the results. Our pipeline achieves a Dice score of more than 82% for post-operative thrombus segmentation and provides a mean relative volume difference between ground truth and automatic segmentation that lays within the experienced human observer variance without the need of human intervention in most common cases."
    Fully automatic detection and segmentation of abdominal aortic thrombus in post-operative CT images using Deep Convolutional Neural Networks.
    López-Linares K et al.
    Med Image Anal. 2018 May;46:202-214. 

  • CT Angiography in the Lower Extremity Peripheral Artery Disease Feasibility of an Ultra-Low Volume Contrast Media Protocol
    Barbora Horehledova et al.
    Cardiovasc Intervent Radiol (2018) 41:1751–1764
  • CT Angiography of the Lower Extremities: Applications
    - Peripheral vascular disease
    - Trauma
    - Pre-operative planning
    - Tumor staging and mapping
    - Infectious disease
  • CT Angiography of the Lower Extremities: Applications
    - Peripheral vascular disease (i.e. cold foot-r/o vessel stenosis)
    - Trauma (i.e. GSW wound or stab wound)
    - Pre-operative planning (fibula harvesting for mandibular reconstruction surgery)
    - Tumor staging and mapping (evaluate mass for pre-operative planning)
    - Infectious disease( R/O abscess, myonecrosis)
  • CT Angiography of the Lower Extremities: Pitfalls
    - Poor injection rate (usually need 4-5 cc/sec)
    - Poor timing of the acquisition (usually too early but may be too late)
    - Patient motion
    - Errors generated by the 3D rendering technique
  • CT Angiography of the Lower Extremities: Pearls
    - use injection rate (usually need 4-5 cc/sec)
    - Second run from just above knee in older patients with PVD
    - Tape patient legs
    - Use 3D after review of data and combine MIP, VRT and CR
  • “A modified three-material decomposition CS algorithm provides increased vascular CNR, equivalent qualitative image quality, and greater diagnostic accuracy for the detection of significant arterial stenosis of the lower extremity runoff on DE-CTA compared with standard image reconstruction.”
    Modified calcium subtraction in dual-energy CT angiography of the lower extremity runoff: impact on diagnostic accuracy for stenosis detection.
    De Santis D et al.
    Eur Radiol. 2019 Sep;29(9):4783-4793
  • "Calcified plaques may lead to overestimation of stenosis severity and false positive results, requiring additional invasive digital subtraction angiography (DSA). • A modified three-material decomposition algorithm for calcium subtraction provides greater diagnostic accuracy for the detection of significant arterial stenosis of the lower extremity runoff compared with standard image reconstruction. • The application of this algorithm in patients with heavily calcified vessels may be helpful to potentially reduce inconclusive CT angiography examinations and the need for subsequent invasive DSA."
    Modified calcium subtraction in dual-energy CT angiography of the lower extremity runoff: impact on diagnostic accuracy for stenosis detection.
    De Santis D et al.
    Eur Radiol. 2019 Sep;29(9):4783-4793
  • Background-—Poor lower extremity physical performance is an independent predictor of unfavorable outcome in patients with peripheral artery disease (PAD); however, few studies have assessed muscle characteristics on imaging directly.
    Conclusions-—Low leg muscle density, but not volume, is a strong, independent predictor of major cardiovascular events among people with PAD. Further research is needed to understand the mechanisms underlying these associations.
    Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
    Morris DR et al.
    J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943.
  • “Peripheral artery disease (PAD) is an important cause of premature death and disability, affecting over 200 mil- lion people worldwide. Patients with PAD have increased risk of leg amputation and cardiovascular events, such as myocardial infarction, stroke, and cardiovascular death. Even with current effective medical therapy, the risk of cardiovascular events is %3 times higher in patients with PAD compared with age- and sex- matched controls. More effective treatments are needed to reduce the high risk of lower limb and cardiovascular events in this population.”
    Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
    Morris DR et al.
    J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943.

  • Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
    Morris DR et al.
    J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943.
  • "Interestingly, low leg muscle density, but not volume, was independently associated with risk of major cardiovascular events. Previous studies demonstrate that decline in muscle strength in older adults is much more rapid than concomitant loss of muscle mass. This could explain why low muscle density, but not volume, was independently associated with risk of major cardiovascular events. Another possible expla- nation is that low muscle density may result from myocyte fat infiltration, which could influence cardiometabolic risk through pro-inflammatory adipokines. Factors contributing to muscle density on CT imaging are not well established."
    Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
    Morris DR et al.
    J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943.
  • "In conclusion, this study showed a strong association between low leg muscle density and clinical events in patients with PAD. Further research is needed to better understand the reasons for this association."
    Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
    Morris DR et al.
    J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943.
  • Purpose: The purpose of this study is to assess the performance of CT angiography (CTA) in the evaluation of penetrating vascular trauma to the extremities in a large cohort of patients at our level I trauma center.
    Results: One hundred and thirty-one (29.4 %) of 446 patients with penetrating trauma demonstrated major vascular injury on CTA, 35 (26.7 %) of whom underwent subsequent surgical repair. None of the patients without vascular injury on CTA underwent subsequent vascular intervention. Fisher’s exact test demonstrated a statistically significant difference in management and requirement for vascular repair in those patients with a vascular injury on CTA when compared to those without a vascular injury (p < 0.0001). The mean attenuation values achieved in upper and lower extremity CTAs in this population exceeded 250 HU.
    Conclusion: Extremity CTA is found to be an accurate tool for surgical triage in patients having sustained penetrating vascular trauma.
    Extremity CTA for penetrating trauma: 10-year experience using a 64-detector row CT scanner.
    Colip CG et al.
    Emerg Radiol. 2017 Jun;24(3):223-232.
  • Aim: To evaluate run-off computed tomography angiography (CTA) of abdominal aorta and lower extremities for detecting musculoskeletal pathologies and clinically relevant extravascular incidental findings in patients with intermittent claudication (IC) and suspected peripheral arterial disease (PAD). Does run-off CTA allow image-based therapeutic decision making by discriminating the causes of intermittent claudication in patients with suspected peripheral arterial disease PAD?
    Discussion: Run-off CTA allows identification of vascular, MSK, and combined causes of IC in patients with suspected PAD and can guide specific therapy. CTA also allowed confident detection of crEVIF although detection did not necessarily trigger workup or treatment.
    Run-Off Computed Tomography Angiography (CTA) for Discriminating the Underlying Causes of Intermittent Claudication
    Alexandra Preuß et al.
    PLoS One. 2016 Apr 7;11(4):e0152780. doi: 10.1371/journal.pone.0152780
  • “Run-off computed tomography angiography (CTA) has become the method of choice for non-invasive imaging of the aorta and lower limb vessels in patients with suspected PAD and is considered to be more accurate than arterial duplex sonography. While still considered the diagnostic standard of reference for PAD, digital subtraction angiography (DSA) is currently being replaced by non-invasive imaging techniques such as CTA or magnetic resonance angiography (MRA). Several studies have shown that CTA is highly accurate in detecting arterial stenosis while avoiding common complications associated with invasive DSA [9]. Furthermore, CTA has become widely used because it is fast and well tolerated by patients and allows precise treatment planning even when using low-dose protocols.”
    Run-Off Computed Tomography Angiography (CTA) for Discriminating the Underlying Causes of Intermittent Claudication
    Alexandra Preuß et al.
    PLoS One. 2016 Apr 7;11(4):e0152780. doi: 10.1371/journal.pone.0152780
  • "Although the focus is on vascular assessment, run-off CT angiography of the aorta and lower extremities also allows differentiation of vascular and musculoskeletal causes of intermittent claudication in a single examination. It facilitates therapeutic decision-making since a considerable number of patients have clinically relevant musculoskeletal findings such as lumbar spinal stenosis or combined vascular and musculoskeletal pathology. Clinically relevant extravascular incidental findings are common on run-off CTA and can be identified on the basis of their CT morphology."
    Run-Off Computed Tomography Angiography (CTA) for Discriminating the Underlying Causes of Intermittent Claudication
    Alexandra Preuß et al.
    PLoS One. 2016 Apr 7;11(4):e0152780. doi: 10.1371/journal.pone.0152780
  • “A low-tube-voltage scan protocol allows for a significant reduction of the injected CM volume and the acquired radiation dose, while maintaining sufficient objective and subjective image quality for the evaluation of PAD, regardless of the lesion severity.”
    CT Angiography in the Lower Extremity Peripheral Artery Disease Feasibility of an Ultra-Low Volume Contrast Media Protocol
    Barbora Horehledova et al.
    Cardiovasc Intervent Radiol (2018) 41:1751–1764
  • “Fleischmann et al. [25] recommend to prolong the injection duration with a corresponding increase in the scan delay to allow an adequate filling distal to the occluded segment. Overall high attenuation values suggest the possibility to reduce CM concentration by mixing the main bolus with saline in order to increase injection volume to prolong the injection time, while the TIL stays the same. The optimum CM volume, concentration, iodine delivery rate (IDR) and injection time for satisfactory attenuation in DPA need to be clarified in a further study. However, the cases with high complete vascular occlusion at the level of CIA or SFA demonstrated that the double-level test bolus technique is able to overcome such severe occlusion, while delivering diagnostic attenuation in all PA and 10/11 ATA segments.”
    CT Angiography in the Lower Extremity Peripheral Artery Disease Feasibility of an Ultra-Low Volume Contrast Media Protocol
    Barbora Horehledova et al.
    Cardiovasc Intervent Radiol (2018) 41:1751–1764
  • CT Angiography of the Lower Extremities: Applications
    - Peripheral vascular disease
    - Trauma
    - Pre-operative planning
    - Tumor staging and mapping
    - Infectious disease
  • CT Angiography of the Lower Extremities: Applications
    - Peripheral vascular disease (i.e. cold foot-r/o vessel stenosis)
    - Trauma (i.e. GSW wound or stab wound)
    - Pre-operative planning (fibula harvesting for mandibular reconstruction surgery)
    - Tumor staging and mapping (evaluate mass for pre-operative planning)
    - Infectious disease( R/O abscess, myonecrosis)
  • CT Angiography of the Lower Extremities: Pitfalls
    - Poor injection rate (usually need 4-5 cc/sec)
    - Poor timing of the acquisition (usually too early but may be too late)
    - Patient motion
    - Errors generated by the 3D rendering technique
  • CT Angiography of the Lower Extremities: Pearls
    - use injection rate (usually need 4-5 cc/sec)
    - Second run from just above knee in older patients with PVD
    - Tape patient legs
    - Use 3D after review of data and combine MIP, VRT and CR
  • “A modified three-material decomposition CS algorithm provides increased vascular CNR, equivalent qualitative image quality, and greater diagnostic accuracy for the detection of significant arterial stenosis of the lower extremity runoff on DE-CTA compared with standard image reconstruction.”
    Modified calcium subtraction in dual-energy CT angiography of the lower extremity runoff: impact on diagnostic accuracy for stenosis detection.
    De Santis D et al.
    Eur Radiol. 2019 Sep;29(9):4783-4793
  • "Calcified plaques may lead to overestimation of stenosis severity and false positive results, requiring additional invasive digital subtraction angiography (DSA). • A modified three-material decomposition algorithm for calcium subtraction provides greater diagnostic accuracy for the detection of significant arterial stenosis of the lower extremity runoff compared with standard image reconstruction. • The application of this algorithm in patients with heavily calcified vessels may be helpful to potentially reduce inconclusive CT angiography examinations and the need for subsequent invasive DSA."
    Modified calcium subtraction in dual-energy CT angiography of the lower extremity runoff: impact on diagnostic accuracy for stenosis detection.
    De Santis D et al.
    Eur Radiol. 2019 Sep;29(9):4783-4793
  • Background-—Poor lower extremity physical performance is an independent predictor of unfavorable outcome in patients with peripheral artery disease (PAD); however, few studies have assessed muscle characteristics on imaging directly.
    Conclusions-—Low leg muscle density, but not volume, is a strong, independent predictor of major cardiovascular events among people with PAD. Further research is needed to understand the mechanisms underlying these associations.
    Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
    Morris DR et al.
    J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943.
  • “Peripheral artery disease (PAD) is an important cause of premature death and disability, affecting over 200 mil- lion people worldwide. Patients with PAD have increased risk of leg amputation and cardiovascular events, such as myocardial infarction, stroke, and cardiovascular death. Even with current effective medical therapy, the risk of cardiovascular events is %3 times higher in patients with PAD compared with age- and sex- matched controls. More effective treatments are needed to reduce the high risk of lower limb and cardiovascular events in this population.”
    Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
    Morris DR et al.
    J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943.

  • Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
    Morris DR et al.
    J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943.
  • "Interestingly, low leg muscle density, but not volume, was independently associated with risk of major cardiovascular events. Previous studies demonstrate that decline in muscle strength in older adults is much more rapid than concomitant loss of muscle mass. This could explain why low muscle density, but not volume, was independently associated with risk of major cardiovascular events. Another possible expla- nation is that low muscle density may result from myocyte fat infiltration, which could influence cardiometabolic risk through pro-inflammatory adipokines. Factors contributing to muscle density on CT imaging are not well established."
    Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
    Morris DR et al.
    J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943.
  • "In conclusion, this study showed a strong association between low leg muscle density and clinical events in patients with PAD. Further research is needed to better understand the reasons for this association."
    Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
    Morris DR et al.
    J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943.
  • Purpose: The purpose of this study is to assess the performance of CT angiography (CTA) in the evaluation of penetrating vascular trauma to the extremities in a large cohort of patients at our level I trauma center.
    Results: One hundred and thirty-one (29.4 %) of 446 patients with penetrating trauma demonstrated major vascular injury on CTA, 35 (26.7 %) of whom underwent subsequent surgical repair. None of the patients without vascular injury on CTA underwent subsequent vascular intervention. Fisher’s exact test demonstrated a statistically significant difference in management and requirement for vascular repair in those patients with a vascular injury on CTA when compared to those without a vascular injury (p < 0.0001). The mean attenuation values achieved in upper and lower extremity CTAs in this population exceeded 250 HU.
    Conclusion: Extremity CTA is found to be an accurate tool for surgical triage in patients having sustained penetrating vascular trauma.
    Extremity CTA for penetrating trauma: 10-year experience using a 64-detector row CT scanner.
    Colip CG et al.
    Emerg Radiol. 2017 Jun;24(3):223-232.
  • Aim: To evaluate run-off computed tomography angiography (CTA) of abdominal aorta and lower extremities for detecting musculoskeletal pathologies and clinically relevant extravascular incidental findings in patients with intermittent claudication (IC) and suspected peripheral arterial disease (PAD). Does run-off CTA allow image-based therapeutic decision making by discriminating the causes of intermittent claudication in patients with suspected peripheral arterial disease PAD?
    Discussion: Run-off CTA allows identification of vascular, MSK, and combined causes of IC in patients with suspected PAD and can guide specific therapy. CTA also allowed confident detection of crEVIF although detection did not necessarily trigger workup or treatment.
    Run-Off Computed Tomography Angiography (CTA) for Discriminating the Underlying Causes of Intermittent Claudication
    Alexandra Preuß et al.
    PLoS One. 2016 Apr 7;11(4):e0152780. doi: 10.1371/journal.pone.0152780
  • “Run-off computed tomography angiography (CTA) has become the method of choice for non-invasive imaging of the aorta and lower limb vessels in patients with suspected PAD and is considered to be more accurate than arterial duplex sonography. While still considered the diagnostic standard of reference for PAD, digital subtraction angiography (DSA) is currently being replaced by non-invasive imaging techniques such as CTA or magnetic resonance angiography (MRA). Several studies have shown that CTA is highly accurate in detecting arterial stenosis while avoiding common complications associated with invasive DSA [9]. Furthermore, CTA has become widely used because it is fast and well tolerated by patients and allows precise treatment planning even when using low-dose protocols.”
    Run-Off Computed Tomography Angiography (CTA) for Discriminating the Underlying Causes of Intermittent Claudication
    Alexandra Preuß et al.
    PLoS One. 2016 Apr 7;11(4):e0152780. doi: 10.1371/journal.pone.0152780
  • "Although the focus is on vascular assessment, run-off CT angiography of the aorta and lower extremities also allows differentiation of vascular and musculoskeletal causes of intermittent claudication in a single examination. It facilitates therapeutic decision-making since a considerable number of patients have clinically relevant musculoskeletal findings such as lumbar spinal stenosis or combined vascular and musculoskeletal pathology. Clinically relevant extravascular incidental findings are common on run-off CTA and can be identified on the basis of their CT morphology."
    Run-Off Computed Tomography Angiography (CTA) for Discriminating the Underlying Causes of Intermittent Claudication
    Alexandra Preuß et al.
    PLoS One. 2016 Apr 7;11(4):e0152780. doi: 10.1371/journal.pone.0152780
  • “A low-tube-voltage scan protocol allows for a significant reduction of the injected CM volume and the acquired radiation dose, while maintaining sufficient objective and subjective image quality for the evaluation of PAD, regardless of the lesion severity.”
    CT Angiography in the Lower Extremity Peripheral Artery Disease Feasibility of an Ultra-Low Volume Contrast Media Protocol
    Barbora Horehledova et al.
    Cardiovasc Intervent Radiol (2018) 41:1751–1764
  • “Fleischmann et al. [25] recommend to prolong the injection duration with a corresponding increase in the scan delay to allow an adequate filling distal to the occluded segment. Overall high attenuation values suggest the possibility to reduce CM concentration by mixing the main bolus with saline in order to increase injection volume to prolong the injection time, while the TIL stays the same. The optimum CM volume, concentration, iodine delivery rate (IDR) and injection time for satisfactory attenuation in DPA need to be clarified in a further study. However, the cases with high complete vascular occlusion at the level of CIA or SFA demonstrated that the double-level test bolus technique is able to overcome such severe occlusion, while delivering diagnostic attenuation in all PA and 10/11 ATA segments.”
    CT Angiography in the Lower Extremity Peripheral Artery Disease Feasibility of an Ultra-Low Volume Contrast Media Protocol
    Barbora Horehledova et al.
    Cardiovasc Intervent Radiol (2018) 41:1751–1764
© 1999-2020 Elliot K. Fishman, MD, FACR. All rights reserved.