Elliot K. Fishman M.D.
Johns Hopkins Hospital

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“The DETECT-A blood test incorporated baseline and confirmation test components that have the potential to detect cancer in many organs. The baseline test component represented an early version of a multi-analyte test, called CancerSEEK. It did not employ the machine learning methods described in to increase sensitivity and specificity. Rather, it used pre-defined thresholds for each DNA and protein biomarker and a confirmation test to enhance specificity. The advances described in and elsewhere to increase sensitivity while maintaining specificity were made only after design and IRB-approval of the DETECT-A study, which occurred in 2016 and 2017, respectively.”
Feasibility of blood testing combined with PET-CT to screen for cancer and guide intervention. 
Lennon AM et al.
Science. 2020 Jul 3;369(6499)

“Cancer treatments are often more successful when the disease is detected early. We evaluated the feasibility and safety of multi-cancer blood testing coupled with PET-CT imaging to detect cancer in a prospective, interventional study of 10,006 women not previously known to have cancer. Positive blood tests were independently confirmed by a diagnostic PET-CT, which also localized the cancer. Twenty-six cancers were detected by blood testing. Of these, 15 underwent PET-CT imaging and nine (60%) were surgically excised. Twenty-four additional cancers were detected by standard-of-care screening and 46 by neither approach. 1.0% of participants underwent PET-CT imaging based on false positive blood tests, and 0.22% underwent a futile invasive diagnostic procedure. These data demonstrate that multi-cancer blood testing combined with PET-CT can be safely incorporated into routine clinical care, in some cases leading to surgery with intent to cure.”
Feasibility of blood testing combined with PET-CT to screen for cancer and guide intervention. 
Lennon AM et al.
Science. 2020 Jul 3;369(6499)

“The aim of this study was to evaluate for agreement with respect to how radiologists report incidental findings encountered on CT.”
Common Incidental Findings on MDCT: Survey of Radiologist Recommendations for Patient Management
Johnson PT, Horton KM, Megibow AJ, Jeffrey RB, Fishman EK
J Am Coll Radiol 2011;8:762-767

“ Seventy percent or greater agreement on interpretation was identified for only 6 findings: recommend ultrasound for a 1-cm thyroid nodule, recommend ultrasound for a 3-cm cyst in postmenopausal woman, follow Fleischner Society recommendations for a 5-mm lung nodule, describe only coronary calcification, and describe as likely benign both short-segment small bowel intussusception and a 1-cm splenic cyst.”
Common Incidental Findings on MDCT: Survey of Radiologist Recommendations for Patient Management
Johnson PT, Horton KM, Megibow AJ, Jeffrey RB, Fishman EK
J Am Coll Radiol 2011;8:762-767

“ Agreement is lacking, both across institutions and within departments, for the management of 6 commonly encountered incidental findings on body CT. Individual departments should develop internal guidelines to ensure consistent recommendations based on existing evidence.”
Common Incidental Findings on MDCT: Survey of Radiologist Recommendations for Patient Management
Johnson PT, Horton KM, Megibow AJ, Jeffrey RB, Fishman EK
J Am Coll Radiol 2011;8:762-767

“ The frequency of IFs, the very high rate of false-positives among incidentalomas, the very low rates of malignancies among incidentalomas, and the potential financial and emotional costs to both patients and the health care system of monitoring IFs necessitate a through informed consent process.”
Incidental Findings and the Need for a Revised Informed Consent Process
Kole J, Fiester A
AJR 2013; 201:1064-1068

“ Given that incidental findings are very common in high-resolution imaging, patients should be provided information about the possibility of an incidental finding as part of radiologic informed consent.”
Incidental Findings and the Need for a Revised Informed Consent Process
Kole J, Fiester A
AJR 2013; 201:1064-1068

How often can you expect to see an incidental finding of note?

“ Of patients undergoing CT angiography of the abdominal aorta and lower extremities, 15% had previously undiagnosed, highly important findings. Radiologists and referring clinicians should be aware of the frequency of these clinically significant extravascular findings at CT angiography.”
Incidence of Highly Important Extravascular Findings Detected on CT Angiography of the Abdominal Aorta and the Lower Extremities
Naidu S et al.
AJR 2010 194:1630-1634

“ Highly important extravascular findings were found in 40 (15%) patients. Of 462 findings overall, 43 (9%) were of high importance, 77 (17%) were of moderate importance, and 342 (74%) were of low importance. The most common highly important findings were indeterminate lesions of the kidney (n=9), lung (n=7) and liver (n=6).”
Incidence of Highly Important Extravascular Findings Detected on CT Angiography of the Abdominal Aorta and the Lower Extremities
Naidu S et al.
AJR 2010’194:1630-1634

“ In our study of 1209 MDCT urography examinations, 6.8% of patients had clinically important or potentially important incidental findings requiring further investigation. Of these clinically significant results proved uncommon with acute findings diagnosed in 0.9% of patients and extraurinary malignancy confirmed in 0.4%.”
Incidental Clinically Important Extraurinary Findings at MDCT Urography for Hematuria Evaluation: Prevalence in 1209 Consecutive Examinations
Song JH et al.
AJR 2012; 199:618-622

“ The prevalence of clinically important incidental extraurinary findings at MDCT urography performed for hematuria was 6.8%.”
Incidental Clinically Important Extraurinary Findings at MDCT Urography for Hematuria Evaluation: Prevalence in 1209 Consecutive Examinations
Song JH et al.
AJR 2012; 199:618-622

“Significant noncardiac findings are common in patients referred to routine preprocedural DSCT for planning TAVI (17.1%).”
Prevalence of noncardiac findings in computed tomography angiography before transcatheter aortic valve replacement.
Staab W et al.
J Cardiovasc Comput Tomogr. 2014 May-Jun;8(3):222-9

“In 60 of 204 DSCT examinations (29.4%) no noncardiac findings were observed. Of the remaining 144 examinations (70.6%), 35 of 204 patients (17.1%) had a total of 37 clinically significant noncardiac findings. Eight malignancies were detected; 5 of them were incidentally diagnosed on DSCT and changed patient management. A total of 223 nonsignificant findings were observed in 116 of 204 patients (56.9%; group A), the most frequent findings were pleural effusions or colorectal diverticulosis.”
Prevalence of noncardiac findings in computed tomography angiography before transcatheter aortic valve replacement.
Staab W et al.
J Cardiovasc Comput Tomogr. 2014 May-Jun;8(3):222-9

“ Of the remaining 144 examinations (70.6%), 35 of 204 patients (17.1%) had a total of 37 clinically significant noncardiac findings. Eight malignancies were detected; 5 of them were incidentally diagnosed on DSCT and changed patient management.”
Prevalence of noncardiac findings in computed tomography angiography before transcatheter aortic valve replacement.
Staab W et al.
J Cardiovasc Comput Tomogr. 2014 May-Jun;8(3):222-9

Prevalence of noncardiac findings in computed tomography angiography before transcatheter aortic valve replacement.
Staab W et al.
J Cardiovasc Comput Tomogr. 2014 May-Jun;8(3):222-9

Purpose: The frequency of computed tomography (CT) imaging of trauma patients has given rise to an increase in the discovery of incidental findings. The purpose of this study was to evaluate the frequency and documentation of follow-up recommendations of incidental findings during the initial trauma evaluation. Secondarily, trauma patients with and without incidental findings were compared. We hypothesized that there would be a high rate of incidental findings in trauma patients and that these findings would be poorly documented.
Results: Of the 1573 CT scans performed, 478 (30.4%) revealed incidental findings. The abdomen/pelvis had the highest rate of incidental findings (61.7%). Of the 416 patients, 295 (70.9%) had a total of 858 incidental findings, with an average of 3 findings per patient. Follow-up was required for 24 (2.8%) incidental findings, and admission/immediate intervention was required for 6 (0.7%) findings. Only 12 (1.4%) incidental findings were documented in the discharge note. Increasing age (p < 0.001), a higher body mass index (BMI) (p = 0.015), and receiving a pan-CT (p < 0.001) increased the odds of having an incidental finding.
Incidental findings in blunt trauma patients: prevalence, follow-up documentation, and risk factors. 
James MK et al. 
Emerg Radiol. 2017;24(4):347-353

Aim: Whole-body computed tomography (CT) for trauma occasionally reveals significant incidental findings not related to trauma, which require an adequate response. In this study, we examined the current state of incidental findings in trauma patients on whole-body CT and the effects of the feedback system.
Results: During the study period, whole-body CT revealed incidental findings in 79 of 199 trauma patients (40.1%). The mean age of the 79 patients with incidental findings was 62.8 ± 19.5 years, and the mean injury severity score was 16.6 ± 10.0. No difference was observed in the severity of trauma, age, or length of hospital stay. The incidental findings were related to the liver/gallbladder in 22 patients, kidneys in 17, lungs in 14, and the intracranial area in 13. The recognition rate of incidental findings after the implementation of the feedback system increased from 23.3% to 32.6%.
Incidental findings on whole-body computed tomography in trauma patients: the current state of incidental findings and the effect of implementation of a feedback system. 
Kumada K et al. 
Acute Med Surg. 2019;6(3):274-278.

“ A homogeneous renal mass measuring greater than 70 HU at unenhanced CT has a greater than 99.9% chance of representing a high attenuation renal cyst rather than a renal cell carcinoma.”
Can High-Attenuation Renal Cysts Be Differentiated from Renal Cell Carcinoma at Unenhanced CT?
Jonisch AI et al.
Radiology 2007; 243:445-450

“ The incidental finding of a renal mass is relatively common at unenhanced CT, but imaging criteria can be used for reliable identification of most of these lesions as benign without further workup. Mean attenuation alone appears reliable for determining which renal mass need further evaluation.”
Incidental Findings of Renal Masses at Unenhanced CT: Prevalence and Analysis of Features for Guiding Management
O’connor SD et al.
AJR 2011; 197:139-145

“ Masses (1cm or larger) containing fat or with attenuation less than 20 HU or greater than 70 HU were considered benign if they did not contain thickened walls or septations, three of more septations, mural nodules, or thick calcifications. Masses with attenuation between 20 and 70 HU or any of these features were considered indeterminate.”
Incidental Findings of Renal Masses at Unenhanced CT: Prevalence and Analysis of Features for Guiding Management
O’connor SD et al.
AJR 2011; 197:139-145

“ All proven RCCs in this series contained substantial noncalcified regions that measured 20-70 HU in ROI attenuation on unenhanced CT. Indeterminate renal lesions on unenhanced CT measuring within this 20-70 HU danger zone warrant further workup, whereas lesions that fall entirely outside this range may be considered benign.”
Renal Cell Carcinoma: Attenuation Values on Unenhanced CT
Pooler BD et al.
AJR 2012; 198:1115-1120

“ Given that renal lesions completely outside this range have proven to be benign in previous work, we conclude that indeterminate renal lesions on unenhanced CT that contain areas of ROI attenuation that cross over into this 20-70 HU danger zone will generally warrant further workup.”
Renal Cell Carcinoma: Attenuation Values on Unenhanced CT
Pooler BD et al.
AJR 2012; 198:1115-1120