Incidentally Detected Bilateral Adrenal Nodules in Patients Without Cancer: Is Further Workup Necessary?

OBJECTIVE: The purpose of this study was to determine the rate of malignancy in incidentally detected bilateral adrenal masses in patients with no known history of cancer. MATERIALS AND METHODS: A retrospective search of CT reports of patients with incidentally detected bilateral adrenal nodules was performed from January 1, 2002, to January 1, 2014. Patients were excluded if they had a known cancer or suspected functioning adrenal tumor; 161 patients were included. Nodules were characterized as benign or malignant on the basis of imaging features at the index CT examination, imaging features at subsequent adrenal protocol CT or MRI, imaging stability for a minimum of 1 year, or clinical follow-up of a minimum of 2 years. RESULTS: Mean nodule size was 1.8 cm (range, 0.7-4.9 cm). There were no cases of primary or secondary adrenal malignancy (95% CI, 0.00-0.023). The nodules diagnosed on index CT scans were 73 adrenal adenomas and two myelolipomas. Seventy-four nodules were subsequently characterized as adrenal adenomas on the basis of imaging findings. Of the 113 indeterminate nodules that had imaging follow-up, 111 were stable at the latest follow-up examination. One nodule grew 26% over 8.1 years, and the other grew 59% over 12.4 years. Clinical follow-up of patients with 60 indeterminate nodules revealed no evidence of adrenal malignancy. CONCLUSION: No case of malignancy was found in 322 incidentally detected bilateral adrenal nodules at CT of patients without known cancer. Imaging follow-up of such lesions may be unnecessary.

Influence of IV Contrast Administration on CT Measures of Muscle and Bone Attenuation: Implications for Sarcopenia and Osteoporosis Evaluation.

OBJECTIVE: The objective of our study was to characterize enhancement of muscle and bone that occurs on standardized four-phase contrast-enhanced CT. MATERIALS AND METHODS: Two musculoskeletal radiologists reviewed standardized four-phase abdominal CT scans obtained with IV contrast material. The psoas area was measured, and the mean attenuation (in Hounsfield units) was recorded for the aorta, psoas muscles, posterior paraspinal muscles, and L4 vertebral body. CT attenuation measures were compared between anatomic regions and imaging phases with the paired t test; associations between measures were examined with the Pearson correlation coefficient (R). RESULTS: The study included 201 patients (97 men, 104 women; mean age, 57.7 ± 12.5 [SD] years). Subject age was inversely correlated with unenhanced attenuation in the psoas muscles, posterior paraspinal muscles, and L4 (p < 0.001). The psoas muscles, posterior paraspinal muscles, and L4 enhanced significantly (p < 0.001) at all three contrast-enhanced phases. The greatest muscle enhancement was observed on delayed phase scans, whereas the greatest enhancement in L4 was seen on portal phase imaging. The unenhanced attenuation of the psoas muscles was significantly and negatively correlated with enhancement of the psoas muscles at the portal and delayed phases (p < 0.05 and p < 0.01, respectively), but these correlations were not seen for the posterior paraspinal muscles. Age was positively correlated with posterior paraspinal muscle enhancement at the portal and delayed phases in men (p < 0.05 and p < 0.01, respectively) but not in women. CONCLUSION: Contrast enhancement of commonly measured muscle and bone regions is routinely observed and should be considered when using CT attenuation values as biomarkers of sarcopenia and osteoporosis. Furthermore, CT enhancement may be significantly influenced by age, sex, and unenhanced tissue attenuation.

Breast Density: Current Knowledge, Assessment Methods, and Clinical Implications.

Breast density is an accepted independent risk factor for the future development of breast cancer, and greater breast density has the potential to mask malignancies on mammography, thus lowering the sensitivity of screening mammography. The risk associated with dense breast tissue has been shown to be modifiable with changes in breast density. Numerous studies have sought to identify factors that influence breast density, including age, genetic, racial/ethnic, prepubertal, adolescent, lifestyle, environmental, hormonal, and reproductive history factors. Qualitative, semiquantitative, and quantitative methods of breast density assessment have been developed, but to date there is no consensus assessment method or reference standard for breast density. Breast density has been incorporated into breast cancer risk models, and there is growing consciousness of the clinical implications of dense breast tissue in both the medical community and public arena. Efforts to improve breast cancer screening sensitivity for women with dense breasts have led to increased attention to supplemental screening methods in recent years, prompting the American College of Radiology to publish Appropriateness Criteria for supplemental screening based on breast density.

Breast Density Legislation Impact on Breast Cancer Screening and Risk Assessment.

OBJECTIVE: To evaluate breast density notification legislation (BDNL) on breast imaging practice patterns, risk assessment, and supplemental screening. METHODS: A 20-question anonymous web-based survey was administered to practicing Society of Breast Imaging radiologists in the U.S. between February and April 2021 regarding breast cancer risk assessment, supplemental screening, and density measurements. Results were compared between facilities with and without BDNL using the two-sided Fisher's exact test. RESULTS: One hundred and ninety-seven radiologists from 41 U.S. states, with (187/197, 95%) or without (10/197, 5%) BDNL, responded. Fifty-seven percent (113/197) performed breast cancer risk assessment, and 93% (183/197) offered supplemental screening for women with dense breasts. Between facilities with or without BDNL, there was no significant difference in whether risk assessment was (P = 0.19) or was not performed (P = 0.20). There was no significant difference in supplemental screening types (P > 0.05) between BDNL and non-BDNL facilities. Thirty-five percent (69/197) of facilities offered no supplemental screening studies, and 25% (49/197) had no future plans to offer supplemental screening. A statistically significant greater proportion of non-BDNL facilities offered no supplemental screening (P < 0.03) and had no plans to offer supplemental screening compared to BDNL facilities (P < 0.02). CONCLUSION: Facilities in BDNL states often offer supplemental screening compared to facilities in non-BDNL states. Compared to BDNL facilities, a statistically significant proportion of non-BDNL facilities had no supplemental screening nor plans for implementation. Our data suggest that upcoming federal BDNL will impact how supplemental screening is addressed in currently non-BDNL states.

Impact of the COVID-19 Pandemic on Breast Imaging Education.

OBJECTIVE: To determine the impact of the COVID-19 pandemic on breast imaging education. METHODS: A 22-item survey addressing four themes during the early pandemic (time on service, structured education, clinical training, future plans) was emailed to Society of Breast Imaging members and members-in-training in July 2020. Responses were compared using McNemar's and Mann-Whitney U tests; a general linear model was used for multivariate analysis. RESULTS: Of 136 responses (136/2824, 4.8%), 96 U.S. responses from radiologists with trainees, residents, and fellows were included. Clinical exposure declined during the early pandemic, with almost no medical students on service (66/67, 99%) and fewer clinical days for residents (78/89, 88%) and fellows (48/68, 71%). Conferences shifted to remote live format (57/78, 73%), with some canceled (15/78, 19%). Compared to pre-pandemic, resident diagnostic (75/78, 96% vs 26/78, 33%) (P < 0.001) and procedural (73/78, 94% vs 21/78, 27%) (P < 0.001) participation fell, as did fellow diagnostic (60/61, 98% vs 47/61, 77%) (P = 0.001) and procedural (60/61, 98% vs 43/61, 70%) (P < 0.001) participation. Most thought that the pandemic negatively influenced resident and fellow screening (64/77, 83% and 43/60, 72%, respectively), diagnostic (66/77, 86% and 37/60, 62%), and procedural (71/77, 92% and 37/61, 61%) education. However, a majority thought that decreased time on service (36/67, 54%) and patient contact (46/79, 58%) would not change residents' pursuit of a breast imaging fellowship. CONCLUSION: The pandemic has had a largely negative impact on breast imaging education, with reduction in exposure to all aspects of breast imaging. However, this may not affect career decisions.

Adaptations of Breast Imaging Centers to the COVID-19 Pandemic: A Survey of California and Texas.

OBJECTIVE: To determine the early impact of the COVID-19 pandemic on breast imaging centers in California and Texas and compare regional differences. METHODS: An 11-item survey was emailed to American College of Radiology accredited breast imaging facilities in California and Texas in August 2020. A question subset addressed March-April government restrictions on elective services ("during the shutdown" and "after reopening"). Comparisons were made between states with chi-square and Fisher's tests, and timeframes with McNemar's and paired t-tests. RESULTS: There were 54 respondents (54/240, 23%, 26 California, 28 Texas). Imaging volumes fell during the shutdown and remained below pre-pandemic levels after reopening, with reduction in screening greatest (ultrasound 12% of baseline, mammography 13%, MRI 23%), followed by diagnostic MRI (43%), procedures (44%), and diagnostics (45%). California reported higher volumes during the shutdown (procedures, MRI) and after reopening (diagnostics, procedures, MRI) versus Texas (P = 0.001-0.02). Most screened patients (52/54, 96% symptoms and 42/54, 78% temperatures), and 100% (53/53) modified check-in and check-out. Reading rooms or physician work were altered for social distancing (31/54, 57%). Physician mask (45/48, 94%), gown (15/48, 31%), eyewear (22/48, 46%), and face shield (22/48, 46%) use during procedures increased after reopening versus pre-pandemic (P < 0.001-0.03). Physician (47/54, 87%) and staff (45/53, 85%) financial impacts were common, but none reported terminations. CONCLUSION: Breast imaging volumes during the early pandemic fell more severely in Texas than in California. Safety measures and financial impacts on physicians and staff were similar in both states.

Incidentally detected biliary ductal dilatation on contrast-enhanced CT: what is the incidence of occult obstructing malignancy?

PURPOSE: The purpose of this study was to determine the incidence of occult obstructing malignancy in the setting of asymptomatic biliary ductal dilatation incidentally detected and without identifiable cause on contrast-enhanced CT. METHODS: A retrospective search identified patients with biliary ductal dilatation on contrast-enhanced CT from March 30, 2007 to November 1, 2017. Patients with biliary symptomatology or clinical concern for an obstructing process, an explanation for biliary ductal dilatation on index CT, intrahepatic without extrahepatic biliary ductal dilatation, concurrent pancreatic ductal dilatation, and inadequate follow-up were excluded. A reference standard of at least 1 year of imaging follow-up or 2 years of clinical follow-up was used to exclude occult obstructing malignancy. RESULTS: 156 patients were included; 120 patients met imaging follow-up criteria and 36 patients met clinical follow-up criteria. No cases of occult malignancy were identified as the source of biliary ductal dilatation (95% CI 0.0-1.9%). LFTs were available for 131 patients, of which 36 were elevated (27%). One case demonstrated a 1.2-cm ampullary adenoma on endoscopic retrograde cholangiopancreatography (occult on follow-up MRI, normal LFTs at the time of the index CT). CONCLUSION: Asymptomatic biliary ductal dilatation incidentally detected and without identifiable cause on contrast-enhanced CT is likely benign in patients with normal LFTs, and further workup may not be warranted.

Inverse association between brown adipose tissue activation and white adipose tissue accumulation in successfully treated pediatric malignancy.

BACKGROUND: Although the accumulation of white adipose tissue (WAT) is a risk factor for disease, brown adipose tissue (BAT) has been suggested to have a protective role against obesity. OBJECTIVE: We studied whether changes in BAT were related to changes in the amounts of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) in children treated for malignancy. DESIGN: We examined the effect of BAT activity on weight, SAT, and VAT in 32 pediatric patients with cancer whose positron emission tomography-computed tomography (PET-CT) scans at diagnosis showed no BAT activity. Changes in weight, SAT, and VAT from diagnosis to remission for children with metabolically active BAT at disease-free follow-up (BAT+) were compared with those in children without visualized BAT when free of disease (BAT-). RESULTS: Follow-up PET-CT studies (4.7 ± 2.4 mo later) after successful treatment of the cancer showed BAT+ in 19 patients but no active BAT (BAT-) in 13 patients. BAT+ patients, in comparison with BAT- patients, gained significantly less weight (3.3 ± 6.6% compared with 11.0 ± 11.6%; P = 0.02) and had significantly less SAT (18.2 ± 26.5% compared with 67.4 ± 71.7%; P = 0.01) and VAT (22.6 ± 33.5% compared with 131.6 ± 171.8%; P = 0.01) during treatment. Multiple regression analysis indicated that the inverse relations between BAT activation and measures of weight, SAT, and VAT persisted even after age, glucocorticoid treatment, and the season when the PET-CT scans were obtained were accounted for. CONCLUSION: The activation of BAT in pediatric patients undergoing treatment of malignancy is associated with significantly less adipose accumulation. This trial was registered at clinicaltrials.gov as NCT01517581.