Publications

Despite guidelines developed to standardize the diagnosis and management of gastrointestinal (GI) bleeding, significant variability remains in recommendations and practice. The purpose of this survey was to obtain information on practice patterns for the evaluation of overt lower GI bleeding (LGIB) and suspected small bowel bleeding. A 34-question electronic survey was sent to all Society of Abdominal Radiology (SAR) members. Responses were received from 52 unique institutions (40 from the United States). Only 26 (50%) utilize LGIB management guidelines. 32 (62%) use CT angiography (CTA) for initial evaluation in unstable patients. In stable patients with suspected LGIB, CTA is the preferred initial exam at 21 (40%) versus colonoscopy at 24 (46%) institutions. CTA use increases after hours for both unstable (n = 32 vs. 35, 62% vs. 67%) and stable patients (n = 21 vs. 27, 40% vs 52%). CTA is required before conventional angiography for stable (n = 36, 69%) and unstable (n = 15, 29%) patients. 38 (73%) institutions obtain two post-contrast phases for CTA. 49 (94%) institutions perform CT enterography (CTE) for occult small bowel bleeding with capsule endoscopy (n = 26, 50%) and CTE (n = 21, 40%) being the initial test performed. 35 (67%) institutions perform multiphase CTE for occult small bowel bleeding. In summary, stable and unstable patients with overt lower GI are frequently imaged with CTA, while CTE is frequently performed for suspected occult small bowel bleeding.

PURPOSE: To identify T1D -filtering methods, which can specifically isolate various ranges of T1D components as they may be sensitive to different microstructural properties.

METHODS: Modified Bloch-Provotorov equations describing a bi-T1D component biophysical model were used to simulate the inhomogeneous magnetization transfer (ihMT) signal from ihMTRAGE sequences at high RF power and low duty-cycle with different switching time values for the dual saturation experiment: Δt = 0.0, 0.8, 1.6, and 3.2 ms. Simulations were compared with experimental signals on the brain gray and white matter tissues of healthy mice at 7T.

RESULTS: The lengthening of Δt created ihMT high-pass T1D -filters, which efficiently eliminated the signal from T1D components shorter than 1 ms, while partially attenuating that of longer components (≥ 1 ms). Subtraction of ihMTR images obtained with Δt = 0.0 ms and Δt = 0.8 ms generated a new ihMT band-pass T1D -filter isolating short-T1D components in the 100-µs to 1-ms range. Simulated ihMTR values in central nervous system tissues were confirmed experimentally.

CONCLUSION: Long- and short-T1D components were successfully isolated with high RF power and low duty-cycle ihMT filters in the healthy mouse brain. Future studies should investigate the various T1D -range microstructural correlations in in vivo tissues.

PURPOSE: To assess the long-term malignancy risk of incidental small pancreatic cysts.

MATERIALS AND METHODS: In this HIPAA-compliant, IRB-approved, retrospective, multi-institutional study, the long-term incidence of pancreatic cancer was compared between patients with and without small pancreatic cysts. Patients with incidental pancreatic cysts ≥ 0.5 and < 2.0 cm in maximal diameter, detected on MRI performed between 1999 and 2011, represented the "small pancreatic cyst" group. Patients that underwent MRI between 2005 and 2011 and had no reported pancreatic cysts represented the comparison "no cyst" group.

RESULTS: The "small pancreatic cyst" group included 267 patients, ages 63.4 ± 11.8 years, 166/267 (62%) women with a mean follow-up of 8.6 ± 4.3 years, median 9.2 years; the "no cyst" group included 1,459 patients, ages 64.6 ± 12 years, 794/1,459 (54%) women with a mean follow-up of 7.0 ± 4.2 years, median 7.8 (p values 0.12, 0.02, < 0.001, respectively). Two/267 (0.7%) patients developed pancreatic cancer at a separate location from the known cyst in the "small pancreatic cyst" group, with a cancer rate of 0.9 (95% CI 0.1-3.1) cases per 1,000 patient-years. In the "no cyst" cohort, 18/1,459 (1.2%) patients developed pancreatic cancer, with a cancer rate of 1.8 (95% CI 1.2-3.1) cases per 1,000 patient-years (p = 0.6). The all-cause mortality was similar in both groups: 57/267 (21%) vs. 384/1,459 (26%) (p = 0.09).

CONCLUSION: The long-term risk of pancreatic malignancy in asymptomatic patients with incidental pancreatic cysts less than 2 cm is 0.9 cases per 1,000 patient-years of follow-up, similar to those without pancreatic cysts. These very few pancreatic cancers developed at a separate location from the known cyst.

KEY POINTS: • After a median of 9.2 years of follow-up, the risk of pancreatic malignancy in patients with an asymptomatic small pancreatic cyst was 0.9 cases per 1,000 patient-years of follow-up, similar to those without pancreatic cysts. • Very few pancreatic cancer cases developed in the location separate from the known pancreatic cyst.

Mucin-producing neoplasms in the abdomen and pelvis are a distinct entity, separate from simple fluid-containing neoplasms and loculated fluid collections. Mucin is a thick gelatinous substance and-owing to its high water content-has imaging features that can be mistaken for those of simple fluid-containing neoplasms with multiple imaging modalities. However, mucin-producing neoplasms arise from specific organs in the abdomen and pelvis, with unique imaging appearances, knowledge of which is important to guide accurate diagnosis and management. With its large field of view and high soft-tissue resolution, MRI has advantages over other imaging modalities in characterizing these neoplasms. The authors focus on the spectrum of MRI features of such mucin-producing neoplasms and illustrate how-despite a varied organ origin-some of these neoplasms share similar MRI and histopathologic features, thereby helping narrow the differential diagnosis. One common finding in these tumors is that the presence of internal complexity and solid enhancing components increases as the degree of malignant transformation increases. Lack of internal complexity generally indicates benignity. These tumors have a varied range of prognosis; for example, a low-grade appendiceal mucinous neoplasm is indicative of a good prognosis, while a mucinous tumor of the rectum is known to manifest at an early age with aggressive behavior and poorer prognosis compared with its nonmucinous counterpart. Online supplemental material is available for this article. ©RSNA, 2022.

OBJECTIVES: Pulmonary disease is a common extraarticular manifestation of RA associated with increased morbidity and mortality. No current strategies exist for screening this at-risk population for parenchymal lung disease, including emphysema and interstitial lung disease (ILD).

METHODS: RA patients without a diagnosis of ILD or chronic obstructive pulmonary disease underwent prospective and comprehensive clinical, laboratory, functional and radiological evaluations. High resolution CT (HRCT) scans were scored for preclinical emphysema and preclinical ILD and evaluated for other abnormalities.

RESULTS: Pulmonary imaging and/or functional abnormalities were identified in 78 (74%) of 106 subjects; 45% had preclinical parenchymal lung disease. These individuals were older with lower diffusion capacity but had similar smoking histories compared with no disease. Preclinical emphysema (36%), the most commonly detected abnormality, was associated with older age, higher anti-cyclic citrullinated peptide antibody titres and diffusion abnormalities. A significant proportion of preclinical emphysema occurred among never smokers (47%) with a predominantly panlobular pattern. Preclinical ILD (15%) was not associated with clinical, laboratory or functional measures.

CONCLUSION: We identified a high prevalence of undiagnosed preclinical parenchymal lung disease in RA driven primarily by isolated emphysema, suggesting that it may be a prevalent and previously unrecognized pulmonary manifestation of RA, even among never smokers. As clinical, laboratory and functional evaluations did not adequately identify preclinical parenchymal abnormalities, HRCT may be the most effective screening modality currently available for patients with RA.

BACKGROUND AND PURPOSE: Spinal cord compression (SCC) requires rapid diagnosis in the emergent setting; however, current MRI protocols may be cumbersome for patients and clinicians. We sought to validate an abbreviated total spine MRI (TS-MRI) protocol using standard non-contrast sequences in the detection of SCC and other clinically significant findings (OCSF).

METHODS: Two hundred six TS-MRI scans obtained over a 30-month period for SCC were included. Sagittal T2 (T2sag), sagittal T1 (T1sag), and sagittal STIR (IRsag), as well as axial T2 (T2ax) images, were individually assessed independently by 2 reviewers for SCC, cauda equina compression (CEC), and OCSF. A protocol consisting of all the sequences was considered the gold standard. Sensitivity and specificity of single and combined MRI sequences for SCC/CEC and OCSF were determined and were tested for noninferiority relative to standard non-contrast sequences using a 5% noninferiority margin.

RESULTS: An abbreviated protocol of IRsag + T2ax provided the best performance with sensitivity and specificity of 100% (95%CI, 96.0-100.0) and 98.6% (95%CI, 95.6-99.7) for SCC/CEC and 100.0% (95%CI, 96.7-100.0), and 99.3% (95%CI, 96.6-99.9) for OCSF. The mean difference of sensitivity and specificity between IRsag + T2ax and standard protocol was 0.0% (95%CI, 0.0-4.0) and - 2.1% (95%CI, - 5.4 to - 0.6) for SCC/CEC and 0.0% (95%CI, 0.0-3.3) and - 1.5% (95%CI, - 4.8 to - 0.3) for OCSF, all within the noninferiority margin of 5%.

CONCLUSIONS: An abbreviated TS-MRI protocol of IRsag + T2ax is noninferior to the standard non-contrast protocol, potentially allowing for faster emergent imaging diagnosis and triage.

PURPOSE: As men age, the prostate continues to grow on average 2.5% per year. While the variable growth rate of the total prostate gland is recognized, the growth rate of different prostate zones remains largely unclear. We evaluated the growth patterns of the prostate zones and identified clinical parameters contributing to the zonal growth rates.

MATERIALS AND METHODS: Prostate magnetic resonance imaging (MRI) data and clinical information were obtained retrospectively on 156 patients who had at least 3 prostate MRIs between 2003 and 2018. Different prostate zonal volumes were measured and analyzed. The outcome was analyzed using linear regression.

RESULTS: We observed that prostate growth rates vary depending on body mass index (BMI), transition zone index (TZI), the prostate zone and 5-alpha reductase inhibitor (5ARI) use. The peripheral zone volume growth rates increased with age and peaked at 60-70 years of age (p=0.047), while the transition zone volume demonstrates continuous growth without a peak through all ages. BMI and TZI are associated with the growth rate of the peripheral zone (p=0.026, p <0.001, respectively) but not the transition zone growth rate. 5ARI use is significantly associated with the reduction in the transition zone growth rate (p=0.033), not the peripheral zone. In addition, patients with TZI greater than 60% had the most significant reduction in the transition zone growth rate while taking 5ARI (p <0.001).

CONCLUSIONS: Transition and peripheral zones of the prostate grow at variable rates. BMI and TZI affect peripheral zone growth rate, while 5ARI use reduces the transition zone growth rate.

PURPOSE: The aim of this study was to investigate breast radiologists' practices related to recording sex and gender in the electronic medical record, knowledge and attitudes about breast cancer screening recommendations for transgender individuals, and experience and willingness to enter screening mammography data from transgender patients into databases that document service provision and outcomes of cancer detection protocols.

METHODS: A 19-question anonymous survey was distributed by e-mail to all active physician members of the Society of Breast Imaging. Response characteristics were assessed as frequencies and percentages and compared between groups using the Fisher exact test or χ2 test. The degree of agreement between questions was assessed using the McNemar test.

RESULTS: Four hundred one radiologists across the United States and Canada responded (response rate 18%). Recording birth-assigned sex distinct from gender identity was reported by 44 of 352 respondents (13%). Depending on geographic region, 38% to 62% of breast radiologists followed screening guidelines for transgender women, and 226 of 349 (65%) did not provide screening recommendations for transgender men. Of 400, 324 (81%) believed that the evidence base for screening transgender individuals is incomplete, and 247 of 352 (70%) were either unsure of or had no Lesbian, Gay, Bisexual, Transgender, Queer competency training. A majority (247 of 401 [62%]) of respondents reported that they would enroll transgender patients in existing or novel national databases.

CONCLUSIONS: In the practice of breast imaging, there is a substantial need to record transgender and other gender-nonconforming information. Breast radiologists differ in their practice and knowledge regarding screening of transgender women and men but expressed interest in contributing data to facilitate longitudinal databases needed to inform cancer screening guidelines.

BACKGROUND: Normal-appearing adrenal glands on cross-sectional imaging may still be the source of aldosterone production in primary aldosteronism (PA).

METHODS: We evaluated the prevalence of aldosterone production among morphologically normal-appearing adrenal glands and the impact of this phenomenon on interpretations of localization studies and treatment decisions. We performed a retrospective cohort study of PA patients with at least 1 normal adrenal gland and reanalyzed contemporary studies to assess interpretations of imaging and adrenal venous sampling (AVS) at the individual patient and adrenal levels.

RESULTS: Among 243 patients, 43 (18%) had bilateral normal-appearing adrenals and 200 (82%) had a unilateral normal-appearing adrenal, for a total of 286 normal-appearing adrenal glands. 38% of these normal-appearing adrenal glands were a source of aldosteronism on AVS, resulting in discordance between imaging and AVS findings in 31% of patients. Most patients with lateralizing PA underwent curative unilateral treatment (80%); however, curative treatment was pursued in 92% of patients who had concordant imaging-AVS results but in only 38% who had discordant results (P < 0.05). In young patients, imaging-AVS discordance was detected in 32% of those under 45 years and 21% of those under 35 years. Among 20 contemporary studies (including 4,904 patients and 6,934 normal-appearing adrenal glands), up to 64% of normal-appearing adrenals were a source of aldosteronism resulting in 31% of patients having discordant results.

CONCLUSIONS: Morphologically normal-appearing adrenal glands are commonly the source of aldosterone production in PA, even among young patients. The lack of awareness of this issue may result in inappropriate treatment recommendations.