Faculty Bibliography

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies, with a dismal survival rate. Screening the general population for early detection of PDAC is not recommended, but because early detection improves survival, high-risk individuals, defined as those meeting criteria based on a family history of PDAC and/or the presence of known pathogenic germline variant genes with PDAC risk, are recommended to undergo screening with MRI and/or endoscopic ultrasound at regular intervals. The Pancreatic Cancer Early Detection (PRECEDE) Consortium was formed in 2018 and is composed of gastroenterologists, geneticists, pancreatic surgeons, radiologists, statisticians, and researchers from 40 sites in North America, Europe, and Asia. The overarching goal of the PRECEDE Consortium is to facilitate earlier diagnosis of PDAC for high-risk individuals to increase survival of the disease. A standardized MRI protocol and reporting template are needed to enhance the quality of screening examinations, improve consistency of clinical management, and facilitate multiinstitutional research. We present a consensus statement to standardize MRI screening and reporting for individuals with elevated risk of pancreatic cancer.

OBJECTIVE:To assess current practice patterns with respect to protocols used for incidental pancreatic cyst follow-up, management guidelines, and template reporting. METHODS:The Society of Abdominal Radiology Disease Focused Panel on intraductal pancreatic neoplasms distributed an anonymous 14-question survey to its members in June 2018 that focused on current utilization of incidental pancreatic cyst guidelines, protocols, and template reporting. RESULTS:Among the 1,390 e-mail invitations, 323 responded and 94.7% (306 of 323) completed all questions. Respondents were mainly radiologists (93.8%, 303 of 323) from academic institutions (74.7%, 227 of 304) in North America (93.7%, 286 of 305). Of respondents, 42.5% (136 of 320) preferred 2017 ACR recommendations, 17.8% (57 of 320) homegrown systems, 15.0% (48 of 320) Fukuoka guidelines, and 7.8% (25 of 320) American Gastroenterological Association guidelines. The majority (68.7%, 222 of 323) agreed or strongly agreed that developing a single international consensus recommendation for management was important, and most radiologists preferred to include them in reports (231 of 322, 71.7%); yet only half included recommendations in >75% of reports (161 of 321). Magnetic resonance cholangiopancreatography was the modality of choice for follow-up of <2.5 cm cysts. Intravenous contrast was routinely used by 69.7% (212 of 304). Standardized reporting templates were rarely used in practice (12.8% 39 of 306). CONCLUSIONS:Nearly 7 of 10 radiologists desire a unified international consensus recommendation for management of incidental cystic pancreatic lesions; ACR 2017 recommendations are most commonly used, followed by homegrown systems and Fukuoka guidelines. The majority of radiologists routinely use magnetic resonance cholangiopancreatography with intravenous contrast for follow-up of incidental cystic lesions, but template reporting is rarely used.

Background Dual-energy CT enterography (DECTE) has been shown to be useful in characterizing Crohn disease activity compared with clinical markers of inflammation but, to the knowledge of the authors, comparison has not been made with histopathologic specimens. Purpose To compare mucosal iodine density obtained at DECTE from Crohn disease-affected bowel with histopathologic specimens from surgically resected ileocolectomy bowel segments or terminal ileum colonoscopic biopsies in the same patients. Materials and Methods This was a retrospective study. Bowel segments in adults with Crohn disease who underwent DECTE from January 2017 to April 2019 within 90 days of ileocolectomy or colonoscopy were retrospectively evaluated with prototype software allowing the semiautomatic determination of inner hyperdense bowel wall (mucosal) mean iodine density, normalized to the aorta. Mean normalized iodine density and clinical activity indexes (Crohn Disease Activity Index [CDAI] and Harvey-Bradshaw Index [HBI]) were compared with histologic active inflammation grades by using two-tailed t tests. Receiver operating characteristic curves were generated for mean normalized iodine density, CDAI, and HBI to determine sensitivity, specificity, and accuracy. A P value less than .05 was considered to indicate statistical significance. Results The following 16 patients were evaluated (mean age, 41 years ± 14 [standard deviation]): 10 patients (five men, five women; mean age, 41 years ± 15) with 19 surgical resection specimens and six patients with terminal ileum colonoscopic mucosal biopsies (four men, two women; mean age, 43 years ± 14). Mean normalized iodine density was 16.5% ± 5.7 for bowel segments with no active inflammation (n = 8) and 34.7% ± 9.7 for segments with any active inflammation (n = 17; P < .001). A 20% mean normalized iodine density threshold had sensitivity, specificity, and accuracy of 17 of 17 (100%; 95% CI: 80.5, 100), six of eight (75%; 95% CI: 35, 97), and 23 of 25 (92%; 95% CI: 74, 99), respectively, for active inflammation. Clinical indexes were similar for patients with and without active inflammation at histopathologic analysis (CDAI score, 261 vs 251, respectively [P = .77]; HBI score, 7.8 vs 6.4, respectively [P = .36]). Conclusion Iodine density from dual-energy CT enterography may be used as a radiologic marker of Crohn disease activity as correlated with histopathologic analysis. © RSNA, 2021 See also the editorial by Ohliger in this issue.

Ileal pouch anal anastomosis (IPAA) is gold standard surgical procedure for treatment of ulcerative colitis and majority of patients with familial adenomatous polyposis. This procedure allows preservation of fecal continence and gastrointestinal continuity. However, it is associated with a wide variety of complications, which often have nonspecific and overlapping clinical presentations, making imaging an important part of work up for pouch dysfunction. The purpose of this article is to propose structured reporting templates for Magnetic Resonance Imaging (MRI) and Water Soluble Contrast Enema (WSCE) in IPAA patients based on our referral pouch center's experience. Included will be a review of salient surgical technique, pouch anatomy and imaging protocols, with an emphasis on systematic search pattern for evaluation of ileal pouch complications using proposed structured reporting MRI and WSCE templates.

OBJECTIVE:The aim of this study was to determine accuracy of height and weight prediction by a 3-dimensional (3D) camera. METHODS:A total of 453 patients whose computed tomography imaging used a 3D camera from December 19, 2018 to March 19, 2019 were retrospectively identified. An image of each patient was taken before the computed tomography by a 3D camera mounted to the ceiling. Using infrared imaging and machine learning algorithms, patient height and weight were estimated from this 3D camera image. A total of 363 images were used for training. The test set consisted of 90 images. The height and weight estimates were compared with true height and weight to determine absolute and percent error. A value of P < 0.05 indicated statistical significance. RESULTS:There was 2.0% (SD, 1.4) error in height estimation by the 3D camera, corresponding to 3.35 cm (SD, 2.39) absolute deviation (P = 1, n = 86). Weight estimation error was 5.1% (SD, 4.3), corresponding to 3.99 kg (SD, 3.11) absolute error (P = 0.74, n = 90). CONCLUSION/CONCLUSIONS:Pictures obtained from a 3D camera can accurately predict patient height and weight.

There have been many publications detailing imaging features of malignant transformation of intraductal papillary mucinous neoplasms (IPMN), management and recommendations for imaging follow-up of diagnosed or presumed IPMN. However, there is no consensus on several practical aspects of imaging IPMN that could serve as a clinical guide for radiologists and enable future data mining for research. These aspects include how to measure IPMN, define reporting terminology, standardize reporting and unify guidelines for surveillance. The Society of Abdominal Radiology (SAR) created multiple Disease-Focused Panels (DFP) comprised multidisciplinary panel members who focus on a particular disease, with the goal to develop ways for radiologists to improve patient care, education, and research. DFP members met to identify the current controversies and limitations of imaging pancreatic IPMN. This paper aims to provide a practical review of the key imaging characteristics of IPMN for trainees and practicing radiologists, to guide uniformity of performance and interpretation of surveillance imaging studies, and to improve communication with clinicians by providing a lexicon and reporting template based on the experience of the SAR-DFP panel members.

OBJECTIVE:The objective of this study was to determine if dual-energy computed tomography enterography (DECTE)-obtained iodine density can predict medical management change or surgery in Crohn disease patients. METHODS:The most active-appearing bowel segment on DECTE in 21 Crohn disease patients was retrospectively interrogated with prototype software determining the percentage of bowel wall (I) in specified ranges. Patients were categorized into 3 groups after DECTE: (1) no management change, (2) outpatient medication change, and (3) inpatient admission or surgery. Crohn's disease activity index was calculated. Group 3's percentage iodine density of >3 mg/mL and Crohn's disease activity index were compared with group 1/2. Crohn's disease activity index and percentage iodine density of >2 mg/mL were compared for groups 2/3 versus group 1 patients. RESULTS:There were 5 group 1, 6 group 2, and 10 group 3 patients. Group 3 patients had higher frequency of iodine density >3 mg/mL (27%) compared with groups 1/2 patients (12.6%) (P < 0.05). Crohn's disease activity index was similar (P = 0.98). Groups 2/3 patients had 60.5% iodine density of >2 mg/mL, whereas group 1 patients had 31.7% iodine density of >2 mg/mL (P < 0.05). Crohn's disease activity index was similar (P = 0.12). CONCLUSIONS:Iodine density from DECTE may predict medical or surgical Crohn disease management.

PURPOSE/OBJECTIVE:To compare CT isocenter accuracy, patient dose, and scan time in adults imaged with and without use of a 3D camera. METHOD/METHODS:571 CT examinations utilizing a 3D camera for initial patient positioning (optional radiographer isocenter adjustment) and 504 examinations scanned without the camera between 10/1/2018 and 3/19/2019 were retrospectively identified. All exams were chest or abdominopelvic CTs. The isocenters of these exams were compared with the true isocenters defined as the manually delineated centroid of the body in the CT volume. The size specific dose estimate (SSDE) (mGy) of radiation dose obtained from departmental software for the 4 most common protocols on one CT scanner was compared before and after implementation of the 3D camera. The times required for the entire scan and just the topogram "scout" were compared with and without the 3D camera for noncontrast chest and abdominopelvic CT enterography protocols. 2-tailed t-tests and Mann-Whitney U tests were used (P < 0.05 indicated statistical significance). RESULTS:The deviation from true isocenter was 6.8 ± 6.1 mm (P = 0.043) and 16.3 ± 14.0 mm (P < 0.01) with and without the 3D camera, respectively (P < 0.01). CT radiographers accepted isocenter location without alteration in 93 % of examinations. Average SSDE savings with the 3D camera ranged 1.0-2.4 mGy (21-31 %) for the 4 most commonly performed protocols (p < 0.01). Median scout time savings was 32 s (Camera vs. No-Camera cohorts) (P < 0.01). Average noncontrast chest CT and CT enterography scan time savings were 19 s and 17 s with the 3D camera, respectively (P < 0.01). CONCLUSIONS:The 3D camera improved accuracy of patient positioning while reducing radiation dose and examination time. Implementation of a 3D camera helps standardize workflow in a busy clinical practice.

This study aimed to conduct a systematic literature review of small bowel adenocarcinoma (SBA) associated with small bowel Crohn's disease (CD). A systematic literature review was conducted using MEDLINE, PubMed, Embase, CINAHL, Cochrane and Google Scholar databases. Data regarding demographics, presentation, diagnosis, treatment and survival were extracted. The review included articles that reported the location of SBA in the setting of CD and excluded articles that did not state the CD location and/or cancer type. We identified 218 patients diagnosed with SBA in the setting of small bowel Crohn's disease. SBA should be in the differential diagnosis in patients with long-standing ileal CD presenting with small bowel obstruction, anaemia and perforation. SBA in the setting of CD presents diagnostic and treatment challenges; however, a high clinical index of suspicion may lead to early diagnosis and increased survival.
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PURPOSE/OBJECTIVE:For more than half of Crohn's disease patients, strictures will cause bowel obstructions that require surgery within 10 years of their initial diagnosis. This study utilizes computed tomography imaging and clinical data obtained at the initial emergency room visit to create a prediction model for progression to surgery in Crohn's disease patients with acute small bowel obstructions. METHODS:A retrospective chart review was performed for patients who presented to the emergency room with an ICD-10 diagnosis for Crohn's disease and visit diagnosis of small bowel obstruction. Two expert abdominal radiologists evaluated the CT scans for bowel wall thickness, maximal and minimal luminal diameters, length of diseased segment, passage of oral contrast, evidence of penetrating disease, bowel wall hyperenhancement or stratification, presence of a comb sign, fat hypertrophy, and small bowel feces sign. The primary outcome was progression to surgery within 6 months of presentation. The secondary outcome was time to readmission. RESULTS:Forty patients met the inclusion criteria, with 78% receiving medical treatment alone and 22% undergoing surgery within 6 months of presentation to the emergency room. Multivariable analysis produced a model with an AUC of 92% (95% CI 0.82-1.00), 78% sensitivity, and 97% specificity, using gender, body mass index, and the radiographic features of segment length, penetrating disease, and bowel wall hyperenhancement. CONCLUSIONS:The model demonstrates that routine clinical and radiographic data from an emergency room visit can predict progression to surgery, and has the potential to risk stratify patients, guide management in the acute setting, and predict readmission.