Faculty Bibliography

PURPOSE/OBJECTIVE:Pancreatic cystic lesions (PCL) commonly undergo surveillance using MRI with MR cholangiopancreatography (MRCP). Our objective is to compare the performance of a single-shot fat-saturated T2-weighted technique with deep-learning reconstruction (DL HASTE-FS) to a conventional T2-weighted Half fourier Single-shot Turbo spin-Echo (HASTE) sequence and to MRCP for the purpose of PCL detection, characterization, and surveillance. METHODS:In this retrospective study, 91 consecutive patients underwent 3T abdominal MRI with MRCP protocol including DL HASTE-FS and conventional HASTE between 8/2/2023 and 10/3/2023. Three abdominal radiologists rated overall and lesion-specific image quality on a 5-point Likert scale, including pancreatic margin and duct sharpness, and PCL conspicuity. A subset of 70 preselected index PCLs were evaluated for cyst features, confidence of diagnosing side-branch IPMN, and suitability of DL HASTE-FS in replacing MRCP for PCL surveillance. RESULTS:DL HASTE-FS received higher scores for pancreatic duct border sharpness (4.1 vs. 3.9; p = .004), pancreatic duct visibility compared to MRCP (2.0 vs. 1.9; p = .04), cyst conspicuity (4.4 vs. 3.9; p < .001), and sharpness of cyst wall and internal septations (4.3 vs. 3.7; p < .001) compared to conventional HASTE. In contrast, conventional HASTE received higher scores for pancreatic margin sharpness (4.2 vs. 3.8; p < .001) and peripancreatic vessel clarity (4.2 vs. 3.4; p < .001). For the 70 preselected index PCLs, readers visualized more PCLs and had higher confidence in diagnosing SB-IPMN on DL HASTE-FS than on conventional HASTE (3.6 vs. 3.4; p < .001). Finally, DL HASTE-FS was deemed a suitable replacement to MRCP for more cases than conventional HASTE (83% vs. 48%; p < .001). CONCLUSION/CONCLUSIONS:DL HASTE-FS outperforms conventional HASTE for PCL detection and characterization, and is a suitable alternative to 3D MRCP in the context of PCL surveillance, potentially reducing exam time and cost.

OBJECTIVES/OBJECTIVE:Pancreatic ductal adenocarcinoma (PDAC) screening is recommended for High-Risk Individuals (HRI) with Familial Pancreatic Cancer (FPC) or certain pathogenic germline variants (PGVs). Screening MRI commonly identifies pancreatic cystic lesions (PCLs), but comparative data between HRI and average-risk individuals (ARI) are limited. We aimed to quantify and characterize PCL differences between these groups. METHODS:In this retrospective study, 317 HRI were age-, sex- and race-matched to 634 ARI undergoing MRI/MRCP between 7/2018-9/2024. Demographics, genetic factors, and baseline MRI/MRCP outcomes were analyzed. HRI were classified as FPC or PGV±PDAC family history. Statistical analysis compared: all HRI vs. all ARI; single HRI subgroups vs. matched ARI; single HRI subgroups vs. other HRI. RESULTS:HRIs were more likely to have PCLs than ARIs (50.8% vs. 25.7%, P <0.001). FPC HRI were more likely to have PCLs (54.1% vs. 44.4%, P =0.049) than PGV HRI. However, PCLs in HRI were smaller than in ARI (7.4±5.7 vs. 10.8±12.6 mm; P =0.002). HRI and ARI did not differ regarding worrisome feature prevalence. No solid lesions were observed. CONCLUSIONS:PCLs are significantly more common among HRI than matched ARI, although typically small and low-risk. Future longitudinal studies should determine whether the higher prevalence of PCLs among HRI translates into increased risk of PCL-derived malignancy or reflects heighted detection on MRI.

BACKGROUND/UNASSIGNED:Acute pancreatitis (AP) is a common gastrointestinal disease with a rising global incidence. While most cases are mild, severe AP (SAP) carries high mortality. Early and accurate severity prediction facilitates management optimization. However, existing clinical severity prediction models, such as Bedside Index of Severity in Acute Pancreatitis (BISAP) and Modified CT Severity Index (mCTSI), have modest accuracy and often rely on data unavailable at admission. PURPOSE/UNASSIGNED:This study proposes a deep learning (DL) model to predict AP severity using abdominal contrast-enhanced CT scans acquired within 24 hours of admission. MATERIALS AND METHODS/UNASSIGNED: = 518 patients). RESULTS/UNASSIGNED: = .002). In retrospective triage analysis, the model correctly identified 50%-73% of patients who progressed to SAP and 40%-73% of those with MAP. CONCLUSION/UNASSIGNED:The proposed DL model achieved performance comparable to or better than established prognostic tools and maintained robust external performance. These findings suggest that AI-assisted CT analysis may support early, automated risk stratification of AP.

PURPOSE/OBJECTIVE:To evaluate the association of patient characteristics, community-level social determinants of health, and cyst risk categories with completion of follow-up recommendations for incidental Pancreatic Cystic Lesions (PCLs). METHODS:We retrospectively identified consecutive patients (2013-2023) whose MRI radiology reports described PCLs. A fine-tuned LLaMA-3.1 8B Instruct large language model was used to extract PCL features. Lesions were classified using the 2017 ACR white paper: Category 1 (low risk), Category 2 (worrisome features), or Category 3 (high-risk stigmata). We recorded demographics and follow-up imaging or endoscopic ultrasound dates. Community-level factors were characterized by the 2020 CDC Social Vulnerability Index (SVI), stratified into quartiles. The primary outcome, "inappropriate follow-up," combined late and no follow-up. Multivariable binomial regression was applied to evaluate associations with inappropriate follow-up. RESULTS:In 7,745 patients (mean age 66.3 years; 4,796 women), 92.9% (7,198/7,745) of cysts were Category 1, 6.4% (498/7,745) were Category 2, and 0.6% (49/7,745) were Category 3. Only 36.3% of patients completed appropriate follow-up, 12.1% were late, and 51.6% were lost to follow-up. Inappropriate follow-up was high in every cyst category: 64.2% in Category 1, 59.4% in Category 2 and 49.0% in Category 3. In multivariable analysis, non-English primary language (RR 1.08; 95% CI, 1.02-1.14) and residing in more vulnerable communities of the 3rd quartiles of the socioeconomic Social Vulnerability Index subcategory (RR 1.07; 95% CI, 1.02-1.12) were associated with inappropriate follow-up. Higher age-adjusted Charlson Comorbidity Index (CCI ≥ 4) (RR .84; 95% CI, .79-.88), CCI 2-3 (RR .84; 95% CI, .79-.88), and higher-risk cysts in patients under 65 years of age (RR .76; 95% CI, .65-.89) were associated with completed follow-up. CONCLUSION/CONCLUSIONS:Follow-up completion for incidental PCLs was low. Factors most consistently associated with follow-up completion were language barriers, residence in socioeconomically vulnerable communities, age-adjusted CCI and higher-risk features among those under 65 years.

Background MR enterography (MRE) is increasingly used to guide treatment and improve outcomes in Crohn disease (CD). An abbreviated MRE (A-MRE) protocol-omitting contrast and antiperistaltic agents-may reduce scanning time and cost and improve compliance. Purpose To compare intrareader concordance and interreader agreement in detecting disease activity and disease-related complications using contrast-enhanced MRE (CE-MRE) versus an A-MRE protocol in participants with CD. Materials and Methods In this secondary analysis of a prospective study, 10 abdominal radiologists independently reviewed MRE examinations from a prospective study of participants with CD before and after treatment with biologics, using both A-MRE and CE-MRE protocols, at least 1 month apart. Interreader agreement and intrareader concordance were assessed using Gwet first agreement coefficient (AC1) at both the segment and participant levels for the presence of active inflammation, associated indicative features, and complications. Diagnostic accuracy of the simplified MR index of activity (sMaRIA) was evaluated against ileocolonoscopy when available. Results This study included 60 participants (median age, 36 years [IQR, 28-44 years]; 40 female; 80 examinations). Interreader agreement for detecting intestinal active disease was high and comparable between A-MRE and CE-MRE at the participant level (AC1, 0.87 [95% CI: 0.79, 0.95] vs 0.91 [95% CI: 0.85, 0.97]). For strictures, similar interreader agreement was observed between protocols (AC1: A-MRE, 0.61 [95% CI: 0.47, 0.74] vs CE-MRE, 0.50 [95% CI: 0.35, 0.65]). For penetrating complications, the interreader agreement was also similar between protocols (A-MRE, 0.71 [95% CI: 0.56, 0.86] vs CE-MRE, 0.76 [95% CI: 0.63, 0.90]). The intrareader concordance between protocols for detecting active inflammation and CD complications was almost perfect for all readers (AC1 range, 0.86-1.00). In the terminal ileum, sMaRIA showed high sensitivity (A-MRE, 96.4%; CE-MRE, 98.4%) and specificity (A-MRE, 68.1%; CE-MRE, 71.4%) for detecting inflammation. Conclusion An A-MRE protocol demonstrated comparable interreader agreement to conventional CE-MRE and high intrareader concordance for detecting active CD and related complications in participants with CD. © The Author(s) 2026. Published by the Radiological Society of North America under a CC BY 4.0 license. Supplemental material is available for this article. See also the editorial by Ohliger in this issue.

PURPOSE/OBJECTIVE:To develop and evaluate a hybrid large language model (LLM)- and rule-based algorithm for tracking pancreatic cystic lesions (PCLs) across serial radiology reports and apply it to a single-center cohort to characterize cyst growth using first-to-last and consecutive comparisons. METHODS:This retrospective study included all abdominal imaging reports interpreted by abdominal radiologists between 2005 and 2024. A validated LLM identified reports describing PCLs. A hybrid algorithm combining LLM-extracted cyst features (size, location) with rule-based logic matched dominant cysts across serial reports. Two blinded radiologists independently annotated cyst matches in a subset of reports. Agreement between algorithm and radiologists was assessed using percent agreement and Cohen's κ. Discrepancies were adjudicated by a third radiologist for error analysis. Absolute size-based growth was assessed according to American College of Radiology (ACR) criteria, whereas cyst growth rate as a worrisome feature was assessed per Kyoto criterion, using both first-to-last and consecutive studies. Predictors of meeting the Kyoto cyst growth rate criterion were analyzed using multivariable Cox regression. RESULTS:In 58 patients with 418 longitudinal reports, agreement with the adjudicated reference standard was 96%. Cohen's κ was 0.81 (95% CI: 0.66-0.91). The overall cohort included 8,176 patients (61.8% female; mean age 67.6 ± 11.7 years) with 8,389 cysts across 28,489 reports over 40.6 ± 28.5 months (annual growth rate = 0.35 mm/year). ACR absolute growth criteria classified a higher proportion of cysts than the Kyoto cyst growth rate criterion using first-to-last examinations (16.3% vs. 7.4%, p < 0.001), whereas Kyoto cyst growth rate criterion identified a higher proportion using consecutive examinations (21.4% vs. 14%, p < 0.001). Larger baseline cyst size predicted meeting the Kyoto cyst growth rate criterion (HR 1.9-4.0; highest HR 4.0, 95% CI 3.08-5.21; p < 0.001). CONCLUSION/CONCLUSIONS:A hybrid LLM-rule-based algorithm enables reliable automated longitudinal tracking of PCLs across serial radiology reports. When applied at scale, cyst growth classification varied according to the guideline framework and interval comparison method used, and baseline cyst size was the strongest predictor of meeting Kyoto growth rate threshold.

OBJECTIVE:To describe the imaging appearances and treatment response patterns of the pancreatic neuroendocrine tumors (panNETs) following radiofrequency ablation (RFA). METHODS:From an internal database, 17 patients (8 male; mean age: 67±14 y) with 18 pathology-proven, localized, nonfunctioning panNETs <3 cm who underwent EUS-RFA for curative intent were included. A total of 32 preablation and 33 postablation scans were included (CT, MRI, or 68Ga-DOTATATE PET). Lesion size and enhancement on CT/MRI were independently assessed by 2 readers, while SUVmax was extracted from the original PET reports by a separate reviewer. The Wilcoxon signed-rank and McNemar tests were performed. Treatment response is defined as a complete response (loss of enhancement and SUVmax), a partial response (decrease in size, enhancement, or SUVmax), or no response (no change). RESULTS:Mean lesion size decreased from 1.4​​​​​​±0.5​ cm preablation to 0.3±0.5 cm postablation (P<0.0001). Mean SUVmax declined from 17.3±11.2 to 3.1±6.0 (P<0.001). Hyperenhancement was present in 15/18 (83.3%) lesions preablation versus 5/18 (27.8%) postablation (P<0.01). Of these 15 hyperenhancing lesions, 11 were solid, 3 were cystic, and 1 was mixed cystic and solid. Complete response occurred in 12/18 (66.7%) lesions, with either complete disappearance 5/12 (41.4%) or bland cavity formation 7/12 (58.5%). Partial response occurred in 5/18 (27.8%) lesions; 4/5 decreased in size (mean±SD: 1.4±0.5 cm preablation vs. 0.6±0.7 cm postablation), and 3/5 demonstrated decreased SUVmax. One patient with partial response underwent 2 repeat ablations with an ultimate decrease in SUVmax from 34.1 to 5.9. One solid, hyperenhancing pancreatic body lesion demonstrated no response (1.3 cm); preablation SUVmax was 10.8, but they did not undergo postablation DOTATATE PET. One patient developed postablation pancreatitis. Mean clinical follow-up was 650 days (423). CONCLUSION/CONCLUSIONS:RFA is an emerging treatment for small, nonfunctioning panNET. Postablation imaging findings most commonly included complete resolution of the tumor, decreased enhancement, decreased SUVmax, and formation of a bland cavity. As interest in this technique continues to grow, radiologists' familiarity with expected post-treatment imaging appearances and their associated response patterns is essential for accurate assessment.

RATIONALE AND OBJECTIVES/OBJECTIVE:Prostate multiparametric magnetic resonance imaging (MRI) is recommended for prostate cancer detection, staging, and surveillance. Incidental bladder lesions are encountered on these studies but remain under-characterized in the literature. The patient characteristics associated with malignancy for these lesions are not well defined. We evaluated the prevalence, histopathologic outcomes, clinical characteristics, and associations with malignancy for incidental bladder lesions on prostate MRI. MATERIALS AND METHODS/METHODS:A retrospective review included 31,241 patients undergoing prostate MRI examinations from January 2013 to January 2023. Imaging reports and medical records were analyzed for incidental bladder lesions, demographic data, clinical symptoms, urinalysis findings, and histopathologic outcomes. Lesions were categorized based on biopsy results or negative clinical follow-up for bladder tumors in chart review. Logistic regression analysis and receiver operating characteristic analyses were performed. RESULTS:Incidental bladder lesions occurred in 0.74% (230/31,241) of examinations, with biopsy-confirmed bladder cancer in 0.11% of patients (34/31,241) or 14.8% (34/230) of cases with lesions. In multivariable analysis, gross hematuria had the strongest association with biopsy-proven bladder cancer (OR 9.26, 95% CI 4.12-20.79, p<0.001). A logistic regression model incorporating age, smoking status, and gross hematuria yielded area under the curve of 0.762 for bladder cancer. CONCLUSION/CONCLUSIONS:Incidental bladder lesions on prostate MRI may represent opportunities for early detection of bladder cancer, but also have potential for harms related to unnecessary procedures. Considering the presence of gross hematuria, possibly stated as part of the MRI referral or patient questionnaire, could improve risk stratification of encountered bladder lesions and early cancer detection.

Ovarian cancer remains the sixth most common cause of cancer mortality in women in the United States and is a leading cause of mortality among patients with gynecologic malignancies. Imaging plays an important role in pretreatment staging of epithelial ovarian cancers, the evaluation of posttreatment response, and follow-up. Accurate pretreatment imaging is integral to determine appropriate first-line therapy. By delineating the extent of disease, imaging can assist decision making regarding the likelihood of optimal primary cytoreduction or need for neoadjuvant chemotherapy when optimal cytoreduction is not felt to be achievable. Contrast-enhanced CT serves as a mainstay modality for the pretreatment assessment of ovarian cancer, with MRI, PET/CT, and, in some instances, PET/MRI used in the pretreatment setting. CT and PET/CT are also integral to assessing response, including in the suspected recurrence setting, with MRI and PET/MRI being used in select cases. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.