Linda C. Kelahan

Liver US–derived attenuation coefficient performed better than normalized local variance and hepatorenal ratio in determining steatosis grade in participants with metabolic dysfunction–associated steatotic liver disease; when these markers were combined, reclassification of steatosis grade improved.

Background/Objectives: The aim of this study was to develop and validate a robust, radiomics-based classification model that uses pre-treatment MRI to non-invasively differentiate among major soft tissue sarcoma (STS) subtypes and a benign mimic. Methods: In this retrospective study, a cohort of 332 patients with biopsy-proven leiomyosarcoma, myxofibrosarcoma, myxoid liposarcoma, dedifferentiated liposarcoma, and undifferentiated pleomorphic sarcoma, along with the benign mimic intramuscular myxoma, was analyzed. Pre-treatment T1-weighted fat-saturated contrast-enhanced and T2-weighted fat-saturated MRI sequences were used for analysis. Following manual tumor segmentation, 1240 three-dimensional radiomic features were extracted. An XGBoost classifier was trained and validated using a robust 250-iteration bootstrap framework with nested cross-validation to ensure rigorous feature selection and unbiased performance evaluation. The model’s performance was assessed independently on T1-only, T2-only, and combined T1+T2 feature sets. Results: The combined T1 and T2 model achieved superior performance with an accuracy of 0.68 ± 0.04 and an AUC of 0.92 ± 0.02. At the subtype level, balanced accuracy was highest for intramuscular myxoma (0.91 ± 0.05), dedifferentiated liposarcoma (0.84 ± 0.06), and leiomyosarcoma (0.83 ± 0.05). SHAP analysis identified key features driving predictions, such as low T2 GLSZM Zone Size Entropy for myxoma and high T2 GLSZM Gray-Level Variance for leiomyosarcoma, which aligns with known pathological characteristics. Misclassifications predominantly occurred between subtypes with overlapping radiomic profiles. Conclusions: Radiomics applied to pre-treatment MRI enables robust, non-invasive classification of STS subtypes, demonstrating strong clinical potential for improving diagnostic confidence and informing triage strategies.

Internal hernias in patients who have undergone Roux-en-Y gastric bypass can result in serious complications such as small bowel obstruction and bowel necrosis, and CT can facilitate early diagnosis.

Background/Objectives: Brain metastasis from uterine leiomyosarcoma (ULMS) is an exceptionally rare complication of an aggressive malignancy. With fewer than 40 cases previously documented, a significant knowledge gap exists regarding its clinical course, management, and outcomes. This study provides the largest analysis of ULMS brain metastases to date, integrating a systematic literature review with a novel case report illustrating the disease’s uniquely rapid progression. Methods: Following PRISMA guidelines, we systematically reviewed four major databases to identify all reported cases of intracranial metastasis from ULMS. Data on patient demographics, clinico-radiological features, treatments, and survival were extracted and analyzed. Methodological quality was assessed using a modified Joanna Briggs Institute (JBI) tool. Results: We analyzed 34 studies with 39 individual cases. Additionally, this review was supplemented by one new illustrative case from our institution. The median patient age was 51.5 years, and most presented with focal neurological symptoms. Common imaging findings included hyperdense lesions on CT and homogeneously enhancing, dural-based masses on MRI, which mimic other intracranial pathologies. Though surgery was the most frequent intervention (76.9%), median survival after a brain metastasis diagnosis was a grim 5 months, with no significant difference observed between treatment modalities. Our illustrative case was remarkable for an extremely rapid volumetric doubling time averaging just 7.3 days. Conclusions: Brain metastasis from ULMS is a lethal event with an extremely poor prognosis. Nonspecific imaging features create diagnostic challenges, necessitating histopathological confirmation. Current therapies, including surgery and radiotherapy, offer palliative benefit but do not significantly alter survival. The aggressive biological behavior demonstrated here underscores the urgent need for increased clinical awareness and collaborative research to develop more effective management strategies and improve outcomes for this devastating diagnosis.

Esophageal motility disorders can have a major impact on quality of life. Dysphagia is the most commonly reported symptom; however, patients with esophageal dysmotility can also present with other symptoms such as chest pain and tightness, food impaction, regurgitation and heartburn. It is important to be aware of the spectrum of esophageal motility disorders so that timely and accurate diagnosis can be made. The Chicago Classification uses a hierarchical classification system that divides motility disorders as disorders of outflow obstruction and disorders of peristalsis. The disorders of esophago-gastric junction (EGJ) outflow include Type I, II and III achalasia and EGJ outflow obstruction. The disorders of peristalsis include absent contractility, distal esophageal spasm, hypercontractile esophagus, and ineffective esophageal motility. There are several diagnostic tools such as endoscopy, barium esophagram, high resolution manometry, and functional luminal imaging probe that can aid in evaluating esophageal motility disorders. A multidisciplinary approach including a primary care physician, radiologist, gastroenterologist, and surgeon may be beneficial for accurate diagnosis and proper treatment. The purpose of this paper is to discuss the diagnosis and management of esophageal dysmotility disorders other than achalasia. Graphical abstract

Background/Objectives: To correlate size changes in undifferentiated pleomorphic sarcoma (UPS) on magnetic resonance imaging (MRI) after neoadjuvant chemoradiation therapy (nCRT) with pathological response, risk of local recurrence, and therapeutic regimens. Methods: This retrospective study analyzed clinical, pathological, and imaging data from 39 biopsy-proven UPS subjects. Four readers measured the tumor dimensions before and after nCRT, including two perpendicular axial diameters and the longest coronal/sagittal diameter. Three cross-sectional areas and bounding volume were also calculated. Responders (pR) were defined as having ≤10% viable cells and non-responders (pNR) as having more. Inter-reader agreement was evaluated using Kendall’s concordance coefficient. Changes in tumor size were compared between pR and pNR using one-way ANOVA and Tukey’s HSD test for multiple comparisons of means. Results: pR showed a greater increase in size across all measurements compared to pNR. For the longest axial diameter, the mean increase was 30% ± 35% for pR and 14% ± 31% for pNR, with a mean difference (pR-pNR) of 16% (95% CI: 6–27%, p = 0.003). In tumors treated with radiotherapy alone, pR exhibited larger size increases in all dimensions compared to pNR. In contrast, in the chemoradiation group, pR showed a slight increase, while pNR generally shrank, although these differences did not reach statistical significance. Notably, pNR with local recurrence exhibited a reduction in all tumor dimensions compared to pNR without local recurrence. Conclusions: This exploratory study suggests that tumor size changes may predict pathological response and local recurrence after nCRT in UPS; however, the small sample size limits the generalizability of these findings.

Background/Objectives: Radiomic features exhibit a correlation with tumor size on pretreatment images. However, on post-treatment images, this association is influenced by treatment efficacy and varies between responders and non-responders. This study introduces a novel model, called baseline-referenced Delta radiomics, which integrates the association between radiomic features and tumor size into Delta radiomics to predict chemotherapy response in liver metastases from breast cancer (BC) and colorectal cancer (CRC). Materials and Methods: A retrospective study analyzed contrast-enhanced computed tomography (CT) scans of 83 BC patients and 84 CRC patients. Among these, 57 BC patients with 106 liver lesions and 37 CRC patients with 109 lesions underwent post-treatment imaging after systemic chemotherapy. Radiomic features were extracted from up to three lesions per patient following manual segmentation. Tumor response was assessed by measuring the longest diameter and classified according to RECIST 1.1 criteria as progressive disease (PD), partial response (PR), or stable disease (SD). Classification models were developed to predict chemotherapy response using pretreatment data only, Delta radiomics, and baseline-referenced Delta radiomics. Model performance was evaluated using confusion matrix metrics. Results: Baseline-referenced Delta radiomics performed comparably or better than established radiomics models in predicting tumor response in chemotherapy-treated patients with liver metastases. The sensitivity, specificity, and balanced accuracy in predicting response ranged from 0.66 to 0.97, 0.81 to 0.97, and 80% to 90%, respectively. Conclusions: By integrating the relationship between radiomic features and tumor size into Delta radiomics, baseline-referenced Delta radiomics offers a promising approach for predicting chemotherapy response in liver metastases from breast and colorectal cancer.

Pathologic conditions of the biliary system, although common, can be difficult to diagnose clinically. Challenges in biliary imaging include anatomic variants and the dynamic nature of the biliary tract, which can change with age and intervention, blurring the boundaries of normal and abnormal. Choledochal cysts can have numerous appearances and are important to diagnose given the risk of cholangiocarcinoma potentially requiring surgical resection. Choledocholithiasis, the most common cause of biliary dilatation, can be difficult to detect at US and CT, with MRI having the highest sensitivity. However, knowledge of the imaging pitfalls of MRI and MR cholangiopancreatography is crucial to avoid misinterpretation. Newer concepts in biliary tract malignancy include intraductal papillary biliary neoplasms that may develop into cholangiocarcinoma. New paradigms in the classification of cholangiocarcinoma correspond to the wide range of imaging appearances of the disease and have implications for prognosis. Accurately staging cholangiocarcinoma is imperative, given expanding curative options including transplant and more aggressive surgical options. Infections of the biliary tree include acute cholangitis or recurrent pyogenic cholangitis, characterized by obstruction, strictures, and central biliary dilatation. Inflammatory conditions include primary sclerosing cholangitis, which features strictures and fibrosis but can be difficult to differentiate from secondary causes of sclerosing cholangitis, including more recently described entities such as immunoglobulin G4-related sclerosing cholangitis and COVID-19 secondary sclerosing cholangitis. The authors describe a wide variety of benign and malignant biliary tract abnormalities, highlight differentiating features of the cholangitides, provide an approach to interpretation based on the pattern of imaging findings, and discuss pearls and pitfalls of imaging to facilitate accurate diagnosis. ^©RSNA, 2024 Supplemental material is available for this article.

Purpose To assess the diagnostic performance and reliability of 18 CT signs to diagnose cecal volvulus, a surgical emergency, versus a group of non-volvulus mimickers. Materials and methods Four radiologists retrospectively and independently assessed 18 CT signs in 191 patients with cecal volvulus (n = 63) or a non-volvulus control group ((n = 128), including cecal bascule (n = 19), mobile cecum (n = 95), and colonic pseudo-obstruction (n = 14)) at a single institution from 2013 to 2021. Fleiss’ kappa coefficient was used to assess inter-reader agreement. For diagnostic performance metrics, we assessed sensitivity, specificity, and positive and negative predictive values. For predictive performance, all 18 signs were included in bivariate and stepwise lasso multivariate logistic regression models to diagnose cecal volvulus. Performance was assessed by ROC curves. Results 191 patients (mean age: 63 years +/− 15.5 [SD]; 135 women) were included in the study. Nine of the 18 CT signs of cecal volvulus demonstrated good or better (> 0.6) inter-reader agreement. Individual CT signs with sensitivity, specificity, positive and negative predictive values all above 70% for diagnosing cecal volvulus were transition point, bird beak, and X-marks-the-spot. A lasso regression model determined four CT features: transition point, bird beak, coffee bean, and whirl had excellent prediction (AUC = .979) for cecal volvulus if all present. Conclusion CT signs for cecal volvulus that have high sensitivity and specificity include: transition point, bird beak, and X-marks-the-spot and were reliable in distinguishing non-volvulus mimickers. If the following four features were present: transition point, bird beak, coffee bean, and whirl, there was excellent prediction (AUC = .979) for cecal volvulus.

Objective: To evaluate the role of [18F]Fluciclovine PET/CT scan in restaging nmCRPCp and its impact on management. Methods and materials: This retrospective study included all patients with nonmetastatic castrate-resistant prostate cancer, who underwent [18F]Fluciclovine PET/CT scans for restaging who had concern for disease progression. Two radiologists independently reviewed the PET/CT studies, assigned an overall impression, and reported the site and number of radiotracer activities in consensus and impact on management was recorded. Available tissue diagnosis and/or six-month clinical and imaging follow-up were used as reference standards. Results: Thirty-five patients were included in this study. At least one lesion was detected in 73% (26/35) of the scans. Management changed in 71% (25/35) of patients, (22 positives and three negative scans). 26.9% (7/26) of patients were found to have an oligometastatic disease. Based on the reference standards, the diagnostic performance of [18F]Fluciclovine PET/CT in detecting recurrence in nmCRCP has 86%, sensitivity, 83% specificity, 96.1% PPV, and 55.5% NPV. There was no relationship between the Gleason score and a positive PET/CT scan in our patient population. Conclusion: Detecting the source of recurrence is challenging in nmCRCP patients when conventional imaging fails. Given the high PPV, sensitivity, and specificity, [18F]Fluciclovine PET/CT can be used instead of conventional imaging as a first-line choice due to its superiority over bone scan and added value of detecting soft tissue metastasis regardless of the initial Gleason score. Advances in knowledge: The study highlights the added value of [18F]Fluciclovine PET/CT in detecting soft tissue metastasis regardless of the initial Gleason score, which is not possible with conventional imaging such as bone scans. The study highlights the potential role of [18F]Fluciclovine PET/CT guiding management change for nonmetastatic castrate-resistant prostate cancer patients, particularly those with oligometastatic disease.