Acute Abdomen Caused by Infected Mesenteric Cyst.

Teaching point: Computed tomography is essential for timely diagnosing infected mesenteric cysts as a cause of acute abdomen, ultimately requiring complete excision to confirm diagnosis given the potential of malignant transformation.

Impact of ultra-high-resolution imaging of the lungs on perceived diagnostic image quality using photon-counting CT.

OBJECTIVES: To compare clinical image quality and perceived impact on diagnostic interpretation of chest CT findings between ultra-high-resolution photon-counting CT (UHR-PCCT) and conventional high-resolution energy-integrating-detector CT (HR-EIDCT) using visual grading analysis (VGA) scores. MATERIALS AND METHODS: Fifty patients who underwent a UHR-PCCT (matrix 512 × 512, 768 × 768, or 1024 × 1024; FOV average 275 × 376 mm, 120 × 0.2 mm; focal spot size 0.6 × 0.7 mm) between November 2021 and February 2022 and with a previous HR-EIDCT within the last 14 months were included. Four readers evaluated central and peripheral airways, lung vasculature, nodules, ground glass opacities, inter- and intralobular lines, emphysema, fissures, bullae/cysts, and air trapping on PCCT (0.4 mm) and conventional EIDCT (1 mm) via side-by-side reference scoring using a 5-point diagnostic quality score. The median VGA scores were compared and tested using one-sample Wilcoxon signed rank tests with hypothesized median values of 0 (same visibility) and 2 (better visibility on PCCT with impact on diagnostic interpretation) at a 2.5% significance level. RESULTS: Almost all lung structures had significantly better visibility on PCCT compared to EIDCT (p < 0.025; exception for ground glass nodules (N = 2/50 patients, p = 0.157)), with the highest scores seen for peripheral airways, micronodules, inter- and intralobular lines, and centrilobular emphysema (mean VGA > 1). Although better visibility, a perceived difference in diagnostic interpretation could not be demonstrated, since the median VGA was significantly different from 2. CONCLUSION: UHR-PCCT showed superior visibility compared to HR-EIDCT for central and peripheral airways, lung vasculature, fissures, ground glass opacities, macro- and micronodules, inter- and intralobular lines, paraseptal and centrilobular emphysema, bullae/cysts, and air trapping. CLINICAL RELEVANCE STATEMENT: UHR-PCCT has emerged as a promising technique for thoracic imaging, offering improved spatial resolution and lower radiation dose. Implementing PCCT into daily practice may allow better visibility of multiple lung structures and optimization of scan protocols for specific pathology. KEY POINTS: • The aim of this study was to verify if the higher spatial resolution of UHR-PCCT would improve the visibility and detection of certain lung structures and abnormalities. • UHR-PCCT was judged to have superior clinical image quality compared to conventional HR-EIDCT in the evaluation of the lungs. UHR-PCCT showed better visibility for almost all tested lung structures (except for ground glass nodules). • Despite superior image quality, the readers perceived no significant impact on the diagnostic interpretation of the studied lung structures and abnormalities.

Cardiac MRI after Sudden Cardiac Arrest in a Young Woman Prompts Diagnosis of Familial Dilated Cardiomyopathy.

Teaching Point: Familial dilated cardiomyopathy (DCM) predisposes to malignant ventricular arrhythmias and sudden cardiac death, and magnetic resonance imaging (MRI) has important diagnostic value in demonstrating non-ischemic patterns of late gadolinium enhancement (LGE).

Atypical MRI Presentation of High-Grade Chondrosarcoma in the Proximal Femur.

Teaching Point: Although magnetic resonance imaging (MRI) plays a considerable role in the detection and differentiation of chondrosarcoma (e.g., by cortical breakthrough, peritumoral soft tissue edema, and extra-osseous extension), it is important to be aware of atypical features of common bone tumors.

Primary cardiac diffuse large B-cell lymphoma presenting with cardiac tamponade: a case report.

Background: Primary cardiac tumours are extremely rare with an autopsy incidence of 0.05%. They can present with a variety of symptoms, including life-threatening arrhythmia and cardiac tamponade. In this case report, we focus on the diagnostic process and management of a primary cardiac lymphoma (PCL) presenting with cardiac tamponade. Case summary: We report on a 71-year-old male presenting with a large pericardial effusion, tamponade, and a mass in the right atrioventricular groove. Multimodality imaging was performed, including transthoracic echocardiography, computed tomography, magnetic resonance imaging, positron emission tomography, and computed tomography-guided transthoracic biopsy. The final diagnosis of a double-hit diffuse large-cell B-cell lymphoma was made, for which treatment consisting of a combination of chemotherapy and immunotherapy was initiated. Low-dose colchicine was also added to the treatment. Discussion: Primary cardiac lymphoma remains a very rare diagnosis and this case highlights the need for multimodality imaging and imaging-guided biopsy to differentiate cardiac masses. First-line treatment for PCL remains a combination of chemotherapy with immunotherapy, with the addition of low-dose colchicine to prevent recurrence of malignant pericardial effusion.