Spectrum of Heterotopic and Ectopic Splenic Conditions.

A spectrum of heterotopic and ectopic splenic conditions may be encountered in clinical practice as incidental asymptomatic detection or symptomatic diagnosis. The radiologist needs to be aware of these conditions and their imaging characteristics to provide a prompt correct diagnosis and avoid misdiagnosis as neoplasm or lymphadenopathy. Having a strong knowledge base of the embryologic development of the spleen improves understanding of the pathophysiologic basis of these conditions. Spleen-specific imaging techniques-such as technetium 99m (99mTc)-labeled denatured erythrocyte scintigraphy, 99mTc-sulfur colloid liver-spleen scintigraphy, and MRI with ferumoxytol intravenous contrast material-can also be used to confirm the presence or absence of splenic tissue. Heterotopic splenic conditions include splenules and splenogonadal fusion (discontinuous or continuous forms). These heterotopic conditions are caused by incomplete fusion of the splenic primordia (splenule) and abnormal fusion of the gonadal and splenic tissue (splenogonadal fusion). Ectopic splenic conditions arise in patients with a prior splenic injury (splenosis), laxity or maldevelopment of the splenic ligaments (wandering spleen), or heterotaxy syndromes (polysplenia and asplenia). Importantly, these heterotopic and ectopic splenic conditions can also manifest with complications, including vascular torsion and rupture. ©RSNA, 2024.

Intrapatient Changes in CT-Based Body Composition After Initiation of Semaglutide (Glucagon-Like Peptide-1 Agonist) Therapy.

Background: The long-acting glucagon-like peptide-1 receptor agonist semaglutide is used to treat type 2 diabetes or obesity in adults. Clinical trials have observed associations of semaglutide with weight loss, improved diabetic control, and cardiovascular risk reduction. Objective: To evaluate intrapatient changes in body composition after initiation of semaglutide therapy by applying an automated suite of CT-based artificial intelligence (AI) body composition tools. Methods: This retrospective study included adult patients with semaglutide treatment who underwent abdominopelvic CT both within 5 years before and within 5 years after semaglutide initiation, between January 2016 and November 2023. An automated suite of previously validated CT-based AI body composition tools was applied to pre-semaglutide and post-semaglutide scans to quantify visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) area, skeletal muscle area and attenuation, intermuscular adipose tissue (IMAT) area, liver volume and attenuation, and trabecular bone mineral density (BMD). Patients with ≥5-kg weight loss and ≥5-kg weight gain between scans were compared. Results: The study included 241 patients (mean age, 60.4±12.4 years; 151 women, 90 men). In the weight-loss group (n=67), the post-semaglutide scan, versus pre-semaglutide scan, showed decrease in VAT area (341.1 vs 309.4 cm2, p<.001), SAT area (371.4 vs 410.7 cm2, p<.001), muscle area (179.2 vs 193.0, p<.001), and liver volume (2379.0 vs 2578 HU, p=.009), and increase in liver attenuation (74.5 vs 67.6 HU, p=.03). In the weight-gain group (n=48), the post-semaglutide scan, versus pre-semaglutide scan, showed increase in VAT area (334.0 vs 312.8, p=.002), SAT area (485.8 vs 488.8 cm2, p=.01), and IMAT area (48.4 vs 37.6, p=.009), and decrease in muscle attenuation (5.9 vs 13.1, p<.001). Other comparisons were not significant (p>.05). Conclusion: Patients using semaglutide who lost versus gained weight demonstrated distinct patterns of changes in CT-based body composition measures. Those with weight loss exhibited overall favorable shifts in measures related to cardiometabolic risk. Muscle attenuation decrease in those with weight gain is consistent with decreased muscle quality. Clinical Impact: Automated CT-based AI tools provide biomarkers of body composition changes in patients using semaglutide beyond that which is evident by standard clinical measures.

Correlation of HbA1c levels with CT-based body composition biomarkers in diabetes mellitus and metabolic syndrome.

Diabetes mellitus and metabolic syndrome are closely linked with visceral body composition, but clinical assessment is limited to external measurements and laboratory values including hemoglobin A1c (HbA1c). Modern deep learning and AI algorithms allow automated extraction of biomarkers for organ size, density, and body composition from routine computed tomography (CT) exams. Comparing visceral CT biomarkers across groups with differing glycemic control revealed significant, progressive CT biomarker changes with increasing HbA1c. For example, in the unenhanced female cohort, mean changes between normal and poorly-controlled diabetes showed: 53% increase in visceral adipose tissue area, 22% increase in kidney volume, 24% increase in liver volume, 6% decrease in liver density (hepatic steatosis), 16% increase in skeletal muscle area, and 21% decrease in skeletal muscle density (myosteatosis) (all p < 0.001). The multisystem changes of metabolic syndrome can be objectively and retrospectively measured using automated CT biomarkers, with implications for diabetes, metabolic syndrome, and GLP-1 agonists.

Contrast-enhanced ultrasound of renal masses in the pre-transplant setting: literature review with case highlights.

With the rising incidence of chronic kidney disease worldwide, an increasing number of patients are expected to require renal transplantation, which remains the definitive treatment of end stage renal disease. Medical imaging, primarily ultrasonography and contrast-enhanced CT and/or MRI, plays a large role in pre-transplantation assessment, especially in the characterization of lesions within the native kidneys. However, patients with CKD/ESRD often have relative contraindications to CT- and MR-contrast agents, limiting their utilization within this patient population. Contrast-enhanced ultrasound (CEUS), which combines the high temporal and spatial resolution of ultrasonography with intravascular microbubble contrast agents, provides a promising alternative. This review aims to familiarize the reader with the literature regarding the use of CEUS in the evaluation of cystic and solid renal lesions and provide case examples of its use at our institution in the pre-transplant setting.

Interobserver Agreement Between Primary Sonographers and Secondary Overreaders for Screening and Surveillance Liver Ultrasounds Using Ultrasound Liver Imaging Reporting and Data System.

ABSTRACT: The authors aim to identify if primary sonographers and secondary reviewers, both radiologists and sonographers, are likely to assign the same Ultrasound Liver Imaging Reporting and Data System (US LI-RADS) scores for liver surveillance ultrasounds. Institutional review board approval was obtained. Sonographers were familiarized with US LI-RADS via radiologist-led lectures. Three sonographers prospectively scored 170 screening examinations using US LI-RADS recommendations. Scans were retrospectively rescored by a fourth sonographer and a radiologist, both of whom were blinded to the original scores. Results were analyzed with weighted and nonweighted Cohen kappa statistical analysis methods. There was near-perfect agreement between primary and secondary sonographers and primary sonographer and radiologist (kappa of 0.87 and 0.92, respectively) for US LI-RADS category (cat) scores. However, only substantial and moderate agreements were noted for visualization (vis) scores between primary and secondary sonographers and primary sonographer and radiologist (weighted kappa of 0.73 and 0.48, respectively). There was vis score disagreement between the primary sonographer and radiologist in 60 (35.3%) cases. In 35 (20%) cases, the radiologist assigned a lower/more conservative vis score. There was vis score disagreement between the primary and secondary reviewing sonographers in 30 (17.6%) cases. In 12 (7%) cases, the secondary sonographer assigned a more conservative vis score. Although a good degree of concordance was noted between the groups, radiologists will need to generate their own US LI-RADS scoring to accurately reflect their impression and appropriately steer management.

Role of Ultrasound for Chronic Liver Disease and Hepatocellular Carcinoma Surveillance.

Ultrasound plays a vital role in the evaluation of patients with chronic liver disease and in hepatocellular carcinoma (HCC) surveillance in populations at risk for developing HCC. Semiannual ultrasound for HCC surveillance is universally recommended by all liver societies around the world. Advanced ultrasound techniques, such as elastography and contrast-enhanced ultrasound, offer additional benefits in imaging evaluation of chronic liver disease. Major benefits of ultrasound include its high safety profile and relatively low cost.

Correlation of placental MR imaging signs and pathologic diagnosis of placenta accreta spectrum: Retrospective single center case series.

INTRODUCTION: Alongside initial screening obstetric US, use of placental MRI has been increasing in the last few decades to aid with antenatal diagnosis and delivery planning in Placenta Accreta Spectrum (PAS). The aim of this study was to determine if the MRI pathophysiological sign subcategories described in the current literature can predict the severity of pathologic diagnosis. METHODS: Institutional imaging records were reviewed for placental MRIs performed for suspicion of PAS in the last decade. Electronic health records were searched for patient history and pathology. The 59 MRI studies were reviewed using the 11 MRI signs described by the SAR and ESUR joint consensus statement. Further breakdown of the signs was divided by underlying pathophysiologic subcategories including gross morphologic, interface and tissue architecture signs. RESULTS: Pathologic diagnosis yielded 34 cases: accreta 4/34, incerta 14/34, percreta 10/34 and normal 6/34. Of the accreta cases all of them demonstrated at least two interface and half of the cases had tissue architecture signs, 13/14 increta cases demonstrated interface signs and 12/14 demonstrated tissue architecture signs, 9/10 percreta cases had two interface and at least six demonstrated three tissue architecture signs. Statistical analysis showed significant difference between pathologic diagnosis and the number of positive interface signs with p = 0.02. DISCUSSION: Interface signs were the most objective and sensitive MRI subcategory. Statistical analysis determined there was a significant difference between PAS diagnosis and number of interface signs present. This subcategory has the most overlap with classic US signs which are traditionally used before MRI referral.

Reporting of acute pancreatitis by radiologists-time for a systematic change with structured reporting template.

Acute pancreatitis has a wide array of imaging presentations. Various classifications have been used in the past to standardize the terminology and reduce confusing and redundant terms. We aim to review the historical and current classifications of acute pancreatitis and propose a new reporting template which can improve communication between various medical teams by use of appropriate terminology and structured radiology template. The standardized reporting template not only conveys the most important imaging findings in a simplified yet comprehensive way but also allows structured data collection for future research and teaching purposes.