Multicenter Validation of Abbreviated MRI for Detecting Early-Stage Hepatocellular Carcinoma.

Background Abbreviated MRI is a proposed paradigm shift for hepatocellular carcinoma (HCC) surveillance, but data on its performance are lacking for histopathologically confirmed early-stage HCC. Purpose To evaluate the sensitivity and specificity of dynamic contrast-enhanced abbreviated MRI for early-stage HCC detection, using surgical pathologic findings as the reference standard. Materials and Methods This retrospective study was conducted at three U.S. liver transplant centers in patients with cirrhosis who underwent liver resection or transplant between January 2009 and December 2019 and standard "full" liver MRI with and without contrast enhancement within 3 months before surgery. Patients who had HCC-directed treatment before surgery were excluded. Dynamic abbreviated MRI examinations were simulated from the presurgical full MRI by selecting the coronal T2-weighted and axial three-dimensional fat-suppressed T1-weighted dynamic contrast-enhanced sequences at precontrast, late arterial, portal venous, and delayed phases. Two abdominal radiologists at each center independently interpreted the simulated abbreviated examinations with use of the Liver Imaging Reporting and Data System version 2018. Patients with any high-risk liver observations (>LR-3) were classified as positive; otherwise, they were classified as negative. With liver pathologic findings as the reference standard for the presence versus absence of early-stage HCC, the sensitivity, specificity, and their 95% CIs were calculated. Logistic regression was used to identify factors associated with correct classification. Results A total of 161 patients with early-stage HCC (median age, 62 years [IQR, 58-67 years]; 123 men) and 138 patients without HCC (median age, 55 years [IQR, 47-63 years]; 85 men) were confirmed with surgical pathologic findings. The sensitivity and specificity of abbreviated MRI were 88.2% (142 of 161 patients) (95% CI: 83.5, 92.5) and 89.1% (123 of 138 patients) (95% CI: 84.4, 93.8), respectively. Sensitivity was lower for Child-Pugh class B or C versus Child-Pugh class A cirrhosis (64.1% vs 94.2%; P < .001). Conclusion With surgical pathologic findings as the reference standard, dynamic abbreviated MRI had high sensitivity and specificity for early-stage hepatocellular carcinoma detection in patients with compensated cirrhosis but lower sensitivity in those with decompensated cirrhosis. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Kim in this issue.

Osseous Injury Associated With Ligamentous Tear of the Knee.

One of the most common knee injuries is ligament tear, which may initially manifest as an osseous injury in radiographs. Radiologists should therefore be able to recognize ligament tears of the knee as osseous abnormalities in images. This review focuses on the imaging features of knee ligament injuries and their related osseous injuries: anterior cruciate ligament (ACL) tear with Segond fracture; associated marrow contusion; ACL avulsion fracture; posterior cruciate ligament (PCL) tear with osseous avulsion of the ligament including arcuate sign; reverse Segond fracture; PCL avulsion fracture; medial collateral ligament tear with Pellegrini-Stieda disease; lateral collateral ligament tear with avulsion fracture of the fibular head; and patellar ligament injuries with Osgood-Schlatter and Sinding-Larsen-Johansson.

Management of a sandbag accident in an MRI unit.

Our aim is to report the cause and management of a ferromagnetic sandbag accident that occurred when an unconscious patient was sent for brain MRI. A 2-kg sandbag had been placed in the vicinity of his right groin to aid hemostasis after a femoral venous puncture for thrombocytopenia. His clothing and blanket had not been examined thoroughly before he was moved to the scanner and the sandbag went unnoticed. Its attraction to the scanner and adherence to the scanner rim resulted in a minor abrasion and bruise on the patient's face. We decided to manually remove some of the pellets from the sandbag after cutting the vinyl bag at one corner with a nonferromagnetic screwdriver. Piece-meal removal of about two-thirds of the pellets facilitated removal of the remaining pellets and the sandbag as a whole. The word "sandbag" is misleading and led to a lack of communication between the clinical team and the MRI staff and failure by the MRI staff to recognize a sandbag as a ferromagnetic object. Careful manual removal of small amounts of pellets can be used to avoid more time- and labor-intensive strategies to deal with a sandbag accident (e.g., magnet quench or ramp-down). Installation of a ferromagnetic material detector to screen patients before entering the scanner room is recommended.

Follicular Dendritic Cell Tumor in Liver: A Case Report and Collective Review.

Follicular dendritic cells (FDC) are a subset of the immune system and present in the germinal centers of lymphoid follicles in the spleen and lymph nodes. They are functionally as antigen-presenting cells and thus improving the quality of the humoral immune response. Follicular dendritic cell tumor is rare but considered low-grade sarcoma. Including our case, there were totally 17 cases with FDC tumor involved the liver from Medline. In these cases, the mean age was 47 years old, ranged from 19 to 82. It was much more common in females than in males (13:4). The clinical manifestations of these patients included abdominal discomfort, palpable mass, weight loss and malaise. The average size of the tumor was 11 cm. Most of the FDC tumors were associated with Epstein-Barr virus expression, 13/17 (76.5%). Surgical resection remains the mainstay of the treatment.