CT and MR features of hepatic ischemia/necrosis after hepatosplenic surgery and upper gastrointestinal hemorrhage

Objective To investigate the CT and MR imaging features of hepatic ischemia/necrosis after hepatosplenic surgery and upper gastrointestinal hemorrhage. Methods A total of 36 patients diagnosed with hepatic ischemia/necrosis by both medical imaging and clinical diagnosis shortly after hepatosplenic surgery and upper gastrointestinal hemorrhage were collected, including 9 patients with liver cancer resection, 5 patients with liver cancer ablation (microwave ablation/radiofrequency ablation, argon-helium knife, alcohol injection), 11 patients with spleen resection, and 11 patients with upper gastrointestinal bleeding. Conventional liver CT and / or MR plain and dynamic enhancement scan were performed to comprehensively analyze the morphology and density/signal performance of the lesions. Results (1) Number of lesions: All cases had multiple lesions. (2) Distribution of lesions: scattered in the liver lobes, clustered or regional distribution, mainly in the periphery of the liver. (3) Size of lesions: the boundary of the nodular lesion was clear, and the single maximum diameter was 1.0-1.5 cm. It can be fused into a wedge-shaped patch or a segmental/sub-segmental large patch with a slight mass effect. (4) CT density or MR signal characteristics: CT plain scan showed slightly low density; MR plain scan showed slightly low signal on T1WI, high signal on T2WI, slightly high signal on DWI and no lipid/fat on dual phase imaging; 24 out of 36 cases (66.7%) showed no enhancement, while some lesions showed thin ring enhancement on the edge; emboli were found in the main and/or branches of portal vein (21/36 cases, 58.3%). (5) In the short-term review (minimum 5 days), the lesions became smaller or disappeared, and the local liver volume became smaller or the surface was depressed. Conclusions Hepatic ischemia/necrosis occurs after hepatosplenic surgery and upper gastrointestinal hemorrhage. The imaging manifestations are multiple nodular or flaky hypovascular foci, and the short-term review shows a markedly improvement. It needs to be differentiated from infection and metastasis of malignant tumors after operation. Key words: Hepatectomy; Splenectomy; Upper gastrointestinal hemorrhage; Ischemia; Necrosis; Computed Tomography, X-ray; Magnetic resonance imaging