Background: Acute pancreatitis (AP) is characterized by acute onset, rapid development, and poor prognosis. Timely diagnosis and identification of the cause are the key to formulating the clinical program and improving the prognosis. There were several studies on this topic but the results varied. This study systematically evaluated and analyzed reports on the comparison of magnetic resonance imaging (MRI) and computed tomography (CT) for the diagnosis of AP in recent years, providing evidence for clinical diagnosis and treatment. Methods: The databases of PubMed, Web of Science, The Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang Data were searched for literature on MRI and CT in the diagnosis of AP. After evaluating the articles and extracting the data, the software RevMan 5.4 and Stata 16.0 were used for meta-analysis.Results: A total of 9 articles were included in the selection, with a total of 566 patients having undergone diagnosis. Meta-analysis showed that for MRI, the diagnostic sensitivity was 92%, 95% confidence interval

Background: To analyze the imaging and clinical data of patients with localized pseudo-subarachnoid hemorrhage (pseudo-SAH), so as to improve the correct understanding of this sign by radiologists. Methods: The imaging and clinical data of patients with localized pseudo-SAH on head CT scan without contrast from January 2013 to March 2022 were retrospectively analyzed, and the imaging and clinical characteristics were summarized. Results: The etiology of 9 patients with pseudo-SAH was viral encephalitis (2 cases), acute cerebral infarction (4 cases) and hypoxic ischemic encephalopathy (3 cases). All patients underwent CT scan without contrast, CT scan with contrast, MRI and lumbar puncture examination. All patients' head CT scan without contrast showed local swelling of brain tissue (less than two lobes), stenosis and occlusion of adjacent subarachnoid space, with its inner strip of high-density shadow. CT scan with contrast found that the high density shadow was significantly enhanced. MRI and lumbar puncture were performed to rule out true SAH and confirm pseudo-SAH. Finally, 8 patients were discharged from hospital after treatment, and 1 patient died of multiple organ failure. Conclusion: Localized pseudo-SAH often indicates localized brain lesions and has a relatively good prognosis. It has certain characteristics in CT value, enhancement mode and morphology.