Shock liver, leading to ischemic hepatitis, may be secondary to systemic hypoxic or hypotensive causes leading to hypoperfusion of the liver, which may show hypoenhancement of a portion of the liver or entire liver parenchyma. Selective hepatic hypoperfusion due to hepatic arterial of portal venous occlusion could be reversible because of dual blood supply but may result in liver failure or hepatic infarction [40]. There are advantages to including the pelvis in the CT abdomen and pelvis examination, including detecting pelvic ascites as well as collateral vessels in instances of portal venous hypertension. CT Abdomen and Pelvis Without and With IV Contrast CT of the abdomen and pelvis with and without IV contrast is not typically useful for this clinical scenario because there is no benefit from adding unenhanced images. MR Elastography Abdomen Currently there is no role for MR elastography to diagnose acute hepatic inflammation from various causes. Superimposed acute inflammation in chronic viral hepatitis does not impact correlation of stiffness with stage of fibrosis [41,42]. MRI Abdomen with MRCP Although abdominal US is the preferred modality of choice in severely elevated aminotransferase, MRI with IV contrast can be obtained to assess parenchymal inflammation, perfusion, and vascular patency. Inflamed liver parenchyma shows increased signal intensity on T2-weighted images and decreased signal on T1- weighted images with heterogeneous perfusion, similar to CT. Periportal edema can be appreciated as a hyperintense signal on T2-weighted images. Heterogeneous enhancement of the liver in the arterial phase is seen in acute hepatic inflammation from various causes [43-48]. Perihepatic fluid and gallbladder wall edema can be seen on T2-weighted images in acute hepatitis. Hepatic capsular edema may be present in fulminant hepatitis with resultant heterogeneous enhancement on postgadolinium T1- weighted images.
Abnormal Liver Function Tests. Shock liver, leading to ischemic hepatitis, may be secondary to systemic hypoxic or hypotensive causes leading to hypoperfusion of the liver, which may show hypoenhancement of a portion of the liver or entire liver parenchyma. Selective hepatic hypoperfusion due to hepatic arterial of portal venous occlusion could be reversible because of dual blood supply but may result in liver failure or hepatic infarction [40]. There are advantages to including the pelvis in the CT abdomen and pelvis examination, including detecting pelvic ascites as well as collateral vessels in instances of portal venous hypertension. CT Abdomen and Pelvis Without and With IV Contrast CT of the abdomen and pelvis with and without IV contrast is not typically useful for this clinical scenario because there is no benefit from adding unenhanced images. MR Elastography Abdomen Currently there is no role for MR elastography to diagnose acute hepatic inflammation from various causes. Superimposed acute inflammation in chronic viral hepatitis does not impact correlation of stiffness with stage of fibrosis [41,42]. MRI Abdomen with MRCP Although abdominal US is the preferred modality of choice in severely elevated aminotransferase, MRI with IV contrast can be obtained to assess parenchymal inflammation, perfusion, and vascular patency. Inflamed liver parenchyma shows increased signal intensity on T2-weighted images and decreased signal on T1- weighted images with heterogeneous perfusion, similar to CT. Periportal edema can be appreciated as a hyperintense signal on T2-weighted images. Heterogeneous enhancement of the liver in the arterial phase is seen in acute hepatic inflammation from various causes [43-48]. Perihepatic fluid and gallbladder wall edema can be seen on T2-weighted images in acute hepatitis. Hepatic capsular edema may be present in fulminant hepatitis with resultant heterogeneous enhancement on postgadolinium T1- weighted images.