Chen et al [27] showed higher liver stiffness in patients with steatosis and lobular inflammation than in those with steatosis and lower stiffness when compared with those with parenchymal fibrosis in fatty liver. Chemical shift imaging using T1 gradient echo exploits the differences in the resonance frequencies of water and fat proton signals yielding 2-point Dixon T1 in-phase and opposed-phase with fat and iron depiction. However, T2* decay from hepatic iron can erroneously lead to an underestimation of liver fat content by reducing in-phase signal, particularly at longer time to echo [28-31]. Proton density fat fraction is a quantitative and reproducible method for fat estimation that uses chemical shift while eliminating or reducing the effects of confounding factors, such as T2 decay. Proton density fat fraction is an accurate (area under the receiver operating characteristic curve = 98.9%; 95% confidence interval, 96.8%-100%) and reliable tool for hepatic lipid assessment (grade 1 or higher) across different vendors and magnetic field strengths. Recent investigations suggest that quantitative MR methods may serve as a comparable or even better reference standard for fat quantification to reference standard liver biopsy [32,33]. MRI Abdomen Without and With IV Contrast With MRCP There is no relevant literature to support the use of MRI abdomen without and with IV contrast with MR cholangiopancreatography (MRCP) in this clinical scenario. Variant 2: Abnormal liver function tests. Hepatocellular predominance with moderate or severe aminotransferase increase. Initial imaging. Breu et al [34], in a large multicenter study, found ischemic hepatitis to be the most common cause for markedly elevated aminotransferase ALT/AST level (5000 IU/L). Ischemic liver injury is a serious condition because it can progress to liver failure and high mortality [35].
Abnormal Liver Function Tests. Chen et al [27] showed higher liver stiffness in patients with steatosis and lobular inflammation than in those with steatosis and lower stiffness when compared with those with parenchymal fibrosis in fatty liver. Chemical shift imaging using T1 gradient echo exploits the differences in the resonance frequencies of water and fat proton signals yielding 2-point Dixon T1 in-phase and opposed-phase with fat and iron depiction. However, T2* decay from hepatic iron can erroneously lead to an underestimation of liver fat content by reducing in-phase signal, particularly at longer time to echo [28-31]. Proton density fat fraction is a quantitative and reproducible method for fat estimation that uses chemical shift while eliminating or reducing the effects of confounding factors, such as T2 decay. Proton density fat fraction is an accurate (area under the receiver operating characteristic curve = 98.9%; 95% confidence interval, 96.8%-100%) and reliable tool for hepatic lipid assessment (grade 1 or higher) across different vendors and magnetic field strengths. Recent investigations suggest that quantitative MR methods may serve as a comparable or even better reference standard for fat quantification to reference standard liver biopsy [32,33]. MRI Abdomen Without and With IV Contrast With MRCP There is no relevant literature to support the use of MRI abdomen without and with IV contrast with MR cholangiopancreatography (MRCP) in this clinical scenario. Variant 2: Abnormal liver function tests. Hepatocellular predominance with moderate or severe aminotransferase increase. Initial imaging. Breu et al [34], in a large multicenter study, found ischemic hepatitis to be the most common cause for markedly elevated aminotransferase ALT/AST level (5000 IU/L). Ischemic liver injury is a serious condition because it can progress to liver failure and high mortality [35].