MR perfusion techniques have been described and found to be relatively accurate for the diagnosis and staging of liver fibrosis [30]. However, like CT perfusion, these are dependent on details of the acquisition and processing techniques and can be quite laborious, so they are not broadly used in clinical practice. US Abdomen Conventional US can be used in the assessment of liver fibrosis for detecting ultrastructural changes such as surface nodularity, coarsened echotexture, and lobar atrophy/hypertrophy, similar to conventional CT and MRI [24,33,34]. Chronic Liver Disease US has an advantage in that high spatial resolution imaging of the liver surface can be performed with high frequency transducers, which can demonstrate subtle surface nodularity. US Abdomen with IV Contrast US abdomen with IV contrast or CEUS has been assessed for evaluation of liver fibrosis. Similar to CT and MRI perfusion techniques, CEUS uses contrast media transit characteristics to make deductions about liver hemodynamics that relate to the presence and severity of liver fibrosis [35,36]. Although early data on the utility of CEUS for assessing liver fibrosis and portal hypertension are promising, this is an area of ongoing research at this time. US Duplex Doppler Abdomen Doppler US can demonstrate hemodynamic alterations indicative of portal hypertension, though these are typically only seen in the setting of long-standing fibrosis or cirrhosis [40,41]. Though only moderately sensitive for advanced fibrosis/cirrhosis, it can be used for initial assessment of patients with suspected long-standing chronic liver disease in combination with conventional grayscale US. Cirrhosis due to vascular conditions is a special case in which surveillance for HCC is more complex. Underlying vascular conditions include Budd-Chiari syndrome, hepatic congestion particularly in the setting of congenital heart disease, hereditary hemorrhagic telangiectasia, and others.
Chronic Liver Disease. MR perfusion techniques have been described and found to be relatively accurate for the diagnosis and staging of liver fibrosis [30]. However, like CT perfusion, these are dependent on details of the acquisition and processing techniques and can be quite laborious, so they are not broadly used in clinical practice. US Abdomen Conventional US can be used in the assessment of liver fibrosis for detecting ultrastructural changes such as surface nodularity, coarsened echotexture, and lobar atrophy/hypertrophy, similar to conventional CT and MRI [24,33,34]. Chronic Liver Disease US has an advantage in that high spatial resolution imaging of the liver surface can be performed with high frequency transducers, which can demonstrate subtle surface nodularity. US Abdomen with IV Contrast US abdomen with IV contrast or CEUS has been assessed for evaluation of liver fibrosis. Similar to CT and MRI perfusion techniques, CEUS uses contrast media transit characteristics to make deductions about liver hemodynamics that relate to the presence and severity of liver fibrosis [35,36]. Although early data on the utility of CEUS for assessing liver fibrosis and portal hypertension are promising, this is an area of ongoing research at this time. US Duplex Doppler Abdomen Doppler US can demonstrate hemodynamic alterations indicative of portal hypertension, though these are typically only seen in the setting of long-standing fibrosis or cirrhosis [40,41]. Though only moderately sensitive for advanced fibrosis/cirrhosis, it can be used for initial assessment of patients with suspected long-standing chronic liver disease in combination with conventional grayscale US. Cirrhosis due to vascular conditions is a special case in which surveillance for HCC is more complex. Underlying vascular conditions include Budd-Chiari syndrome, hepatic congestion particularly in the setting of congenital heart disease, hereditary hemorrhagic telangiectasia, and others.