The utility of imaging for diagnosis of cirrhosis and accuracy for characterizing HCC is less well established, particularly because these patients often develop benign regenerative liver nodules. Optimal utilization of imaging in these patients must be established for each condition based on available data and is not addressed in this document. Chronic Liver Disease in whom the utility of US may be limited. Little value has been demonstrated for the addition of noncontrast to contrast-enhanced CT in this setting. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT is not a useful test for screening or surveillance for HCC. FDG uptake by HCC is highly variable, and combined with high background liver FDG uptake, the PET portion of these examinations adds little to multiphase contrast-enhanced CT [49]. MR Elastography Abdomen MR elastography has been investigated for the assessment of focal liver lesions with modest success [50]. However, limited spatial resolution and coverage of MR elastography renders it of limited utility for screening and surveillance. MRI Abdomen Dynamic contrast-enhanced MRI has been shown to be the most accurate modality in detecting and characterizing HCC, with sensitivity reported between 47% to 95% even for lesions <2 cm [46-48,51-54]. MRI most commonly serves as a second-line confirmatory diagnostic test for assessing nodules detected with US, though it may have a role for screening and surveillance of patients in whom US is expected to be of lower utility [55]. Because the detection and characterization of HCC relies mainly on the perfusion features of liver lesions, MRI without IV contrast is not typically performed for this purpose. MRI with hepatobiliary contrast agents has been shown to be similarly sensitive for detection of HCC compared with extracellular agents, and potentially more sensitive (up to 96% in a recent meta-analysis but only 88% in a more recent study) for detection of small lesions [56].
Chronic Liver Disease. The utility of imaging for diagnosis of cirrhosis and accuracy for characterizing HCC is less well established, particularly because these patients often develop benign regenerative liver nodules. Optimal utilization of imaging in these patients must be established for each condition based on available data and is not addressed in this document. Chronic Liver Disease in whom the utility of US may be limited. Little value has been demonstrated for the addition of noncontrast to contrast-enhanced CT in this setting. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT is not a useful test for screening or surveillance for HCC. FDG uptake by HCC is highly variable, and combined with high background liver FDG uptake, the PET portion of these examinations adds little to multiphase contrast-enhanced CT [49]. MR Elastography Abdomen MR elastography has been investigated for the assessment of focal liver lesions with modest success [50]. However, limited spatial resolution and coverage of MR elastography renders it of limited utility for screening and surveillance. MRI Abdomen Dynamic contrast-enhanced MRI has been shown to be the most accurate modality in detecting and characterizing HCC, with sensitivity reported between 47% to 95% even for lesions <2 cm [46-48,51-54]. MRI most commonly serves as a second-line confirmatory diagnostic test for assessing nodules detected with US, though it may have a role for screening and surveillance of patients in whom US is expected to be of lower utility [55]. Because the detection and characterization of HCC relies mainly on the perfusion features of liver lesions, MRI without IV contrast is not typically performed for this purpose. MRI with hepatobiliary contrast agents has been shown to be similarly sensitive for detection of HCC compared with extracellular agents, and potentially more sensitive (up to 96% in a recent meta-analysis but only 88% in a more recent study) for detection of small lesions [56].