What is the utility of CT (Computed Tomography) triple phase liver in the workup of cirrhosis?

From the Guidelines

CT triple phase liver imaging is a highly recommended diagnostic tool in the workup of cirrhosis, providing comprehensive assessment of liver morphology, vascular changes, and detection of hepatocellular carcinoma (HCC) with high specificity and sensitivity, as supported by the most recent guidelines and studies 1.

Key Benefits of CT Triple Phase Liver Imaging

• Comprehensive assessment of liver morphology, including characteristic changes such as nodular liver surface, lobar atrophy/hypertrophy, and widened fissures
• Effective demonstration of portal hypertension manifestations, including varices, splenomegaly, and ascites
• High specificity and sensitivity for detecting HCC, which appears hypervascular during the arterial phase with "washout" in later phases
• Evaluation of portal vein patency and identification of portal vein thrombosis, which may be tumor-related or due to decreased flow

Diagnostic Criteria and Recommendations

• The LI-RADS CT/MR v2018 or the LI-RADS CEUS v2017 criteria should be used for non-invasive diagnosis of HCC 1
• The diagnosis is based on the combination of major imaging features, including tumour size, rim and non-rim arterial hyperenhancement, peripheral and non-peripheral washout, enhancing capsule, and threshold growth
• A definite HCC (i.e., LR-5) is present if a lesion >20 mm shows non-rim APHE and at least one additional major feature among a non-peripheral washout, an enhancing capsule, and threshold growth 1

Clinical Implications

• CT triple phase liver imaging provides crucial information for disease staging, complication management, transplant evaluation, and ongoing surveillance for HCC development in cirrhosis patients
• The use of CT triple phase liver imaging can help improve patient outcomes by enabling early detection and treatment of HCC, as well as monitoring of disease progression and response to treatment 1

From the Research

Utility of CT Triple Phase Liver in Workup of Cirrhosis

• The CT triple phase liver protocol is useful in the detection of hepatocellular carcinoma (HCC) in cirrhotic liver, with a higher detection rate compared to single-phase CT 2.
• The triple-phase protocol includes arterial phase (AP), portal-venous phase (PP), and delayed phase (DP), which provides additional information and improves the detection of HCC 2.
• A study found that the delayed phase (DP) showed a significantly higher detection rate of HCC compared to the portal-venous phase (PP) (p = 0.008) 2.
• The combination of AP and DP phases detected all HCC lesions, while the combination of AP and PP phases detected only 40 lesions out of 49 2.
• Another study found that triple arterial phase CT of the liver with a radiation dose equivalent to that of single arterial phase CT is feasible and provides equivalent to superior image quality and equal HCC detection rate 3.
• The use of triple-phase CT also helps to characterize benign lesions that simulate tumor tissue, such as focal fibrosis, infarcted regenerative nodules, and hemangiomas 4.
• Optimization of scan delays using bolus-tracking techniques is crucial to obtain optimal vascular and lesional contrast in triple-phase CT of the liver 5.
• A study found that a scan delay of 8 s after trigger threshold is reached in the lower thoracic aorta is optimal for early arterial phase imaging, which is most helpful for assessment of hepatic arterial tree (CT angiography) 5.
• The appearances of HCC on triple-phase CT images are similar to those described for single-detector helical scanners, with a high prevalence of hypervascular HCC and most lesions showing washout on portal venous images 6.