Evaluating the role of quantitative computed tomography perfusion parameters in differentiating hepatocellular carcinoma from other hepatic neoplasms.

Background: Differentiating the various liver tumors is pivotal due to distinct treatments and prognoses. Sometimes, it is difficult to accurately differentiate hepatocellular carcinoma (HCC) from other hepatic neoplasms non-invasively because of overlap in the triple-phase contrast-enhanced computed tomography (CECT) features, contraindication of an invasive biopsy, particularly in multifocal lesions with cirrhosis or ascites or when an MRI is unavailable or not feasible.

Objectives: To assess the utility of CT perfusion (CTP) parameters in differentiating HCC from other hepatic neoplasms.

Methods: Forty-eight patients with suspicious liver lesions underwent CTP imaging. Perfusion parameters were assessed within the tumor and the adjacent normal liver using the post-processing software. Statistical significance (p-value), sensitivity, and specificity value of the individual parameters were assessed. The receiver operating characteristic (ROC) curve analysis was done to threshold values of the parameters.

Results: The mean values of perfusion parameters like HAP (hepatic arterial perfusion), PVP (portal venous perfusion), HPI (hepatic perfusion index), BF (blood flow), BV (blood volume), MTT (mean transit time), and TTP (time to peak) were statistically significant (p-value < 0.05) between HCC and other hepatic neoplasms. Among the parameters, BV had the greatest AUC of 0.938. With a threshold value of 8.3 ml/100 ml/min, the sensitivity and specificity were 96.6% and 80%, respectively, in distinguishing HCC from other hepatic neoplasms. HPI, BF, BV, and TTP were statistically significant in differentiating hypervascular metastases from HCCs. HAP, HPI, BF, BV, and TTP were statistically significant in differentiating HCC from hypovascular metastases. BF and BV were significant in differentiating hypervascular from hypovascular metastases. HAP, PVP, HPI, BF, BV, and TTP were statistically significant in differentiating HCCs from intrahepatic cholangiocarcinomas.

Conclusion: CTP provides a quantitative, non-invasive method to differentiate HCC from other hepatic neoplasms with high efficacy. It can be a problem-solving tool when a conventional CECT scan cannot characterize a lesion as HCC, where biopsy is not feasible.