Perfusion changes in hepatocellular carcinoma and surrounding liver parenchyma based on perfusion CT imaging

Abstract

Abstract Purpose The aim of this study was to use computed tomography perfusion imaging (CTPI) to compare and analyze the differences in perfusion parameters between hepatocellular carcinoma (HCC) and surrounding tumor tissue before and after transarterial chemoembolization (TACE) to diagnose HCC and evaluate its curative effect. Methods Twenty-one HCC patients were examined by CTPI before and four weeks after TACE. Regions of interest (ROIs) were placed in the tumor (T1), peritumoral-1 cm (T2), peritumoral-2 cm (T3), and background liver parenchymal (T4) areas before TACE and in the residual tumor (T1a)/lipiodol-retaining (T1b) areas after TACE. The perfusion parameters included hepatic arterial perfusion (HAP), portal venous perfusion (PVP), total liver perfusion (TLP), the hepatic perfusion index (HPI), and the time to peak (TTP). Results A total of 32 lesions were detected, 11 lesions contained residual lesions, and 21 patients had good lipiodol deposition after TACE. The HAP and HPI signals demonstrated a decreasing trend (T1/T1a > T2 > T3 > T4), whereas the PVP and TLP signals showed an increasing trend (T1/T1a < T2 < T3 < T4) in the preoperative and postoperative residual groups, except for HAP and TLP in the T2 vs. T3, or HAP, HPI and TTP inT3 vs. T4 in postoperative residual, the remaining parameters are statistically significant. (p < 0.05). No blood perfusion was detected at T1b in the postoperative lipiodol-retaining group, and both the HAP and HPI signals reached their highest levels at T2, whereas the PVP, TLP, and TTP signals were highest at T4. The parameters of the T4 group were significantly different from those of the T2 and T3 groups (p < 0.05). Compared with those in the preoperative and residual groups, in the postoperative lipiodol group, the HAP and HPI were significantly lower, the PVP was significantly greater in T2 and T3, and TLP were significantly greater in T2 (p < 0.05). Conclusion CTPI can be used to evaluate the blood flow of hepatocellular carcinoma patients and surrounding areas before and after treatment. After TACE, the difference in perfusion in each area of the residual tumor group exhibited little change, while the difference in blood flow between the tumor and its surrounding area with dense lipiodol deposition greatly changed, which decreased the difference in perfusion between the tumor and the adjacent area. These findings provide reference data for the selection of treatment methods and postoperative evaluation.