Study on the Hemodynamics of Residual Viable Tumor in Hepatocellular Carcinoma after Transarterial Chemoembolization Using Dual-energy Spectral CT

Objective: To evaluate the correlation between dual-energy spectral CT (DEsCT) and CT perfusion (CTP) parameters in residual viable tumor (RVT) after transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC), and to explore the value of DEsCT in assessing the hemodynamics of RVT. Methods: 78 HCC patients who underwent one-stop dual-energy spectral CT combined with low-dose CT perfusion scans 4-6 weeks after TACE were retrospectively enrolled. DEsCT parameters were measured and calculated in RVT, including arterial and portal venous phase iodine concentration (IC_AP, IC_PVP), normalized iodine concentration (NIC_AP, NIC_PVP), tumor iodine uptake ratio (TUR_AP, TUR_PVP), spectral curve slope (λ_{HU AP}, λ_{HU PVP}), and iodine concentration ratio (IC ratio). CTP parameters were also measured in RVT, including hepatic arterial fraction (HAF), blood flow (BF), blood volume (BV), and hepatic arterial blood flow (Hep.BF). Spearman correlation analysis was performed to assess the correlation between the two sets of parameters, with r > 0.25 and P < 0.05 considered statistically significant. Results: The DEsCT parameters of RVT, including IC_AP, NIC_AP, λ_{HU AP}, TUR_AP, NIC_PVP, and IC ratio, showed good correlations with CTP parameters such as HAF, BF, and Hep.BF (0.4 < r < 0.9). Among them, the IC ratio exhibited the strongest correlation with HAF (r=0.868).The dose-length product (DLP) of this scanning protocol was (1389.06±69.32) mGy·cm, and the effective radiation dose was (20.84±1.04) mSv. Conclusion: The multiparametric DEsCT parameters of RVT in HCC after TACE were significantly correlated with CTP parameters, which can serve as valuable imaging indicators reflecting the hemodynamics of RVT.