Quantitative 4D transcatheter intraarterial perfusion MRI for monitoring chemoembolization of hepatocellular carcinoma

Purpose: To develop a fully quantitative 4D transcatheter intraarterial perfusion (TRIP) magnetic resonance imaging (MRI) technique and prospectively test the hypothesis that quantitative 4D TRIP-MRI can be used clinically to monitor intraprocedural liver tumor perfusion reductions during transcatheter arterial chemoembolization (TACE). Materials and Methods: TACE was performed within an x-ray digital subtraction angiography (DSA)-MRI procedure suite in 16 patients with hepatocellular carcinoma. Quantitative 4D TRIP-MRI with targeted radiofrequency field mapping and dynamic longitudinal relaxation rate mapping was used to monitor changes in tumor perfusion during TACE. First-pass perfusion analysis was performed to produce intraprocedural blood flow (Fρ) maps. Mean liver tumor perfusions before and after TACE were compared with a paired t-test (α = 0.05). Results: Perfusion reductions were successfully measured with quantitative 4D TRIP-MRI in 22 separate tumors during 18 treatment sessions. Mean tumor perfusion Fρ decreased from 16.3 (95% confidence interval [CI]: 10.7-21.9) before TACE to 5.0 (95% CI: 3.5-6.5) (mL/ min/100 mL) after TACE. Tumor perfusion reductions were statistically significant (P < 0.0005), with a mean absolute perfusion change of 11.4 (95% CI: 5.6-17.1) (mL/min/100 mL) and a mean percentage reduction of 61.0% (95% CI: 48.3%-73.6%). Conclusion: Quantitative 4D TRIP-MRI can be successfully performed within clinical interventional settings to monitor intraprocedural changes in liver tumor perfusion during TACE.