Quantitative liver tumor blood volume measurements by a C-arm CT post-processing software before and after hepatic arterial embolization therapy: comparison with MDCT perfusion.

PURPOSE We aimed to determine whether the C-arm computed tomography (CT) blood volume (BV) imaging of hepatic tumors performed with a new prototype software is capable of measuring the BV changes in response to hepatic arterial treatments and to validate these quantitative measurements with commercially available multidetector computed tomography (MDCT) perfusion software. METHODS A total of 34 patients with hepatic tumors who underwent either radioembolization (RE, n=21) or transarterial chemoembolization (TACE, n=13) were included in the study. Using a prototype software by Siemens Healthcare, 74 C-arm CT BV measurements were obtained in both pre- and postembolization settings (three patients had additional BV measurements before and after work-up angiography for RE). Ten of 34 patients underwent MDCT perfusion study before embolization, enabling comparison of BV measurements using C-arm CT versus MDCT methods. RESULTS The mean BV of 14 tumor lesions in 10 patients on MDCT perfusion was highly correlated with the BV values on C-arm CT (r=0.97, P < 0.01). The BV values obtained by C-arm CT decreased from 140.6±28.3 mL/1000 mL to 45.9±23.5 mL/1000 mL after TACE (66.37% reduction) and from 175.6±29.4 mL/1000 mL to 84.1±22.5 mL/1000 mL after RE (53.75% reduction). DISCUSSION Quantitative BV measurement with C-arm CT is well-correlated with MDCT BV measurements, and it is a promising tool to monitor perfusion changes during hepatic arterial embolization.