C-arm CT during hepatic arteriography tumour-to-liver contrast: intraindividual comparison of three different contrast media application protocols.

Objective: To compare tumour-to-liver contrast (TLC) of C-arm CT during hepatic arteriography (CACTHA) acquired using three protocols in patients with HCC.

Methods: This prospective study was IRB approved and informed consent was obtained from each patient. Twenty-nine patients (mean age, 68 ± 7 years; 27 men) with 55 HCCs (mean diameter, 2.6 ± 1.5 cm) underwent three different CACTHA protocols in random order before chemoembolisation. Contrast medium (100 mg iodine/ml) was injected into the common hepatic artery (flow rate 4 ml/s). The imaging delay for the start of the CACTHA examination was 4 s (protocol A), 8 s (protocol B) and 12 s (protocol C) (total amount of injected contrast medium: 48 ml, 64 ml, 80 ml). TLC was measured by placing regions of interest (ROIs) in the HCC and liver parenchyma. Mixed model ANOVAs and Bonferroni corrected post hoc tests were used for statistical analysis.

Results: Mean values for TLC were 132 ± 3.3 HU, 186 ± 5.8 HU and 168 ± 2.8 HU for protocols A, B and C. Protocol B provided significantly higher TLC than protocols A and C (p < 0.001).

Conclusion: TLC was significantly higher using an imaging delay of 8 s compared with a delay of 4 or 12 s.