CT Hepatic Arteriography for Improved Detection and Ablation of Occult HCC Nodules: A Retrospective Analysis.

[PURPOSE] Accurate preprocedural imaging is crucial for optimizing percutaneous thermal ablation of hepatocellular carcinoma (HCC) thermal ablation. However, some nodules may remain undetected using conventional contrast-enhanced CT (CECT) and MRI (CEMRI), due to poor conspicuity. CT hepatic arteriography (CTHA) is an imaging technique that improves the detection of primary/secondary liver tumors. We aimed to assess the diagnostic performance of CTHA in detecting occult HCC nodules in cirrhotic patients undergoing percutaneous microwave ablation and to evaluate its impact on pretreatment planning.

[MATERIALS AND METHODS] This retrospective, single-center study analyzed 38 CTHA-guided ablation procedures performed in 35 cirrhotic patients with confirmed HCC, from November 1, 2022, to December 31, 2024. All patients underwent preprocedural CECT /CEMRI within eight weeks before ablation. The number of additional nodules detected by CTHA and their suitability for immediate ablation were assessed.

[RESULTS] CTHA identified seven occult HCCs in 6/38 procedures (15.8%). The mean size of newly detected lesions was 13 mm (IQR 9). All additionally detected nodules were ablated during the same sessions. In 4/38 CTHAs (10.5%), vascular variants precluding a whole liver opacification were encountered. Technical success was achieved in 93.1% of all procedures, with a low rate of grade 1-3 complications (18.4%) and no severe ones. Eight treatments (21.6%) were followed by disease progression apart from the ablation zone.

[CONCLUSION] CTHA enhances occult HCC detection, enabling immediate ablation and potentially improving outcomes. However, unusual vascular anatomy may hinder a comprehensive liver evaluation.