The evaluation of non-contrast MRA using a modified balanced steady state free precession technique in the follow-up of renal artery aneurysm after embolotherapy.

Purpose: To evaluate the feasibility and clinical utility of non-contrast magnetic resonance angiography (NC-MRA) using a modified balanced steady-state free precession (b-SSFP) technique combined with arterial spin labeling (ASL) for post-embolotherapy follow-up of renal artery aneurysms (RAAs), with digital subtraction angiography (DSA) as the reference standard.

Method: A total of 57 patients with RAAs underwent embolotherapy between June 2013 and July 2024. Among them, 15 RAAs from 14 patients underwent post-embolization surveillance with the NC-MRA and DSA. NC-MRA was performed at 12 months after coil embolization, followed by DSA. On NC-MRA images, complete occlusion is indicated by the absence of high signal within the aneurysm, whereas on DSA images, complete occlusion is defined as the absence of contrast enhancement within the aneurysm. We compare the NC-MRA and DSA results for each aneurysm during follow-up.

Results: Of the 15 aneurysms, 12 achieved complete occlusion and 3 exhibited incomplete occlusion. There was no aneurysmal growth, and no adverse events such as rupture or renal infarction occurred. We acquired 15 groups of follow-up MRA and DSA images, and the results were in perfect concordance.

Conclusion: The NC-MRA using the modified b-SSFP combined with ASL shows good agreement with DSA in assessing recanalization of RAAs after embolotherapy and may serve as a reliable, non-invasive follow-up modality.