The clinical value of ceMRA versus DSA for follow-up of intracranial aneurysms treated by coil embolization: an assessment of occlusion classifications and impact on treatment decisions.

OBJECTIVE

The aim of this study was a detailed analysis of the value of contrast-enhanced magnetic resonance angiography (ceMRA) compared to digital subtraction angiography (DSA) for follow-up imaging of intracranial aneurysms treated by coil embolization.

METHODS

Patients with coiled aneurysms and follow-up exams including both DSA and 3 T ceMRA were retrospectively identified. In blinded readings, both modalities were graded according to the modified Raymond-Roy classification (MRRC) and the Meyers scale. Additionally, readers were asked to make a decision regarding retreatment/follow-up based on the respective imaging findings.

RESULTS

The study comprised 92 patients harboring 102 coiled aneurysms. There was good intermethod agreement of DSA and ceMRA concerning both the MRRC (κ = 0.64) and the Meyers scale (κ = 0.74). Agreement regarding occlusion of < 90% of the aneurysm (Meyers grade ≥ 2) was very good (κ = 0.87). Regarding the detection of a remnant with contrast between the coil mass and the aneurysm wall (MRRC IIIb), there were 12 discrepant findings and agreement was good (κ = 0.70). Comparing treatment/follow-up decisions, the two methods agreed very well (κ = 0.92). In seven patients with discrepant treatment decisions, the authors concurred with DSA in four cases and with ceMRA in three cases when evaluating both modalities together. Interval aneurysm growth was found in more cases with ceMRA (n = 19) than with DSA (n = 16).

CONCLUSIONS

CeMRA is very unlikely to miss a relevant aneurysm remnant and thus could be suitable as the primary follow-up method. In case of remnant growth or recurrence, however, additional DSA might be required to guide treatment decisions.

KEY POINTS

• There is high accordance between ceMRA and DSA regarding the evaluation of intracranial aneurysms treated by endovascular coil embolization, but closer analysis also revealed relevant differences. • CeMRA could be suitable as the primary follow-up imaging modality, potentially eliminating the need for routine DSA. • DSA will still be required in case of aneurysm remnant growth or recurrence as detected by ceMRA.