Follow-up of coiled intracranial aneurysms: comparison of 3D time-of-flight and contrast-enhanced magnetic resonance angiography at 3T in a large, prospective series.

OBJECTIVES

To compare 3D-TOF magnetic resonance angiography (MRA) and contrast-enhanced MRA (CE-MRA) sequences at 3T in the follow-up of coiled aneurysms with digital subtracted angiography (DSA) as the gold standard.

METHODS

DSA, 3D-TOF and CE-MRA were performed in a prospective series of 126 aneurysms in 96 patients (57 female, 39 male; age: 25-75 years, mean: 51.3 ± 11.3 years). The quality of aneurysm occlusion was assessed independently and anonymously by a core laboratory.

RESULTS

Using DSA (gold standard technique), total occlusion was depicted in 57 aneurysms (45.2%), neck remnant in 34 aneurysms (27.0%) and aneurysm remnant in 35 aneurysms (27.8%). Sensitivity, specificity, positive predictive value and negative predictive value were very similar with 3D-TOF and CE-MRA. Visibility of coils was much better with 3D-TOF (95.2%) than with CE-MRA (23.0%) (P < 0.001). Also, substantial artefacts were less frequent with 3D-TOF (4.0%) than with CE-MRA (11.9%; P = 0.012).

CONCLUSIONS

In this large prospective series of patients with coiled aneurysms, at 3T 3D-TOF MRA was equivalent to CE-MRA for the evaluation of aneurysm occlusion, but coil visibility was superior at 3D-TOF. Thus the use of 3D-TOF at 3T is recommended for the follow-up of coiled intracranial aneurysms.

KEY POINTS

• Different Magnetic Resonance (MR) imaging techniques are used to evaluate intracranial aneurysms. • At 3T MR, 3D-TOF and CE-MRA appear equivalent for evaluating coiled aneurysms.. • Coils are better visualised on 3D-TOF than on CE-MRA. • Combined analysis of 3D-TOF and CE-MRA does not seem helpful. • At 3T, 3D-TOF techniques are recommended for monitoring patients with coiled aneurysms.