Comparison of TOF MRA, contrast-enhanced MRA and subtracted CTA from CTP in residue evaluation of treated intracranial aneurysms

Abstract

AIM: To compare effectiveness of contrast-enhanced magnetic resonance angiography (CE-MRA), 3D-Time-of-flight magnetic resonance angiography (3D-TOF-MRA) and subtracted computed tomography angiography from computed tomography perfusion (sub-CTA) in residue evaluation of intracranial aneurysms treated either with coiling or clipping. MATERIAL and METHODS: Sixteen treated aneurysms, which were evaluated with three methods within two weeks after the operation, were enrolled. The success of each imaging technique in the demonstration of residue aneurysm and nearby vessels was compared by Fisher's Exact Test. The differences among the three methods were evaluated by Cochran's Q test (p ≤ 0.05). RESULTS: Perfusion abnormality was noted in 81% of clipped and none of coiled patients. Vessel visualization in the vicinity of aneurysm was better in sub-CTA, followed by CE-MRA. In clipped aneurysms, sub-CTA revealed residue aneurysms in 16.7% of the patients while 3D-TOF-MRA and CE-MRA revealed none. In coiled aneurysms, CE-MRA revealed residue aneurysms in 100%, and TOF-MRA in 33.3% while sub-CTA revealed none. Although dramatic differences were noted in the evaluation of residue aneurysm as well as nearby vessel visualization, no statistical significance was noted due to very few patients in the subcategories. CONCLUSION: This is the first study comparing the effectiveness of CE-MRA, 3D-TOF MRA and sub-CTA in residue aneurysm evaluation although our results were suggestive, not conclusive. Vessel visualization in the vicinity of the aneurysm was better in sub-CTA in all cases regardless of coiling or clipping. Residue aneurysms were more commonly revealed by CE-MRA in coiled patients and more commonly and better shown by sub-CTA in clipped patients in addition to showing perfusion abnormality that was more common in clipped patients.