Value of 3-D-MT-TONE-Time-of-Flight magnetic resonance angiography in the detection of intracranial aneurysms in comparison to digital subtraction angiography - A prospective study

Purpose: To evaluate the efficiency and accuracy of the optimized 3-D-MT-TONE-magnetic resonance angiography (MRA) with that of intraarterial digital subtraction angiography (DSA) in the detection of intracranial aneurysms. Material and methods: From March 1994 to March 1995 30 patients with 38 aneurysms were prospectively subjected to MRA as well as to DSA. Respiratory insufficient patients were excluded from MRA. Results: The aneurysm size ranged from 3-50 mm with an average size of 9 mm. Correct diagnosis was done in 33 aneurysms (86.8%) in 26 of the patients. In 4 patients (13.3%) with 5 aneurysms, the blinded readers made an incorrect diagnosis due to degradation of image quality. One (2.6%) aneurysm was falsely described via MRA. as well as via DSA. The sensitivity was 86.8%. In the control group of 30 patients three aneurysms were found, therefore the specificity was 90% and we could calculate a positive predictive value of 97.1%, a negative predictive value of 84.4% and a correct diagnosis of 90.1%. Conclusion: Our results show that MT-TONE-MRA is a useful non-invasive technique with improved vascular detail and vascular background for detection of intracranial aneurysm. Further technical improvements are necessary for better visualisation of pathological findings in the carotid siphon, where only 60% of the aneurysms could be clearly detected.