INTRACRANIAL ANEURYSMS - DETECTION AND CHARACTERIZATION WITH MR-ANGIOGRAPHY WITH USE OF AN ADVANCED POSTPROCESSING TECHNIQUE IN A BLINDED-READER STUDY

PURPOSE: To assess magnetic resonance (MR) angiography for the detecti on and characterization of angiographically proved intracranial aneury sms by using an advanced method of postprocessing, in a blinded-reader study. MATERIALS AND METHODS: One hundred fifty-eight vessels were ex amined with catheter angiography and three-dimensional time-of-flight MR angiography in 44 patients with 63 aneurysms and 15 patients with n o aneurysm at catheter angiography. Postprocessing was performed offli ne with an advanced multifeature-extraction, ray-tracing algorithm. MR angiograms were interpreted independently by three neuroradiologists blinded to the catheter angiographic results for presence, location, s ize, and morphology of the aneurysm. Proof of diagnosis was consensus reading of catheter angiograms. RESULTS: Mean sensitivity for detectio n of aneurysms was 75% (range, 70%-79%). As a screening tool (ie, dete ction of at least one aneurysm necessitating catheter angiography), me an sensitivity was 91% for all aneurysms and 95% for aneurysms larger than 3 mm. This method was not adequate for detection of lobulation or size of aneurysm. CONCLUSION: MR angiography with an advanced method of postprocessing can result in highly sensitive, specific studies for the diagnosis of intracranial aneurysms that are of sufficient size t o be considered for surgical treatment, but it is inadequate for chara cterization of aneurysms.