INTRACRANIAL ANEURYSMS - DEPICTION ON MR ANGIOGRAMS WITH A MULTIFEATURE-EXTRACTION, RAY-TRACING POSTPROCESSING ALGORITHM

PURPOSE: To compare a new method for postprocessing data, soft thresho lding and depth cueing of unrestricted techniques (STANDOUT), with max imum intensity projection (MIP) for magnetic resonance (MR) angiograms of intracranial aneurysms. MATERIALS AND METHODS: Eighteen patients w ith 19 intracranial aneurysms were studied. Images generated with STAN DOUT were compared with those of MIP for both three-dimensional (3D) t ime-of-flight (TOF) and 3D phase-contrast (PC) techniques. Images were assessed for detection of aneurysms, scored for delineation of aneury smal features and overall MR angiographic characteristics, and compare d with catheter angiograms. RESULTS: Both postprocessing techniques de monstrated aneurysms on most TOF and PC MR angiograms. Statistically s ignificant improvement of aneurysmal features, aneurysmal neck definit ion, and delineation of adjacent arterial anatomy was seen on both TOF and PC MR angiograms with STANDOUT. Feature definition was most impro ved for smaller aneurysms. TOF and PC MR angiograms with STANDOUT show ed improved elimination of artifactual intraluminal signal loss in nor mal large vessels, reduced artifactual narrowing of vessel caliber, an d better small vessel delineation. CONCLUSION: STANDOUT has great bene fits for postprocessing of intracranial MR angiograms, regardless of t he technique of data acquisition.