title: Intracranial aneurysms: depiction on MR angiograms with a multifeature-extraction, ray-tracing postprocessing algorithm.
abstract: OBJECTIVE
  To compare a new method for postprocessing data, soft thresholding and depth cueing of unrestricted techniques (STANDOUT), with maximum intensity projection (MIP) for magnetic resonance (MR) angiograms of intracranial aneurysms.
  
  
  METHODS
  Eighteen patients with 19 intracranial aneurysms were studied. Images generated with STANDOUT were compared with those of MIP for both three-dimensional (3D) time-of-flight (TOF) and 3D phase-contrast (PC) techniques. Images were assessed for detection of aneurysms, scored for delineation of aneurysmal features and overall MR angiographic characteristics, and compared with catheter angiograms.
  
  
  RESULTS
  Both postprocessing techniques demonstrated aneurysms on most TOF and PC MR angiograms. Statistically significant improvement of aneurysmal features, aneurysmal neck definition, and delineation of adjacent arterial anatomy was seen on both TOF and PC MR angiograms with STANDOUT. Feature definition was most improved for smaller aneurysms. TOF and PC MR angiograms with STANDOUT showed improved elimination of artifactual intraluminal signal loss in normal large vessels, reduced artifactual narrowing of vessel caliber, and better small vessel delineation.
  
  
  CONCLUSIONS
  STANDOUT has great benefits for postprocessing of intracranial MR angiograms, regardless of the technique of data acquisition.
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia 19104.
authors.forename: S W
authors.initials: SW
authors.lastname: Atlas
authors.forename: J
authors.initials: J
authors.lastname: Listerud
authors.forename: W
authors.initials: W
authors.lastname: Chung
authors.forename: E S
authors.initials: ES
authors.lastname: Flamm
mesh_terms: D002536:Cerebral Arteries / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D002532:Intracranial Aneurysm / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D011446:Prospective Studies