title: Wall imaging of cerebral aneurysms with a modified surface-rendering technique of spiral CT.
abstract: BACKGROUND
  There has been no detailed documentation of the advantages of three-dimensional (3D) wall imaging of cerebral aneurysms. The usefulness of such endoscopic images obtained with modified spiral computed tomography angiography (CTA) was therefore examined in comparison with conventional spiral CTA and digital subtraction angiography (DSA).
  
  
  METHODS
  Fifteen of 45 patients who underwent conventional spiral CTA in our department in the past 4 years, were further studied with a technical modification of surface-rendering reconstruction in spiral CT. Endoscopic images were obtained by regulating the lower and higher thresholds of spiral CT scans in processing. Digital subtraction angiography was also performed for 14 of the 15 patients. The 3D wall images of the cerebral aneurysms were assessed in comparison with findings from conventional CTA and DSA.
  
  
  RESULTS
  The true orifice of the aneurysms could be visualized with the endoscopic mode in all of the 15 cases. In paraclinoid aneurysms, particularly below the anterior clinoid process, the relationships to associated vessels and bone structures were more clearly disclosed with this mode. The endoscopic images of aneurysms with rigid clots or neighboring distended veins were not as adversely affected as conventional CTA. In 4 of the 15 the wall imaging precisely located the branches arising from the dome of aneurysms which DSA could not.
  
  
  CONCLUSIONS
  Wall imaging of complex or small cerebral aneurysms provided valuable information on their relationships to associated arteries and surrounding bony structures. The endoscopic mode, a simple modification of surface rendering, is easily available in commercial CT processing packages.
authors.affiliation: Department of Neurosurgery, Okanami General Hospital, Ueno, Mie, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Hashimoto
authors.forename: J
authors.initials: J
authors.lastname: Lida
authors.forename: Y
authors.initials: Y
authors.lastname: Hironaka
authors.forename: Y
authors.initials: Y
authors.lastname: Shin
authors.forename: T
authors.initials: T
authors.lastname: Sakaki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D017546:Angioscopy; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000473:pathology; D002533:Cerebral Angiography / Q000379:methods*; D002536:Cerebral Arteries / Q000000981:diagnostic imaging* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D002532:Intracranial Aneurysm / Q000150:complications / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D013345:Subarachnoid Hemorrhage / Q000209:etiology; D014057:Tomography, X-Ray Computed / Q000379:methods*