title: Detection of the residual lumen of intracranial aneurysms immediately after coil embolization by three-dimensional digital subtraction angiographic virtual endoscopic imaging.
abstract: OBJECTIVE
  Detection of a small residual lumen after coil embolization is often difficult because of the coil mass and the overlap of the cerebral arteries. The purpose of this study was to assess the usefulness of virtual endoscopic (VE) analysis of three-dimensional digital subtraction angiographic (DSA) images for evaluation of aneurysmal occlusion immediately after the procedure.
  
  
  METHODS
  Twenty-seven intracranial aneurysms were treated with coil embolization using a three-dimensional DSA system. Biplane and rotational DSA scanning was performed before and immediately after the procedures. VE images were obtained at a separate workstation, after transfer of the rotational images. Two-dimensional (2D) DSA images and VE images obtained after the procedure were assessed with respect to aneurysmal occlusion. Morphological outcomes and other factors, including location, size, volumetric ratio (coil volume/aneurysm volume), and residual sites, were also evaluated.
  
  
  RESULTS
  Seven aneurysms were evaluated as complete occlusion (CO) on both 2D DSA images and VE images. Twelve aneurysms exhibited residual lumina on both 2D DSA images and VE images. Five aneurysms were evaluated as CO on 2D DSA images and as incomplete occlusion on VE images. There were no recurrences among the aneurysms that were evaluated as CO on VE images. Two of five aneurysms that were evaluated as CO on 2D DSA images and as incomplete occlusion on VE images demonstrated regrowth in follow-up examinations. Residual sites and volumetric ratios were correlated with aneurysmal regrowth.
  
  
  CONCLUSIONS
  VE imaging can demonstrate a residual lumen more frequently than can 2D DSA imaging and is useful for evaluating aneurysmal occlusion after coil embolization.
authors.affiliation: Department of Radiology, Nagatomi Neurosurgical Hospital, Oita, Japan. h-kiyosue@mvi.biglobe.ne.jp
authors.forename: Hiro
authors.initials: H
authors.lastname: Kiyosue
authors.forename: Mika
authors.initials: M
authors.lastname: Okahara
authors.forename: Shuichi
authors.initials: S
authors.lastname: Tanoue
authors.forename: Takaharu
authors.initials: T
authors.lastname: Nakamura
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Nagatomi
authors.forename: Hiromu
authors.initials: H
authors.lastname: Mori
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction / Q000592:standards; D002533:Cerebral Angiography / Q000592:standards; D004621:Embolization, Therapeutic / Q000295:instrumentation*; D004864:Equipment and Supplies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000592:standards; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D013997:Time Factors; D014584:User-Computer Interface