title: Virtual pyeloscopy using volumetric depth peeling.
abstract: OBJECTIVE
  The aim of the study is to test a new volume-rendering method, volumetric depth peeling (VDP), for use in virtual pyeloscopy.
  
  
  METHODS
  VDP was applied to axial contrast-enhanced source computed tomographic (CT) images and coronal reformatted maximum intensity projections of three contrast-filled gloves containing objects of varying density. Similar renderings were performed on CT urograms performed to evaluate hematuria (n = 20). Renderings were assessed for anatomic appearance of ureters and specific calyces in comparison with source images.
  
  
  RESULTS
  Objects of soft-tissue and calcific density ranging in size from 4 to 20 mm were identified by using VDP within the glove phantoms. Normal and deformed renal calyces were well visualized by using VDP; however, two stones were not identified. The minimal ureteral width that could be visualized was 3 mm.
  
  
  CONCLUSIONS
  VDP may be a useful technique for virtual pyeloscopy providing that a robust and user-friendly computer interface can be developed.
authors: Department of Radiology, University of North Carolina at Chapel Hill, 27599, USA. julia_fielding@med.unc.edu
authors: Julia R
authors: JR
authors: Fielding
authors: David
authors: D
authors: Borland
authors: Kang Hoon
authors: KH
authors: Lee
authors: John P
authors: JP
authors: Clarke
authors: Eric
authors: E
authors: Wallen
authors: Raj
authors: R
authors: Pruthi
authors: Russell M
authors: RM
authors: Taylor