title: Current computed tomography techniques can detect duct of Bellini plugging but not Randall's plaques.
abstract: OBJECTIVE
  To assess the ability of noninvasive computed tomography (CT) scans to detect interstitial calcium phosphate deposits (Randall's plaques) and duct of Bellini plugs, which are possible stone precursor lesions.
  
  
  METHODS
  At time of percutaneous nephrolithotomy (PCNL) for stone removal, all accessible individual papillae of 105 patients were endoscopically visualized and video recorded. Image-processing software was used to estimate the percentage of papillary surface occupied by plaque or plug in each pole (upper, middle, lower). The location of stones was also recorded. A radiologist blinded to the mapping results scored presurgical (n = 98) and postsurgical (n = 105) abdominal CT scans for the presence or absence of calcification by pole.
  
  
  RESULTS
  The cohort was a mean age of 56 years (range, 23-84 years). Maximum papillary surface area of each area of the kidney occupied by plug correlated with CT calcifications on pre- and postprocedure images by rank sum test. However, maximum plaque surface area did not correlate with radiographic findings (P = .10-.90 for each pole by rank sum test). Sensitivity was 81% and specificity was 69% of CT to detect plugs of at least 1% of the papillary surface area.
  
  
  CONCLUSIONS
  Calcifications seen on current generation clinical CT scans correspond to ductal plugging involving at least 1% of the papillary surface area. Current clinical CT scan technology appears inadequate for detecting Randall's plaques.
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, MN, USA. krambeck.amy@mayo.edu
authors.forename: Amy E
authors.initials: AE
authors.lastname: Krambeck
authors.forename: John C
authors.initials: JC
authors.lastname: Lieske
authors.forename: Xujian
authors.initials: X
authors.lastname: Li
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Bergstralh
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Rule
authors.forename: David
authors.initials: D
authors.lastname: Holmes
authors.forename: Cynthia M
authors.initials: CM
authors.lastname: McCollough
authors.forename: Terri J
authors.initials: TJ
authors.lastname: Vrtiska
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002130:Calcium Phosphates; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007669:Kidney Calculi / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000209:etiology; D007685:Kidney Tubules, Collecting / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D002130:Calcium Phosphates; C020243:calcium phosphate