title: Registration of prostate histology images to ex vivo MR images via strand-shaped fiducials.
abstract: OBJECTIVE
  To present and evaluate a method for registration of whole-mount prostate digital histology images to ex vivo magnetic resonance (MR) images.
  
  
  METHODS
  Nine radical prostatectomy specimens were marked with 10 strand-shaped fiducial markers per specimen, imaged with T1- and T2-weighted 3T MRI protocols, sliced at 4.4-mm intervals, processed for whole-mount histology, and the resulting histological sections (3-5 per specimen, 34 in total) were digitized. The correspondence between fiducial markers on histology and MR images yielded an initial registration, which was refined by a local optimization technique, yielding the least-squares best-fit affine transformation between corresponding fiducial points on histology and MR images. Accuracy was quantified as the postregistration 3D distance between landmarks (3-7 per section, 184 in total) on histology and MR images, and compared to a previous state-of-the-art registration method.
  
  
  RESULTS
  The proposed method and previous method had mean (SD) target registration errors of 0.71 (0.38) mm and 1.21 (0.74) mm, respectively, requiring 3 and 11 hours of processing time, respectively.
  
  
  CONCLUSIONS
  The proposed method registers digital histology to prostate MR images, yielding 70% reduced processing time and mean accuracy sufficient to achieve 85% overlap on histology and ex vivo MR images for a 0.2 cc spherical tumor.
authors.affiliation: Robarts Research Institute, London, Canada.
authors.forename: Eli
authors.initials: E
authors.lastname: Gibson
authors.forename: Cathie
authors.initials: C
authors.lastname: Crukley
authors.forename: Mena
authors.initials: M
authors.lastname: Gaed
authors.forename: José A
authors.initials: JA
authors.lastname: Gómez
authors.forename: Madeleine
authors.initials: M
authors.lastname: Moussa
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Chin
authors.forename: Glenn S
authors.initials: GS
authors.lastname: Bauman
authors.forename: Aaron
authors.initials: A
authors.lastname: Fenster
authors.forename: Aaron D
authors.initials: AD
authors.lastname: Ward
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001706:Biopsy / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D057918:Fiducial Markers; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008875:Middle Aged; D010363:Pattern Recognition, Automated / Q000379:methods*; D011467:Prostate / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D055815:Young Adult