title: Preliminary experience with a novel method of three-dimensional co-registration of prostate cancer digital histology and in vivo multiparametric MRI.
abstract: OBJECTIVE
  To assess a novel method of three-dimensional (3D) co-registration of prostate cancer digital histology and in-vivo multiparametric magnetic resonance imaging (mpMRI) image sets for clinical usefulness.
  
  
  METHODS
  A software platform was developed to achieve 3D co-registration. This software was prospectively applied to three patients who underwent radical prostatectomy. Data comprised in-vivo mpMRI [T2-weighted, dynamic contrast-enhanced weighted images (DCE); apparent diffusion coefficient (ADC)], ex-vivo T2-weighted imaging, 3D-rebuilt pathological specimen, and digital histology. Internal landmarks from zonal anatomy served as reference points for assessing co-registration accuracy and precision.
  
  
  RESULTS
  Applying a method of deformable transformation based on 22 internal landmarks, a 1.6 mm accuracy was reached to align T2-weighted images and the 3D-rebuilt pathological specimen, an improvement over rigid transformation of 32% (p = 0.003). The 22 zonal anatomy landmarks were more accurately mapped using deformable transformation than rigid transformation (p = 0.0008). An automatic method based on mutual information, enabled automation of the process and to include perfusion and diffusion MRI images. Evaluation of co-registration accuracy using the volume overlap index (Dice index) met clinically relevant requirements, ranging from 0.81-0.96 for sequences tested. Ex-vivo images of the specimen did not significantly improve co-registration accuracy.
  
  
  CONCLUSIONS
  This preliminary analysis suggests that deformable transformation based on zonal anatomy landmarks is accurate in the co-registration of mpMRI and histology. Including diffusion and perfusion sequences in the same 3D space as histology is essential further clinical information. The ability to localize cancer in 3D space may improve targeting for image-guided biopsy, focal therapy, and disease quantification in surveillance protocols.
authors.affiliation: Division of Urologic Oncology, New York University Langone Medical Center, New York, NY, USA; Department of Urology and Renal Transplantation, Côte de Nacre University Hospital, Caen, France; CNRS, UMR 6301 ISTCT, CERVOxy Group, GIP CYCERON, France; CEA, DSV/I2BM, UMR 6301 ISTCT, France; UNICAEN, UMR 6301 ISTCT, F-14074 Caen, France; Normandie University, France. Electronic address: clementorczyk@yahoo.fr.
authors.forename: C
authors.initials: C
authors.lastname: Orczyk
authors.forename: H
authors.initials: H
authors.lastname: Rusinek
authors.forename: A B
authors.initials: AB
authors.lastname: Rosenkrantz
authors.forename: A
authors.initials: A
authors.lastname: Mikheev
authors.forename: F-M
authors.initials: FM
authors.lastname: Deng
authors.forename: J
authors.initials: J
authors.lastname: Melamed
authors.forename: S S
authors.initials: SS
authors.lastname: Taneja
mesh_terms: D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011467:Prostate / Q000473:pathology / Q000601:surgery; D011471:Prostatic Neoplasms / Q000473:pathology*; D020728:Transurethral Resection of Prostate / Q000379:methods