title: Quantitative study of prostate cancer using three dimensional fiber tractography.
abstract: OBJECTIVE
  To investigate feasibility of a quantitative study of prostate cancer using three dimensional (3D) fiber tractography.
  
  
  METHODS
  In this institutional review board approved retrospective study, 24 men with biopsy proven prostate cancer underwent prostate magnetic resonance imaging (MRI) with an endorectal coil on a 1.5 T MRI scanner. Single shot echo-planar diffusion weighted images were acquired with b = 0.600 s/mm(2), six gradient directions. Open-source available software TrackVis and its Diffusion Toolkit were used to generate diffusion tensor imaging (DTI) map and 3D fiber tracts. Multiple 3D spherical regions of interest were drawn over the areas of tumor and healthy prostatic parenchyma to measure tract density, apparent diffusion coefficient (ADC) and fractional anisotropy (FA), which were statistically analyzed.
  
  
  RESULTS
  DTI tractography showed rich fiber tract anatomy with tract heterogeneity. Mean tumor region and normal parenchymal tract densities were 2.53 and 3.37 respectively (P < 0.001). In the tumor, mean ADC was 0.0011 × 10(-3) mm(2)/s vs 0.0014 × 10(-3) mm(2)/s in the normal parenchyma (P < 0.001). The FA values for tumor and normal parenchyma were 0.2047 and 0.2259 respectively (P = 0.3819).
  
  
  CONCLUSIONS
  DTI tractography of the prostate is feasible and depicts congregate fibers within the gland. Tract density may offer new biomarker to distinguish tumor from normal tissue.
authors.affiliation: Sandeep Hedgire, Alexey Tonyushkin, Aoife Kilcoyne, Jason A Efstathiou, Peter F Hahn, Mukesh Harisinghani, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Hedgire
authors.affiliation: Sandeep Hedgire, Alexey Tonyushkin, Aoife Kilcoyne, Jason A Efstathiou, Peter F Hahn, Mukesh Harisinghani, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States.
authors.forename: Alexey
authors.initials: A
authors.lastname: Tonyushkin
authors.affiliation: Sandeep Hedgire, Alexey Tonyushkin, Aoife Kilcoyne, Jason A Efstathiou, Peter F Hahn, Mukesh Harisinghani, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States.
authors.forename: Aoife
authors.initials: A
authors.lastname: Kilcoyne
authors.affiliation: Sandeep Hedgire, Alexey Tonyushkin, Aoife Kilcoyne, Jason A Efstathiou, Peter F Hahn, Mukesh Harisinghani, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Efstathiou
authors.affiliation: Sandeep Hedgire, Alexey Tonyushkin, Aoife Kilcoyne, Jason A Efstathiou, Peter F Hahn, Mukesh Harisinghani, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States.
authors.forename: Peter F
authors.initials: PF
authors.lastname: Hahn
authors.affiliation: Sandeep Hedgire, Alexey Tonyushkin, Aoife Kilcoyne, Jason A Efstathiou, Peter F Hahn, Mukesh Harisinghani, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States.
authors.forename: Mukesh
authors.initials: M
authors.lastname: Harisinghani
keywords: Diffusion tensor imaging; Magnetic resonance imaging; Prostate cancer; Tract density; Tractography