title: Short-term reproducibility of apparent diffusion coefficient estimated from diffusion-weighted MRI of the prostate.
abstract: OBJECTIVE
  The purpose of the study is to determine short-term reproducibility of apparent diffusion coefficient (ADC) estimated from diffusion-weighted magnetic resonance (DW-MR) imaging of the prostate.
  
  
  METHODS
  Fourteen patients with biopsy-proven prostate cancer were studied under an Institutional Review Board-approved protocol. Each patient underwent two, consecutive and identical DW-MR scans on a 3T system. ADC values were calculated from each scan and a deformable registration was performed to align corresponding images. The prostate and cancerous regions of interest (ROIs) were independently analyzed by two radiologists. The prostate volume was analyzed by sextant. Per-voxel absolute and relative percentage variations in ADC were compared between sextants. Per-voxel and per-ROI variations in ADC were calculated for cancerous ROIs.
  
  
  RESULTS
  Per-voxel absolute difference in ADC in the prostate ranged from 0 to 1.60 × 10(-3) mm(2)/s (per-voxel relative difference 0% to 200%, mean 10.5%). Variation in ADC was largest in the posterior apex (0% to 200%, mean 11.6%). Difference in ADC variation between sextants was not statistically significant. Cancer ROIs' per-voxel variation in ADC ranged from 0.001 × 10(-3) to 0.841 × 10(-3) mm(2)/s (0% to 67.4%, mean 11.2%) and per-ROI variation ranged from 0 to 0.463 × 10(-3) mm(2)/s (mean 0.122 × 10(-3) mm(2)/s).
  
  
  CONCLUSIONS
  Variation in ADC within the human prostate is reasonably small, and is on the order of 10%.
authors: Department of Radiology, University of Chicago, 5841 S. Maryland Avenue, MC 2026, Chicago, IL, 60637, USA. sadinski@uchicago.edu.
authors: Meredith
authors: M
authors: Sadinski
authors: Department of Radiology, University of Chicago, 5841 S. Maryland Avenue, MC 2026, Chicago, IL, 60637, USA. mmedved@uchicago.edu.
authors: Milica
authors: M
authors: Medved
authors: Department of Radiology, University of Chicago, 5841 S. Maryland Avenue, MC 2026, Chicago, IL, 60637, USA. drikarademir@hotmail.com.|Department of Radiology, Eskisehir Military Hospital, 26020, Eskisehir, Turkey. drikarademir@hotmail.com.
authors: Ibrahim
authors: I
authors: Karademir
authors: Department of Radiology, University of Chicago, 5841 S. Maryland Avenue, MC 2026, Chicago, IL, 60637, USA. shiyang219@gmail.com.
authors: Shiyang
authors: S
authors: Wang
authors: Department of Radiology, University of Chicago, 5841 S. Maryland Avenue, MC 2026, Chicago, IL, 60637, USA. yhpeng@btju.edu.cn.|School of Electronic and Information Engineering, Beijing Jiaotong University, No. 3 Shangyuancun, Haidian District, Beijing, 100044, China. yhpeng@btju.edu.cn.
authors: Yahui
authors: Y
authors: Peng
authors: Department of Radiology, University of Chicago, 5841 S. Maryland Avenue, MC 2026, Chicago, IL, 60637, USA. y-jiang@uchicago.edu.
authors: Yulei
authors: Y
authors: Jiang
authors: Department of Radiology, University of Chicago, 5841 S. Maryland Avenue, MC 2026, Chicago, IL, 60637, USA. ssammet@radiology.bsd.uchicago.edu.
authors: Steffen
authors: S
authors: Sammet
authors: Department of Radiology, University of Chicago, 5841 S. Maryland Avenue, MC 2026, Chicago, IL, 60637, USA. gskarczm@uchicago.edu.
authors: Gregory
authors: G
authors: Karczmar
authors: Department of Radiology, University of Chicago, 5841 S. Maryland Avenue, MC 2026, Chicago, IL, 60637, USA. aoto@radiology.bsd.uchicago.edu.
authors: Aytekin
authors: A
authors: Oto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: ADC; DWI; MRI; Prostate; Reproducibility