title: DWI-associated entire-tumor histogram analysis for the differentiation of low-grade prostate cancer from intermediate-high-grade prostate cancer.
abstract: OBJECTIVE
  To investigate diagnostic efficiency of DWI using entire-tumor histogram analysis in differentiating the low-grade (LG) prostate cancer (PCa) from intermediate-high-grade (HG) PCa in comparison with conventional ROI-based measurement.
  
  
  METHODS
  DW images (b of 0-1400 s/mm(2)) from 126 pathology-confirmed PCa (diameter >0.5 cm) in 110 patients were retrospectively collected and processed by mono-exponential model. The measurement of tumor apparent diffusion coefficients (ADCs) was performed with using histogram-based and ROI-based approach, respectively. The diagnostic ability of ADCs from two methods for differentiating LG-PCa (Gleason score, GS ≤ 6) from HG-PCa (GS > 6) was determined by ROC regression, and compared by McNemar's test.
  
  
  RESULTS
  There were 49 LG-tumor and 77 HG-tumor at pathologic findings. Histogram-based ADCs (mean, median, 10th and 90th) and ROI-based ADCs (mean) showed dominant relationships with ordinal GS of Pca (ρ = -0.225 to -0.406, p < 0.05). All above imaging indices reflected significant difference between LG-PCa and HG-PCa (all p values <0.01). Histogram 10th ADCs had dominantly high Az (0.738), Youden index (0.415), and positive likelihood ratio (LR+, 2.45) in stratifying tumor GS against mean, median and 90th ADCs, and ROI-based ADCs. Histogram mean, median, and 10th ADCs showed higher specificity (65.3%-74.1% vs. 44.9%, p < 0.01), but lower sensitivity (57.1%-71.3% vs. 84.4%, p < 0.05) than ROI-based ADCs in differentiating LG-PCa from HG-PCa.
  
  
  CONCLUSIONS
  DWI-associated histogram analysis had higher specificity, Az, Youden index, and LR+ for differentiation of PCa Gleason grade than ROI-based approach.
authors.affiliation: Department of Radiology, The First Affiliated Hospital with Nanjing Medical University, No. 300, Guangzhou Road, Nanjing, 210000, China. njmu_wcj@163.com.
authors.forename: Chen-Jiang
authors.initials: CJ
authors.lastname: Wu
authors.affiliation: Department of Radiology, The First Affiliated Hospital with Nanjing Medical University, No. 300, Guangzhou Road, Nanjing, 210000, China. njmu_wq@163.com.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Pathology, The First Affiliated Hospital with Nanjing Medical University, Nanjing, China. njmu_hl@163.com.
authors.forename: Hai
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Radiology, The First Affiliated Hospital with Nanjing Medical University, No. 300, Guangzhou Road, Nanjing, 210000, China. njmu_wxn@163.com.
authors.forename: Xiao-Ning
authors.initials: XN
authors.lastname: Wang
authors.affiliation: Department of Radiology, The First Affiliated Hospital with Nanjing Medical University, No. 300, Guangzhou Road, Nanjing, 210000, China. njmu_lxs@163.com.
authors.forename: Xi-Sheng
authors.initials: XS
authors.lastname: Liu
authors.affiliation: Department of Radiology, The First Affiliated Hospital with Nanjing Medical University, No. 300, Guangzhou Road, Nanjing, 210000, China. njmu_shb@163.com.
authors.forename: Hai-Bin
authors.initials: HB
authors.lastname: Shi
authors.affiliation: Department of Radiology, The First Affiliated Hospital with Nanjing Medical University, No. 300, Guangzhou Road, Nanjing, 210000, China. njmu_zyd@163.com.
authors.forename: Yu-Dong
authors.initials: YD
authors.lastname: Zhang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011467:Prostate / Q000473:pathology; D011471:Prostatic Neoplasms / Q000473:pathology*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: ADC; DWI; Histogram analysis; ROI