Premium
Reducing the influence of b‐value selection on diffusion‐weighted imaging of the prostate: Evaluation of a revised monoexponential model within a clinical setting
Author(s) -
Mazaheri Yousef,
Vargas Hebert Alberto,
Akin Oguz,
Goldman Debra A.,
Hricak Hedvig
Publication year - 2012
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.22888
Subject(s) - medicine , prostatectomy , effective diffusion coefficient , nuclear medicine , prostate , prostate cancer , magnetic resonance imaging , receiver operating characteristic , institutional review board , diffusion mri , logistic regression , biopsy , radiology , cancer , surgery
Purpose: To compare the accuracy of standard and revised monoexponential models of diffusion‐weighted magnetic resonance imaging (DW‐MRI) data for differentiating malignant from benign prostate tissue, using surgical pathology as the reference standard. Materials and Methods: The Institutional Review Board waived informed consent for this Health Insurance Portability and Accountability Act (HIPAA)‐compliant, retrospective study of 46 patients (median age = 61 years; range: 42–85 years) who underwent DW‐MRI between May and December 2008 before radical prostatectomy for biopsy‐proven prostate cancer, had no prior treatment, and had whole‐mount step‐section pathology maps available showing at least one peripheral zone (PZ) lesion >0.1 cm 3 . DW‐MRI data were obtained for b‐values of 0, 400, and 700 s/mm 2 . Apparent diffusion coefficients (ADCs) were estimated from PZ regions of interest (ROIs) on b = 0, 700 and b = 0, 400 s/mm 2 images, using a standard monoexponential model. The true diffusion coefficient ( D ) and perfusion fraction ( f ) were measured using a revised monoexponential model incorporating all three b‐values. Areas under receiver operating characteristic curves (AUCs) were calculated to assess the accuracy of individual parameters and a logistic regression model combining D and f ( D+f ) in distinguishing malignant ROIs; P < 0.05 denoted significance. Results: ADC 400 (AUC = 0.81, P < 0.0001), ADC 700 (AUC = 0.79, P < 0.0001), D (AUC = 0.71, P = 0.0001) and D + f distinguished malignant from benign ROIs (AUC = 0.82, P < 0.0001), but f did not (AUC = 0.56, P = 0.28); D + f was significantly more accurate than D ( P = 0.016) but not more accurate than ADC 400 ( P = 0.26) or ADC 700 ( P = 0.12). Conclusion: The true diffusion coefficient provides an additional DW‐MRI parameter for distinguishing prostate cancer that is less influenced than the ADC by b‐value selection. J. Magn. Reson. Imaging 2011;35:660‐668. © 2011 Wiley Periodicals, Inc.