Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York, USA.
Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York, USA.
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.
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 cm3 . DW-MRI data were obtained for b-values of 0, 400, and 700 s/mm2 . Apparent diffusion coefficients (ADCs) were estimated from PZ regions of interest (ROIs) on b = 0, 700 and b = 0, 400 s/mm2 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.
ADC400 (AUC = 0.81, P < 0.0001), ADC700 (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 ADC400 (P = 0.26) or ADC700 (P = 0.12).
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.
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Mazaheri Y, Vargas HA, Akin O, Goldman DA, Hricak H. Are you the author?
Reference: J Magn Reson Imaging. 2011 Nov 8. Epub ahead of print.
doi: 10.1002/jmri.22888
PubMed Abstract
PMID: 22069141
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