Author/Authors :
Rezaeyan ، A Department of Medical Physics - Faculty of Medicine - Ahvaz Jundishapur University of Medical Sciences , Tahmasebi Birgani ، M J Department of Medical Physics - Faculty of Medicine - Ahvaz Jundishapur University of Medical Sciences , Chegeni ، N Department of Medical Physics - Faculty of Medicine - Ahvaz Jundishapur University of Medical Sciences , Sarkarian ، M Department of Urology - Golestan Hospital - Ahvaz Jundishapur University of Medical Sciences , Hanafi ، M Gh Department of Radiology - Faculty of Medicine - Ahvaz Jundishapur University of Medical Sciences , Akbarizadeh ، Gh Department of Electrical Engineering - Faculty of Engineering - Shahid Chamran University of Ahvaz
Abstract :
Background: Diffusionweighted imaging (DWI) is a main component of multiparametric MRI for prostate cancer detection. Recently, high b value DWI has gained more attention because of its capability for tumor characterization. Objective: To assess based on histopathological findings of transrectal ultrasound (TRUS)guided prostate biopsy as a reference, an increase in signal intensity of prostatic lesions in comparison with normal background tissue on high bvalue diffusionweighted images could be a sign of malignancy. Material and Methods: Fiftythree consecutive patients retrospectively included in the study. All patients underwent routine TRUSguided prostate biopsies involving 12 cores after the magnetic resonance imaging (MRI) examinations. In seventeen patients (n =35 lesions), the prostate cancer was histologically confirmed by TRUSguided prostate biopsy. The biopsy results of other patients were negative. Signal intensities on the high bvalue (1600 s/mm2) images of the peripheral zone, the central gland, and the defined lesions were evaluated using region of interestbased measurements. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for prostate cancer detection using signal intensity of high b value diffusionweighted images were calculated. Results: In the patients with confirmed prostate cancer, fourteen had visually increased SI on the high bvalue images. The SI of lesions for these patients was higher than the SI of peripheral zone (22±18%) or central gland (31±20%). In patients with a negative biopsy, eight had visually increased SI on the high bvalue images. The SI of lesions for these patients was 23±21% and 35±18% higher than the SI in the peripheral zone and the central gland, respectively. The sensitivity, specificity, PPV, and NPV for prostate cancer using SI of high b value DWI were 71, 87, 62, and 87 %, respectively. Conclusion: Visually increased SI on the high bvalue images can be an indication of malignancy, although some benign lesions also show this increase in signal intensity.
