Tsutomu Tamada MD, PhD, Presenter: Nothing to Disclose

Teruki Sone MD, PhD, Abstract Co-Author: Nothing to Disclose

Naoto Egashira MD, Abstract Co-Author: Nothing to Disclose

Yoshimasa Jo MD, PhD, Abstract Co-Author: Nothing to Disclose

Akira Yamamoto MD, Abstract Co-Author: Nothing to Disclose

Takenori Yamashita, Abstract Co-Author: Nothing to Disclose

Shigeki Imai MD, Abstract Co-Author: Nothing to Disclose

Masao Fukunaga MD, PhD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

To identify age-related and zonal anatomical changes of apparent diffusion coefficient (ADC) values of prostate in healthy adult men, and to investigate the utility of ADC values in discriminating tumor from normal prostatic tissues in patients with prostate cancer.

A total of 114 healthy volunteer and 90 prostate cancer patients underwent prostate MRI including diffusion-weighted imaging (DWI) using b-factors of 0 and 1000 sec/mm2 with a 1.5T MR unit. ADC values were measured from 6 locations in peripheral zone (PZ) and 2 locations in central gland (CG) in normal subjects, and tumor locations of PZ or transition zone (TZ) in patients with prostate cancer. Prostate cancer was diagnosed on combined T2WI, dynamic contrast-enhanced MRI and DWI according to the standard criteria, and tumor location was decided considering the result of biopsy as gold standard.

No significant differences were identified in ADC values among measured subregions in PZ or CG of normal prostate. However, mean ADC values were 1.64 ± 0.27 x10-3 mm2/sec for PZ and 1.26 ± 0.12 x10-3 mm2 /sec for CG, representing a significant difference. In addition, significant positive correlations were identified between ADC values in both PZ and CG regions and subject age (r=0.526, p-3 mm2/sec) and TZ (0.94 ± 0.21 x10-3 mm2/sec) were significantly lower than those of their corresponding normal regions (p<0.0001). Furthermore, significant negative correlations were identified between ADC values in both PZ and TZ cancer and tumor Gleason score (r=−0.283, p=0.0179; r=−0.4, p=0.0225, respectively).

ADC values in both PZ and CG of normal prostate increase with age, and those of prostate cancer in PZ and TZ decrease according to the increase of Gleason score. These results must be taken into consideration when using DWI in diagnosis of prostate cancer.

When using DWI in diagnosis of prostate cancer, changes of ADC values with age and histological grade need to be considered.

Tamada, T, Sone, T, Egashira, N, Jo, Y, Yamamoto, A, Yamashita, T, Imai, S, Fukunaga, M, et al, , et al, , Apparent Diffusion Coefficient Values in Normal and Malignant Prostatic Tissues: Correlation with Age, Zonal Anatomy, and Histological Grade.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5000288.html