Purpose:
To compare peak enhancement (pe), determined from dynamic contrast-enhanced (dce) magnetic resonance imaging (mri) and the magnetic resonance (mr) directionally-averaged apparent diffusion coefficient () in glandular versus stromal prostatic tissues and, with this comparison, to infer if the hypothesis that gadolinium-dtpa (gd-dtpa) does not enter healthy glands or ducts is plausible.
Materials and methods:
Mri, mr spectroscopic imaging, dce mri and mr diffusion were evaluated in 17 untreated subjects with suspected or proven prostate cancer. pe and were compared in glandular-ductal tissues [normal peripheral zone and glandular benign prostatic hyperplasia (bph)] and stromal-low ductal tissues (central gland/mixed bph and stromal bph).
Results:
The glandular-ductal tissues had lower pe [125+/-6.4 (% baseline)] and higher [1.57+/-0.15 (s/10(-3) mm2)] than the stromal-low ductal tissues [pe=132+/-5.5 (% baseline) (p< .0008), =1.18+/-0.20 (s/10(-3) mm2) (p< 1 x 10(-8))]. a statistical model based upon stepwise regression was generated and completely separated the tissue types: ductal measure = 448+669 x (s/10(-3) mm2)-10.7 x pe (1/%), r2=1.0 and p<8 x 10(-10).
Conclusions:
The very different mr results in the glandular-ductal versus stromal-low ductal tissues suggest that these tissues have different underlying structure. these results support the hypothesis that gd-dtpa does not enter healthy prostatic glands or ducts. this may explain the higher pe and lower that previously have been reported in prostate cancer versus healthy tissue.