Prostate Cancer : Are There Differences between Native Diffusion-weighted Images and the Apparent Diffusion Coefficient Map in Tumor Detection and Characterization?

Introduction: While recent studies have supported the utility of diffusion-weighted imaging (DWI) in the detection of prostate cancer (PCa), these studies have employed varying methodology for the acquisition, processing, and interpretation of DWI. For instance, these studies have differed in whether the interpreting radiologists reviewed both the native diffusion-weighted images (nDWI) and apparent diffusion coefficient (ADC) maps in a joint fashion [1], only nDWI [2], or only the ADC map [3-5]. Although differences in the relative utility of nDWI and the ADC map have been reported for other organs such as the lung [6] and liver [7], such a comparison has not to our knowledge previously been performed in the prostate. Therefore, the purpose of this study was to compare the visibility of PCa on nDWI and the ADC map as well as to assess the histologic and MRI features of PCa that influence the visibility of tumor foci on these respective image sets.