Diffusion‐weighted MRI and its role in prostate cancer

Abstract

In the last 5 years, the multiparametric approach has been investigated as the method for the MRI of prostate cancer. In multiparametric MRI of the prostate, at least two functional MRI techniques, such as diffusion-weighted MRI (DW-MRI) and dynamic contrast-enhanced MRI, are combined with conventional MRI, such as T2 -weighted imaging. DW-MRI has the ability to qualitatively and quantitatively represent the diffusion of water molecules by the apparent diffusion coefficient, which indirectly reflects tissue cellularity. DW-MRI is characterized by a short acquisition time without the administration of contrast medium. Thus, DW-MRI has the potential to become established as a noninvasive diagnostic method for tumor detection and localization, tumor aggressiveness, local staging and local recurrence after various therapies. Accordingly, radiologists should recognize the principles of DW-MRI, the methods of image acquisition and the pitfalls of image interpretation.

High b Value (2,000 s/mm2) Diffusion-Weighted Magnetic Resonance Imaging in Prostate Cancer at 3 Tesla: Comparison with 1,000 s/mm2 for Tumor Conspicuity and Discrimination of Aggressiveness

“…In particular, diffusion-weighted MRI (DW-MRI), which is a functional MR technique that does not use contrast agents, is noninvasive and can easily acquire images with fast image acquisition and high contrast resolution [6]. Image characteristics of DW-MRI are reflected by differences in the rates of water molecule movement in different biologic tissues, and this movement is inversely correlated with tissue cellularity [6]. Therefore, restriction of the water molecule movement, as assessed by DW-MRI, might be a useful indicator of prostate tumor aggressiveness and malignant potential [5], [6].…”

“…Image characteristics of DW-MRI are reflected by differences in the rates of water molecule movement in different biologic tissues, and this movement is inversely correlated with tissue cellularity [6]. Therefore, restriction of the water molecule movement, as assessed by DW-MRI, might be a useful indicator of prostate tumor aggressiveness and malignant potential [5], [6]. In addition, DW-MRI can evaluate differences in water molecule diffusion by qualitative visual assessment using relative signal intensity and also by quantitative assessment by calculating the apparent diffusion coefficient (ADC) [5], [6].…”

“…Therefore, restriction of the water molecule movement, as assessed by DW-MRI, might be a useful indicator of prostate tumor aggressiveness and malignant potential [5], [6]. In addition, DW-MRI can evaluate differences in water molecule diffusion by qualitative visual assessment using relative signal intensity and also by quantitative assessment by calculating the apparent diffusion coefficient (ADC) [5], [6]. Although the ADC represents capillary perfusion and diffusion characteristics, use of a large b value can reduce the influence of capillary perfusion [7], [8].…”

Improving non-invasive detection of prostate cancer using diffusion-weighted MRI

“…Over the past number of years, the application of DW-MRI has progressed to include both diagnostic and prognostic roles in oncology. Its benefits include speed of acquisition (1-5 minutes to perform) and excellent soft tissue definition without the requirement of intravenous or oral contrast media [13] . It also provides qualitative and quantitative information that is used in the assessment of various tumours [14] .…”

Molecular Imaging is the Key Driver for Clinical Cancer Diagnosis in the Next Century!

“…Functional imaging by magnetic resonance (MR), such as MR spectroscopy (MRS) and Diffusion Imaging (MR-DWI), could be perfectly applied into clinic on breast and prostate cancer [4][5][6]. A promising example is the molecular imaging study of calcium sensing receptor (CaSR) expression on breast cancer [7].…”