mpMRI

Multiparametric MRI (mpMRI) is an imaging approach that combines anatomical and functional MRI sequences to evaluate tissue characteristics, particularly in cancer diagnosis and management. It integrates high-resolution T2-weighted imaging with functional techniques such as diffusion-weighted imaging (DWI) and dynamic contrast-enhanced MRI (DCE-MRI); sometimes magnetic resonance spectroscopy (MRS) is included. The combination improves lesion detection and characterization by providing information on cellularity, vascularity, and tissue architecture.

In the context of the prostate, mpMRI is widely used to detect and localize clinically significant cancers, guide targeted biopsies, stage disease, and inform treatment planning. The interpretive framework is often expressed as PI-RADS, a scoring system that rates lesions from 1 to 5 based on probability of clinically significant cancer. In addition to initial diagnosis, mpMRI is used for staging, assessment of treatment response, and monitoring after focal therapies or radical treatment. It can also be used in other indications and organs, such as liver, kidney, and brain, though protocols and interpretation are more variable; many centers favor bpMRI, a biparametric protocol that omits DCE-MRI to shorten exam time when appropriate.

Advantages include improved detection of significant cancers, precise lesion localization, and the potential to reduce unnecessary biopsies and overtreatment. Limitations include variability in scanner hardware and protocols, dependence on radiologist experience, susceptibility and motion artifacts, contraindications to gadolinium contrast, cost, and limited availability in some settings.

Safety considerations focus on gadolinium-based contrast agents, which carry a risk of adverse reactions and, in some cases, concerns about deposition in tissues; renal function should be assessed and macrocyclic agents may be preferred in patients with kidney impairment.