Prostate MRI is a fundamental tool for the diagnosis and characterization of prostate lesions. According to the PI-RADS v2.1 guidelines, a multiparametric prostate MRI (mpMRI) examination of the prostate must include high-spatial-resolution T2-WI, DWI with a high b-value and corresponding ADC map, and a dynamic T1-weighted sequence acquired during the intravenous administration of a paramagnetic contrast agent (DCE). The DCE sequence is essential for assessing the presence of early contrast enhancement in the context of focal peripheral zone lesions with indeterminate characteristics on diffusion imaging. However, the intravenous administration of a paramagnetic contrast agent entails additional costs and potential risks for patients.

On the other hand, the "Arterial Spin Labeling" (ASL) technique is a non-invasive perfusion technique that uses water protons as endogenous tracers, without contrast agents. By inverting the longitudinal T1 magnetization of protons and subtracting images with and without labeling, it is possible to obtain a quantitative measurement of tissue perfusion.

This study focuses on evaluating the potential role of arterial spin labeling (ASL) as an alternative to dynamic contrast enhancement (DCE) in the assessment of peripheral zone prostatic lesions on MRI.