Prostate multiphase imaging refers to a diagnostic radiological technique that utilizes multiphase contrast-enhanced imaging, often with Magnetic Resonance Imaging (MRI) or Computed Tomography (CT), to evaluate the prostate gland with high anatomical and functional detail. This imaging approach is particularly useful for detecting, characterizing, and staging prostate cancer, one of the most common cancers in men worldwide. The "multiphase" term refers to the acquisition of images during different phases of contrast enhancement—typically including non-contrast, arterial, venous, and delayed phases—which allows radiologists to assess the dynamic behavior of prostate tissues and any associated lesions. In prostate MRI, the multiphase protocol is often integrated into a multiparametric MRI (mpMRI) study, which combines T2-weighted imaging, diffusion-weighted imaging (DWI), dynamic contrast-enhanced imaging (DCE), and sometimes spectroscopy. The dynamic contrast-enhanced (DCE) portion, which is most relevant to the concept of multiphase imaging, tracks the movement of contrast agent through the prostate vasculature over time, helping to differentiate benign from malignant tissue based on vascular characteristics. Cancerous tissue typically shows early and rapid uptake of contrast followed by washout, while benign tissue may enhance more slowly and less intensely. This vascular pattern provides valuable information for tumor localization, especially in areas where traditional imaging may not clearly define lesions. In addition to detecting cancer, prostate multiphase imaging helps in assessing extraprostatic extension, seminal vesicle invasion, and lymph node involvement, all of which are important for staging the disease and determining treatment strategies. It also plays a vital role in active surveillance, guiding biopsies, evaluating recurrence after treatment, and planning for focal therapies like high-intensity focused ultrasound (HIFU) or radiotherapy. In contrast-enhanced CT, although less commonly used due to inferior soft tissue resolution compared to MRI, multiphase protocols can be used in staging advanced prostate cancer, especially to assess nodal or osseous metastases. Multiphase imaging is also useful in evaluating benign prostatic hyperplasia (BPH), prostatitis, and other inflammatory or infectious conditions, especially when complicated by abscesses or anatomical anomalies. Despite its utility, prostate multiphase imaging is not without limitations. It requires intravenous contrast, which may be contraindicated in patients with renal insufficiency or contrast allergies. The need for precise timing, high temporal resolution, and patient cooperation (especially during MRI) can pose technical challenges. Furthermore, interpretation requires significant expertise and standardized reporting systems such as PI-RADS (Prostate Imaging Reporting and Data System) to ensure consistent evaluation and communication of findings. Recent advancements, including AI-assisted interpretation and improved MRI protocols, continue to enhance diagnostic accuracy and reduce variability. In conclusion, prostate multiphase imaging is a crucial component in the modern diagnostic armamentarium for prostate disease. It offers valuable anatomical and functional information that improves the detection, characterization, and management of prostate conditions—particularly prostate cancer—allowing for better patient outcomes through more accurate diagnosis, staging, and monitoring. As imaging technology continues to evolve, prostate multiphase imaging will likely become even more integrated into precision medicine and personalized treatment planning for men’s health. https://prostatemultiphase.ca/