Not always a perfect match: discrepancies between PSMA PET/CT and MRI in prostate cancer diagnosis and staging

Magnetic resonance imaging (MRI) and prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) are increasingly used together in patients with suspected or confirmed prostate cancer (PCa). Discordant findings are common because these modalities evaluate different biological and anatomical aspects of the disease. MRI is best suited for intraprostatic lesion detection and local staging, whereas PSMA PET/CT is superior for assessing nodal and distant metastases and may also contribute to selected diagnostic pathways. This review explains the reasons for these discrepancies, discusses their clinical implications, and provides practical guidance for interpreting and managing discordant findings.