Abstract

Positron emission tomography/magnetic resonance imaging (PET/MRI) allows for the combined use of metabolic or functional imaging information obtained from PET with the anatomical and functional imaging information from MRI. PET/MRI offers several advantages, such as improved local tumor (T) staging due to superior soft tissue resolution of MRI, fewer fusion artifacts compared to PET/computerized tomography (PET/CT) in organs with changing volumes or motion, and reduced exposure to ionizing radiation. Most studies on the use of PET/MRI for prostate cancer have focused on its indications for detecting primary lesions, T staging, and detecting local recurrence. In these indications, PET/MRI presents a better alternative compared to PET/CT or MRI alone. However, there are limited studies on the use of PET/MRI for nodal and metastatic staging in prostate cancer, and it has not demonstrated a significant advantage over PET/CT. There are few clinical studies on the use of PET/MRI in bladder cancer, but it has been shown to have higher accuracy than MRI alone in detecting primary tumors and lymph node or organ metastases. Limited studies on renal cell carcinoma, which is the most common primary kidney malignancy, suggest that PET/MRI holds promise for distinguishing renal lesions. There is insufficient research on the use of PET/MRI for testicular and penile cancers, so these tumors are not covered in the current review.