The Epididymis: An Ultrasound Primer-What the Radiologist Needs to Know

The epididymis, a crucial component of the male reproductive system, plays a pivotal role in sperm maturation, transport, and storage. It can be affected by a diverse spectrum of pathologies, including congenital anomalies, infectious and inflammatory diseases, cystic and neoplastic lesions, and traumatic injuries. These conditions can present with overlapping clinical symptoms such as scrotal pain, swelling or infertility, making imaging essential for accurate diagnosis and appropriate management. Ultrasound is the primary imaging modality for evaluating epididymal abnormalities due to its high resolution, real-time capabilities, and lack of ionizing radiation. Doppler ultrasound enhances diagnostic precision by assessing vascularity, particularly in inflammatory and neoplastic conditions. Magnetic resonance imaging provides superior soft tissue contrast and is useful for characterizing complex or indeterminate lesions, while computed tomography is primarily reserved for staging malignancies or evaluating severe trauma. This pictorial review aims to provide an overview of epididymal pathologies by correlating clinical presentation with multimodal imaging findings, predominantly with the use of ultrasound. Emphasis is placed on characteristic imaging features that facilitate differentiation between benign and malignant conditions, guiding radiologists in forming accurate differential diagnoses. By illustrating key pathologic entities, this review seeks to enhance diagnostic confidence and improve clinical decision-making in the assessment of epididymal disorders.