Sonographic Scrotal Anatomy

High resolution ultrasound allows an excellent evaluation of the different organs contained in the scrotal sac. The testes are paired organs with smooth surface homogeneous echotexture. The epididymis is usually set on the upper and posterior-lateral aspect of the testis, but anatomical variations exist. The epididymal head is almost isoechoic to testis, while the remaining portions are usually less echogenic. The vas deferens and vessels are identified in the spermatic cord in virtually all subjects. Appendages of the testis and of the epididymis are often recognized. Doppler interrogation allows evaluation of flow characteristics of intratesticular and funicular vessels. This chapter describes the normal appearance of the scrotal content at color doppler ultrasound. Specific topics discussed are ultrasound appearance of anatomical variations of the testis and epididymis and color doppler features of the testicular and extratesticular vessels.