Differential diagnosis of scrotal masses by ultrasound.

Ultrasound is the mainstay for imaging of the scrotum. It is used primarily for determining the location and nature of palpable lesions and to demonstrate nonpalpable lesions. Scrotal US is characterized by high sensitivity in the detection of intrascrotal abnormalities and is a very good mode for differentiating testicular from paratesticular lesions. However, scrotal US is limited in determining whether a focal testicular lesion is benign or malignant. The limitations of gray-scale US in the assessment of an acute scrotum and in particular of testicular torsion have now been overcome by color-coded duplex sonography and power Doppler.