[Sonography of the scrotum].

Ultrasonography (US) has become the method of choice for imaging in diseases affecting the scrotum. With the development of high resolution transducers using colour Doppler and pulsed Doppler, it is now possible to make accurate diagnoses. Sonography is able to distinguish immediately between intra- and extratesticular lesions. It is also possible to differentiate between cystic and solid tumours. Solid testicular tumours may be detected without difficulty and thus the patient's dignity is practically assured (98 % of solid testicular tumours are malignant). In cases of acute diseases of the scrotum, sonography nearly always permits a differentiation between torsion and inflammation, thus avoiding the risk of unnecessary operations. The review covers the introduction, anatomy, the scanning protocol for scrotal ultrasound and pathological changes. Testicular tumours and torsion are discussed in detail. Variations from the norm and pitfalls are outlined so as to help avoid making misdiagnoses.