Scrotal ultrasound is excellent for initial evaluation of the scrotum and can directly demonstrate abnormalities within the testis and the peritesticular structures, such as varicocoeles and epididymal abnormalities, as well as visualising secondary changes caused by distal genital duct obstruction.
It is usually an outpatient procedure performed in the radiology department of a hospital or at a doctor’s office. It is a safe, painless, and noninvasive procedure and does not employ ionising radiation.
A high-frequency (9-15 MHz)linear-array transducer with adequate length for longitudinal measurement of the testis is usually used, except in certain circumstances (e.g. massive hydrocele), when a lower MHz transducer is used.
Patient is kept in supine lying down position (patient may be upright when looking for an inguinal hernia) scrotum is supported on a towel laid over the thighs. The testes should be examined in orthogonal transverse and longitudinal planes, and colour Doppler evaluation and volume measurements should be performed routinely.
Volume measurement is usually calculated as length×height×width×0.51. A total volume (both testes) of >30 ml and a single testicular volume of 12–15 ml is generally considered normal scrotum should be examined for extratesticular masses or processes