Thyroid nodules cannot be accurately characterised using grey-scale US or colour-Doppler US.

No abstract

Injury to the penis may result from penetrating or nonpenetrating trauma. Nonpenetrating injury to the erect penis can produce albugineal tear, intracavernous hematoma or extraalbugineal hematoma from rupture of the dorsal vessels. Nonpenetrating injury to the flaccid penis usually follows blunt perineal traumas producing extratunical or cavernosal haematomas, or cavernosal artery tear followed by high flow priapism. Differential diagnosis between albugineal tear and other penile injuries must be obtained as soon as possible, since early surgical repair of albugineal tear reduces significantly the rate of postraumatic curvature and fibrosis. Ultrasonography (US) is able to detect the exact site of the tear in most patients as an interruption of the thin echogenic line of the tunica albuginea. Other imaging techniques are rarely required in the clinical practice. Color Doppler US is the imaging modality of choice to evaluate patients with high flow priapism. Focal or diffuse cavernosal fibrosis can be identified with US as echogenic areas in the cavernosal bodies. Postraumatic erectile dysfunction can result from fibrotic changes, nerve and vascular impairment or both. Doppler evaluation of penile vasculature is required in young patients with postraumatic impotence before surgical revascularization procedures.

A number of surgical procedures that significantly change the penile anatomy and vasculature can be used to manage pathologic conditions of the penis (eg, congenital and acquired deformities, erectile dysfunction, priapism). Phallic reconstruction surgery can be used for sex reassignment and after penile amputation or for correction of congenital malformations. Color Doppler ultrasonography (US) clearly depicts the normal penile anatomy and postoperative changes (eg, changes of the tunica albuginea, extraalbugineal pathologic fluid collections, cavernosal tissue changes produced by scars and fibrosis). It is also effective in evaluating surgery-related complications and determining the causes of erectile dysfunction and other unsatisfactory long-term results. Moreover, color Doppler US of the penile vessels and vascular anastomoses following revascularization allows direct evaluation of flow characteristics, shunt patency, and venous engorgement. Color Doppler US is the imaging modality of choice in evaluating patients who have undergone penile surgery.