The role of ultrasound to evaluate the disorders of sex development: a pictorial essay.

Ultrasonography is usually the first modality used to evaluate patients with disorders of sex development (DSD). To determine the sex in patients with DSD, the following four categories are carefully evaluated: chromosomal, gonadal, anatomical internal genitalia, and external genitalia. However, in the clinical setting, the only information that sonographers have prior to ultrasound examination is the appearance of the external genitalia. The following DSD presentations are commonly observed: (1) male external genitalia present at birth, without testis in the scrotum or with a small penis; (2) female external genitalia present at birth, with an inguinal hernia or clitoromegaly; (3) neonates with ambiguous genitalia at birth; and (4) female or male external genitalia without sexual maturity. In this retrospective study of several clinical cases, we demonstrated an ultrasound-based sex determination approach for these clinical presentations. We found that sonographers evaluated the external genitalia in relation to the distal urethra within the corpus spongiosum and corpus cavernosum and the presence or absence of follicles within the detected gonads to determine the sex of the patient.