Imaging of disorder of sex development

Disorders of sex development (DSDs), formerly termed ambiguous genitalia, are a group of conditions where the external genitalia appear abnormal. It represents a true medical and social emergency that needs a multidisciplinary team approach for elucidation. The pediatric radiologist plays an important role in defining the genital anatomy that remains one of the most important factors in sex determination, in addition to chromosomal analysis.

A retrospective study, conducted between January 1995 and December 2010.

Imaging studies (ultrasound, genitogram, and/or magnetic resonance imaging) were performed in patients with ambiguous genitalia, confirmed by chromosomal analysis and appropriate hormonal investigations.

The sensitivity of ultrasound is 89.5%, while its specificity reaches 100%. Retrograde genitogram is more invasive and less sensitive, as the yield of determining the presence of a uterus +/- vagina is 84.2%. However, magnetic resonance imaging (MRI) is more sensitive for gonadal tissue identification. Its specificity reaches up to 100% and can provide detailed internal structures (uterus, fallopian tubes, and gonads).

Ultrasound examination is still the main modality of choice for screening patients with ambiguous genitalia. It is cheap and readily available everywhere. In addition to elucidating the uterus in 89.5%, it can also give more information on the adrenal glands. However, genitography is good--84.2% in elucidating genital anatomy--but it gives no information of the gonads and it is time consuming and invasive. MRI is helpful in cases with equivocal ultrasound, reaches 100% in elucidating internal extractor, and therefore could be reserved for that.