Does MRI add to ultrasound in the assessment of disorders of sex development?

Objective: The objective of the study was to evaluate the need of magnetic resonance imaging and using different approaches (transabdominal, endoluminal and transperineal) in the proper assessment of disorders of sex development regarding gonadal detection and gender differentiation.
Subjects and Methods: Twenty five patients with abnormalities of sex disorders were included. They were classified into two groups according to the time of clinical presentation: Group 1 (early onset) included eight cases. Their age ranged from one month to 12 years (mean age=3.0). They presented with overt genital ambiguity of clitoral hypertrophy in a phenotypic female, non palpable testes or micropenis in a phenotypic male. Group 2 (late onset) included 17 cases. Their age ranged from 16 to 33 years (mean age 18.1). This group presented by distressing puberty symptoms of primary amenorrhea in a female phenotype or undescended testis and behaving as a male. Cases were subjected to Ultrasound and MR imaging examinations. Imaging results were correlated results of chromosomal and hormonal assays as well as laparoscopy findings.
Results: The study included: 10/25 cases (40%) of female pseudo-hermaphroditism, 13/25 cases (52%) of male pseudo-hermaphroditism, one case (4%) of true hermaphroditism and one case (4%) of pure gonadal dysgenesis. The accuracy of multi approach ultrasound was 89.8% compared to 85.7% in MR imaging.
Conclusion: Ultrasound should be considered the initial screening modality in the assessment of developmental sex disorders. MRI examination could be reserved for gonad identification when ultrasound examination fails to do so and for corrective surgery guidance.
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