[Magnetic resonance imaging in the evaluation in utero of Siamese twins].

The authors report a case of twins conjoined at the umbilicus and diagnosed by ultrasound after 19 weeks of amenorrhoea in whom an assessment in utero was carried out using magnetic resonance imaging after the patient had been curarized. A review of the literature on this very difficult problem of conjoined twins has given us the possibility to assess the diagnostic measures as well as the prognosis of this pathology. In particular we point out the results that can be obtained using MRI in utero during the second and third trimesters of the pregnancy.