2008-01-09-23 Sirenomelia © Werner www.thefetus.net/
Heron Werner, MD.
Clínica de Diagnóstico por Imagem – CDPI, Rio de Janeiro, Brazil.
Lethal malformation characterized by lower extremity fusion and association with other skeletal abnormalities and gastrointestinal and genitourinary malformations. The most common signs are fused lower extremities, anhydramnios due to bilateral renal agenesis and pulmonary hypoplasia.
We report a case that was difficult to evaluate by ultrasound due to anhydramnios, but fetal MRI could help to evaluate lower extremities and confirm the bilateral renal agenesis in 26 weeks gestation.
Images 1, 2: 2D images showing an anechoic mass close to the fetal head (red arrows). Note the anhydramnios and the difficulty to evaluate the lower extremities.
Images 3, 4: Image 3 shows a 3D image of a mass close to the fetal head (red arrows). Image 4 shows fused lower extremities with the visualized femur.
Images 5, 6: MRI (T2-weighted) shows absence of a normal lumbosacral spine.
Images 7, 8: MRI (T2-weighted) shows absence of a normal lumbosacral spine.
Images 9, 10: MRI (T2-weighted) shows fetal head and face.
Images 11, 12: Postnatal images. The single fused lower extremity can be seen.