Heron Werner, MD & Pedro Daltro, MD
ClÃnica de Diagnóstico por Imagem (CDPI) & Instituto Fernandes Figueira (IFF) – FIOCRUZRio de Janeiro – Brazil
Dorothy I. Bulas M.D.Professor of Radiology and Pediatrics
Children's National Medical Center
George Washington University Medical Center
111 Michigan Ave, NW,  Washington D.C. 20010
Iniencephaly is a malformation that consists in the complex alteration of the embryonic development around the third week. It is characterized by an accentuated retroflexion of the cephalic pole. It is a sequence of rare alterations, where there is a defect of the occipital region that involves the foramen magnum and alterations in the vertebral axis without visualization of the posterior arch. 84 percent of the diseased fetuses present associative anomalies, such as: hydrocephaly, Dandy-Walker malformation, encephalocele, meningocele, diaphragmatic hernia, omphalocele, cardiac anomalies, and anomalies of the aortic arch and of the kidneys, etc. (Isfer, 1996; Romero, 1988). An ultrasonographic diagnosis is necessary when there is no entire visualization of the vertebral column in the longitudinal plane, besides the hyper extension of the fetus’s cephalic pole.