Goubaa Mohamed MD Djerba Tunisia

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This is a 25-year-old female, G2 PO, with a history of one spontaneous first trimester abortions, now seen for a routine obstetrical check-up approximately 12 weeks after her last menstrual period. Physical examination revealed a normal pregnancy.
An ultrasound was performed. What abnormality is present in the fetal head?

Cette Patiente est âgée de 25 ans, G2 PO, avec antécédent d'avortement spontané au premier trimestre, enceinte actuellement à 12 semaines d'aménorrhée et venant faire son examen obstétrical de routine. L'examen physique n'a pas décelé d'anomalie. Une échographie a été réalisée. La tête fotale est anormale !




Abdominal Scan

acrania acranie fetus foetus pregnancy grossesse

acrania malformation bone cranium crâne

Prgnancy acrania

Transvaginal Scan

Acranie grossesse Anencephalia

Acrania Doppler pregnancy

video (Cilck below, cliquez en bas)

Video 1 frontal

video 2 frontal

video 3 frontal

video 4 frontal

video 5 transversal caudal to cranial

Click on the image below
Cliquez sur les images en bas



Video Abdominal and vaginal sonography demonstrates Acrania at 12 weeks gestation. Coronal and sagittal transvaginal US images of the fetal head show an absent cranial vault and an amorphous mass of neural tissue. The facial structures and orbits are present. Note the presence of echogenic free-floating particles in the amniotic fluid. L échographie abdominale et endovaginale, de cette grossesse de 12 semaines, montre une acranie (absence des os de la voûte crânienne). Les coupes frontales et sagittales et les vidéos montrent l'absence des os du crane et le cerveau baigne librement dans le liquide amniotique. Les structures faciales et les orbites sont présents. Notez la présence des particules échogènes libres flottantes dans le fluide amniotique.



diagnosis : Acrania diagnostic : Acranie



cliquez ici


This is a rare anomaly distinct from anencephaly. There is partial or complete absence of the cranial vault. Brain tissue is always present but it may be abnormal. Thus the presence of brain tissue on sonography helps to differentiate from anencephaly.
Acrania is a serious malformation that occurs because of abnormal migration of mesenchymal tissue, which normally covers the cerebral hemispheres. This faulty migration results in the faulty formation of the cranial bones, muscles, and dura mater (7).

Sonography :
The diagnosis of acrania can be established sonographically even in the first trimester if a large mass of disorganized brain tissue covered only by a thin membrane is detected (6). 3-D US may contribute to early detection of fetal acrania (1).
Typically, there is progression in utero from a relatively normal-appearing brain to an amorphous brain mass to no recognizable brain tissue, which is the usual US appearance of anencephaly in the second and third trimesters. In the first trimester, the brain of affected fetuses may appear relatively normal or may demonstrate varying degrees of distortion and disruption (exencephaly). However, the important US feature is an absent cranium, which allows diagnosis from 11 weeks onward (3, 5). At 11-14 weeks gestation, no vault ossification is visible. The absence of cranial ossification may be noted, and the head may appear abnormal. Brain tissue may appear to be unorganized and have irregular echogenicities. A high percentage (90%) of fetuses with acrania had echogenic amniotic fluid (4). The abnormal brain tissue of acrania is destroyed by amniotic fluid exposure and atrophy and becomes the rudimentary brain found in anencephaly.

Differential :
* Large cephaloceles : in cephaloceles, the cranial vault can always be detected and a part of the brain is intracranial.
* Anencephaly : cerebral tissue is completely absent.
* osteogenesis imperfecta and hypophosphatasia (6)

Acrania is a lethal malformation. death of the neonate is unavoidable. Antenatal identification allows the clinician to make appropriate and timely management decisions.

Reference :
* 1: Liu IF, Chang CH, Yu CH, Cheng YC, Chang FM. Prenatal diagnosis of fetal acrania using three-dimensional ultrasound. Ultrasound Med Biol. 2005 Feb;31(2):175-8.
* 2: Fong KW, Toi A, Hornberger LK, Keating SJ, Johnson JA. Detection of fetal structural abnormalities with US during early pregnancy. Radiographics. 2004 Jan-Feb;24(1):157-74.
* 3: Cincore V, Ninios AP, Pavlik J, Hsu CD. Prenatal diagnosis of acrania associated with amniotic band syndrome. Obstet Gynecol. 2003 Nov;102(5 Pt 2):1176-8.
* 4: Cafici D, Sepulveda W. First-trimester echogenic amniotic fluid in the acrania-anencephaly sequence. J Ultrasound Med. 2003 Oct;22(10):1075-9; quiz 1080-1.
* 5: Chatzipapas IK, Whitlow BJ, Economides DL. The 'Mickey Mouse' sign and the diagnosis of anencephaly in early pregnancy. Ultrasound Obstet Gynecol. 1999 Mar;13(3):196-9.
* 6: Weissman A, Diukman R, Auslender R. Fetal acrania: five new cases and review of the literature. J Clin Ultrasound. 1997 Nov-Dec;25(9):511-4. Review.
* 7: Bar-Hava I, Bronshtein M, Ornoy A, Ben-Rafael Z. [First trimester sonographic diagnosis of acrania] Harefuah. 1993 Jun 1;124(11):685-7, 739.