Prenatal demonstration of normal variants of the pericallosal artery by 3D ultrasound.

PURPOSE: To demonstrate the different normal variants of the fetal pericallosal artery (PCA) with the different branching forms of callosomarginal artery (CMA) by three-dimensional glass body-rendering.

MATERIALS AND

METHODS

With the use of the glass body mode (grey scale ultrasound and color or power Doppler), 3-D ultrasound permits precise imaging of the fetal pericallosal artery, an important anatomic landmark of the corpus callosum. This rendering mode enabled us for the first time to demonstrate sonographically the origin, course and branching pattern of the pericallosal artery with the callosomarginal artery.

RESULTS

In 452 fetus between 18 and 41 weeks of gestation 5 variants of branching of the fetal A. callosomarginalis from the pericallosal artery were found using three-dimensional ultrasonography. The CMA was absent in 36.06 % of the 452 fetal brains studied. In 63.94 % the CMA was present and arose from four different segments of the anterior cerebral artery (ACA) from the A3 segment in 59.17 %, from the A2 segment in 20.7 %, from the A4 segment in 13.15 % and from the A1 segment in 7.61 % of the cases.

CONCLUSIONS

The use of 3-D power Doppler sonoangiography enables the precise demonstration of the normal variants of the fetal pericallosal artery with different origins of the callosomarginal artery. The knowledge of normal variants helps to detect pathological forms of the pericallosal artery.