Jianhui Li MD, Presenter: Nothing to Disclose

Purpose: to study the bioeffect of diagnostic dynamic three-dimensional （3d） ultrasound on ultrastructure of cerebral cells of fetal mice in late pregnancy.

Methods: 30 pregnant mice carrying E16 fetuses were randomly allocated into 6 groups, unexposed group, pseudo-exposed group, 5min-exposed group, 10min- exposed, 20min-exposed and 30min-exposed groups, 5 in each group. Exposed mice were put under the dynamic 3d ultrasound system’s probe for 5 to 30 min. Mice in pseudo-exposed group did not receive ultrasound wave. After birth 10 pups of each group were randomly selected , executed and the right parietal lobes were taken as specimen. The specimen were fixed with glutaraldehyde and osmic acid, and later observed under the transmission electron microscope.

Results: There were no obvious abnormal changes for unexposed group, pseudo-exposed group, 5min-exposed group under transmission electron microscope. 10min-exposed group showed some mitochondrion enlargement, crista breakage，a few apoptosis cells were seen. More abnormal mitochondrion and apoptosis cells were observed in 20min-exposed and 30min-exposed groups.

Conclusion ：Dynamic 3d ultrasound irradiation for more than 10 minutes may result in abnormal  morphological changes of neurons and apoptosis in fetal mouse cerebrum.

The experiment supplies some reference data for dynamic 3D ultrasound obstetrical examination. Long time exposure to fetal brain may lead to some damage.The Principle ALARA is strongly recommended.

Li, J, Bioeffect of Diagnostic Dynamic Three-dimensional Ultrasound on Ultrastructure of Cerebral Cells of Fetal Mice in Late Pregnancy.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11006620.html