Jun Zhang MD, Presenter: Nothing to Disclose

Qi-yong Guo MD, Abstract Co-Author: Nothing to Disclose

To compare prenatal magnetic resonance imaging (MRI) and ultrasonography (US) for the diagnosis of fetal posterior cranial fossa anomalies.

Images of 67 fetuses (22－39 weeks of gestation, average 30 weeks) with posterior cranial fossa anomalies diagnosed at US were evaluated; in these fetuses, prenatal MR imaging was performed within two days of US. Prenatal US and MR imaging findings were compared with postnatal diagnoses.Postnatal evaluation included follow-up MR imaging, autopy, surgery, computed tomography and physical examination.

In 28 diagnostic cases, US and MR imaging findings were in complete agreement with postnatal diagnoses. MR imaging correctly provided additional information to the US -determined diagnosis in another twenty and correctly changed the US diagnosis in fourteen. The MR imaging- determined diagnosis was incorrect and the US diagnosis was correct in two cases. In five cases, the diagnoses at both US and MR imaging were incorrect when correlated with the postnatal outcome. MR imaging was most valuable in the assessment of anomalies of the posterior cranial fossa .

When a posterior cranial fossa anomaly is detected or suspected at US, MR imaging may demonstrate additional findings that can alert diagnosis and case management, sometimes MR imaging may change the diagnosis of US in complicated pregnancies.

dealing with MR and US 1.5 T superconductive MR unit

Zhang, J, Guo, Q, Fetal Posterior Cranial Fossa Anomalies: Comparison of Magnetic Resonance Imaging and Ultrasonography for Diagnosis.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5014612.html