gms | German Medical Science

Objective: The diagnosis of caniosynostosis is based primarily on the characteristic head deformity which will develop dependent to the site of suture fusion. In some cases typical features are missing where further imaging is required to differentiate between true craniosynostosis and deformational plagiocephaly which show up as an increasing entity of false positive synostotic findings. To protect infants from radiation, either x-ray or CT-imaging, near- field high frequency ultrasound has been evaluated in the diagnosis of synostotic sutures.

Methods: In an initial study synostotic sutures of 26 infants, aged between 2 and 7 months, were investigated sonographically. Its morphologic characteristics, bony thickness and suture width were analyzed with a high frequency ultrasound system (Siemens Elegra, 7.5 MHz linear scanner) by two independent investigators. The results were correlated to the sonographic findings of 100 healthy infants and compared to CT-imaging. Additionally specimens of fused and non-fused segments were histopathologically analyzed to illustrate the clinical and sonographic findings.

Results: Hyperechogenic bridging or ridging due to osseous thickening in synostotic sutures and hypoechogenic gaps in normal sutures were highly reliable findings sonographically. Partial suture fusion was seen in 21 patients and total fusions in five. Compared to CT-imaging (15 fused sutures, 11 with partial fusion) no synostosis was missed sonographically and its resolution found to be more than two times higher than CT-imaging (0.4 vs. 1 mm).

Conclusions: Ultrasound in the diagnosis of craniosynostosis turned out to be a highly reliable examination tool preventing infants from radiation. Since this initial study a standardized protocol in diagnosing craniofacial deformities has been introduced in our daily practice confirming ultrasound to be quick, easy to handle and less expensive thereby therapeutic implications can be made by this procedure immediately.