Cranial Suture Measurement by 2-point Method in Ultrasound Screening of Craniosynostosis

Diagnostic imaging for craniosynostosis currently relies entirely on radiation images, but it has been estimated that a risk of cancer from diagnostic x-rays may exist. Use of ultrasound imaging has been reported, but very little has been written on normal findings of the cranial suture. Also, ultrasound diagnostic methods have not been established. To obtain images for the diagnosis of abnormal sutures in craniosynostosis, we investigated the normal ultrasonographic appearance of the suture. To establish screening methods for craniosynostosis, we prepared a 2-point method for simple evaluation and confirmed its usefulness.

Ultrasonography was performed in infants with normal head, deformational plagiocephaly, and craniosynostosis. We focused on the measurement indices and decided on the order for making our observations. Furthermore, we developed an evaluation method (2-point method) and recorded our finding in a useful table.

We could clearly judge whether the cranial suture was patent or closed and were able to measure the suture width. Even for 2-year-old children, the width of the sutures at the points measured exceeded the echocardiographic resolution. By using the 2-point evaluation method, all the sutures could be inspected in about 2 minutes. Sensitivity was 100% and specificity was 95.1%.

Our present studies showed that normal or abnormal suture can be clearly distinguished by ultrasound. By evaluating the fixed points instead of the whole line, it was possible to shorten the inspection time. Ultrasound screening by applying the 2-point method is very useful.