Computerized tomography of cranial sutures. Part 2: Abnormalities of sutures and skull deformity in craniosynostosis.

Preoperative computerized tomographic (CT) scans of 24 children who had surgery for either single or multiple craniosynostoses were compared with skull radiographs and operative and pathological findings. In addition to providing accurate imaging of calvarial and skull base deformities secondary to premature suture closure, high-resolution CT with bone definition algorithms supplied valuable detail of anatomical changes at the abnormally developed suture. The CT findings varied with the location of the suture. Thickened bony ridges predominated at the sagittal suture, focal bone thickening and erosions were more likely to be found at the metopic suture, and parasutural sclerosis was the prevalent finding on one side of the lambdoid suture. No evidence of the suture could be detected in the majority of patients with complete coronal craniosynostosis. Radiographs of the skull were shown to be a relatively insensitive means of imaging the zone of limited fusion, especially the lambdoid suture. An excellent correlation was found between the CT scan and the operative and pathological findings. There was histological evidence of progressive suture fusion in virtually all patients. An asymmetrically narrowed lucent zone with parasutural sclerosis or bony ridges seen on CT scans correlated well with fibrous union of the suture found on histological examination. The authors conclude that high-definition CT used in conjunction with bone windows and thin and coronal slices for the evaluation of sagittal sutures is a useful imaging method for the evaluation of craniosynostosis.