Neuroimaging in the Craniosynostoses

Growth restriction occurring at stenosed sutures leads to compensatory growth at adjacent open sutures, resulting in fairly predictable craniofacial phenotypes. Following clinical assessment, imaging evaluation is performed to define the site and extent of craniosynostosis, to determine the presence or absence of underlying brain deformation or malformation and to evaluate pre- and postoperative complications of craniosynostosis. Imaging techniques may include focused US of the involved sutures if suspicion of isolated metopic, lambdoid or sagittal synostosis. Ultra-low-dose (20–30 mAs) CT with three-dimensional reformatted images is utilized to evaluate the hemi-ring, skull base synchondroses, and foramina and foramen magnum in more complicated, syndromic, or preoperative cases. Evidence for intracranial hypertension may be seen on brain CT or MRI both pre- and postoperatively, associated with sinovenous occlusion, hydrocephalus, and Chiari 1 malformations. Anomalous or vigorous collateral venous drainage may be mapped preoperatively with CTV or MRV.