- DEFINITION OF CRANIOSYNOSTOSIS
Craniosynostosis is the process of premature sutural closure,
taking place during a period of continuing brain growth; craniostenosis is the result of this process.
The premature fusion of the suture inhibits skull growth perpendicular to the affected sutures,
leading to skull base asymmetry,
cranio-facial asymmetry and limitation of brain growth.
Virchow in 1851 was the first to report the pathophysiology of craniosynostosis.
He recognized that ‘bony expansion ceases in a direction perpendicular to the synostosed suture,
with compensatory expansion in the opposite direction’.
Fig. 2: Virchow’s law.
References: Department of Bio-imaging and Radiological Sciences, Catholic University of Rome - Rome/IT
- CLASSIFICATION OF CRANIOSYNOSTOSIS
Traditionally,
craniosynostosis is classified according to the sutures involved and the association with other malformations.
Fig. 3: Classification of craniosynostosis (1): sutures involved.
References: Department of Bio-imaging and Radiological Sciences, Catholic University of Rome - Rome/IT
Fig. 4: Classification of craniosynostosis (2): association with other malformations.
References: Department of Bio-imaging and Radiological Sciences, Catholic University of Rome - Rome/IT
Fig. 5: Classification of craniosynostosis (3): pansynostosis VS single suture synostosis.
References: Department of Bio-imaging and Radiological Sciences, Catholic University of Rome - Rome/IT
- RADIOLOGICAL ASSESSMENT
HRCT is an excellent method to identify normal sutures of the skull and their premature closure,
allowing to evaluate the skull symmetry and to perform a morphometric analysis of the skull base and vault.
MR imaging allows to assess parenchimal anomalies that could be associated with craniosynostosis (Arnold-Chiari malformation,
hydrocephalus,
defects in the corpus callosum).
Fig. 6: Radiological assessment.
References: Department of Bio-imaging and Radiological Sciences, Catholic University of Rome - Rome/IT
- NORMAL SUTURES ANATOMY
The knowledge of normal suture anatomy is crucial to provide an accurate imaging of calvarial and skull base deformities.
The skull can be divided in FOUR ARCHES all converging on the sphenoidal bone.
Each arch is formed by minor and major sutures.
We named “minor” the sutures extended toward the skull base.
Fig. 7: Anatomy (1): the different arches drawn on the skull.
References: Department of Bio-imaging and Radiological Sciences, Catholic University of Rome - Rome/IT
Fig. 8: Anatomy (2): sagittal arch.
References: Department of Bio-imaging and Radiological Sciences, Catholic University of Rome - Rome/IT
Fig. 9: Anatomy (3): coronal arch.
References: Department of Bio-imaging and Radiological Sciences, Catholic University of Rome - Rome/IT
Fig. 10: Anatomy (4): lambdoid arch.
References: Department of Bio-imaging and Radiological Sciences, Catholic University of Rome - Rome/IT
Fig. 11: Anatomy (5): parieto-squamosal arch.
References: Department of Bio-imaging and Radiological Sciences, Catholic University of Rome - Rome/IT