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BACKGROUND Calculation of intracranial volume from neuroimaging can be complex and time consuming. In the adult population, there is evidence suggesting that owing to its strong correlation, head circumference (HC) may be used as a surrogate for intracranial volume (ICV). We were interested in studying the correlation between HC and ICV in patients with craniosynostosis. METHODS After institutional review board approval, a retrospective review was performed on patients with craniosynostosis. GE Healthcare AdW 4.3 volume assessment software was used to calculate ICV and HC based on preoperative computed tomographic scans. Pearson correlation was used to estimate correlation coefficients between ICV and HC for this patient population, with 0 to 0.3 considered a weak correlation, 0.4 to 0.6 considered a moderate correlation, 0.7 to 1 considered a strong correlation, and P < 0.05 was considered statistically significant. RESULTS A total of 196 craniosynostosis patients were included in this study. There were 121 male and 75 female patients. Seventy-nine patients had metopic, 45 had coronal, 64 had sagittal, and 8 had lambdoid synostosis. Mean age was 8.2 months. Mean HC and ICV were 42.9 cm and 829 cm, respectively. Overall, there was a strong correlation between HC and ICV (r = 0.81). Patients were further categorized by craniosynostosis type. Very strong correlation was obtained for patients with coronal (0.89), metopic (0.98), and lambdoid craniosynostosis (0.97). Strong correlation was obtained for patients with sagittal synostosis (0.73). When categorized by sex, a stronger correlation was obtained for female patients (0.84) compared with male patients (0.80). Statistical significance was reached for all reported correlations. CONCLUSION Our preliminary data suggest that a very strong correlation exists between HC and ICV for male and female patients with all types of craniosynostosis, making HC a useful surrogate for ICV in this patient population.

BACKGROUND The aims of the current analysis were to study the change in ventricular volume (VV) obtained with cranial distraction in patients with craniosynostosis and compare it with the change in total intracranial volume (ICV) and brain volume. METHODS After institutional review board approval, a retrospective review was performed on patients undergoing cranial distraction over a 5-year period. GE Healthcare AdW 4.3 volume assessment software was utilized to calculate preoperative and postdistraction ICV, VV, and whole-brain volume. Data were also collected on patient demographics, age at the time of distraction, time spent in distraction and consolidation, and length of stay. t Tests were used for comparison. RESULTS Twenty-three patients met our inclusion criteria. Forty-eight percent of patients (n = 11) had right-sided cranial distraction, 30% (n = 7) had bilateral distraction, and 22% of patients (n = 5) had left-sided distraction. At the preoperative stage, mean head circumference was 42.5 ± 4.7 cm, mean ICV was 810.1 ± 27 cm, mean non-VV (NVV) was 796.2 ± 268 cm, and mean VV was 13.9 ± 9 cm. After a mean of 27.4 mm of distraction, occurring over a mean of 26 days and consolidation period of 149 days, a second computed tomography scan was obtained. Mean postdistraction head circumference was 49.1 ± 3.9 cm, mean ICV was 1074.1 ± 203 cm, mean NVV was 1053.5 ± 197 cm, and VV was 20.6 ± 14 cm. Mean % increase in ICV at this stage was 47.4%; mean % NVV increase was 48.5% as opposed to 60.3% increase in VV. CONCLUSIONS Cranial distraction is known to effectively increase ICV. Our study suggests that the effect of this volumetric increase is much more pronounced on the VV compared with the brain volume. Further studies are underway to investigate whether this short-term marked increase in VV is sustained over a long-term period.