A new predictive modality of cranial bone thickness

The objective of this study was to evaluate A-mode ultrasound in the assessment of cranial bone thickness utilizing an in vivo animal model. A prospective study was performed that identified four standardized calvarial points in 10 Landrace porcine skulls. The individual points were scanned with an A-mode ultrasonic transducer to obtain bone thickness measurements. The same points were measured subsequently using digital calipers for objective comparison. The accuracy of each of the measurement modalities was evaluated for inter- and intrarater reliability. The association between ultrasonic and caliper measurements was evaluated using Student's t-test, Pearson's correlation coefficient, and linear regression models to assess the effect of confounding variables. The mean difference between the ultrasonic and the caliper values was 0.31 +/- 0.22 mm (standard deviation). The statistical analyses employed strongly supported the predictive value of ultrasound as a function of the true calvarial thickness (p < 0.05, r > 0.88, R2 = 0.89). The results suggest that ultrasound is an accurate reflection of cranial bone thickness in an in vivo animal skull model. The development of a portable, noninvasive ultrasonic device can have substantial clinical implications for craniomaxillofacial surgery.