Autopsy calibration of carotid artery B-mode ultrasound imaging: effects of pressure on residual lumen size.

The accuracy of B-mode ultrasound (9 MHz) vascular imaging was studied on seven carotid arteries obtained at autopsy. Parallel cross-sectional images on five serial planes of each artery were compared with readings on corresponding sections of silicone rubber replicas of the vessel lumens and with histologic sections. A close correlation between ultrasound and cast measurements was observed (r = 0.88, p less than 0.01), and both corresponded well with histologic measurements. Longitudinal ultrasound views of the arteries were employed to determine changes of normal vessel diameter (maximum lumen diameter) and residual lumen diameter with increasing arterial pressure. In the specimens studied, compression of lesions occurred in addition to circumferential vessel enlargement, and the rate of compression of lesions exceeded that of circumferential vessel diameter enlargement.