System for estimating sclerosis of in vivo arteries based on ultrasound B-mode image analysis

A new system has been developed for estimating hardening of the carotid artery by B-mode (Brightness-mode) image analysis. The method is based on in vivo stiffness, Eth, calculated from the variation of carotid-duct-diameter with changing of systolic and diastolic blood pressures. In addition from the results of tensile and internal pressure tests using in vitro human and animal arteries specimens, we found a correlation between Eth estimated from radial bulge of artery and mechanical tensile strength. Thus, using a correlation curve a technique for estimating in vivo Eth as well as tensile strength of carotid artery can be predicted. Then, to be a simple routine medical examination, a prototype software was developed, which is capable to measure the diameter changes by the image processing based on 30-image/s and one pixel size data (in case of the report, 0.0713 mm/pixel) of an ultrasound device. The total examination time for both sides of the common carotid arteries was within 300 seconds. To examine the validity of this technique, some clinical data were also shown. The result indicated that the stiffness Eth, strength, and critical burst pressure are useful symptom indices for arterial sclerosis, especially for finding the beginning sclerosis that would start early twenties.