Increasing Bandwidth of Ultrasound Radio Frequency Echoes Using Wiener Filter for Improvement of Accuracy in Measurement of Intima–Media Thickness

It is very important to make early diagnoses of atherosclerosis for the prevention of lifestyle-related diseases. The intima–media thickness (IMT) is used as a diagnostic index of cerebrovascular diseases and atherosclerosis throughout the body including the coronary artery. In the field of the medical diagnostics, ultrasonic equipment using a pulse–echo method is widely used. In conventional ultrasonic diagnostic equipment, ultrasonic images are obtained by receiving ultrasonic echoes and converting their amplitudes into brightness. In general, ultrasonic B-mode images are degraded by the narrow-band characteristics of the ultrasonic transducer. In the present study, a method was proposed for shortening the lengths of the received ultrasonic pulses from an object of interest using a Wiener filter. As a result, the lengths of ultrasonic pulses were shortened and the visibility of interfaces of the intima–media complex of the carotid arterial wall was improved by the proposed method, which realizes accurate measurement of the IMT.