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.