Comparison of Methods Used for Ultrasonic Examinations of IMT in the Wall of the Carotid Artery Model

The aim of this paper is to compare the results of examinations of the intima-media thickness
(IMT) in the wall of the carotid artery model by means of zero-crossing and correlation
methods. The research was carried out on the elastic artery model (a pipe made of latex), with
the internal diameter of 3, 5 and 8 mm and the wall thickness of 0.75, 1.25 and 2 mm. A numerical
solver was created for the purpose of calculating the fields of ultrasonic beams and
scattered fields under different boundary conditions, different angles and transversal displacements
of ultrasonic beams in respect of the position of the arterial wall. A VED ultrasonic
apparatus was used during the investigations. The frequency of the transmitted ultrasound
was 6.75 MHz. The numerical solver was used for the creation of ultrasonic RF reference signals.
A good conformity was obtained between changing the numerical reference of the IMT
and the results of determining the IMT by both the zero-crossing method and the correlation
method.