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Carotid intima-media thickness

Eric de Groot, MD, PhD
John JP Kastelein, MD, PhD, FESC
Raphael Duivenvoorden, MD, PhD
Section Editor
Christopher P Cannon, MD
Deputy Editor
Brian C Downey, MD, FACC


Over the past decades, significant efforts have been made to develop noninvasive atherosclerosis imaging techniques that can serve as a surrogate end point for cardiovascular disease. One of the rationales for atherosclerosis imaging originates from autopsy studies in adolescents and young adults, which have revealed that atherosclerosis is present early in life and precedes the occurrence of cardiovascular events. Consequently, using imaging to detect early atherosclerosis has the potential to predict the risk of future cardiovascular events as well as evaluate cardiovascular drug efficacy. One of the most widely used and best validated atherosclerosis imaging techniques is the carotid intima-media thickness (CIMT) measurement.

The techniques for imaging and measuring CIMT along with the potential clinical applications of CIMT will be discussed. Carotid artery imaging for the detection of significant obstruction carotid disease is discussed separately. (See "Evaluation of carotid artery stenosis".)


CIMT can be imaged using either ultrasound or magnetic resonance imaging, although there is much greater experience and data available with ultrasound imaging.

Imaging acquisition — The large superficial arteries, in particular the carotid arteries (figure 1), can be visualized at high resolution with B-mode (or "brightness" mode) ultrasound using linear array transducers for superficial and vascular structures (frequency ranges 5 to 15 MHz). The resolution obtained with these transducers is on the order of 0.027 mm axially and 0.25 mm laterally. In most scan protocols, carotid ultrasound images are obtained from the near and far walls of the right and left distal common carotid arteries, the carotid bifurcation (image 1), and the proximal internal carotid arterial segments. CIMT in an individual patient is therefore often a composite of intima-media thickness measurements of various arterial segments, sometimes under multiple insonation angles. (See "Basic principles and safety of diagnostic ultrasound in obstetrics and gynecology", section on 'Resolution'.)

Measurement technique — For CIMT measurements, longitudinal images of the carotid arteries are obtained in which the leading edges of the lumen-intima and media-adventitia interfaces (the "double-line pattern") of the arterial wall represent intima-media complex (image 1) [1,2]. Typically, normal common carotid CIMT at age 10 is approximately 0.4 to 0.5 mm, while from the fifth decade of life onward this progresses to 0.7 to 0.8 mm or more.


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Literature review current through: Sep 2016. | This topic last updated: Jan 14, 2016.
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