Microwave Radiometry Shown to Detect Inflammatory Plaque Activation in Carotid Arteries
May 1, 2012—In the Journal of the American College of Cardiology, Konstantinos Toutouzas, MD, et al published findings from the first in vivo application of microwave radiometry in human carotid arteries for detecting local inflammatory plaque activation (2012;59:1645–1653).
According to the investigators, the study sought to determine whether temperature differences can be measured noninvasively in vivo by microwave radiometry and if they are associated with ultrasound and histological findings.
The background of the investigation is that studies of human carotid artery samples have shown increased heat production and that microwave radiometry allows noninvasive in vivo measurement of internal tissue temperatures.
As detailed in the Journal of the American College of Cardiology, the study was composed of 34 patients undergoing carotid endarterectomy who had been screened for carotid atherosclerosis by ultrasound and microwave radiometry. Healthy volunteers were enrolled as a control group. The investigators analyzed plaque texture, plaque surface, and plaque echogenicity. Temperature difference was defined as maximal minus minimum temperature. A study of the association of thermographic findings with ultrasound and histological findings was performed.
The investigators found that the temperature difference was higher in atherosclerotic carotid arteries (compared with the carotid arteries of patients in the control group; P < .01), fatty plaques (compared with mixed and calcified plaques; P < .01), plaques with an ulcerated surface (compared with plaques that had an irregular or regular surface; P < .01), heterogeneous plaques (compared with homogenous plaques; P < .01), and specimens with a thin fibrous cap and intense expression of CD3, CD68, and vascular endothelial growth factor (compared with specimens with a thick cap and low expression of CD3, CD68, and vascular endothelial growth factor; P < .01).
From this data, the investigators concluded that microwave radiometry provides noninvasive in vivo temperature measurements of carotid plaques, which reflects inflammatory plaque activation.