P.075 Tissue Characterization of Carotid Wall in Mildly Diseased Arteries: Comparison of Videodensitometric Analysis and Integrated Backscatter

Abstract

Background

Integrated backscatter analysis (IBS) is the reference technique for tissue characterization by ultrasound. However, this approach is equipment-dependent, so that its practical use on wide-scale basis is limited. By contrast, videodensitometric analysis (VDA) on 2D images can be performed on standard recordings.

Aim of the study

To compare results of VDA against IBS on common carotid artery wall (CCA) in a study population including normal subjects and patients with cardiovascular risk factors.

Methods

Sixty subjects (fifty males, age 49 ± 11) referred for diagnostic carotid scan, were studied by high resolution system (7.5 MHz linear probe) implemented with acoustic densitometry package for IBS assessment. Diastolic CCA images were acquired bilaterally in 2D mode and IBS. IBS and VDA were performed in regions of interest including the intima-media (IMT), one cm before the flow divider.

Results

On 120 arteries (average IMT 0.71 ± 0.29 mm), mean IBS value (dB) was directly related to mean gray levels (r = 0.357, p< 0.001). Mean gray levels and their standard deviation correlated each other (r = 0.71, p<0.0001). A significant relation (p<0.05) with age was found for IMT (direct, r = 0.25) and mean IBS (inverse, r = -0.22), but not for mean gray levels.

Conclusion

VDA of CCA IMT may represent an acceptable surrogate estimate for tissue characterization, of possible interest for multicentre studies. The inverse relation of mean IBS value with age is in keeping with the hypothesis of an age-related atheromasic deposition. IBS may have higher sensitivity in differentiating early atherosclerosis from “healthy” arterial aging.