Integrated backscatter analysis identified atheromatous regions in 63% of myocardial infarction patients and 29% of high-risk middle-aged subjects, compared to 11% in low-risk subjects.
Observational
Can quantitative ultrasonic tissue characterization using integrated backscatter analysis identify high-risk atherosclerotic alterations in human carotid arteries?
Integrated backscatter analysis with carotid ultrasonography can identify high-risk atherosclerotic plaques in individuals with early-stage disease, providing prognostic information beyond conventional B-mode imaging.
Absolute Event Rate: 63% vs 11%
BACKGROUND: Recently, ultrasonic tissue characterization of the composition of plaques has been performed in a quantitative fashion on the basis of integrated backscatter (IBS) analysis, but most of those studies have used high-frequency ultrasound to obtain microscopic images. METHODS AND RESULTS: We performed B-mode measurement and IBS signal analysis with acoustic densitometry with a 7.5-MHz linear-array transducer in freshly excised human aortas (n=58) (normal, atheromatous, and fibrous tissue) obtained at autopsy. Atheromatous and fibrous tissue had a similar intima-media thickness (IMT), but the IBS value in atheromatous specimens was lower than that in fibrous specimens. We further applied this method to human carotid ultrasonography. The subjects were young (80 regions), middle aged with 1 or no coronary risk factors (low risk) (120 regions), middle aged with >/=2 coronary risk factors (high risk) (240 regions), or elderly (80 regions) or were patients with myocardial infarction (MI) with multivessel disease (90 regions). The IMT was similar in middle-aged, elderly, and MI subjects. In contrast, the IBS value was significantly higher in elderly subjects and lower in high-risk middle-aged and MI subjects compared with that in low-risk middle-aged subjects. The percent of regions diagnosed as atheromatous (IBS less than mean minus 2-SD value of IBS in young subjects) was 11% in low-risk middle-aged subjects, 29% in high-risk middle-aged subjects, and 63% in the MI group. CONCLUSIONS: In conjunction with conventional B-mode imaging, IBS analysis with carotid ultrasonography appeared to provide prognostic information to identify a high-risk group with systemic atherosclerosis, which could lead to coronary heart disease in individuals with early-stage disease.
Takiuchi et al. (Tue,) conducted a observational in Systemic atherosclerosis. Integrated backscatter (IBS) analysis vs. Low-risk middle-aged subjects was evaluated on Percent of regions diagnosed as atheromatous. Integrated backscatter analysis identified atheromatous regions in 63% of myocardial infarction patients and 29% of high-risk middle-aged subjects, compared to 11% in low-risk subjects.