Intravascular ultrasound imaging in the assessment of atherosclerotic plaques in rabbit abdominal aorta: comparison with histologic findings.
OBJECTIVE
To examine the correlation between the echogenicity and the components of atherosclerotic plaques in rabbit.


METHODS
The atherosclerotic plaque formation in the abdominal aortas of hyperlipidemic or normolipidemic rabbits was stimulated by inserting polyethylene tubing. Intravascular ultrasound (30-MHz, 4.5 F catheter) investigation was performed at locations in the vessel. The intravascular ultrasound images of the plaques were evaluated and compared with the histologic findings.


RESULTS
Ultrasound images delineated areas showing hyperechoic or hypoechoic ultrasound beams in the plaques. Histologic studies revealed that the hyperechoic areas were closely associated with a dense fibrous extracellular matrix, whereas the hypoechoic areas corresponded to lesions showing a marked accumulation of foamy macrophages or proteoglycan-rich loose myxoid extracellular matrix with smooth muscle cell proliferation.


CONCLUSIONS
A good correlation between ultrasound images and histologic features was observed. These results suggest that intravascular ultrasound imaging could provide useful information for assessing the tissue characteristics of atherosclerotic lesions.
Ochiai
Reiji
R
Department of Radiology, Miyazaki Medical College, Kiyotake, Japan. ochiair@post1.miyazaki-med.ac.jp
Kisanuki
Atsushi
A
Asada
Yujiro
Y
Asato
Mikio
M
Tamura
Shozo
S
Sumiyoshi
Akinobu
A
D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging* / Q000473:pathology; D001161:Arteriosclerosis / Q000000981:diagnostic imaging* / Q000473:pathology; D004195:Disease Models, Animal; D007150:Immunohistochemistry; D009131:Muscle, Smooth, Vascular / Q000000981:diagnostic imaging / Q000473:pathology; D011817:Rabbits; D014463:Ultrasonography