Intravascular ultrasound imaging of atherosclerotic renal arteries: comparison between in vitro and in vivo studies.
BACKGROUND
Intravascular ultrasound (IVUS) imaging, a new modality, may be feasible and useful for the assessment of atherosclerotic renal arteries. However, comparison between in vivo and in vitro studies to confirm pathological changes corresponding with IVUS findings obtained from renal arteries was not fully evaluated.


METHODS
We evaluated ultrasound images of 18 post-mortem human renal arteries and cross-sectional IVUS images of main renal arteries in five patients with renal artery stenosis (RAS) or essential hypertension.


RESULTS
In vitro studies have shown that renal-artery images had three layers when the arteries had fibrous intimal thickening and medial hypertrophy. Renal arteries, in which the fibrous intima was not well developed, showed circumferentially homogeneous bright echoes. In patients with atherosclerotic RAS and essential hypertension, IVUS images showed hyperechoic areas in the renal arterial walls, probably due to atherosclerosis. Typical three-layered ultrasound appearance was not easily seen during in vivo studies.


CONCLUSIONS
Our findings suggest that hyperechoic images can be a diagnostic clue of atherosclerosis However, in vitro results do not always correspond exactly to in vivo findings, and caution is needed when findings from in vitro IVUS imaging studies are applied to in vivo studies.
Yasuda
G
G
Second Department of Internal Medicine, Yokohama City University School of Medicine, Yokohama, Japan.
Takizawa
T
T
Takasaki
I
I
Shionoiri
H
H
Umemura
S
S
Shimoyama
K
K
D000293:Adolescent; D000368:Aged; D001161:Arteriosclerosis / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000000981:diagnostic imaging / Q000473:pathology; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D012077:Renal Artery / Q000000981:diagnostic imaging* / Q000473:pathology; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging / Q000473:pathology; D018084:Ultrasonography, Interventional