Intravascular ultrasound and magnetic resonance imaging in the assessment of atherosclerotic lesions in rabbit aorta. Correlation to histopathologic findings.
OBJECTIVE
The authors compare the usefulness of intravascular ultrasound (IVUS) and magnetic resonance imaging (MRI) for quantitation of atherosclerosis in hyperlipidemic rabbits, correlated with histopathology.


METHODS
Magnetic resonance imaging with T1- and T2-weighted spin echo sequences and three-dimensional time-of-flight MR angiography of the abdominal aorta was performed on seven rabbits using a 1.5 T MR imager and a standard head coil. X-ray angiography and IVUS examination (3.5 F/30 MHz imaging catheter) was performed via carotid artery access.


RESULTS
Time-of-flight MR angiography source images provided the best resolution and plaque-lumen contrast in visual comparison between the different MRI sequences. Intra- and interobserver reproducibilities of the lesion thickness and area measurements were similar in IVUS and MRI (Pearson correlations 0.52-0.97; P < 0.01). The measurements from IVUS and MRI correlated closely with each other as well as with those made from histopathologic specimens (Pearson correlations 0.50-0.79; P < 0.001). The measurements from IVUS were somewhat more accurate than those made from MRI.


CONCLUSIONS
Both MRI and IVUS with clinically available imaging equipments are feasible and accurate for the quantitation of experimental atherosclerosis of rabbit aorta.
Department of Clinical Radiology, Kuopio University Hospital, University of Kuopio, Finland.
H I
HI
Manninen
R L
RL
Vanninen
M
M
Laitinen
H
H
Räsänen
P
P
Vainio
J S
JS
Luoma
T
T
Pakkanen
H
H
Tulla
S
S
Ylä-Herttuala
D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000473:pathology; D001018:Aortic Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D001161:Arteriosclerosis / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D006949:Hyperlipidemias / Q000150:complications / Q000473:pathology; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D015588:Observer Variation; D011817:Rabbits; D018084:Ultrasonography, Interventional