High-resolution MRI of deep-seated atherosclerotic arteries using motexafin gadolinium.
OBJECTIVE
To evaluate the potential of using motexafin gadolinium (MGd) to characterize atherosclerotic plaques of deep-seated arteries with MRI.


METHODS
We exposed vascular endothelial cells (EC) and smooth muscle cells (SMC) in vitro to varying concentrations of MGd. The fluorescence properties of MGd were then exploited using confocal microscopy to image exposed cells. For an in vivo validation study, we performed surface coil-based and intravascular coil-based high-resolution MRI of the iliac arteries and the abdominal aorta of three atherosclerotic Yucatan pigs. Subsequently, MGd enhancement of the target vessel walls was quantitatively evaluated and MR images were correlated with histology of the target vessels.


RESULTS
The in vitro study confirmed the intracellularization of MGd in both cell types and determined the optimum MGd dosage of 0.004 mmol/kg that produced the sufficiently high intracellular fluorescent intensity. The in vivo study showed a steady increase of MGd enhancement to approximately 25% at three hours postinjection of MGd. MRI showed areas of strong enhancement along the lumen boundary, which corresponded to fibrous tissue seen in histology.


CONCLUSIONS
This study provides initial evidence that MGd may enhance MR vessel wall imaging for the characterization of plaque in deep-seated arteries.
Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Chris
C
Brushett
Bensheng
B
Qiu
Ergin
E
Atalar
Xiaoming
X
Yang
D000818:Animals; D001012:Aorta, Abdominal / Q000473:pathology*; D001161:Arteriosclerosis / Q000175:diagnosis*; D002478:Cells, Cultured; D003287:Contrast Media; D019786:Gadolinium DTPA; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008665:Metalloporphyrins; D013552:Swine
D003287:Contrast Media; D008665:Metalloporphyrins; C437683:motexafin gadolinium; D019786:Gadolinium DTPA