An MRA study of vascular stenosis in a pig model using CH3-DTPA-Gd (NMS60) and Gd-DTPA.
OBJECTIVE
This study used an experimental arterial stenosis model in pigs to evaluate the utility of a new medium-weight MRI contrast agent, NMS60 (a synthetic oligomeric Gd complex containing three Gd(3+) atoms, molecular weight of 2158 Da) compared to Gd-DTPA for contrast-enhanced MRA.


METHODS
We used six male white hybrid pigs. Under anesthesia, one femoral artery was exposed and an inflatable cuff placed around it. The cuff was tightened around the vessel until 80-90% stenosis was achieved using digital subtraction angiography as a guide. Animals were then immediately transferred to the MRI scanner and images acquired pre- and postcontrast injection (0.1 or 0.2 mmol Gd/kg Gd-DTPA or NMS60, as a rapid bolus) using high-resolution and dynamic MRA.


RESULTS
The dynamic MRA scans acquired during contrast bolus injection clearly showed the stenosed femoral artery as a segment of close to zero enhancement during the arterial phase of the bolus transit, while on the high-resolution scans the stenosis was difficult to detect due to venous signal contamination. The signal-to-noise at peak enhancement on the dynamic scans was significantly greater with 0.1 mmol Gd/kg NMS60 compared to 0.1 mmol Gd/kg Gd-DTPA (14.6 vs. 9.9, P < .05) and not significantly greater than 0.2 mmol Gd/kg (14.6 vs. 12.8).


CONCLUSIONS
This new medium-weight contrast agent demonstrated significantly greater enhancement than Gd-DTPA and may be valuable to aid detection of vascular stenosis in humans.
D'Arceuil
Helen E
HE
Lucas MRS/I Center, Department of Radiology, Stanford University, Stanford, CA 94305-5105, USA. helen@nmr.mgh.harvard.edu
de Crespigny
Alexander J
AJ
Pelc
Lorie
L
Howard
Diane
D
Alley
Mark
M
Seri
Shigemi
S
Hashiguchi
Yuji
Y
Nakatani
Akira
A
Moseley
Michael E
ME
D015901:Angiography, Digital Subtraction / Q000379:methods; D000818:Animals; D001157:Arterial Occlusive Diseases / Q000175:diagnosis* / Q000503:physiopathology; D003251:Constriction, Pathologic / Q000503:physiopathology; D003287:Contrast Media / Q000008:administration & dosage; D004195:Disease Models, Animal; D005263:Femoral Artery / Q000503:physiopathology*; D019786:Gadolinium DTPA; D007091:Image Processing, Computer-Assisted / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D009942:Organometallic Compounds; D013552:Swine; D013997:Time Factors
D003287:Contrast Media; C403805:NMS60; D009942:Organometallic Compounds; D019786:Gadolinium DTPA