Comparison of intraarterial MR angiography at 3.0 T with X-ray digital subtraction angiography for detection of renal artery stenosis in swine.
OBJECTIVE
To compare the accuracy of catheter-directed intraarterial (IA) magnetic resonance (MR) angiography at 3.0 T with that of x-ray digital subtraction angiography (DSA) for the measurement of renal artery stenosis (RAS) in swine.


METHODS
Unilateral hemodynamically significant RAS (>50%) was induced surgically in six pigs with use of reverse cable ties. One to two weeks after surgery, each pig underwent x-ray DSA and MR angiography before and after percutaneous transluminal balloon angioplasty (PTA). X-ray DSA was performed before and after PTA of RAS by injection of iodinated contrast agent through a 5-F multiple-side hole angiographic catheter placed in the abdominal aorta under fluoroscopic guidance. MR angiography of RAS was performed before and after PTA of RAS on a 3.0-T clinical MR imager with use of gadolinium-based contrast agent. MR angiography and DSA images were analyzed with the full width at half maximum method. Percent stenosis measurements between x-ray DSA and MR angiography were compared with a paired t test and were correlated with linear regression and Bland Altman analysis (alpha = 0.05).


RESULTS
Six cases of RAS were induced and imaged successfully with DSA and MR angiography techniques before and after PTA. On x-ray DSA, median stenoses was 64% (95% CI 57%-80%) before PTA and 20% (95% CI 5%-32%) after PTA. Corresponding MR angiography median stenosis measurement was 69% (95% CI 58%-80%) before PTA and 26% (95% CI 16%-36%) after PTA. A paired t test comparison did not show a difference between DSA and MR angiography (P = .16). RAS measurements on MR angiography correlated closely (P < .01) with DSA measurements (r(2) = 0.92).


CONCLUSIONS
In swine, the accuracy of catheter-directed IA MR angiography with use of a clinical 3.0-T MR imaging unit for the measurement of RAS was similar to that of conventional x-ray DSA.
Rhee
Thomas K
TK
Department of Radiology, Northwestern University, 448 East Ontario Street, Suite 700, Chicago, IL 60611, USA.
Park
Jonathan K
JK
Cashen
Ty A
TA
Shin
Wanyong
W
Schirf
Brian E
BE
Gehl
James A
JA
Larson
Andrew C
AC
Carr
James C
JC
Li
Debiao
D
Carroll
Timothy J
TJ
Omary
Reed A
RA
D015901:Angiography, Digital Subtraction; D000800:Angioplasty, Balloon; D000818:Animals; D003287:Contrast Media; D007472:Iohexol; D016014:Linear Models; D018810:Magnetic Resonance Angiography / Q000379:methods*; D012078:Renal Artery Obstruction / Q000175:diagnosis* / Q000000981:diagnostic imaging; D013552:Swine
D003287:Contrast Media; D007472:Iohexol