PURPOSE: To compare subtracted and nonsubtracted gadolinium-enhanced m
agnetic resonance (MR) angiography and cardiac-synchronized time-of-fl
ight MR angiography for help in detecting pelvic-region stenoses. MATE
RIALS AND METHODS: Twenty-eight patients with intermittent claudicatio
n underwent MR angiography with a 1.5-T system; two-dimensional cardia
c-synchronized time-of-flight MR angiograms and three-dimensional MR a
ngiograms (without and with gadolinium enhancement) were obtained. Sub
tracted images were obtained by subtracting unenhanced data from enhan
ced data of identical volumes, and maximum intensity projection images
were constructed, which two observers independently evaluated in blin
ded fashion, with conventional angiographic results as the reference s
tandard. RESULTS: Sensitivity and specificity for grading of hemodynam
ically significant stenoses (greater than or equal to 50% lumen reduct
ion) on subtracted MR angiograms were 94% and 93%, respectively. Sensi
tivity of subtracted images was significantly higher compared with tha
t of time-of-flight images (P < .05) but not with that of nonsubtracte
d images. Contrast-to-noise ratio on subtracted images was significant
ly higher compared with that on nonsubtracted images (P < .05) but not
with that on time-of-flight images. There was good correlation betwee
n stenosis length measurements on gadolinium-enhanced MR angiograms an
d those on conventional angiograms. CONCLUSION: Subtracted MR angiogra
phy is superior to cardiac-synchronized time-of-flight MR angiography
for imaging of iliac and upper femoral arteries and provides higher co
ntrast-to-noise ratio, fewer artifacts, and easier image interpretabil
ity than nonsubtracted MR angiography.