Peripheral vascular disease: blinded study of dedicated calf MR angiography versus standard bolus-chase MR angiography and film hard-copy angiography.
OBJECTIVE
To compare the accuracy of contrast material-enhanced three-dimensional (3D) dedicated calf magnetic resonance (MR) angiography with that of bolus-chase MR angiography, with conventional angiography as the reference standard, in patients with symptomatic peripheral vascular disease (PVD).


METHODS
Thirty men with symptomatic PVD were examined. MR angiography was performed at 1.5 T before conventional angiography. MR angiographic examination included 3D contrast-enhanced dedicated calf MR angiography and three-station bolus-chase MR angiography. Two radiologists blinded to conventional angiographic results evaluated the MR angiograms independently. Two angiographers evaluated the conventional angiograms in consensus. Calf artery segments were graded as having 50% or less stenosis, greater than 50% stenosis, or occlusion or as being nondiagnostic. Statistical analyses were performed with paired permutation testing.


RESULTS
Analyses of 472 calf segments and 420 pelvic and thigh segments were performed. Of the 472 calf segments, three and 75 segments (reader 1) and seven and 91 segments (reader 2) were graded as nondiagnostic at dedicated calf MR angiography and bolus-chase MR angiography, respectively. Differences in diagnostic grade between the two examinations were significant (P <.001), accounting for within-subject correlations, with a mean estimated difference of -17.1% (95% confidence interval [CI]: -25.8%, -8.4%). In the calf arteries, the dedicated and bolus-chase MR angiographic sequences had diagnostic accuracies, respectively, of 81.5% (reader 1) and 79.1% (reader 2) and of 67.8% (reader 1) and 63.4% (reader 2). The dedicated calf sequence was significantly more accurate than the bolus-chase sequence (P =.001). The point estimate of the difference was 14.7%, with estimated correct diagnosis rates of 80.3% and 65.6% for the dedicated calf and bolus-chase examinations, respectively (95% CI for difference: 4.0%, 25.4%). The diagnostic accuracy of bolus-chase MR angiography at the pelvis-thigh level was slightly higher when it was performed first: 81.9% (reader 1) and 83.8% (reader 2) versus 74.3% (reader 1) and 80.0% (reader 2) when it was performed last. The difference was not significant (P =.21).


CONCLUSIONS
Use of dedicated calf MR angiography led to significantly increased diagnostic accuracy in the calf arteries compared with standard bolus-chase MR angiography. Use of the dual-bolus technique did not jeopardize the diagnostic accuracy in the pelvic and thigh arteries.
Binkert
Christoph A
CA
Dotter Interventional Institute and Department of Diagnostic Radiology, Oregon Health & Science University, Portland, Ore, USA. cbinkert@partners.org
Baker
Phillip D
PD
Petersen
Bryan D
BD
Szumowski
Jerzy
J
Kaufman
John A
JA
D000368:Aged; D000369:Aged, 80 and over; D002932:Cineangiography; D003251:Constriction, Pathologic / Q000175:diagnosis; D003287:Contrast Media; D003308:Copying Processes; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000175:diagnosis*; D015203:Reproducibility of Results; D016037:Single-Blind Method
D003287:Contrast Media