Dynamic contrast-enhanced MR angiography from the distal aorta to the ankle joint with a step-by-step technique.
OBJECTIVE
The aim of this study was to visualize the arteries from the distal aorta to the ankle joint and to determine the accuracy of MR angiography for detecting stenoses and occlusions.


METHODS
Twenty-four patients with peripheral arterial occlusive disease underwent digital subtraction angiography and were examined on a 1.5-T MR scanner. The transit time for contrast material was determined with a test bolus injection. A T1-weighted three-dimensional gradient-echo sequence with short TR and TE was used for a dynamic measurement at the level of the iliac arteries, the upper leg, and the lower leg arteries. For each level a single dose of gadolinium was injected into an antecubital vein with an MR power injector. Maximal-intensity-projection reconstructions were calculated after subtraction of the first measurement at each level. Two experienced MR radiologists who were unaware of the digital subtraction angiography results interactively evaluated both the MIP reconstructions and the single slices on a workstation, first independently and then in a consensus interpretation.


RESULTS
With digital subtraction angiography, 80 hemodynamically significant stenoses and 39 occlusions were detected. For the stenoses and occlusions, a sensitivity of 100% was found for MR angiography. The specificity for the assessment of stenoses and occlusions was 98% and 94%, respectively, for the iliac arteries; 98% and 94%, respectively, for the upper leg arteries; and 94% and 95%, respectively, for the lower leg arteries. Most false-positive findings of occlusion were due to metal stents present in the iliac (n = 3) and upper leg (n = 4) arteries.


CONCLUSIONS
The MR imaging technique that we used revealed the arteries from the distal aorta to the ankle and proved to be reliable at showing arterial stenoses and occlusions.
Huber
A
A
Department of Clinical Radiology, Klinikum der LMU, Grobetahadern, Marchioninistr. 15, 81377 München, Germany.
Heuck
A
A
Baur
A
A
Helmberger
T
T
Waggershauser
T
T
Billing
A
A
Heiss
M
M
Petsch
R
R
Reiser
M
M
D000368:Aged; D015901:Angiography, Digital Subtraction; D000843:Ankle Joint / Q000098:blood supply* / Q000000981:diagnostic imaging; D001018:Aortic Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D001157:Arterial Occlusive Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003287:Contrast Media / Q000008:administration & dosage; D005189:False Positive Reactions; D019786:Gadolinium DTPA / Q000008:administration & dosage; D006801:Humans; D007083:Iliac Artery / Q000000981:diagnostic imaging / Q000473:pathology; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007275:Injections, Intravenous; D007866:Leg / Q000098:blood supply* / Q000000981:diagnostic imaging; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity; D015607:Stents; D013382:Subtraction Technique
D003287:Contrast Media; D019786:Gadolinium DTPA