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[Time-resolved MR angiography of the renal artery: morphology and perfusion]
U J Krause1, T Pabst, H Köstler
1Institut für Röntgendiagnostik der Universität Würzburg. krause@mail.uni-wuerzburg.de
Purpose:
To prove the hypothesis that renal artery stenosis and changes in renal perfusion can be detected with contrast-enhanced time-resolved MR angiography in a single examination.
Material And Methods:
In 71 patients, 137 renal arteries and 14 accessory renal arteries were studied. The examinations were performed on a 1.5 T system. A T 1 -weighted gradient echo sequence with a temporal resolution of 7 s was used. Single dose of contrast material (0.1 mmol/kg Gd-DTPA) was injected with a power injector with a flow rate of 2 ml/s. Criterion for the assessment of renal perfusion was the slope ratio of the signal intensity time curve in both kidneys.
Results:
Forty renal artery stenoses and one occlusion of a renal artery were detected. In 48 kidneys (35 %) segmental arteries were evaluated. The accuracy of the slope ratio (limit value 0.75) concerning the detection of unilateral renal artery stenosis was 92.6 % (sensitivity 75 %, specificity 95.7 %).
Conclusion:
Time-resolved MR angiography can detect changes in renal perfusion in patients with unilateral renal artery stenosis.