Efficacy of Test Injection Technique with a Small Amount of Contrast Medium on Contrast Enhanced MR Angiography of the Renal Artery

We examined the possibility of selective contrast enhanced renal MR angiography through the trial of a test injection technique with a small amount of contrast medium(test injection). The subjects were two volunteers and four patients suspected of having renal disease. With test injection, we instituted a transaxial section above the renal artery and used the 2D-FAST SPGR method at pulse sequence. The SAT technique was carried out in the superior and inferior directions, to suppress the influence of pulsation. With the images we obtained, we set an ROI on the abdominal aortic artery and inferior vena cava, and plotted the time intensity curve. Out of consideration for the difference in peak time between the artery and vein(A-V window), we determined the delay time on 3D contrast enhanced MR angiography. We were able to acquire only selective renal artery images. It was found that the renal vein will be drawn or no renal artery will be drawn on studies performed without determining adequate injection timing. This method was found to be useful in improving the above-mentioned disadvantages.