Since the noise level inside the scanner is quite high, you may want to ask about bringing headphones and a radio or tape player to drown it out and take your mind off the test. You disrobe and don a hospital gown. Test procedure You may or may not receive an injection of a contrast dye as you lie on a narrow table that slides into a large tube, called the CT scanner. You must remain motionless during the scan. After the test You are monitored for about 30 minutes for any ill effects from the dye, after which you can resume normal activities.
Factors affecting results Failure to fast before the procedure.
Failure to lie motionless during the scan. Recent tests involving dye or other foreign substances may affect the accuracy of the test images. The radiologist reads the series of cross-sectional views of the kidney to see exactly where abnormalities lie. It provides a high-resolution image of kidney structure and anatomy. The test involves some, although relatively minimal, radiation as well as the injection of radiopaque contrast dye.