My doctor has ordered a few tests to rule out kidney issues and I m wondering if all are necessary and if yes what order I should do them in so as not to provoke renal failure. I have to do a CT pyeloscan & delayed image, a MAG3 renal scan with lasix and a KUB supine and erect. I have right renal ptosis seen in an ultrasound and have symptoms from severe edema to not being able to stand for more than 30 minutes. My blood and urine tests are normal. I ve read of the risks of taking a contrast agent both iodine and gadolinium and I am afraid of doing the CT Scan with all the radiation. Is a nuclear renal scan with lasix washout safer and provide similar results as the CT scan. I am thinking of doing the KUB x-rays first as no contrast dye is involved. After do I do both the nuclear renal scan and the CT scan? Also, is it possible to do the CT scan and renal scan in different positions as lying down may not show all the problems?