nuclear renal scan and obesity

Question
I am a healthy 33 year old man with unilateral renal agenesis.  Last year I had a cardiac workup which was fine but initially had a false negative on the nuclear scans due to my size, 6'3'' and 300lbs.  Does a nuclear renal scan have the same chance for inaccuracy as I am a large man.  A renal ultrasound came out fine as did blood and urine tests.  Could the scan show a false negative and which is better the ultrasound or the nuclear?  Also is it safe with my condition to get a CT scan with IV dye?  Thankyou


Answer
Hi Jim,



Thanks for your question on "Allexperts".



A nuclear renal scan shows the function of the kidney, whereas an ultrasound shows the structure. These tests are complimentary to each other. There can be no comparison because they provide different sets of information.



I see no problem to having a CT scan with dye.



Sincerely,



Dr. Shah