<<Disclaimer: Verify this information before applying it to your situation.>>
 
     Just to add my two bits worth.  I had a CT scan last November
     following an apparently ruptured liver cyst, found in an ultrasound
     after a severe bout of abdo pain, but not found 6 weeks later.  I had
     no reaction to the contrast medium except a metalic taste in the mouth
     which was expected.
 
     I live in Australia, the contrast may be different.
 
     Jim