Re: ultrasound vs CT with contrast.
I had a head and neck CT with contrast last summer.
The ENT told me that a head and neck CT is basically useless without the contrast, because it's hard to differentiate between all the different stuff in there.
My results were fine, and the CT scan itself was nothing. The contrast dye just made me feel slightly warm. it was not an unpleasant feeling (except that I was scared to death, lol).
Nothing about the experience was painful or unpleasant, except having the IV inserted.
If I had to do it again, i wouldn't be scared.