Bad Veins

So I had my pre-op testing yesterday.  The nurse had no problems drawing blood, but when I went for the CT scan they needed a big vein which I did not have.  The CT tech had to stick me 4 times until she got a big enough vein for the dye for the scan.  I have bad veins to begin with and she said that they were all small and flat, basically not good for the study.  After 20 minutes, she did finally find something.