 [ Symptoms ] i am having trouble keeping my penis hard during vaginal sex the feelingsensation in my penis seems to disappear i am having trouble keeping my penis hard during vaginal sex often times the feelingsensation in my penis seems to disappear and my hard on quickly disappears this is never an issue with oral sex or from handjobs and alcohol is not a factor either this is the first steady girlfriend i have ever had and find her beyond attractive more so than anyone other sexual partner in my past i have never had a steady sexual partner in my past so the problem never had a chance to come to light [ Disease ] there are several possibilities why your ct scan may have been cancelled your doctor who ordered the ct scan should be able to tell you the reason often there is concern if a person is blood work shows an abnormal creatinine test prior to getting a ct with contrast dye the creatinine test indicates how well your kidneys are functioning the use of contrast dye with a ct scan can sometimes cause kidney problems especially in people who already have impaired kidney function