CT Prep

Common Questions about CT Scans

• What are the common reasons for a CT Scan?
  • To help diagnose the cause of symptoms.
  • To further examine abnormal x-rays.
  • To detect and evaluate the extent of tumors, or assess whether tumors are responding to treatment.
• What do CT scans include and what do they look like?
  • A CT scan has 3 views:  Axial, Coronal and Sagittal.

  

• What is the difference between a CT WITHOUT CONTRAST and a CT WITH CONTRAST?
  • Your doctor will determine whether contrast is needed for your exam.  
  • If you have an allergy to contrast, please notify your doctor or technologist.
  • Contrast is the thick liquid injected into a vein through an IV, PORT or PICC line.
  • Contrast contains iodine (similar to what is used in table salt) and on the CT scan it makes blood vessels appear bright white compared to other surrounding “gray” soft tissues. This allows a better look at blood flow.

  CT OF THE ABDOMEN (AXIAL VIEW)

  WITHOUT CONTRAST                       WITH CONTRAST

  

• Why is lab work needed within 30 days prior to a CT WITH CONTRAST for most patients?
  • Contrast puts an extra burden on your kidneys to process this thick liquid.
  • Certain lab values reflect how well your kidneys function: 
    • GFR:  Glomerular filtration rate
    • CREAT:  Creatinine 
    • BUN:  Blood urea nitrogen
  • Your doctor and technologist must check that these values are normal prior to giving contrast.
• Why shouldn’t I eat before my CT scan?
  • If your CT is with contrast sometimes it can make you feel nauseous as a result it is best to complete your scan on an empty stomach.
  • Food in the stomach can obstruct other important body parts the radiologist may need to see. 
• Why is it important to drink 16 oz. of water before my appointment?
  • It is important to be well hydrated so your stomach is full of water and easier to “see through” on CT.
  • Also, if contrast is given through an IV, extra water helps “plump up” your veins making them easier to find.