What is a Diagnostic X-ray?

Diagnostic Imaging / What is a Diagnostic X-ray?

Because the human body is so complex, there are many ways to look at the organs, tissues, and bony structures within the body. X-rays are a form of radiation, like light or radio waves, that are focused into a beam, much like a flashlight beam.

X-rays can pass through most objects, including the human body. X-rays make a picture by striking a detector that sends the pictures to a computer. Dense tissues in the body, such as bones, block (absorb) many of the X-rays and look white on an X-ray picture. Less dense tissues, such as muscles and organs, block fewer of the X-rays (more of the X-rays pass through). They look like shades of grey on an X-ray. X-rays that pass only through air look block on the picture.

Patient Preparation Instructions

Outpatients may walk in for any routine diagnostic x-ray exam at Knox Community Hospital or the Knox Medical Pavilion.  There is no preparation necessary for routine x-ray exams.

  • If your doctor has ordered a contrast X-ray exam, the exam must be scheduled.
  • If you are scheduled for an Intravenous Pyelogram (IVP) exam, please see IV contrast prep under CT (Section). Your doctor will also prescribe a Magnesium Citrate prep kit obtained from a local pharmacy.  This kit must be taken before your IVP exam to cleanse your colon.  Please follow product instructions.
  • If you are scheduled for any other contrast x-ray exams, please arrive 30 minutes prior to your scheduled exam time.
  • If you are scheduled for Upper GI exam, please do not eat or drink anything for 4-6 hours prior to your exam
  • If you are scheduled for a Small Bowel exam, please do not eat or drink anything after midnight.  If you are scheduled for a T-tube cholangiogram, Fistulogram  please do not eat or drink anything after midnight and refer to the invasive procedure guidelines.
  • If you are scheduled for a Barium Enema (BE) please do not eat or drink anything after midnight.  Your doctor will also prescribe a Magnesium Citrate prep kit obtained from a local pharmacy.  This kit must be taken before your BE exam to cleanse your colon.  Please follow product instructions.
  • If you are scheduled for a Arthrogram, Nephrostomy, Spinal Taps, Venogram, or Myelogram please refer to invasive procedure guidelines for prep instructions.
  • If you are scheduled for an Esophagram (Barium Swallow), Peg Tube Check, Cystogram, Voiding Cystourethrogram, Galactogram, Sialogram, or Hysterosalpingogram, there is no preparation required.

These are preparation guidelines for imaging exams performed at Knox Community Hospital (KCH).  If you have any questions regarding prep for your exam, please contact us at 740.393.9038.

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