X-Rays | Computed Tomography (CT) Scan | ALARA | Radiation Exposure and Pregnancy
| BUN and Creatinine Testing | MRI Safety (Magnetic Resonance)


People are exposed to radiation from natural sources every day. This radiation comes from naturally occurring sources in the ground, as radon, and also from cosmic radiation. The amount of normal occurring radiation varies depending on where you live. People who live in Colorado receive more radiation than those who live near sea level. To compare, the radiation an individual will receive from a chest X-ray is equal to the amount of radiation exposure an individual would receive in 10 days from our natural surroundings.


X-rays are a form of electromagnetic radiation, along with radio waves and light waves. X-ray has a higher energy level than light waves, and because of this, they can pass through your body. Your body absorbs some X-rays and some X-rays pass through. The amount of X-rays, which pass through your body, depends on the density of the tissue. Tissue, which is denser, like bone or tumors, absorbs more X-rays than skin or other soft tissue.

X-ray exams provide valuable information that assists your physician in making an accurate diagnosis. The decision to have an X-ray exam is medically based upon the benefit of the exam versus the potential risk to the patient from radiation.

X-rays can cause damage in two ways. Damage may be caused by the interaction of an X-ray and the DNA bonds in the nucleus of a patient’s cell. This has a very small probability. The second way, which has a higher probability, an X-ray indirectly produces ion pairs in tissues as it passes through the body. The ion pairs may interact with DNA causing cell damage.

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Computed Tomography (CT) Scan

X-ray techniques have been refined which allow us to discover more sophisticated information about our bodies. A Computed Tomography (CT) scanner is a donut like machine that uses X-rays to image individual cross-sectional slices through the body. The X-rays that penetrate the patient are detected and are constructed into an image by a computer. Computed Tomography (CT) produces images, which are localized, cross-sections, while conventional X-ray produces an image corresponding to tissues on top of each other.

The amount of radiation an individual will receive during a CT scan is more than an ordinary X-ray of the same part, because of the thin, cross-sectional slices. Radiologists and technologists have been trained to use the minimum amount of radiation necessary to obtain the needed results.

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HCA subscribes to a radiation safety policy referred to as “ALARA”, which is an acronym for As Low As Reasonably Achievable. The aim of this policy is to minimize the radiation exposure or amount of dose while still achieving the benefit of the exam.

The principle is that any amount of radiation exposure can cause detrimental biological effects in a person creating an increased risk of genetic mutations or cancer. In actuality, the risk of radiation-induced cancer by X-ray radiation exposure is approximately 1 in 2000 in an individual. The natural risk of cancer in the U.S. population is approximately 1 in 5. Therefore, the risk of radiation-induced cancer is significantly smaller that the natural risk for cancer.

There are three major factors involved with maintaining “ALARA” doses:

  • Reduce the amount of exposure time to the X-ray
  • Increase the distance from the X-ray source (doubling the distance from the radiation source will decrease the radiation exposure by a factor of 4)
  • Use shielding – lead absorbs X-rays, and is an effective way to reduce dose and protect specific areas of the body.

State legislation requires that protective shielding be provided to patients who are less than 50 years of age unless the shielding interferes with the X-ray examination.

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Radiation Exposure and Pregnancy

There are radiation related risks throughout pregnancy that are relative to the stage of pregnancy. The human embryo and fetus is much more sensitive to the effects of radiation exposure than adults. Radiation exposure during the first trimester is significantly more damaging because the embryo’s cells are duplicating at a very rapid pace. During the second trimester the risk decreases somewhat, and is the least damaging in the third trimester.

The health risks associated with radiation to the fetus are cumulative. Risks could include prenatal deaths, physical abnormalities, and mental retardation. Other harmful effects could include the onset of cancer, cataracts, and a decrease in the average life span.

Informing the technologists that you are or might be pregnant is important so that your medical care can be appropriated optimized. The primary goal in performing an examination on a pregnant female utilizing ionizing radiation or X-rays, is to facilitate the well being of the mother, and second, the viability and well being of the fetus. All pregnant patients will be evaluated individually by their referring physician and the radiologists.

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BUN and Creatinine Testing

  • Contrast Agents are often utilized to enhance the image quality
  • Some patients may have clinical indications, which require testing their blood as a precautionary measure prior to the injection of the contrast
  • Our Imaging Centers provide this testing onsite for the patient’s convenience

The Imaging staff will have the results in minutes regarding if the contrast is safe for the patient.

Benefits include:

  • On-the-Spot Accuracy
  • Convenience
  • Patient Safety
  • Time Savings for the patient and the staff

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MRI Safety (Magnetic Resonance)

MRI does not use radiation to produce images. MRI uses magnetic frequencies. Our goal is to maintain a safe MRI environment for our patients and our MR healthcare workers. Promote awareness and understand MRI safety.

Maintaining a safe MRI environment has become a priority as our MR environment continues to grow.

We have developed a Pre-MRI patient safety check list for our staff, to help decrease some of our patient’s questions and or concerns. See attached questionnaire.

MRI screening is crucial to ensure the safety of all those who encounter the MRI environment. All implants and devices will be given special consideration in your safety. All procedures will be followed precisely.

Your environment will be treated with respect and caution by all of our staff. Our staff will monitor your examinations and you will be encouraged to report any unusual sensations. Communication between our patients and the MRI technologist will be ongoing and frequent.

The MRI can be performed through clothing and bones. Scrubs or a hospital gown will need to be worn, without metal fasteners. Please remove metallic objects like hairpins, jewelry, eyeglasses, clocks, hearing aids and removable dental work.

The MRI can appear to be like a short tunnel; a possible issue is the claustrophobia that some patients experience.

If your Physician has referred you for an examination during which you will receive an injection of Gadolinium contrast material into a vein, only about 2.4% of patients have an adverse reaction. The most common side effects may be:

  • Nausea
  • Headaches
  • Dizziness
  • Rash or hives

These reactions will generally go away within 24 hours. We recommend that you notify your primary care provider if any reactions continue.

MRI Coils

Coils are part of the hardware of the MRI machines and are used to create a magnetic field or to detect a changing magnetic field by voltage induced in the conductive wire. The perfect coil produces a uniform magnetic field without significant radiation.


A pacemaker is a device that is used for internal or external battery-operated cardiac pacing. These devices are susceptible to static field within the MRI. Please notify your technician if you have a pacemaker in place.

Contrast Agents

These are chemical substances introduced to the area being imaged, to increase the image quality between normal and abnormal tissue.

Your MRI is cost-effective by eliminating the need for invasive radiographic procedures, biopsies and exploratory surgery. MRI scans can save money while minimizing patient risk and discomfort. MRI can eliminate unnecessary diagnostic procedures that miss occult disease. MRI has replaced 50% of x-ray exams.

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