What Is Computed Tomography and What Is It Used For?

Below we will explain what computed tomography is and what its main applications are. This radiology and imaging study is one of the most frequently ordered by experts to make their diagnoses.

One of our main wishes is to have health and well-being, and for this to be possible, it is essential that whenever we experience any symptom or trauma, we see a specialist physician, who will tell us the next steps to take. While we do indeed need to wait for these instructions, it is important to know that our physician may very well request imaging studies in order to make a diagnosis.

This is because  symptoms alone, or a simple description of what happened, are not enough for the physician to determine the extent of any condition affecting our body, whether due to an illness, or after suffering an accident, blow, or fall. So do not be surprised if, when you visit the specialist, they ask you to undergo radiology and imaging studies, since this is one of the most reliable methods for examining the internal structure of the human body.

What Is Computed Tomography and What Is It Used For?

One of the most common imaging studies is computed tomography, or computed axial tomography (CT or CAT scan), which involves two techniques for obtaining detailed images of a body area of interest. The first is the use of X-rays through a tube that rotates around you, allowing captures to be taken from different directions. The second is computer technology.

Computer technology is what allows the physician to obtain more detailed and sophisticated images of the body. In addition, this technique allows for computer manipulation to more precisely view small areas of the body, such as blood vessels, the bronchi, sections of the spinal cord, and tissues, among others.

It should be noted that the advantages mentioned above give computed tomography scans added value and therefore a higher price compared with plain radiographs (X-rays). In addition, although the process is painless, it takes a bit longer (around 30 minutes).

The above is due to the fact that the technologist or radiologist must follow a set of steps to ensure a quality tomography image, such as proper calibration of the equipment. If this is not done correctly, the study may not turn out well and you would have to undergo the radiation again. That is why we suggest going to a quality laboratory, clinic, or hospital.

Contrast Media in Computed Tomography

In certain cases, and to achieve better visualization of the inside of the body, the patient may be instructed to receive a contrast medium. This can be administered orally or intravenously.

These contrast agents are widely used and are not risky. However, you should tell whoever is performing the study if you feel any symptom of excessive heat or pressure when it is administered, as this could indicate an allergy. Afterward, it is advisable to drink plenty of fluids to help flush it out.

The facility where you have the study performed will give you the appropriate instructions for preparation before and after the study if a contrast agent has been indicated.

What Can a Physician See With a CT Scan?

Since CT scans produce sophisticated images that can be professionally manipulated on a computer to get a better view of your body's internal structure, their scope is considerably broad. 

This is why a physician may order one to evaluate any of the following diseases or medical conditions:

• Investigating possible internal bleeding, for example after cardiovascular damage.
• Assessing internal injuries or fractures of both the skeletal and muscular systems.
• Locating tumors, clots, or infections. On this last point, we can mention pulmonary conditions such as pneumonia, in which contrast agents are commonly used to highlight the condition.
• Guiding surgical procedures to determine where to make incisions. A simple example is biopsies.
• Monitoring conditions such as cancer or pulmonary diseases.

Is Getting a CT Scan Dangerous?

Indeed, when you undergo a CT scan, your body receives radiation that is higher than what you are usually exposed to naturally. However, technological advances have allowed radiologists to control radiation doses in order to reduce the associated risks.

These doses depend on the area being scanned. For example, for the abdomen and pelvis, there is an exposure of 10mSv, equivalent to two and a half years of natural background radiation. For the lungs and chest, the figure is 1.5mSv, corresponding to 6 months; and for the teeth, at 0.18 mSv, it is similar to 22 days of radiation.

How Do I Prepare for a CT Scan?

In general, no prior or special preparation is required. In some cases, you may be asked to fast or stop taking fluids or medications beforehand, but this usually occurs only when contrast media are used.

It is suggested that you wear comfortable clothing. You may be asked to remove your clothes and put on a medical gown. Likewise, you will not be allowed to wear any metal accessories of any kind. 

Notify the physician if you suspect you might be pregnant, or if you are pregnant, before undergoing the study.

When it is time to begin, you will simply need to lie down on a table. The study will be finished within 10 to 30 minutes.

How Will I Get the Results of My CT Scan?

The results are generally accompanied by an interpretation from the radiologist. Keep in mind that only your physician knows what each term means, and it is up to them to decide what steps to take regarding your treatment.

You will generally receive your results between one and three days after your study is performed. Many laboratories and hospitals allow you to view them digitally. That way, you can save them and easily share them with additional physicians, for example if you need a second opinion.

References

• Computed Tomography. MedlinePlus.
• X-Rays, CT Scans, and MRIs. OrthoInfo.
• CT Scan. Mayo Clinic.
• Radiation Risks from Imaging Tests. American Cancer Society.