About CT Scans

Human imaging is a crucial field in medicine for evaluating and diagnosing a variety of diseases and conditions. One such technique called computed tomography, or CT scan, has become one of the most frequently used imaging techniques since its inception in the 1970's. The scan uses x-ray beams to generate cross-sectional views of the inside of the body.

Applications

CT scans are used frequently to diagnose muscle and bone abnormalities such as tumors and fractures. They are used to located tumors, infections, or blood clots in the blood vessels of the body. A CT scan helps guide needles or probes during procedures such as surgeries, biopsies, or ablation therapy. It is helpful in detecting and monitoring diseases such as cancer and heart disease, and is very useful in emergency situations to detect internal injuries or bleeding. It is considered the best and fastest imaging technique for examining the chest, pelvic, and abdominal region, according to radiologyinfo.org.

Benefits

There are many types of medical imaging techniques, but the CT scan offers many advantages over other techniques. First and foremost, it is a fast, painless, and non-invasive technique that produces an image more detailed than a traditional x-ray. It allows for imaging of the bone, soft-tissue, and blood vessels all at the same time, and the scanning is less sensitive to patient movement as compared to MRI scans. Also, a CT scan can be administered regardless of whether an individual has implanted devices such as a pacemaker.

Risks

There are several risks associated with CT imaging, but in general, the benefits of the resulting images outweigh the risks. The x-rays used in CT scans are a form of ionizing radiation, which has been shown to increase the risk of cancer, according to the National Cancer Institute. Also, there is a risk of an allergic reaction to the contrast material used during the imaging procedure, which most often produces mild hives or itchiness. CT scans should not be used on pregnant women or children unless absolutely necessary, and the information to be gained must far outweigh the associated risks.

Procedure

Before beginning the CT scanning procedure, all jewelry and accessories must be removed to prevent image obstruction or distortion. If contrast material is to be used, it is administered orally, intravenously (IV) injected through a vein in the arm, or administered by an enema. Once prepped, the individual is positioned on the CT scanning table, generally on his back or side. The table slowly moves through a circular CT imaging scanner for image production. It is important to lie still during the process, and sometimes individuals are asked to hold their breath for brief moments in time to prevent blurry images. On average, the entire procedure takes approximately 15 minutes to an hour.

How It Works

A CT scan produces cross-sectional images slices of the body using x-ray beams directed at the body. The x-ray beams, a form of radiation, pass through the body and are absorbed by internal tissues to varying degrees. Special x-ray detectors on the opposing side of the beam detect the amount of radiation absorbed by the body. Computers register this absorption and compile the small slices of data together to generate three-dimensional (3D) images of the inside of the body.