A CT (computed tomography) scan is an imaging test that is often recommended by physicians to help diagnose a range of conditions. Patients usually lie down within the scanning device, and the machine passes x-ray beams though the body to produce an image. CT scans can produce a detailed picture of bone, soft tissue, muscles, internal organs and, crucially, tumors or other irregularities. While CT scans are a very widely used type of diagnostic imaging, they also have some drawbacks for patients.
Advantages: Highly detailed
Of all the internal imaging procedures available to physicians, the CT scan is the most detailed, and can give a doctor the most complete picture of what’s happening inside a patient’s body. They are particularly useful and widely used in diagnosing cancer.
The CT scan procedure is noninvasive and painless, and is generally quick and convenient for most patients. It’s widely available at a range of different treatment centers.
Because CT scan gives a doctor a very clear picture of where a tumor or other problem is located and whether it has spread, it can help her in planning a biopsy, surgery, radiation or other treatment with more precision.
Compared to other diagnostic tests, CT scans deliver a relatively high dose of radiation to the patient. While this is not usually a problem for a single scan, patients who need to undergo repeated tests can be subjected to a significant level of radiation, increasing their cancer risk.
Patients who undergo a CT scan often receive a dose of what’s known as a “contrast material,” containing iodine. This allows specific areas of the body to be highlighted on the scan. Some people can have an allergic reaction to this, and this is the most common side effect CT scan patients complain of. Symptoms can include a metallic taste in the mouth, itchiness, hives and shortness of breath. Contrast materials without iodine are available and are becoming more widely used.
Because a CT scan is so detailed, it can sometimes alert doctors to minor abnormalities in the body that don’t have symptoms related to them and that in the normal course of life would not have caused the patient any problems. However, doctors may feel the obligation to divulge this information to patients, which can cause anxiety and possibly unnecessary follow-up tests or treatments.