CT (Computed Tomography) Scan

CT (computed tomography) Scan: What Is It?

CT stands for Computed Tomographic. A CT scanner uses X-ray technology to create three dimensional images of your body’s internal organs and structures. The scans are used to diagnose medical conditions, such as cancer or heart disease, and to monitor patients before surgery.

A CT scan involves taking pictures of your internal organs and structures, which include your chest wall, lungs, liver, kidneys and other vital organs. The images are then compared against reference material like x-rays to see if there is any abnormalities.

What Are Its Benefits?

CT scans may be used to detect certain types of cancers early. They can also show whether the patient will have complications from surgery or a blood clot forming in their legs during a cardiac arrest.

The scans can also be used to check for damage caused by accidents or natural disasters. For example, they might show how well a building will hold up after being hit by a bomb blast.

How Does It Work?

When you lie down on the CT scanner table, it takes several pictures of your body at different angles so that doctors can see what parts need attention first. Doctors use these images to determine where the problem lies and how best to treat it.

Does It Hurt?

The National Cancer Institute says that CT scans use a small amount of radiation to create images, which is safe. However, it may not be safe for people who have certain types of heart devices. This is why your doctor will take a medical history before the procedure.

What Do The Results Show?

The results can show whether you have osteoporosis or an abnormal growth in your body. It can also show whether you have any blockages in your arteries or build-ups of plaque. These are all conditions that should be treated as soon as possible to prevent more serious health problems in future.

The results will be compared against a database of normal CT scans for the same age and gender, which is used to prevent or diagnose disease.

How Are They Done?

The doctor may ask you to drink a contrast liquid and wait 30 minutes before having the scan done. The contrast liquid helps the radiologist see certain areas of your body more clearly on the scans.

Some people may require you to stop taking certain medicines before the scan, while others may ask you to fast for a few hours before taking the test. Your doctor will advise you on what you should do.

This procedure is painless and does not involve any cutting of skin or incisions. A typical CT scan takes about 15 minutes.

Who Can Benefit From It?

A CT scan is recommended for the following patient groups:

* Those who are at high risk of certain diseases.

* Those who have symptoms that can cause organ damage, such as severe pain in the chest.

* Those who need to have an MRI or traditional x-rays to get a clear diagnosis.

Some patients who may need a CT scan before surgery are those with cancer and bone infections. Other patients who may need a quick scan before surgery are those with tuberculosis (TB).

What Are Its Side-Effects?

A CT scan uses a small amount of radiation, which is safe for the human body. A typical scan takes 15 minutes and exposes you to 10 times the natural background radiation that you are exposed to in a day.

However, some patients may be allergic to the contrast liquid that is used in the procedure. Your attending physician will advise you accordingly.


A CT scan gives very detailed images of your body so that doctors can make a quick and accurate diagnosis on what is causing your medical condition. It is one of the best methods to detect certain types of cancers at an early stage and other conditions that affect internal organs.

However, you should always ask your doctor about the benefits and risks of this scan before undergoing it. Make sure you are feeling well on the day of the procedure and that there are no medical reasons that can prevent you from having one.

A CT scan is typically safe for most patients unless you have an undiagnosed medical condition. If you are pregnant or think you may be, ask your physician for a referral to a doctor who specializes in fetal medicine immediately.

This is not meant to be a replacement for a consultation with your physician and should be used as only a general guideline. Please see your doctor if you have any concerns regarding CT Scans.

Sources & references used in this article:

… tomography angiography of the brain replace lumbar puncture in the evaluation of acute‐onset headache after a negative noncontrast cranial computed tomography … by RF McCormack, A Hutson – Academic Emergency Medicine, 2010 – Wiley Online Library

Clinical validity of a negative computed tomography scan in patients with suspected pulmonary embolism: a systematic review by R Quiroz, N Kucher, KH Zou, F Kipfmueller, P Costello… – Jama, 2005 – jamanetwork.com

The Pittsburgh Lung Screening Study (PLuSS) outcomes within 3 years of a first computed tomography scan by DO Wilson, JL Weissfeld, CR Fuhrman… – American journal of …, 2008 – atsjournals.org

Early chest computed tomography scan to assist diagnosis and guide treatment decision for suspected community-acquired pneumonia by YE Claessens, MP Debray, F Tubach… – American journal of …, 2015 – atsjournals.org

Subarachnoid hemorrhage diagnosis: lumbar puncture is still needed when the computed tomography scan is normal by R Sidman, E Connolly, T Lemke – Academic Emergency …, 1996 – Wiley Online Library

Emergency department discharge of patients with a negative cranial computed tomography scan after minimal head injury by DH Livingston, RF Lavery, MR Passannante… – Annals of …, 2000 – ncbi.nlm.nih.gov

… posttreatment evaluation in Hodgkin’s disease and non-Hodgkin’s lymphoma has higher diagnostic and prognostic value than classical computed tomography scan … by G Jerusalem, Y Beguin, MF Fassotte… – Blood, The Journal …, 1999 – ashpublications.org