What You Need To Know About CT Scans For Cancer Detection

Posted in , , by Echelon Health

In the not-so-distant past, the diagnosis of cancer was seen as a death sentence. With a lack of treatment options, a poor understanding of the disease and underdeveloped imaging techniques, the 10 year survival rate for a cancer patient was around 24% four decades ago. Today, that survival rate has more than doubled to 50% and continues to improve thanks to advancements in cancer screening programs and treatments. Nevertheless, 50% of cancers are still diagnosed at a late stage, according to Cancer Research UK. This is largely because we tend to see our GP only once symptoms are present, by which time treatment options are often limited. This is where preventative health checks come in and a very important screening technique is the CT scan for cancer detection.

What is a CT scan and how does it work?

A CT scan, also known as a Computerised Tomography scan or CAT scan, is a computerised X-ray imaging procedure in which a narrow beam of X-rays are aimed at the body and quickly rotated around it. The resulting X-ray measurements are then processed by advanced computer software that renders cross sectional images (or “slices”) of specific areas of the body in amazing detail and resolution to see deep inside without the need for an invasive procedure.

What is a CT scan used for?

A CT scan provides an array of uses, but it particularly excels in utilising X-ray technology to quickly examine patients who may be suffering from internal injuries that cannot be identified with the naked eye. The revolutionary medical imaging apparatus can produce detailed images of many structures inside the body, this includes:

  • Internal organs
  • Blood vessels
  • Bones


CT scans can be used to: 

  • Determine the location, size and shape of a tumour
  • Diagnose conditions and diseases 
  • Identifying any damage to bones or organs
  • Identifying issues with blood flow or strokes
  • Detecting cancer
  • Monitoring patient’s conditions, such as checking the size of tumours during and after cancer treatment
  • Guide procedures
  • Diagnosing muscle and bone disorders
CT scan for cancer - Echelon Health
An important component of your Echelon Health Assessment is the expert advice you will receive from our renowned physicians, pictured above is our Medical Director Dr Paul Jenkins MA MD FRCP. Up to seven specialist consultants will review the results from your tests and scans, including CTs for cancer detection, each reporting on their particular area of expertise.

What to expect

During a CT scan, a patient will lie on their back on a flatbed that passes into the CT scanner. Throughout the process, a rotating ring  that is attached to the scanner will emit x-ray beams that examine the body and send detailed measurements to the computer. 

Unlike an MRI scan, a CT scanner doesn’t cover the whole of your body at once, so you shouldn’t feel too claustrophobic.

The radiographer will operate the scanner from the next room. Whilst the scan is taking place, a radiographer operates the scanner from the adjacent room. Patients are able to communicate with them through an intercom. 

Each time a scan is taken, patients will need to lie very still and breathe at a normal rate. This ensures that the images aren’t blurred. On the day of your scan, the radiologist will go through this in detail with you. From start to finish, the whole scan will take around 10-20 minutes. 

An important component of your Echelon health assessment is the expert advice you will receive from our renowned physicians, pictured above is our Medical Director Dr Paul Jenkins MA MD FRCP. Up to seven specialist consultants will review the results from your tests and scans, including CTs for cancer detection, each reporting on their particular area of expertise.

MRI vs CT scan for cancer

MRIs and CT scans are both effective diagnostic tools used to capture images within a patient’s body. A CT scan utilises X-Rays to capture the images, whereas MRIs use radio waves. Whilst both techniques are relatively low risk, there are a few differences that may alter a patient’s preferred choice depending on the circumstances. 

CT scans certainly have their advantages over other imaging techniques. Whilst an MRI is best for imaging the brain, spinal cord and prostate gland for example, CT is superior for scanning atherosclerosis inside arteries suggestive of coronary heart disease. It is also fantastic for imaging the lungs and colon and will detect even very small tumours lurking in these tissues. 

CT scans are a lot faster than MRIs and are less invasive in the fact that they only cover a portion of the body, whereas MRI scans will cover the entire body and require a patient to lay still for about 20 – 40 minutes. This can prove very challenging for claustrophobic patients, not to mention the procedure is noisy which means patients must also wear ear protection. 

Like most procedures, there may be some side effects, some more serious than others. CT scans use ionizing radiation, capable of damaging DNA and raising the risk of developing cancer. The extra risk of someone developing fatal cancer from a CT scan procedure is around 1 in 2,000. Because MRIs do not use ionizing radiation, they do not pose the problem of raising the cancer risk. 

For a more in-depth comparison of MRI with CT, please visit our ‘Not All Scanners Are The Same’ blog article.

How accurate is CT scan for cancer?

CT scans are an excellent way to examine the extent of a potential tumour’s shape, size and location. CT scans can even show the blood vessels that are feeding the tumour so they are very accurate. By consistently comparing CT scans that will be carried out during the process of a patient’s cancer treatment, doctores can determine whether the treatment is working or not by looking at the size of the tumour. 

What types of cancer show up on a CT scan?

Cancer can develop in any tissue and therefore it is important that a cancer screening is as comprehensive as possible. CT is not ideal for imaging all tissues, and for these we utilise MRI or ultrasound, however it is by far the best technique for scanning many tissues. Here is how Echelon Health utilises CT scans for cancer detection and other conditions.

CT scan

What it detects

CT Chest Lung cancer
CT Virtual Colonoscopy Colon cancer
CT Abdomen Cancer of the liver, gallbladder, spleen, pancreas, adrenal glands
CT Pelvis Cancer of the kidneys, bladder, lymph glands
CT Heart Calcium deposits which are a sign of atherosclerosis, or ‘furring up’ of the heart arteries
CT Coronary Angiogram Disease of the coronary arteries which supply the heart, including atherosclerosis
CT Aorta Disease of the aorta, which supplies the entire body, including ballooning or weakness
CT Bone Density Accurately measuring bone density and risk of developing osteoporosis.
EOS CT upright skeleton Musculoskeletal system – postural problems, predisposition to spinal disc problems

Early detection helps to identify cancer before it has a chance to metastasise, or spread, to other parts of the body. In fact, a CT scan for cancer detection can identify cancers before they even cause symptoms. Take colon cancers for example. Most develop from tiny polyps which slowly increase in size over many years. This means there is plenty of time to catch things early if a CT virtual colonoscopy is performed. In the same vein, early detection of any cancer will benefit your treatment options and usually result in a more promising outcome. According to Cancer Research UK, lung cancer diagnosed in its earliest stage leads to an 80% one year survival rate as opposed to 15% when diagnosed at the most advanced stage.

It is clear that early detection of disease leads to a long and healthy life. CT is a big player in the world of preventative medicine. However, in order to offer the most comprehensive health assessments in the world, Echelon Health adopted a combination of imaging technologies. These include MRI, ultrasound, a full body mole screen, digital mammogram and blood tests for over 40 parameters.

CT scan advantages and disadvantages

CTs can detect cancers to a fantastically high resolution along with the blood vessels that feed the tumour and other structures nearby.

A CT scan is one of the many methods we use today to detect cancer early, and it comes with many unique benefits. Moreover, the Aquilion ONE CT scanner operated by Echelon Health and housed at our Harley Street Centre is a brilliant technology with numerous benefits;

  • CT is fantastic at imaging the lungs, colon and heart arteries. If a tumour is lurking here it will detect it. In the past our radiologists have detected lung nodules as small as 1-2mm using the Aquilion ONE CT scanner.
  • The Aquilion can image 640 slices of the body with each rotation of its tube, compared to 16-64 slices from many other scanners.
  • With a spatial resolution of 0.3mm, the Aquilion ONE can see inside tissues to an extraordinary level of detail. This is much sharper compared to >0.5 mm for 64 slice scanners.
  • The Aquilion ONE is the only scanner able to image the heart in patients with an irregular heart rhythm and the only scanner capable of real time 4D imaging of moving joints
  • The Aquilion ONE CT scanner emits lower radiation doses and is therefore safer, despite being more powerful than most CTs the NHS operates.

Overall, CT scans prove very beneficial when diagnosing cancer as they have a short study time and provide quality images. However, there are a few disadvantages that patients should know before going for the procedure. For example, patients can experience low levels of radiation exposure. In small doses this is fine, but it is not recommended to go for frequent CT scans as gradual exposure to radiation will increase the risk of cancer overtime. Visit our radiation facts page to find out more. 

Some CT scans require contrast material dye to enhance the images of the inside of the body. This enables radiologists to distinguish normal from abnormal conditions. They can either be swallowed, administered rectally or injected into a blood vessel. Unfortunately, this method may be inappropriate for patients with significant kidney health complications. 

Furthermore, some patients may struggle during a CT scan as the procedure requires breath holding which some people may find discomforting. 

Common CT scan side effects

With any procedure or medication side effects can ensue, and CT scans are not exempt so it’s important to keep an eye out if you have recently undergone a CT scan. Whilst the radiologist will run through this with you, do not be alarmed by any of the side effects noted below. 

Side effects of a CT scan can depend entirely on what focus area of the body you need the procedure for; for example, a patient receiving an abdominal CT scan may experience abdominal cramping, diarrhea, nausea or vomiting and constipation. 

It also depends on if the patient has any underlying conditions e.g. if a patient has either diabetes, asthma, heart disease, thyroid disorders or kidney impairments they may have a higher risk of developing side effects. 

Nevertheless, common side effects include:

  • Dizziness
  • Hot flushes
  • Rashes
  • Itching
  • Runny nose
  • Coughing
  • Constipation
  • Nausea
  • Vomiting

If any of these side effects continue or begin to get worse, please contact a medical professional urgently. Furthermore, those allergic to a radiocontrast agent will be treated with antihistamines and steroids beforehand, if needed. 

Combined medical imaging via CT scans

Here at Echelon Health we offer several health assessment packages. These are all designed to detect cancer, and other diseases, early and give you peace of mind. Each assessment will involve a detailed medical history, an ECG, blood tests and a number of scans tailored to suit your needs. Your results will be analysed by experienced consultants led by our Medical Director and renowned consultant endocrinologist Dr Jenkins MA MD FRCP.

We have many case studies where potentially fatal incidents and illnesses have been abated thanks to our health assessments.

Why might I need a CT scan? 

Your healthcare professional or doctor may have recommended you for a CT scan to accurately diagnose a certain condition you may be suffering from. You may be feeling nervous or anxious about your scan but do not worry, our experienced doctors and radiologists are here for you every step of the way. We will answer any questions you may have throughout the procedure. 

For more information about our CT scans and packages, don’t hesitate to contact us today on +44 (0)20 7580 7688 to speak to our friendly representatives. Alternatively, you can make an enquiry by clicking the button below and we’ll get back to you as soon as possible. 

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