[CT vs PET vs MRI] Compare imaging techniques at a glance: what should you note when buying medical insurance?

CT Scan, PET Scan and MRI are all commonly used imaging diagnostic techniques. In simple terms, they use images to show what is happening inside the body, helping doctors make a diagnosis. However, even when symptoms appear in the same part of the body, doctors will recommend different tests according to the patient’s clinical needs. Patients may wonder: what exactly are the differences between CT, PET and MRI? Which conditions are suitable for which technique? And how do the resulting images differ? 

CT (Computed Tomography):

• Uses X-ray radiation to capture images of the human body from multiple angles, which are then combined by computer technology to produce cross-sectional images, enabling in-depth examination of individual organs or areas. It is commonly used to scan the head, neck, chest, abdomen and pelvis.
• Although X-ray radiation involves exposure to radiation, according to data from the UK National Health Service (NHS), the impact of a CT scan on a patient’s health is very limited, with a patient’s future risk of developing cancer being less than one in 2,000. If not overused, the benefits of undergoing a CT examination generally outweigh the radiation risk.

PET (Positron Emission Tomography):

• The patient needs to be injected with a radioactive isotope, after which a whole-body or localised scan is carried out. Its key feature is the ability to assess the activity level of cancer cells. In addition to cancer, a PET scan can also be used to diagnose inflammation, infection and neurological diseases.

PET-CT (Positron Emission Tomography-Computed Tomography):

• Combining CT and PET, it can diagnose early cancerous changes more effectively, identify the source of cancer, determine the stage of cancer, and detect signs of spread or recurrence. PET-CT scans can examine most tumours, including common cancers such as lung, liver, colorectal and breast cancer.

MRI (Magnetic Resonance Imaging):

• MRI is the only imaging diagnostic technology that does not use X-ray radiation. It uses a strong magnetic field to temporarily realign hydrogen atoms in the body, then releases signals via radio waves, which are converted by computer processing into multi-angle images.
• Compared with other imaging diagnostic technologies, MRI is particularly effective in examining soft tissue and nervous tissue, and is commonly used to assess the brain, ligaments and joints. It can also be used to diagnose certain cancers. 

Regardless of the imaging diagnostic technology used, scan results need to be interpreted by a specially trained doctor. At the same time, diagnosing a disease requires consideration from multiple angles, including clinical symptoms. Patients should communicate with their attending doctor to decide on the most appropriate treatment. If you would like to learn more about individual imaging diagnostic technologies and their prices, please refer to other 10Life articles: CT Scan, PET Scan, MRI.

CT, PET and MRI are all classified as “specified diagnostic imaging tests” under VHIS. With a written referral from a attending doctor, reimbursement will be available regardless of whether these tests are carried out during a hospital stay, or at a clinic or day surgery centre. However, the insured person generally has to bear 30% of the cost, with the insurer paying the remainder.

As for other medical insurance policies that are not VHIS plans, although CT, PET and MRI are also covered, they are generally classified as “miscellaneous expenses” and subject to additional conditions, such as the test having to be carried out during hospitalisation, or the illness in question being diagnosed as a result of the examination. Before taking out a policy, in addition to noting the reimbursement limit, you should also pay attention to whether claims are calculated per injury/illness or per hospitalisation. 

If you would like a preliminary understanding of how different insurance products cover this area, you can use 10Life’s 《Insurance Decoder》to compare products’ coverage for “specified diagnostic imaging tests” and “miscellaneous expenses”.

Source: Hong Kong Integrated Oncology Centre, media reports, Hong Kong Professional Diagnostic Centre, Government VHIS website, private hospitals or medical institutions.

This English version of this article has been generated by machine translation powered by AI. It is provided solely for reference purposes. In the event of any discrepancy or inconsistency between this translation and the original Chinese version, the Chinese version shall prevail.