CT Scan vs MRI

Dr Chiang Yoong Fei, consultant clinical radiologist

Both a CT scan and MRI are useful in managing tumours as they can lead to a definitive diagnosis of tumours/cancers that require tissue biopsy. They can provide an evaluation of the tumour as well as how and where it has spread to other parts of the body. However, they do come with differences.

A CT scan uses x-ray/radiation to produce images while a MRI uses a magnetic field and radiofrequency pulses to produce images.

The advantages of a CT scan are that they are fast; good in acute or emergency settings such as a someone having a stroke, suffering a brain injury, or fracture. However, it comes with radiation risk and may not be appropriate for pregnant women.

On the other hand, a MRI does not have radiation and can give better details when it comes to soft tissue and organs. The disadvantage here is that it is noisy, time consuming, and more expensive. Patients may also experience anxiety or claustrophobia, and a strong magnetic field may be harmful for women in the early stages of their pregnancy. In addition, it is contraindicated in patients with metal clips that are not MRI compatible or a cardiac pacemaker.