Computed Tomography versus Magnetic Resonance Imaging - Which is Better?
Computed tomography and magnetic resonance imaging are the two different types of imaging techniques.
A computed tomography (CT) scanner uses a type of ionizing radiation called x-rays to capture images thereby making it an effective tool for examining tissue composed of elements of a higher atomic number than the tissue surrounding them, such as bone and calcifications within the body.
On the other hand, magnetic resonance imaging uses non-ionizing radio frequency signals to capture images. MRI is a suitable technique for non-calcified tissue, though MR images can also be acquired from bones and teeth as well as fossils.
Computed tomography technique can be enhanced by using contrast elements having higher atomic number than the surrounding flesh such as iodine or barium. On the other hand, contrast agents for MRI are those that have paramagnetic properties. Gadolinium and manganese are examples of the agents that are used for MRI.
Multiple two-dimensional cross-sections of tissue and three-dimensional reconstructions can be generated by CT and MRI scanners. MRI has many properties that may be used to generate image contrast, whereas Computed tomography uses only X-ray attenuation to generate image contrast.
Initially, in case of Computed tomography images could be acquired in the axial plane only. These scans used to be called Computed Axial Tomography scans. Nowadays, multi-detector CT scanners with near-isotropic resolution, allows the CT scanner to produce data that can be retrospectively reconstructed in any plane without much loss of image quality. Magnetic resonance imaging scanners can generate cross-sectional images in any plane.
Computed tomography and magnetic resonance imaging when compared, MRI is the preferred technique when the patient has to undergo the exam more than once. The reason being, the patient is not exposed to harmful ionizing radiation.