Whats the difference between X-ray, CT scan and MRI?
X-rays are high frequency beams of the electromagnetic spectrum that can pass more easily through material with low density (atomic number) than through those with higher density (higher atomic numbers). Hence, solids in the body (bones, kidney stones, etc.) show up easily in an x-ray image. A Computerised Tomography (CT) scan is effectively a more developed version of using x-ray: it uses a highly sensitive x-ray beam focussed on specific parts of the body and a detector picks up the beam as it passes through the body. Magnetic Resonance Imaging (MRI) uses a rapidly oscillating magnetic field perpendicular to a very strong principal magnetic field (about 30,000 times the earth’s magnetic field) along which the organ to be scanned is kept. The oscillating field causes hydrogen atoms within the organ (usually from water in the tissue and blood) to get magnetised in a direction perpendicular to that of the principal magnetic field.
