Imaging Definitions

X-rays

A radiological investigation that utilises wavelike forms of electromagnetic energy carried by particles called photons which exposes photosensitive film to differing° depending on its absorption in the tissue through which it passes.

Ultrasound

A radiological investigation that utilises high frequency sound waves & their echoes off different tissue boundaries to generate a 2 dimensional image which we refer to as an ultrasound.

CAT Scan

A radiological investigation that utilises a revolving X-ray tube & detector to perform thousands of X-rays which are formatted via a computer to generate a 3 dimensional image.

Bone Scan

A nuclear medicine investigation that utilises phosphate derived radioactive isotopes that are injected intravenously. They are taken up preferentially in areas of ↑ bone activity. The radiation given off is used to generate an image that we know as a bone scan.

MRI Scan

A radiological investigation that utilises different responses from tissues when exposed to a radiofrequency pulse whilst in a static magnetic field to generate 2 or 3 dimensional images.

A T1 image is generated by examining the duration taken for atoms to return to their longitudinal axis of polarization.

A T2 image is generated by examining the rate of decay in atoms that are transversely magnetized.