Oldest of the medical imaging techniques
X rays
Helps visualize hard bony structures
Helps locate abnormally dense structures like tumors,
and tuberculosis nodules in the lungs
Developed in the 1950s
Nuclear medicine
Uses radioisotopes to scan the body
Ultrasound imaging
(Ultra sonography)
Uses high frequency sound waves which are reflected and scattered by body tissues. The echoes are analyzed by
computer to construct visual images of body organs.
Used to determine fetal age, position and location of the placenta.
Developed in the 1970s
PET (Positron emission tomography)
Used to study metabolic processes
Provides insights into brain activity of those affected by mentally ill, Alzheimer’s disease and epilepsy
Uses short lived radioisotopes that have been tagged to biological molecules. Gamma rays are analyzed by a omputer
and produces a picture of the brains biochemical activity.
CT
(Computed tomography)
Formally called Computerized axial tomography [CAT]
Used in place of exploratory surgery
Doughnut shaped X ray tube sends information to a computer which gives detailed cross section pictures of the body
Used to evaluate problems that affect the brain, abdomen and calcifications of coronary arteries
Second generation of this type of medical imagery is called DSR [dynamic spatial
reconstruction]
Provides 3-D images of the body organs from any angle and most often used on mobile organs like the lungs
MRI
(Magnetic resonance imaging)
Uses magnetic fields up to 60,000 times stronger than the Earth’s magnetic fields.
Used to detect degenerative diseases like multiple sclerosis
Can suck metal objects like implanted pacemakers and loose tooth fillings through the body
Second generation of this type of imaging is called magnetic resonance spectroscopy [MRS]
Maps the distribution of elements other than hydrogen to reveal more about how disease changes body chemistry