History of Medical Imaging
Ultrasound
X-Ray Tomography
Magnetic Resonance Imaging (MRI)
A Little Review...
- First Clinically used in the 1970's
- Super neat! No ionizing radiation is used for these exams, only sound waves!
- Great imaging modality for non-invasive imaging of the abdomen, masses found on breasts and imaging a fetus during pregancy
Magnetic Resonance Imaging
- In the 1940's, x-ray tomography was introduced, allowing certain structures of the body to be imaged without over or underlying tissues to be displayed.
- How these images were obtained was by rotating the x-ray tube so only the area of interest stayed in focus during tube rotation.
- Evolved in the 1970's
- Another modality that does not use ionizing radiation to aquire images
- Superconducting magnets came onto the scene in the 80-90's starting with 1.5 Tesla and now up to a 3 Tesla
- Tesla is a measurement of the earth's magnetic field
- Who is this fellow?
- What day did he discover X-ray's?
- What type of tube was he using?
Fun Fact: Earth's magnetic field is .00005 Tesla which means a 1.5 Tesla magnet has a field strength 30,000 times stronger!
Nuclear Medicine
Fluoroscopy (1920's)
Computed Tomography
- Computers started to integrate into the medical imaging world in the 1970's with the arrival of Computed Tomography
- Was the first modality to aquire multiple tomographic images/slices of the brain to be viewed.
- Allowed structures of the body to be viewed that are superimposed when using conventional x-ray
Now for some fun! Focus on the word fun here...
https://www.jeopardy.rocks/edit/historyxray
- Wilhelm Conrad Roentgen
- November 8, 1895
- Was working with an early cathode ray ray tube called a Crooke's tube
- As the potential to make the x-ray beam more powerful, the ability to visualize patient motion became possible
- Radiologist's started giving patients radio-opaque barium to observe the GI tract on film
- Allowed diagnosis of cancers of the esophagus, stomach and bowel as well as ulcers diverticulitis and appendicitis
References:
Bradley, W. G. (2008). Proceedings of the American Philosophical Society, Vol. 152, No. 3, pp. 349-361. American Philosophical Society. Stable URL: http://www.jstor.org/stable/40541591
- Came on to the scene for diagnostic imaging in the 1950's
- Nuclear medicine tests use the source of x-rays in radioactive compounds, instead of coming from an x-ray tube. Radiopharmaceuticals are taken intravenously or orally. An external detector such as a gamma camera capture and form images from the radiation emitted by the radiopharmaceuticals.
- Modern tests in Nuc Med include the Positron Emission Tomography Scan (PET Scan)
Fun Fact....
Radiologist's wore red goggles to minimize the time needed to read the dim images