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CT Scan Information From A CT TechnologistWelcome to CT scan info.com. Information on this website site is maintained and updated regularly by a certified and registered CT Technologist so you can be assured that the information here is accurate. Pricing, preparation and the indications and uses for CT over MRI and MRI vs CT can be found by searching this information resource site. Computed tomography (CT), was originally known as "EMI scan" because it was developed at a research branch of Electric and Musical Industries in England. It was later known as Computed Axial Tomography (CAT scan). The "C" is for computed meaning computerized, the "A" for images shown in an axial plane or slice and tomography derived from the Greek tomos meaning slice and graphein meaning to record. As the technology advanced, these slices were able to be stacked and viewed in other planes besides the axial and thus, the axial was dropped and CAT scan is now known as CT Scan (Computed Tomography). CT produces multiple images of data in the form of a slab or a block of the body that is sliced and stacked like a sliced loaf of bread. Any slice, of any desired thickness, from anywhere out of the "loaf" can be taken out of the slab or "loaf" to be viewed and manipulated through a process known as windowing, in order to see various structures based on shades of gray, black and white on a set numbered scale. We can then take that slice, put it back in the "loaf of bread" and stack it again and then rotate it for viewing from different angles. We can lay the stack down, page through it one slice at a time, quickly or slowly, turn it on it's side, roll it over, stand it up or spin it around in a circle. This is all done by computer which can give us the ability to slice the body from front to back, back to front or left side to right side or right side to left side. This enables us to see the body from the front, the side, the back or any angle desired and any depth desired. This is the reason the "A" in CAT Scan was taken out and is now referred to as CT Scan. We are no longer limited to just axial slices only. Three dimensional viewing is now common. Computed Tomography (computerized slicing) took a huge leap in technology in 2001-2003. Improvements on the technology catapulted CT to the forefront of medical imaging. With these improvements, more information was being obtained in a shorter amount of time. It has now become the most widely used imaging modality in trauma situations. The use of CT Scanning is often the deciding exam about whether there is need for surgical intervention in the event of an accident. Trauma surgeons rely on the high yielding data from CT in their assessment of injury. The speed at which the extent of injuries can be seen is only minutes. Injuries from the top of the head to the bottom of the pelvis can be revealed in less than 15 minutes. With the advancement in CT technology's speed, came the ability to see arteries that could not be seen before. "Dye" or Contrast Material in an artery is quickly pumped out leaving only a narrow window of opportunity to see contrast-filled arteries. This faster technology allowed the capture of contrast-filled arteries for greater visualization of arterial anatomy. The ability to see arteries with out having to insert a catheter into an artery and fill it with dye or Contrast Material saved many hours of preparation and exam time and radiation exposure. Now arterial disease and abnormalities can be seen with just a IV placed into a vein and injected with contrast material. Thus, CTA was born. The A in CTA is now known as CT Angiography.
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