CT Scanner

What is it used for?

CT scanning is used by every program and department at Saint Francis Memorial Hospital—Emergency Services, CancerCare, the Spine and Joint Centers, Sports Medicine, Occupational Health, Pulmonary, Cardiac, and General Medicine. Here are some of the specific uses:



· To assess the condition of blood vessels, eliminating the need for higher risk angiograms

· Calcium scoring to evaluate coronary artery disease for prevention and therapy

· Non-invasive colonoscopy for three-dimensional examination of the colon

· Evaluate head injuries, aneurysms, brain tumors and brain damage

· Find tumors and abscesses throughout the body

· Guide biopsies and therapeutic pain procedures

· Diagnose many different cancers, especially lung, liver and pancreatic cancer, allowing the physician to confirm the presence of a tumor, measure its exact size, precise location and extent of the tumor’s involvement with other nearby tissue

· Plan and properly administer radiation treatments for tumors

· Measure bone mineral density to detect osteoporosis

· Diagnose spinal problems and injuries to hands, feet and other skeletal structures

· Quickly identify injuries to the liver, spleen, kidneys, or other internal organs to help save lives

· Make structural measurements for more precise total joint replacement surgery

· Best tool for studying conditions of the chest and abdomen.



What is a CT or “Cat” scan?

CT stands for “computed axial tomography” and may be called a “cat scan.” The CT scanner is a special kind of precision x-ray machine paired with a computer. Together they create highly detailed two- and three-dimensional views of the inside of the body.



CT scanning was developed by a British inventor, Sir Geoffrey Hounsfield in 1973. He received the Nobel Prize for his work. Developments in electronics and computer technology now enable doctors at Saint Francis to use CT scans to painlessly inspect the entire inside of the body.





How does it work?

The donut shape visible in the picture contains a focused x-ray tube mounted opposite an arc-shaped array of detectors. As the patient moves through the scanner on a motorized table, the tube and its detectors rotate around and around the patient in a spiral taking 32 images per second. The detectors measure the strength of the beams. Beams passing through less dense tissue, such as lungs, will be stronger whereas the beams passing through denser tissue such as bone will be weaker. Each image made by the scanner is a cross-section or slice through the body. The detectors send this information to a computer which compiles all the results into a three-dimensional image. That image can be directly viewed by a radiologist, recorded on disk, or transmitted to your personal physician’s office.



The speed and sensitivity of this state of the art scanner means a patient’s chest or abdomen can be precisely scanned in 10 seconds or less. Holding your breath for only 10 seconds is much easier and radiation exposure is reduced.