Digital Imaging: A Whole New World

When the Beatles sang the song “Don’t Ever Change,” they could never have known their music would be a catalyst for an incredible change in the medical world. In 1972, THORN EMI Central Research Laboratories announced the development of the first commercially viable CT system. EMI — also the Beatles record company — used massive profits from record sales to fund scientific research. It has been claimed that the “greatest legacy” of the Beatles is the CT scanner. Although they sang of a different “Revolution,” that is exactly what has happened in the world of CT and imaging as a whole.

The major diagnostic imaging tests include ultrasound and MRI, which use sound waves and magnetic fields, respectively, to create images, and X-ray and CT, which uses X-ray technology. But according to Robert Kolanz, MD, medical director of imaging services at Little Company of Mary Hospital – Torrance, “the workhorse of imaging is CT.”

The first scanners took nearly an hour to generate just 10 images that were 10 mm thick. Now, within seconds, a CT scan can acquire up to 1,000 images as small as 1/2 mm thick.

 
The days of lying on a table for extended periods of time have turned into quicker, more comfortable tests for the patient. Scanners are so fast and tubes spin so quickly that an entire scan can be done in just one breath hold. This translates into clearer images because there is no respiratory effect.

“Better resolution and thinner slices result in more accurate assessments of tumors which then allow treatments to be more precise,” Dr. Kolanz says.

 
Digital imaging has also changed the way diagnostic tests can be read. Through post-processing, the computer can electronically remove parts of a scan. For example, in a CT angiography study, all bone and soft tissue is visible on the initial scan (left image). However, through digital post-processing, bone and soft tissue images can be removed so only the vessels are visible (right image), allowing for a clear, detailed image.   Continue »

Page 1 | Page 2 | Return to Index