MRI
As radiologists, we use many types (modalities) of imaging technology to learn more about how the human body is working without having to resort to surgery. These include: X-rays, computed tomography (CT) scans, and positron emission tomography (PET) scans as well as ultrasound and magnetic resonance imaging (MRI) scans. Regarding this last modality, the idea of using magnets to look at electrically charged particles inside the human body was once ridiculed as crazy. Today, MRI is used in thousands of locations around the world to help radiologists and other health care professionals better understand the human body.
On July 3, 1977, a machine built around a giant magnet took crude images of a test patient’s chest, including the heart and lungs. This marked the first-ever use of a machine to scan the body for signs of cancer. The machine, called Indomitable, was the first human scanner and earliest MRI technology.
Indomitable was conceived and built by State University of New York Downstate Medical Center professor Raymond Damadian. The physician, researcher and inventor discovered how to tell the difference between cancer cells and normal cells after they were magnetized. He believed that if a big enough magnetic resonance imaging (MRI) scanner could be built, cancerous tissue could be detected in humans without surgery and without having to expose the patient to radiation from X-rays.
Damadian patented the concept of nuclear magnetic resonance, which uses magnets and radio waves to see how molecules behave. Numerous other researchers and inventors went on to refine and develop MRI technology, which now produces amazing soft tissue and organ images for the early detection, diagnosis and treatment of cancer, injuries and other disorders.
The Tesla unit – named after inventor Nikola Tesla – is used to tell how strong an MRI’s magnet is, with most ranging from .2 Tesla to 3.0 Tesla, with 1.5 considered “state of the art.” Recent MRI advances include the development of so-called “open” and “wide bore” machines, which are shorter, more open and more comfortable for the patient and can accommodate claustrophobic or very large patients. These advances can help improve image quality just by allowing the patient to be more relaxed and able to hold still longer during exams.
MRI is particularly useful for non-invasive musculoskeletal (muscles and ligaments that connect our bones) imaging and internal organ imaging. MRI also does a great job of looking at the organs of the chest and abdomen, including the heart, liver, kidney, spleen, pancreas and abdominal vessels, helping to better evaluate and diagnose tumors and other problems. Because it involves no radiation exposure, MRI is often preferred for examination of the male and female reproductive systems and surrounding structures.
MRI technology continues to advance with even more powerful equipment and special add-on coils for dedicated breast, prostate and other body-specific MRI imaging. Additionally, cardiac imaging is reaching new levels of detail for imaging of the heart, aorta, coronary arteries and blood vessels to diagnose coronary artery disease and other heart problems.