#61 - Is that really you?

On July 3, 1977, an event took place that would forever alter the landscape of modern medicine. This event was the first MRI exam ever performed on a human being. The first MRI took 5 hours to complete. Magnetic Resonance Imaging is one of the great technology advances of the 20th century.

If you have ever seen an MRI machine, you know that the basic design used in most is a giant cube. The cube in a typical system might be 7 feet tall by 7 feet wide by 10 feet long, although new models are rapidly shrinking. The tall section contains the magnet. There is a horizontal tube running through the magnet from front to back. This tube is known as the bore of the magnet. The patient, lying on his or her back, slides into the bore on a special table. Whether or not the patient goes in head first or feet first, as well as how far in the magnet they will go, is determined by the type of exam to be performed. MRI scanners vary in size and shape, and newer models have some degree of openness around the sides, but the basic design is the same. Once the body part to be scanned is in the exact center or isocenter of the magnetic field, the scan can begin.

In conjunction with radio wave pulses of energy, the MRI scanner can pick out a very small point inside the patient's body and ask it, essentially, "What type of tissue are you?" The point might be a cube that is half a millimeter on each side. The MRI system goes through the patient's body point by point, building up a 2-D or 3-D map of tissue types. It then integrates all of this information together to create 2-D images or 3-D models.

The MRI provides an unparalleled view inside the human body. The level of detail we can see is extraordinary. MRI is the method of choice for the diagnosis of many types of injuries and conditions because of the incredible ability to tailor the exam to the particular medical question being asked. By changing exam parameters, the MRI system can cause tissues in the body to take on different appearances. This is very helpful to the radiologist in determining if something seen is normal or not. We know that when we do "A," normal tissue will look like "B" - if it doesn't, there might be an abnormality. MRI systems can also image flowing blood in virtually any part of the body. This allows us to perform studies that show the arterial system in the body, but not the tissue around it.

Supporting the MRI technology is the PC that is integrated into the system. Processing images and handling all the data is a PC at the MRI's core. Without the PC the MRI data would be too complex to give any meaning.