OPEN MRI UNITS
Open MRI units do not have the same magnetic strength as a traditional closed unit. A smaller strength magnet translates into a lower quality picture. In fact, the magnetic strength of our unit (1.5 Tesla) is more than quadruple that of most open MRI’s (.25 to .50 Tesla).
Open magnets which have been developed more recently, typically are either permanent magnets or resistive electromagnets. The typical open configuration consists of two large, rounded, horizontally oriented metal discs which are the poles of the magnet between which the patient is placed. These magnets have no sides and are thus “open”.
Currently, advanced techniques to detect early stroke, subtle multiple sclerosis plaques and cartilage degeneration in the knee are available only on high field, closed scanners. MRI myelograms can be performed only on high field systems. Ultimately, you should discuss with your doctor and radiologist which type of scanner is best suited for your particular examination.To sum “open MRI” up, an image from an open mri is more like a polaroid picture while a high field “closed” image is like a digital picture. The difference is quite staggering and most radiologist prefer reading a high field image.