MRI: MAGNETIC RESONANCE IMAGING By: Jamie Locke CIS-Spring Professor White

MRI Physical Therapy has come to rely heavily on technological testing to help them with their assessments and observations of their patients. MRIs are “an imaging technique used primarily in medical settings to produce high quality images of the inside of the human body.” (Hornak) MRIs have many advantages because it is noninvasive, it uses non ionizing radiation, and contains discrimination in any imaging place and a high soft-tissue resolution.

HISTORY Magnetic Resonance Imaging did not being as exactly this, it evolved from nuclear magnetic resonance (NMR) experiments which began in 1946. Felix Bloch and Edward Purcell began the first studies of NMRs and won the nobel prize for their discoveries. Raymond Damadian next discovered that NMRs could be used to detect larger objects. Paul Lauterbur was the man who brought about what is known today as the first MRI machine.

HOW DOES AN MRI WORK? MRIs can generate images of any human body part in thin section images from and angle or direction. First, MRI creates a steady state of magnetism within the human body by placing the body in a steady magnetic field. Second, the MRI stimulates the body with radio waves to change the steady-state orientation of protons.  Third, the MRI machine stops the radio waves and registers the body's electromagnetic transmission.

MRI (CONT) Fourth, the transmitted signal are used to construct internal images of the body by computerized axial tomography. Contrary to popular belief, an MRI image is not a photograph. MRIs are a computerized image or map of radio signals coming from the human body. When undergoing an MRI, all metal must be left outside of the room.

IMAGING PRINCIPLE AND MAGNETIC FIELD IMAGING In medical MRIs, radiologists are looking at the NMR signal from water and fat, these two components providing to be the major hydrogen containing components in the human body. A magnetic field gradient is needed to accomplish this and it is a variation in the magnetic field with respect to position.

MOVING MAGNETS The newest technological advancement in the MRI field is using moving magnets to unlock the future of neurosurgery. A compact magnetic device is precisely positions on a patients head on both the left and right sides. This technique is called intraoperative MRI and is currently being used by neurosurgeons at UMDNJ-University Hospital to enhance neurosurgical procedures. images show the exact location of the lesions and avoid healthy tissue.

PRODUCTION OF MRIs As the demand in the use of MRIs increases, the production of the machinery is also increasing. The MRI industry is currently producing over 2,000 units a year and the United States has about 40% of the world marketing and production of MRI machines. There is a symbol known as a Tesla Unit label on every MRI machine produced.

FUTURE OF MRIs The future of MRIs is very promising and further applications of the use of MRIs are currently being assessed. two and three dimensional magnetic resonance angiography that is able to provide a roadmap of the vessels in any given part of the body. In the near future, techniques of MR could replace conventional diagnostic x-ray angiography. The future of MRIs is very hopeful to health professions of the future, including physical therapists.