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.