MRI Spectroscopy is where the study of nuclear magnetic resonance, or updated to the name magnetic resonance imaging, originally developed from.
Dr. Felix Bloch won the Nobel Prize in 1952 for observing and reporting NMR in paraffin wax at 30 MHz (thirty Mega-Hertz) while he worked at Stanford University, sharing the award with Dr. Edward Purcell who worked out of Harvard with H1 (hydrogen). The work from these two scientists lead the way to discoveries of other physics principles and also created the possibility of imaging through the use of the hydrogen atom.
Nuclear Magnetic Resonance was and still is an elegant way of determining chemical structure and makeup of the properties of materials through the use of an electro-magnetic frequency.
MRI spectroscopy displays an important feature of NMR. That is the resonance frequency of a particular substance is directly proportional to the strength of the applied magnetic field. This is the feature exploited in what started off as nuclear magnetic imaging techniques; the name change occurred after the term nuclear alarmed would be patients and practitioners. To desensitize the masses, magnetic resonance imaging became the new term of use for this imaging procedure. The laws of mri spectroscopy state that if a sample is placed in a non-uniform magnetic field then the resonance frequencies of the sample’s nuclei depend on where in the field they are located. Since the resolution of the imaging technique depends on the magnitude of magnetic field gradient, many efforts are made to develop increased field strength, often using superconductive magnets.
Predominantly used with Hydrogen, Carbon 13 or Phosphorus 31 molecules, mri spectroscopy has been and is used for tissue characterization without any physical intervention. In other words, measurement of these chemicals does not require any invasive-ness on behalf of the patient. Once the patient is cleared for MRI safety and access to the MRI exam scanner, then positioning and hardware placement can begin for imaging around the questionable anatomy.
Specific sequences are used to determine the make-up of the tissue after scanning. Critical steps must be taken, and done repeatedly for a sound spectroscopy program.
MRI spectroscopy can be performed on the brain, the breast, liver, heart, muscle, tumors, prostate or most body parts as long as the patient is able to hold very still. MRI scanners must usually have the spectroscopy software to run the sequences and the post processing software to help radiologists and physicists determine the results. The example below demonstrates 3D spectroscopy, also known as CSI (chemical shift imaging) of the bilateral hemispheres of the brain. This is a safe painless process of imaging that acquires signal reflected back from the chemical makeup of the tissues. The patient merely has to lie very still in order for MRI spectroscopy of most anatomy to be successful.
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