MRI scan machine Magnetic resonance imaging (MRI), or nuclear magnetic resonance imaging (NMRI)
By Live Dr - Sat Mar 28, 12:28 pm
Magnetic resonance imaging (MRI), or nuclear magnetic resonance imaging (NMRI), is primarily a medical imaging technique most commonly used in radiology to visualize the internal structure and function of the body. MRI provides much greater contrast between the different soft tissues of the body than computed tomography (CT) does, making it especially useful in neurological (brain), musculoskeletal, cardiovascular, and oncological (cancer) imaging. Unlike CT, it uses no ionizing radiation, but uses a powerful magnetic field to align the nuclear magnetization of (usually) hydrogen atoms in water in the body. Radiofrequency fields are used to systematically alter the alignment of this magnetization, causing the hydrogen nuclei to produce a rotating magnetic field detectable by the scanner. This signal can be manipulated by additional magnetic fields to build up enough information to construct an image of the body.
MRI is a relatively new technology, which has been in use for little more than 30 years (compared with over 110 years for X-ray radiography). The first MRI Image was published in 1973 and the first study performed on a human took place on July 3, 1977.
Magnetic resonance imaging was developed from knowledge gained in the study of nuclear magnetic resonance. In its early years the technique was referred to as nuclear magnetic resonance imaging (NMRI). However, as the word nuclear was associated in the public mind with ionizing radiation exposure it is generally now referred to simply as MRI. Scientists still use the term NMRI when discussing non-medical devices operating on the same principles. The term Magnetic Resonance Tomography (MRT) is also sometimes used. One of the contributors to modern MRI, Paul Lauterbur, originally named the technique zeugmatography, a Greek term meaning “that which is used for joining”. The term referred to the interaction between the static, radiofrequency, and gradient magnetic fields necessary to create an image, but this term was not adopted
New MRI techniques could lead to faster scans
* Potential to more quickly detect disease like cancer
LONDON (Reuters) – Two new techniques using different approaches to see molecular changes inside people’s bodies could lead to faster, more detailed imaging scans that better detect health problems, researchers said on Thursday.
Both magnetic resonance imaging technologies rely on manipulating the spin of molecules to provide more detailed scans that one day could rapidly do things like analyze how well a drug is working or tell how fast tumors are growing at the molecular level, they said.
“Our method has the potential to help doctors make faster and more accurate diagnoses in a wide range of medical conditions,” Gary Green of the University of York, who led one of the studies, said.
“The technique could ultimately replace current clinical imaging technologies that depend on the use of radioactive substances or heavy metals, which themselves can create health concerns.”
Green and colleagues based their technique on manipulating parahydrogen — the fuel used in space shuttles — by transferring its magnetism to a rage of molecules that are much more easily detected.
This means researchers, who are now testing their technique in animals, could potentially increase sensitivity in some scans by more than 1,000 times so data on biological systems that once took 90 days to record could be obtained in seconds, Green said.
A U.S. research team was able to see these molecules by “hyperpolarizing” some atoms in a sample, adjusting the spins of their nuclei to drastically increase their signal.
This technique creates large imbalances among the populations of those spin states and makes the molecules into more powerful magnets, which produce more detailed images.
“You thus have a signal that, at least transiently, can be thousands or tens of thousands times stronger than regular hydrogen in an MRI,” Warren Warren of Duke University, who led the U.S. team, said.
Both sets of researchers published their findings in the journal Science.
(Reporting by Michael Kahn; Editing by Julie Steenhuysen)