Health

Nanoscale MRI: Medicine's next big thing?

BACKGROUND:    Magnetic Resonance Imaging (MRI) is a test that uses a magnetic field and pulses of radio wave energy to make pictures of organs and structures inside the body.  The MRI shows problems that other imaging methods cannot detect and it also gives different information about structures in the body than can be seen with an ultrasound, X-ray, or a CT scan.  The area of the body being examined has to be placed inside a special machine that contains a strong magnet for an MRI test.  The pictures taken by the MRI scan are digital images that can be saved and stored on a computer.  They can also be viewed remotely, like in a clinic or an operating room.  MRI is done for many reasons.  It can be used to find bleeding, tumors, injury, blood vessel diseases, or infection.  (Source: www.webmd.com)

 HOW IT IS DONE:  The patient will have to remove all metal objects and clothing.  The patient will have to lie on their back on a table.  The table will slide into the space that contains the magnet.  A coil device may be placed over or wrapped around the area to be scanned.  The patient has to be completely still while the images are being taken.  An MRI test usually takes 30 to 60 minutes; however, it can last up to two hours.  (Source: www.webmd.com)

RISKS:  There are not any harmful effects from the magnetic field used for MRI, but it is very powerful.  It can affect pacemakers, artificial limbs, and other medical devices that contain iron.  The magnet can even stop a watch if it is too close to it.  Loose metal has the risk of causing damage or injury if it gets pulled toward the magnet.  Metal parts in the eyes can damage the retina.  Iron pigments in tattoos can cause eye and skin irritation.  Some medication patches can cause a burn.  Also, a slight risk of an allergic reaction if contrast material is used during the MRI is possible.   (Source: www.webmd.com)

NEW TECHNOLOGY:  MRI can reveal details of living tissues, organs, and tumors.  The nanoscale MRI can see all the way to the level of atoms.  Doctors believe this could make visual diagnoses of a person's molecules, examine damage on a strand of DNA, watch molecules misfold, and identify a cancer cell by the proteins.  Doctors at The City College of New York used tiny defects in diamonds to sense the magnetic resonance of molecules.  A standard MRI gets a resolution of 100 microns, that is about the width of a human hair.  It can go all the way down to 10 microns, the width of a few blood cells.  The nanoscale MRI would have a resolution 1,000 to 10,000 times better.  Diamonds are crystals made up almost entirely of carbon atoms.  When a nitrogen atom lodges next to a spot where a carbon atom is missing, however, it creates a defect known as nitrogen-vacancy center.  "These imperfections turn out to have a spin, like a little compass, and have some remarkable properties," Carlos Meriles, PhD, was quoted as saying.  Researchers realized that these NV centers could be used as very sensitive sensors.  For example, they can pick up the magnetic resonance of nearby atoms in a cell.  The NVs shine when a light is directed at them, unlike the atoms in a cell.  If you illuminate green light it will flash back red.  "It is a form of what is called optically detected magnetic resonance sends back flashes to say it is alive and well.  The NV can also be thought of as an atomic magnet. You can manipulate the spin of that atomic magnet just like you do with MRI by applying a radio frequency or radio pulses.  Ultimately, one will use a nitrogen-vacancy mounted on the tip of an atomic force microscope, or an array of NVs distributed on the diamond surface, to allow a scanning view of a cell, for example, to probe nuclear spins with a resolution down to a nanometer or perhaps better," Carlos Meriles, PhD, explained. (Source: http://www.ccny.cuny.edu/news/mri-for-nanoscale.cfm)