Magnetic resonance microscopy
- Magnetic resonance microscopy
-
Magnetic Resonance Microscopy (MRM, µMRI) is Magnetic Resonance Imaging (MRI) at a microscopic level. A strict definition is MRI having voxel resolutions of better than 100 µm³ [1].
Nomenclature
Magnetic resonance Microscopy is a term to refer to very high resolution MRI images (<10 micrometres in some cases). The term is most widely used by the High Resolution Magnetic Resonance Imaging group from Duke University, headed by Dr. G. Allan Johnson.
Differences between MRI and MRM
- Resolution: Typical medical MRI resolution is about 1 mm³; the desired resolution of MRM is 100 µm³ or smaller.
- Specimen size: Medical MRI machines are designed so that a patient may fit inside. MRM chambers are usually small, typically less than 1 cm³.
Current status of MRM
Although MRI is very common for medical applications, MRM is still developed in laboratories. The major barriers for practical MRM include:
- Magnetic field gradient: High gradient focus the magnetic resonance in a smaller volume (smaller point spread function), results in a better spatial resolution. The gradients for MRM are typically 50 to 100 times those of clinical systems. However, the construction of radio frequency (RF) coil used in MRM does not allow ultrahigh gradient.
- Sensitivity: Because the voxels for MRM can be 1/100,000 of those in MRI, the signal will be proportionately weaker [2].
Alternative MRM
Magnetic Resonance Force Microscopy (MRFM) has nm³-scale resolutions. It improves the sensitivity issue by introducing microfabricated cantilever to measure tiny signals. The magnetic gradient is generated by a micrometre-scale magnetic tip, yielding a typical gradient 10 million times larger than those of clinical systems. This technique is still in the beginning stage. Because the specimen need to be in high vacuum at cryogenic temperatures, MRFM can be only used for solid state matters.
References
- ^ P. Glover and P. Mansfield, Limits to magnetic resonance microscopy, Rep. Prog. Phys. 65 1489–1511, 2002
- ^ R. Maronpot Applications of Magnetic Resonance Microscopy, Toxicologic Pathology, 32(Suppl. 2):42–48, 2004
External links
Wikimedia Foundation.
2010.
Look at other dictionaries:
Magnetic resonance imaging — MRI redirects here. For other meanings of MRI or Mri, see MRI (disambiguation). Magnetic resonance imaging Intervention Sagittal MR image of the knee ICD 10 PCS B?3?ZZZ … Wikipedia
Magnetic resonance force microscopy — (MRFM) is an imaging technique that acquires magnetic resonance images (MRI) at nanometer scales, and possibly at atomic scales in the future. MRFM is potentially able to observe protein structures which cannot be seen using X ray crystallography … Wikipedia
Magnetic resonance angiography — Intervention Time of flight MRA showing the circle of Willis in the brain. Note the venetian blinds artifact visible as the multiple pseudo stenosis on both the left and right middle cerebral artery … Wikipedia
Magnetic resonance cholangiopancreatography — Intervention MRCP image showing stones in the distal common bile duct: (a) Gallbladder with stones (b) Stone in bile duct (c) Pancreatic duct (d) Duodenum. ICD … Wikipedia
Magnetic resonance neurography — Bilateral Split Sciatic Nerve Magnetic resonance neurography (MRN) is the direct imaging of nerves in the body by optimizing selectivity for unique MRI water properties of nerves. It is a modification of magnetic resonance imaging. This technique … Wikipedia
Magnetic resonance imaging of the brain — MRI of brain and brain stem Intervention Brain MRI ICD 10 PCS B030ZZZ … Wikipedia
Nuclear magnetic resonance — This article is about the physical phenomenon. For its use as a method in spectroscopy, see Nuclear magnetic resonance spectroscopy. NMR redirects here. For other uses, see NMR (disambiguation). First 1 GHz NMR Spectrometer (1000 MHz,… … Wikipedia
Nuclear magnetic resonance spectroscopy of proteins — (usually abbreviated protein NMR) is a field of structural biology in which NMR spectroscopy is used to obtain information about the structure and dynamics of proteins. The field was pioneered by Richard R. Ernst and Kurt Wüthrich[1], among… … Wikipedia
Solid-state nuclear magnetic resonance — (NMR) spectroscopy, characterized by the presence of anisotropic (directionally dependent) interactions.IntroductionBasic conceptsA spin interacts with a magnetic or an electric field. Spatial proximity and/or a chemical bond between two atoms… … Wikipedia
Résonance magnétique nucléaire — Pour les articles homonymes, voir RMN. Premier spectromètre RMN à 1 GHz (23,5 T installé au Centre de RMN à Très Hauts Champs à Lyon en aôut 2009. La résonance magnétique nucléaire (RMN) désigne une propriété de certains noyaux atomiques … Wikipédia en Français
