Magnetic resonance imaging of the brain

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MRI of Brain
MRI of Human Brain.jpg
Cross-sectional T1-weighted MRI of a healthy human brain acquired with an ultra high-field MR of 7 Tesla field strength
ICD-10-PCS B030ZZZ
ICD-9-CM 88.91
OPS-301 code 3-800, 3-820

Magnetic resonance imaging of the brain uses magnetic resonance imaging (MRI) to produce high-quality two- or three-dimensional images of the brain, brainstem, and cerebellum without ionizing radiation (X-rays) or radioactive tracers.

Contents

History

The first MR images of a human brain were obtained in 1978 by two groups of researchers at EMI Laboratories led by Ian Robert Young and Hugh Clow. [1] In 1986, Charles L. Dumoulin and Howard R. Hart at General Electric developed MR angiography, [2] and Denis Le Bihan obtained the first images and later patented diffusion MRI. [3] In 1988, Arno Villringer and colleagues demonstrated that susceptibility contrast agents may be employed in perfusion MRI. [4] In 1990, Seiji Ogawa at AT&T Bell labs recognized that oxygen-depleted blood with dHb was attracted to a magnetic field, and discovered the technique that underlies Functional Magnetic Resonance Imaging (fMRI). [5]

A 'Jedi' helmet, on display at the Science Museum:Medicine:The Wellcome Galleries 'Jedi' helmet Wellcome L0059902.jpg
A 'Jedi' helmet, on display at the Science Museum:Medicine:The Wellcome Galleries

In the early 1980s to the early 1990s, 'Jedi' helmets, inspired by the 'Return of the Jedi' Star Wars film, were sometimes worn by children in order to obtain good image quality. The copper coils of the helmet were used as a radio aerial to detect the signals while the 'Jedi' association encouraged children to wear the helmets and not be frightened by the procedure. These helmets were no longer needed as MR scanners improved.

In the early 1990s, Peter Basser and Le Bihan, working at NIH, and Aaron Filler, Franklyn Howe, and colleagues developed diffusion tensor imaging (DTI). [6] [7] [8] [9] Joseph Hajnal, Young and Graeme Bydder described the use of FLAIR pulse sequence to demonstrate high signal regions in normal white matter in 1992. [10] In the same year, John Detre, Alan P. Koretsky and coworkers developed arterial spin labeling. [11] In 1997, Jürgen R. Reichenbach, E. Mark Haacke and coworkers at Washington University in St. Louis developed Susceptibility weighted imaging. [12]

The first study of the human brain at 3.0 T was published in 1994, [13] and in 1998 at 8 T. [14] Studies of the human brain have been performed at 9.4 T (2006) [15] and up to 10.5 T (2019). [16]

Paul Lauterbur and Sir Peter Mansfield were awarded the 2003 Nobel Prize in Physiology or Medicine for their discoveries concerning MRI.

This axial T2-weighted (CSF white) MR scan shows a normal brain at the level of the lateral ventricles. Normal axial T2-weighted MR image of the brain.jpg
This axial T2-weighted (CSF white) MR scan shows a normal brain at the level of the lateral ventricles.

The record for the highest spatial resolution of a whole intact brain (postmortem) is 100 microns, from Massachusetts General Hospital. The data was published in Scientific Data on 30 October 2019. [17] [18]

Applications

One advantage of MRI of the brain over computed tomography of the head is better tissue contrast, [19] and it has fewer artifacts than CT when viewing the brainstem. MRI is also superior for pituitary imaging. [20] It may however be less effective at identifying early cerebritis. [21]

In the case of a concussion, an MRI should be avoided unless there are progressive neurological symptoms, focal neurological findings or concern of skull fracture on exam. [22] In the analysis of a concussion, measurements of Fractional Anisotropy, Mean Diffusivity, Cerebral Blood Flow, and Global Connectivity can be taken to observe the pathophysiological mechanisms being made while in recovery. [23]

In analysis of the fetal brain, MRI provides more information about gyration than ultrasound. [24]

MRI is sensitive for the detection of brain abscess. [25]

A number of different imaging modalities or sequences can be used with imaging the nervous system:

False color MRI by applying red to T1, green to PD and blue to T2. Click here to scroll through the stack, and for further description of the colors. Brain MRI 0230 15.jpg
False color MRI by applying red to T1, green to PD and blue to T2.

Diagnostic Usage

MRI of the brain and head has multiple diagnostic usages, including identifying aneurysms, strokes, tumors and other brain injury. [30] In many diseases, such as Parkinson's or Alzheimer's, MRI is useful to help differentially diagnose against other diseases. [31] [32] On the topic of diagnosis, MRI data has been used with deep learning networks to identify brain tumors. [33]

See also

Related Research Articles

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References

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  3. ↑ Le Bihan D, Breton E (1987). "Method to Measure the Molecular Diffusion and/or Perfusion Parameters of Live Tissue". US Patent # 4,809,701.
  4. ↑ Villringer A, Rosen BR, Belliveau JW, Ackerman JL, Lauffer RB, Buxton RB, Chao YS, Wedeen VJ, Brady TJ (February 1988). "Dynamic imaging with lanthanide chelates in normal brain: contrast due to magnetic susceptibility effects". Magnetic Resonance in Medicine. 6 (2): 164–74. doi:10.1002/mrm.1910060205. PMID   3367774. S2CID   41228095.
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  22. ↑ American Medical Society for Sports Medicine (24 April 2014), "Five Things Physicians and Patients Should Question", Choosing Wisely: an initiative of the ABIM Foundation , American Medical Society for Sports Medicine, retrieved 29 July 2014
  23. ↑ Churchill Nathan W., Hutchison Michael G., Richards Doug, Leung General, Graham Simon J., Schweizer Tom A. (2017). "The first week after concussion: Blood flow, brain function and white matter microstructure". NeuroImage: Clinical. 14: 480–489. doi:10.1016/j.nicl.2017.02.015. PMC   5334547 . PMID   28280686.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  24. ↑ Garel C (2004). MRI of the fetal brain: normal development and cerebral pathologies. Springer. ISBN   978-3-540-40747-8 . Retrieved 24 July 2011.
  25. ↑ Rath, Tanya J.; Hughes, Marion; Arabi, Mohammad; Shah, Gaurang V. (2012). "Imaging of Cerebritis, Encephalitis, and Brain Abscess". Neuroimaging Clinics of North America. 22 (4). Elsevier BV: 585–607. doi:10.1016/j.nic.2012.04.002. ISSN   1052-5149. PMID   23122258.
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  27. ↑ Tofts, Paul (2005-09-01). Quantitative MRI of the Brain: Measuring Changes Caused by Disease. John Wiley and Sons. pp. 86–. ISBN   978-0-470-86949-9 . Retrieved 18 July 2011.
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  29. ↑ Granacher RP (2007-12-20). Traumatic brain injury: methods for clinical and forensic neuropsychiatric assessment. CRC Press. pp. 247–. ISBN   978-0-8493-8138-6 . Retrieved 18 July 2011.
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