Seminars in Roentgenology
Volume 43, Issue 4 , Pages 259-260, October 2008

Letter from the Editor: The History of MRI

Article Outline

 

The magnetic resonance imaging (MRI) industry is producing over 2000 units per year, with the United States alone having 40% of the world marketing and production of MRI.1 The basic hardware components of all MRI systems are the magnet, producing a stable and very intense magnetic field, the gradient coils, creating a variable field, and radiofrequency coils, which are used to transmit energy and to encode spatial positioning. A computer controls the MRI scanning operation and processes the information. This technology can be simply described in the four following steps: (1) creating a steady state of magnetism within the human body; (2) stimulating the body with radio waves to change the steady-state orientation of protons; (3) stopping the radio waves and registering the body's electromagnetic transmission; and (4) constructing internal images of the body using the transmitted signal and computerized axial tomography.

The first MRI devices were constructed as long narrow tunnels. The magnets became shorter and wider, and in addition to this short-bore magnet design, open MRI machines were created.2 In the future, real-time MRI scans may be available. Individual components of an MRI system are typically manufactured separately and then assembled into a large unit. These units are extremely heavy, sometimes weighing over 100 tons.3

Early MRIs were constructed based solely on the concentration of protons within a given tissue.3 These images, however, did not provide good resolution. MRI became much more useful for constructing an internal image of the body when a phenomena known as relaxation time, the time it takes for the protons to emit their signal, was taken into consideration. In all body tissues, there are two types of relaxation times, T1 and T2, that can be detected. Different types of tissues will exhibit different T1 and T2 values. Today, MRI is capable of providing both morphological and functional information about the body. Numerous sequences have been developed, and continue to be in development, which improve the utility of MRI as a diagnostic tool.

In its development, MRI has incorporated a multidisciplinary team of radiologists, technicians, clinicians, and scientists who have made, and are continuing to make, combined efforts in further extending the clinical usefulness and effectiveness of this technique.4 Listed below are some of the seminal events that have occurred in the history of MRI. See if you can match the names of the investigators with their accomplishments.

My sincere thanks to Dr. David Bluemke for Guest Editing this double issue on MRI: State of the Art. Thanks also to each of the authors, who have applied their expertise to bring us the most up-to-date information on the MRI topics covered.


A.Paul Lauterbur and Peter Mansfield

B.Godfrey Hounsfield and Allan Cormack

C.Paul Lauterbur

D.Felix Bloch and Edward Purcell

E.Jürgen Hennig, A. Nauerth, and Hartmut Friedburg

F.Nikola Tesla

G.J.J. Thomson

H.Erwin Hahn

I.Raymond Damadian

J.Isador Isaac Rabi

K.Richard Ernst


1._____ discovered the rotating magnetic field in 1882 in Budapest, Hungary.

2._____ produced the first NMR image in 1973 in Stony Brook, New York.

3._____ was awarded the Nobel Prize for Physics in 1952 for the first successful nuclear magnetic resonance experiment to study chemical compounds.

4._____ patented the design and use of NMR for detecting cancer in 1974.

5._____ was awarded the Nobel Prize in Medicine or Physiology in 2003 for the invention of magnetic resonance imaging.

6._____ introduced RARE (rapid acquisition with relaxation enhancement) imaging in 1986 (this technique is also known under the commercial names of fast or turbo spin-echo).

7._____ discovered the electron in 1897.

8._____ received the 1944 Nobel Prize in Physics for developing molecular beam magnetic resonance as a technique for studying the magnetic properties and internal structure of molecules, atoms, and nuclei.

9._____ discovered the phenomenon known as “spin echo” in the late 1940s, which proved important for measuring relaxation times.

10._____ won the Nobel Prize in Chemistry in 1991 for his contributions to the development of high-resolution NMR spectroscopy.

11._____ was awarded the Nobel Prize in Physiology or Medicine for the development of computerized tomography.

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References 

  1. Tesla Memorial Society of New York. A short history of the magnetic resonance imaging (MRI). http://www.teslasociety.com/mri.htmAccessed May 20, 2007
  2. Magnetic Resonance Technology Information Portal. MRI History. http://www.mr-tip.com/serv1.php?type=db1&dbs=MRI%20HistoryAccessed May 20, 2007
  3. Magnetic Resonance Imaging (MRI). http://www.madehow.com/Volume-3/Magnetic-Resonance-Imaging-MRI.htmlAccessed May 20, 2007
  4. The University of Manchester. History of MRI. http://www.isbe.man.ac.uk/personal/dellard/dje/history_mri/history%20of%20mri.htmAccessed May 20, 2007
  5. eMedicineHealth. Magnetic Resonance Imaging (MRI). http://www.emedicinehealth.com/script/main/art.asp?articlekey=59322&pf=3&page=1Accessed May 20, 2007
  6. Wikipedia. Raymond Vahan Damadian. http://en.wikipedia.org/wiki/Raymond_Vahan_DamadianAccessed May 20, 2007
  7. EMRF Foundation. FAQs History of MRI. http://www.emrf.org/FAQs%20MRI%20History.htmlAccessed May 20, 2007
  8. The National AcademiesNational Academy of Sciences. Magnetic Resonance Imaging—Summary (Beyond Discovery. the Path from Research to Human Benefit). http://www.beyonddiscovery.org/content/view/article.asp?a=129Accessed May 20, 2007

 Answers: F, C, D, I, A, E, G, J, H, K, B.1, 5, 6, 7, 8

PII: S0037-198X(08)00043-6

doi:10.1053/j.ro.2008.06.001

Seminars in Roentgenology
Volume 43, Issue 4 , Pages 259-260, October 2008

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