Magnetic resonance spectroscopy

from Wikipedia, the free encyclopedia
Magnetic resonance spectroscopy of a section in a patient's brain. In the three MRT images on the left, the measurement area is marked by the white box. On the right the associated NMR spectrum with the peaks of NAA (N-acetylaspartate) Cho (choline) and Cr (creatine / phosphocreatine)

In medicine and biochemistry, magnetic resonance spectroscopy (MRS) is a method based on nuclear magnetic resonance with which biochemical observations can be carried out spatially resolved in a volume element. Different chemical substances (→ metabolites ) in living tissue can be identified and quantified based on their chemical shift .

Basics

The magnetic resonance spectroscopy ( MRS ) is derived from the NMR spectroscopy , and usually refers to the in vivo method for the measurement of metabolite concentrations in various tissues. Most often, measurements are carried out on the hydrogen ( 1 H) nuclei, which are best accessible by NMR and which are present in large quantities in biological tissues , and more rarely on phosphorus ( 31 P) or carbon ( 13 C). (More basics about NMR spectroscopy there.)

With the help of the 1 H-MRS on a clinical magnetic resonance imaging system, N-acetylaspartate can be detected as a neuronal marker or molecules containing choline as a cell membrane marker. In addition, lactate and citrate as well as the CH 2 and CH 3 groups of lipids and other macromolecules can be detected. The 31 P-MRS is mainly used to study cellular energy metabolism, while the 13 C-MRS provides an insight into the cellular glucose metabolism. Clinical studies have mainly been performed on the brain, skeletal muscle, heart, liver and prostate. In recent years, clinical MRS studies in oncology have increased significantly.

technology

The MRS makes it possible to display biochemical properties of tissue and to recognize differences from the physiological norm. Benign prostate tissue contains more citrate but less choline than degenerate tissue. In the living brain, it enables the metabolism of phospholipids and energy-rich phosphates to be represented.

With MRS, a certain volume, which is previously positioned on overview images, can be measured in a tissue. This method is also known as single voxel spectroscopy (SVS). It is also possible to measure several voxels at the same time, a larger localized volume being divided into several small volumes by phase coding. This method is called multivoxel spectroscopy or Chemical Shift Imaging (CSI) and can be carried out in two or three dimensions.

Areas of application

Prostate cancer : When combined with magnetic resonance imaging , three-dimensional MRS can indicate the presence of malignant prostate tissue with a probability of approx. 90% if the results of both procedures are the same. The combination of both procedures can be helpful both in the planning of biopsies and therapies of the prostate, as well as to control the success of a therapy.

Competitive sport : With the 1 H-MRS it is possible to estimate the carnosine content , which correlates with the relative proportion of muscle fiber types. This allows, for example, a prognosis regarding the speed strength potential of muscle groups. The individual comparison of examination results before and after training sessions is also used to assess the training effect.

It is also used in schizophrenia research.

See also

Individual evidence

  1. ↑ C. Geppert: Methodical developments for spectroscopic 1H-NMR imaging. Cuvillier Verlag, 2005, ISBN 3-86537-510-3 , p. 104 ( limited preview in Google book search).
  2. ↑ DA Porter, MA Smith: Magnetic resonance spectroscopy in vivo . In: Journal of biomedical engineering . tape 10 , no. 6 , 1988, pp. 562-568 , PMID 3070174 .
  3. ^ Robert W. Prost: Magnetic resonance spectroscopy . In: Medical Physics . tape 35 , no. 10 , 2008, p. 4530-4544 , doi : 10.1118 / 1.2975225 .
  4. ↑ a b I. Jane Cox: Development and applications of in vivo clinical magnetic resonance spectroscopy . In: Progress in Biophysics and Molecular Biology . tape 65 , no. 1-2 , pp. 45-81 , doi : 10.1016 / S0079-6107 (96) 00006-5 .
  5. ^ A. Shukla-Dave, H. Hricak, PT Scardino: Imaging low-risk prostate cancer . In: Current opinion in urology . tape 18 , no. 1 , 2008, p. 78-86 , doi : 10.1097 / MOU.0b013e3282f13adc .
  6. ↑ JL Spratlin, NJ Serkova, SG Eckhardt: Clinical applications of metabolomics in oncology: a review . In: Clinical Cancer Research . tape 15 , no. 2 , 2009, p. 431-440 , doi : 10.1158 / 1078-0432.CCR-08-1059 .
  7. ↑ a b U. G. Mueller-Lisse, M. Scherr: 1H-MR spectroscopy of the prostate: An overview . In: The Radiologist . tape 43 , no. 6 , 2003, p. 481-488 , doi : 10.1007 / s00117-003-0902-y .
  8. ↑ a b S. Riehemann, HP Volz, S. Smesny, Gabriele Hübner, B. Wenda, Grit Rößger, H. Sauer: Phosphorus Magnetic Resonance Spectroscopy in Schizophrenia Research On the pathophysiology of the cerebral metabolism of high-energy phosphates and membrane phospholipids . In: The neurologist . tape 71 , no. 5 , 2000, pp. 354-363 , doi : 10.1007 / s001150050569 .
  9. ↑ J. Frahm, H. Bruhn, ML Gyngell, KD Merboldt, W. Hänicke, R. Sauter: Localized high-resolution proton NMR spectroscopy using stimulated echoes: Initial applications to human brain in vivo . In: Magnetic Resonance in Medicine . tape 9 , no. 1 , 1989, pp. 79-93 , doi : 10.1002 / mrm.1910090110 .
  10. ↑ Oded Gonen, James B. Murdoch, Radka Stoyanova, Gadi Goelman: 3D multivoxel proton spectroscopy of human brain using a hybrid of 8th-order hadamard encoding with 2D chemical shift imaging . In: Magnetic Resonance in Medicine . tape 39 , no. 1 , 1998, p. 34-40 , doi : 10.1002 / mrm.1910390108 .
  11. ^ A. Baguet, I. Everaert, P. Hespel et al .: A new method for non-invasive estimation of human muscle fiber type composition. In: PLoS ONE. July 7, 2011, doi : 10.1371 / journal.pone.0021956 , PMC 3131401 (free full text).