Elastography
As a newer imaging method, elastography (syn. Elastography) is a further development of both ultrasound diagnostics and magnetic resonance tomography (MRT) and actually goes back to centuries-old manual palpation by hand. It became known as early as 1991, but was not clinically applicable until much later. The corresponding procedures are ultrasound elastography and MR elastography. Elastography is often used to detect tumors .
Working principle
Analogous to manual palpation, elastography uses the fact that tumor tissue is often differently compressible (firmer, coarser) than healthy tissue. This method tries to map the visco-elastic properties of tissue. In ultrasound elastographic examinations, the examiner exerts a slight external pressure on the organ with the ultrasound head during the ultrasound examination . Software evaluates small shifts between the individual images and shows the expansion in a spatially resolved manner. Areas that are stretched a lot are soft; solid areas cannot be compressed. Therefore, differences in elasticity in the tissue can be shown. With automatic MRT elastography, the examined organ is cyclically compressed and relieved again by pressure waves acting automatically from the outside, while synchronous (phase-locked) recordings are made. After the examination, an elastogram is automatically made that shows the differences in elasticity. In this way it may be possible to distinguish benign from malignant tumors.
The Sonoelastische imaging is a similar process in which the propagation velocity of ultrasound in the tissue through the Doppler detected technique.
Applications
- One of the applications is the detection of prostate cancer , thyroid cancer and breast cancer (see also breast ultrasound ). In both cases, however, an exact diagnosis must be made by evaluating a biopsy .
- Another application is the determination of the degree of fibrosis in liver cirrhosis , for example on the basis of hepatitis C (see also transient elastography ).
- The technique is also used to study the extensibility / elasticity of coronary arteries .
- Ultrasound elastography can be used to assess tendon injuries and the effectiveness of rehabilitation measures. In comparison to compression elastography (strain elastography), shear wave elastography provides more objective results.
- Shear wave elastography has been used to measure mechanical properties of muscles .
- Elastography can also be used to distinguish tense muscle fiber bundles and myofascial trigger points from the surrounding tissue.
Specialist literature
- H.-J. Sommerfeld, J. M. Garcia-Schürmann, J. Schewe u. a .: Prostate cancer diagnosis using ultrasound elastography - presentation of a new method and first clinical results. In: Der Urologe, Edition A. Vol. 42, No. 7, 2003, pp. 941-945. PMID 12898038 ; doi : 10.1007 / s00120-003-0297-4 .
- J. Lorenzen, R. Sinkus, G. Adam: Elastography: Quantitative imaging of the elastic tissue properties. In: Fortschr. Röntgenstrasse Vol. 175, No. 5, 2003, pp. 623-630. PMID 12743853 ; doi : 10.1055 / s-2003-39199 .
- I. Sack: Magnetic resonance elastography. In: Dtsch. med. Weekly Vol. 133, No. 6, 2008, pp. 247-251. PMID 18236351 ; doi : 10.1055 / s-2008-1017505 .
Web links
- Ultrasound elastography - dark areas can be prostate cancer , Ärzte Zeitung of January 25, 2006
- Brief introduction to ultrasound elastography, Deutsches Ärzteblatt, April 15, 2005 (PDF file; 38 kB)
- Dissertation on magnetic resonance elastography, University of Heidelberg, 2004 (PDF file; 4.42 MB)
Individual evidence
- ^ R. Prado-Costa, J. Rebelo, J. Monteiro-Barroso, AS Preto: Ultrasound elastography: compression elastography and shear-wave elastography in the assessment of tendon injury . In: Insights into Imaging . tape 9 , no. 5 , 2018, p. 791-814 , doi : 10.1007 / s13244-018-0642-1 , PMID 30120723 , PMC 6206379 (free full text).
- ^ S. Sadeghi, C. Newman, DH Cortes: Change in skeletal muscle stiffness after running competition is dependent on both running distance and recovery time: a pilot study . In: PeerJ . tape 6 , 2018, p. e4469 , doi : 10.7717 / peerj.4469 , PMID 29576951 , PMC 5853607 (free full text).
- ↑ Hans Ulrich Hecker, Angelika Steveling, Elmar T. Peuker, Kay Liebchen: Pocket Atlas Acupuncture and Trigger Points , Haug Fachbuch, 2015, ISBN 978-3-8304-7842-3 . P. 213 .
- ^ DG Simons: New views of myofascial trigger points: etiology and diagnosis . In: Archives of Physical Medicine and Rehabilitation . tape 89 , no. 1 , 2008, p. 157-159 , doi : 10.1016 / j.apmr.2007.11.016 , PMID 18164347 .
- ↑ TP Do, GF Heldarskard, LT Kolding, J. Hvedstrup, HW Schytz: Myofascial trigger points in migraine and tension-type headache . In: The Journal of Headache and Pain . tape 19 , no. 1 , 2018, p. 84 , doi : 10.1186 / s10194-018-0913-8 , PMID 30203398 , PMC 6134706 (free full text).