T2 mapping - myocardium
T2 mapping is a magnetic resonance imaging technique used to calculate the T2 times of a certain tissue and display them voxel-vice on a parametric map. It has been used for tissue characterization of the myocardium 1-5 and has been investigated for cartilage 6,7 and other tissues 4.
The T2 time, also referred to as the spin-spin or transverse relaxation, is a time constant for the decay of transverse magnetization 1-3 and is tissue-specific in regard to its ability to differentiate normal from abnormal 5,6.
Alterations in the T2 time is not specific for a single disease, but reflect changes in tissue composition and can be used to receive further valuable information about certain disease processes and together with other parameters or in the context of a certain clinical scenario 1. This can help in the diagnosis of a disease or the assessment of disease activity 1 or its repair 6.
T2 values reflect water content in the respective tissue4 and within the myocardium T2 maps are mainly used for the evaluation of myocardial edema in the context of myocardial inflammation or myocardial infarction, but also in other pathologies 1,4.
T2 mapping has been conducted with T2 turbo spin multi-echo (T2-TSE) 2,5, T2 prepared steady-state free precession (T2p-SFFP) 2,5,8,9, as well as T2 gradient spin echo mapping sequences (T2-GraSE) 10,11. No matter which acquisition technique used a series of co-registered images is acquired with different T2 echo times 1-4,6-8.
T2 values can then be computed pixel-wise from a signal intensity versus echo time curve fitting model 1-3,12. The variation of other weight factors, e.g. T1 off-resonance, needs to be corrected if not negligible small and displacement between the images of the series should be avoided, in order to get accurate values 1,12.
The respective voxels can then be quantified and evaluated on the basis of normal reference values in diffuse disease. In focal disease, the voxels can be compared to the spared healthy myocardium.
Advantages vs other T2w images
T2-mapping offers potential for more objective detection and quantification of myocardial edema than standard black-blood T2 and STIR image, which are often of limited value due to susceptibility or slow-motion artefacts and have limited value for quantitative evaluation 1,2,9.
T2 time is related to the water content of the respective tissue, hence the myocardium and thus prolonged T2 reflects myocardial edema 1-4,9.
Myocardial T2 tends to decrease at higher magnetic field strength 13.
T2-mapping can detect and assess myocardial edema in a variety of cardiac pathologies including 1-5,8,10,15-17:
- acute coronary syndrome/myocardial infarction
- assessing disease activity
- Tako-tsubo cardiomyopathy
- heart transplant rejection
- cardiac amyloidosis
In addition, it is of some use in the following pathologies due to low values 1,3:
Normal values of T2 times differ depending on magnetic field strength (1,5 and 3 Tesla), acquisition sequence (T2-SSFP, GraSE). Because of variations between scanners the primary use of a local reference range is recommended 1,4 and if a local reference range is not available quantitative results should not be clinically reported 1,4.
- 1. Daniel R. Messroghli, James C. Moon, Vanessa M. Ferreira, Lars Grosse-Wortmann, Taigang He, Peter Kellman, Julia Mascherbauer, Reza Nezafat, Michael Salerno, Erik B. Schelbert, Andrew J. Taylor, Richard Thompson, Martin Ugander, Ruud B. van Heeswijk, Matthias G. Friedrich. Clinical recommendations for cardiovascular magnetic resonance mapping of T1, T2, T2* and extracellular volume: A consensus statement by the Society for Cardiovascular Magnetic Resonance (SCMR) endorsed by the European Association for Cardiovascular Imaging (EACVI). (2017) Journal of Cardiovascular Magnetic Resonance. 19 (1): 1. doi:10.1186/s12968-017-0389-8
- 2. Salerno M, Kramer CM. Advances in parametric mapping with CMR imaging. (2013) JACC. Cardiovascular imaging. 6 (7): 806-22. doi:10.1016/j.jcmg.2013.05.005 - Pubmed
- 3. Ferreira VM, Piechnik SK, Robson MD, Neubauer S, Karamitsos TD. Myocardial tissue characterization by magnetic resonance imaging: novel applications of T1 and T2 mapping. (2014) Journal of thoracic imaging. 29 (3): 147-54. doi:10.1097/RTI.0000000000000077 - Pubmed
- 4. Dekkers IA, Lamb HJ. Clinical application and technical considerations of T & T(*) mapping in cardiac, liver, and renal imaging. (2018) The British journal of radiology. 91 (1092): 20170825. doi:10.1259/bjr.20170825 - Pubmed
- 5. Kim PK, Hong YJ, Im DJ, Suh YJ, Park CH, Kim JY, Chang S, Lee HJ, Hur J, Kim YJ, Choi BW. Myocardial T1 and T2 Mapping: Techniques and Clinical Applications. (2017) Korean journal of radiology. 18 (1): 113-131. doi:10.3348/kjr.2017.18.1.113 - Pubmed
- 6. Nieminen MT, Nissi MJ, Mattila L, Kiviranta I. Evaluation of chondral repair using quantitative MRI. (2012) Journal of magnetic resonance imaging : JMRI. 36 (6): 1287-99. doi:10.1002/jmri.23644 - Pubmed
- 7. Guermazi A, Alizai H, Crema MD, Trattnig S, Regatte RR, Roemer FW. Compositional MRI techniques for evaluation of cartilage degeneration in osteoarthritis. (2015) Osteoarthritis and cartilage. 23 (10): 1639-53. doi:10.1016/j.joca.2015.05.026 - Pubmed
- 8. Huang TY, Liu YJ, Stemmer A, Poncelet BP. T2 measurement of the human myocardium using a T2-prepared transient-state TrueFISP sequence. (2007) Magnetic resonance in medicine. 57 (5): 960-6. doi:10.1002/mrm.21208 - Pubmed
- 9. Shivraman Giri, Yiu-Cho Chung, Ali Merchant, Georgeta Mihai, Sanjay Rajagopalan, Subha V Raman, Orlando P Simonetti. T2 quantification for improved detection of myocardial edema. (2009) Journal of Cardiovascular Magnetic Resonance. 11 (1): 1. doi:10.1186/1532-429X-11-56 - Pubmed
- 10. Alois M Sprinkart, Julian A Luetkens, Frank Träber, Jonas Doerner, Jürgen Gieseke, Bernhard Schnackenburg, Georg Schmitz, Daniel Thomas, Rami Homsi, Wolfgang Block, Hans Schild, Claas P Naehle. Gradient Spin Echo (GraSE) imaging for fast myocardial T2 mapping. (2015) Journal of Cardiovascular Magnetic Resonance. 17 (1): 1. doi:10.1186/s12968-015-0127-z - Pubmed
- 11. Baeßler B, Schaarschmidt F, Stehning C, Schnackenburg B, Maintz D, Bunck AC. Cardiac T2-mapping using a fast gradient echo spin echo sequence - first in vitro and in vivo experience. (2015) Journal of cardiovascular magnetic resonance : official journal of the Society for Cardiovascular Magnetic Resonance. 17: 67. doi:10.1186/s12968-015-0177-2 - Pubmed
- 12. Akçakaya M, Basha TA, Weingärtner S, Roujol S, Berg S, Nezafat R. Improved quantitative myocardial T mapping: Impact of the fitting model. (2015) Magnetic resonance in medicine. 74 (1): 93-105. doi:10.1002/mrm.25377 - Pubmed
- 13. Baeßler B, Schaarschmidt F, Stehning C, Schnackenburg B, Maintz D, Bunck AC. A systematic evaluation of three different cardiac T2-mapping sequences at 1.5 and 3T in healthy volunteers. (2015) European journal of radiology. 84 (11): 2161-70. doi:10.1016/j.ejrad.2015.08.002 - Pubmed
- 14. Verhaert D, Thavendiranathan P, Giri S, Mihai G, Rajagopalan S, Simonetti OP, Raman SV. Direct T2 quantification of myocardial edema in acute ischemic injury. (2011) JACC. Cardiovascular imaging. 4 (3): 269-78. doi:10.1016/j.jcmg.2010.09.023 - Pubmed
- 15. Paaladinesh Thavendiranathan, Michael Walls, Shivraman Giri, David Verhaert, Sanjay Rajagopalan, Sean Moore, Orlando P. Simonetti, Subha V. Raman. Improved Detection of Myocardial Involvement in Acute Inflammatory Cardiomyopathies Using T2 Mapping. (2012) Circulation: Cardiovascular Imaging. 5 (1): 102-10. doi:10.1161/CIRCIMAGING.111.967836 - Pubmed
- 16. Asad A. Usman, Kirsi Taimen, Marie Wasielewski, Jennifer McDonald, Saurabh Shah, Shivraman Giri, William Cotts, Edwin McGee, Robert Gordon, Jeremy D. Collins, Michael Markl, James C. Carr. Cardiac Magnetic Resonance T2 Mapping in the Monitoring and Follow-up of Acute Cardiac Transplant Rejection. (2012) Circulation: Cardiovascular Imaging. 5 (6): 782-90. doi:10.1161/CIRCIMAGING.111.971101 - Pubmed
- 17. Lota AS, Gatehouse PD, Mohiaddin RH. T2 mapping and T2* imaging in heart failure. (2017) Heart failure reviews. 22 (4): 431-440. doi:10.1007/s10741-017-9616-5 - Pubmed
- 18. Kotecha T, Martinez-Naharro A, Treibel TA, Francis R, Nordin S, Abdel-Gadir A, Knight DS, Zumbo G, Rosmini S, Maestrini V, Bulluck H, Rakhit RD, Wechalekar AD, Gilbertson J, Sheppard MN, Kellman P, Gillmore JD, Moon JC, Hawkins PN, Fontana M. Myocardial Edema and Prognosis in Amyloidosis. (2018) Journal of the American College of Cardiology. 71 (25): 2919-2931. doi:10.1016/j.jacc.2018.03.536 - Pubmed