Extracellular volume - myocardium
Citation, DOI, disclosures and article data
At the time the article was created Joachim Feger had no recorded disclosures.View Joachim Feger's current disclosures
At the time the article was last revised Joachim Feger had no recorded disclosures.View Joachim Feger's current disclosures
Extracellular volume (ECV) refers to the space or volume of a tissue, which is not occupied by cells. Apart from the usual extracellular space, which surrounds the cells of a specific tissue it also includes the intracapillary plasma volume 1,2. It measures the space, which is occupied by the extracellular matrix 1-4.
On this page:
A series of native T1 and postcontrast T1 images an acquired and co-registered. This can be done by an equilibrium infusion or after a bolus injection after waiting for a sufficient amount of time (15min) 1-5. T1 values can then be calculated pixel-wise from a signal intensity versus time curve fitting model 2. The administration of gadolinium leads to a shortening of the T1 value. Extracellular volume can be then calculated using the following formula 4:
ECV = (1-hct) [(1/pT1my - 1/nT1my) / (1/pT1bp - 1/nT1bp)]
nT1 = native T1, pT1 = postcontrast T1, my = myocardium, bp = blood pool, hct = hematocrit
It is of interest in the myocardium as a biomarker for interstitial disease. In the absence of any diffuse infiltrative disease or myocardial edema, it can be also considered as a biomarker for myocardial fibrosis 1-4.
Apart from fibrosis, it is elevated in the following myocardial diseases 1-4:
- ATTR-amyloidosis – prognostic value
- acute myocardial infarction / myocardial necrosis
- myocardial scar tissue/replacement fibrosis
Low values can occur in 4:
- lipomatous metaplasia/fat
- cardiac thrombus
Unlike native T1, extracellular volume seems not to be dependant on field strength, but similar to native T1 it varies between systole and diastole 2,4. There are only minor differences in regard to the myocardial region 6.
- 1. Moon J, Messroghli D, Kellman P et al. Myocardial T1 Mapping and Extracellular Volume Quantification: A Society for Cardiovascular Magnetic Resonance (SCMR) and CMR Working Group of the European Society of Cardiology Consensus Statement. J Cardiovasc Magn Reson. 2013;15(1):92. doi:10.1186/1532-429X-15-92 - Pubmed
- 2. Messroghli D, Moon J, Ferreira V et al. 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). J Cardiovasc Magn Reson. 2017;19(1):75. doi:10.1186/s12968-017-0389-8 - Pubmed
- 3. Ferreira V, Piechnik S, Robson M, Neubauer S, Karamitsos T. Myocardial Tissue Characterization by Magnetic Resonance Imaging: Novel Applications of T1 and T2 Mapping. J Thorac Imaging. 2014;29(3):147-54. doi:10.1097/RTI.0000000000000077 - Pubmed
- 4. Haaf P, Garg P, Messroghli D, Broadbent D, Greenwood J, Plein S. Cardiac T1 Mapping and Extracellular Volume (ECV) in Clinical Practice: A Comprehensive Review. J Cardiovasc Magn Reson. 2016;18(1):89. doi:10.1186/s12968-016-0308-4 - Pubmed
- 5. Schelbert E & Messroghli D. State of the Art: Clinical Applications of Cardiac T1 Mapping. Radiology. 2016;278(3):658-76. doi:10.1148/radiol.2016141802 - Pubmed
- 6. Kawel N, Nacif M, Zavodni A et al. T1 Mapping of the Myocardium: Intra-Individual Assessment of the Effect of Field Strength, Cardiac Cycle and Variation by Myocardial Region. J Cardiovasc Magn Reson. 2012;14(1):27. doi:10.1186/1532-429X-14-27 - Pubmed