- Email: [email protected]
Re: Assessment of myocardial fibrosis with T1 mapping MRI. A reply
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Correspondence / Clinical Radiology 71 (2016) 1309e1310
5. Rutherford E, Talle M, Mangion K, et al. Defining myocardial tissue abnormalities in end-stage renal failure with cardiac magnetic resonance imaging using native T1 mapping. Kidney Int 2016 Oct;90(4):845e52. 6. Maestrini V, Treibel T, White S, et al. T1 Mapping for characterization of intracellular and extracellular myocardial diseases in heart failure. Curr Cardiovasc Imaging Rep 2014;7(9287).
M.K. Hayer*, C.J. Ferro, J.N. Townend, R.P. Steeds, N.C. Edwards University Hospitals Birmingham NHS Foundation Trust, Edgbaston, Birmingham, UK * Guarantor and correspondent. E-mail address: [email protected] (M.K. Hayer) http://dx.doi.org/10.1016/j.crad.2016.09.005 Ó 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
Re: Assessment of myocardial fibrosis with T1 mapping MRI. A reply SirdWe thank Hayer et al. for their interest in our manuscript and their comments, with which we largely agree. Certainly diffuse interstitial myocardial fibrosis appears to be a final common pathway in many cardiac pathologies, including chronic kidney disease. The challenge that we therefore face is in teasing out the relative contributions of different potential aetiological factors (including the important contribution of age), particularly in individual patients with multiple comorbidities. Moreover T1 mapping may also reflect changes in the intravascular space (and intercellular space for native T1) and so is not necessarily specific for fibrosis. Although the concept of native T1 as a continuous variable reflecting general cardiovascular
DOIs of original article: http://dx.doi.org/10.1016/j.crad.2016.09.005, http://dx.doi.org/10.1016/j.crad.2016.02.013.
risk is intriguing, it is only likely to be clinically relevant if the principle precipitant can be identified and treated. Ultimately there are cheaper and more accessible non-specific risk markers that are either available (e.g., BNP) or emerging (high-sensitivity troponin) that might better fill this space. In our opinion advanced imaging needs to provide a degree of specificity in order to be clinically useful and justify its additional expense. Finally, there is the related issue of the wide overlap in T1 values observed between different disease states and indeed control subjects. This is compounded by the relatively narrow range over which T1 mapping values vary (e.g., ECV 30% for severe fibrosis and ECV 26% for normal myocardium) compared to the accuracy in the measurements (ECV 1e2%). As a consequence, it is hard to envisage T1 mapping being useful currently in tracking changes in myocardial fibrosis over time or in response to therapeutic intervention. The exception being perhaps rare conditions such as Fabry’s disease or amyloidosis. We therefore maintain that there is a need to develop better T1 mapping parameters or complimentary magnetic resonance approaches before this imaging technique is ready for widespread clinical use. a
R.J. Everetta,*, M.R. Dwecka, S. Mirsadraeeb British Heart Foundation/University Centre for Cardiovascular Science, University of Edinburgh, UK b
Royal Brompton and Harefield NHS Trust, London, UK * Guarantor and correspondent. E-mail address: [email protected] (R.J. Everett)
http://dx.doi.org/10.1016/j.crad.2016.09.004 Ó 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
Correspondence / Clinical Radiology 71 (2016) 1309e1310
5. Rutherford E, Talle M, Mangion K, et al. Defining myocardial tissue abnormalities in end-stage renal failure with cardiac magnetic resonance imaging using native T1 mapping. Kidney Int 2016 Oct;90(4):845e52. 6. Maestrini V, Treibel T, White S, et al. T1 Mapping for characterization of intracellular and extracellular myocardial diseases in heart failure. Curr Cardiovasc Imaging Rep 2014;7(9287).
M.K. Hayer*, C.J. Ferro, J.N. Townend, R.P. Steeds, N.C. Edwards University Hospitals Birmingham NHS Foundation Trust, Edgbaston, Birmingham, UK * Guarantor and correspondent. E-mail address: [email protected] (M.K. Hayer) http://dx.doi.org/10.1016/j.crad.2016.09.005 Ó 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
Re: Assessment of myocardial fibrosis with T1 mapping MRI. A reply SirdWe thank Hayer et al. for their interest in our manuscript and their comments, with which we largely agree. Certainly diffuse interstitial myocardial fibrosis appears to be a final common pathway in many cardiac pathologies, including chronic kidney disease. The challenge that we therefore face is in teasing out the relative contributions of different potential aetiological factors (including the important contribution of age), particularly in individual patients with multiple comorbidities. Moreover T1 mapping may also reflect changes in the intravascular space (and intercellular space for native T1) and so is not necessarily specific for fibrosis. Although the concept of native T1 as a continuous variable reflecting general cardiovascular
DOIs of original article: http://dx.doi.org/10.1016/j.crad.2016.09.005, http://dx.doi.org/10.1016/j.crad.2016.02.013.
risk is intriguing, it is only likely to be clinically relevant if the principle precipitant can be identified and treated. Ultimately there are cheaper and more accessible non-specific risk markers that are either available (e.g., BNP) or emerging (high-sensitivity troponin) that might better fill this space. In our opinion advanced imaging needs to provide a degree of specificity in order to be clinically useful and justify its additional expense. Finally, there is the related issue of the wide overlap in T1 values observed between different disease states and indeed control subjects. This is compounded by the relatively narrow range over which T1 mapping values vary (e.g., ECV 30% for severe fibrosis and ECV 26% for normal myocardium) compared to the accuracy in the measurements (ECV 1e2%). As a consequence, it is hard to envisage T1 mapping being useful currently in tracking changes in myocardial fibrosis over time or in response to therapeutic intervention. The exception being perhaps rare conditions such as Fabry’s disease or amyloidosis. We therefore maintain that there is a need to develop better T1 mapping parameters or complimentary magnetic resonance approaches before this imaging technique is ready for widespread clinical use. a
R.J. Everetta,*, M.R. Dwecka, S. Mirsadraeeb British Heart Foundation/University Centre for Cardiovascular Science, University of Edinburgh, UK b
Royal Brompton and Harefield NHS Trust, London, UK * Guarantor and correspondent. E-mail address: [email protected] (R.J. Everett)
http://dx.doi.org/10.1016/j.crad.2016.09.004 Ó 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.