Comparison of T1 mapping techniques for ECV quantification. Histological validation and reproducibility of ShMOLLI versus multibreath-hold T1 quantification equilibrium contrast CMR

Journal of Cardiovascular Magnetic Resonance

Research

Stefan Neubauer¹  Stefan K Piechnik¹  Neil Roberts²  Andrew S Flett³  Steve K White³  James C Moon³  Viviana Maestrini³  Sanjay M Banypersad³  Daniel M Sado³  Marianna Fontana³ 

[1] Department of Cardiovascular Medicine Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, OX3 9DU, Oxford, United Kingdom;The Heart Hospital, 16-18 Westmoreland Street, W1G 8PH, London, United Kingdom;The Heart Hospital, 16-18 Westmoreland Street, W1G 8PH, London, United Kingdom;Institute of Cardiovascular Science, University College London, WC1E 6BT, London, United Kingdom;

关键词: Interstitial space;    Fibrosis;    CMR;   

DOI  :  10.1186/1532-429X-14-88

 received in 2012-06-26, accepted in 2012-12-19,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundMyocardial extracellular volume (ECV) is elevated in fibrosis or infiltration and can be quantified by measuring the haematocrit with pre and post contrast T1 at sufficient contrast equilibrium. Equilibrium CMR (EQ-CMR), using a bolus-infusion protocol, has been shown to provide robust measurements of ECV using a multibreath-hold T1 pulse sequence. Newer, faster sequences for T1 mapping promise whole heart coverage and improved clinical utility, but have not been validated.MethodsMultibreathhold T1 quantification with heart rate correction and single breath-hold T1 mapping using Shortened Modified Look-Locker Inversion recovery (ShMOLLI) were used in equilibrium contrast CMR to generate ECV values and compared in 3 ways.Firstly, both techniques were compared in a spectrum of disease with variable ECV expansion (n=100, 50 healthy volunteers, 12 patients with hypertrophic cardiomyopathy, 18 with severe aortic stenosis, 20 with amyloid). Secondly, both techniques were correlated to human histological collagen volume fraction (CVF%, n=18, severe aortic stenosis biopsies). Thirdly, an assessment of test:retest reproducibility of the 2 CMR techniques was performed 1 week apart in individuals with widely different ECVs (n=10 healthy volunteers, n=7 amyloid patients).ResultsMore patients were able to perform ShMOLLI than the multibreath-hold technique (6% unable to breath-hold). ECV calculated by multibreath-hold T1 and ShMOLLI showed strong correlation (r2=0.892), little bias (bias -2.2%, 95%CI -8.9% to 4.6%) and good agreement (ICC 0.922, range 0.802 to 0.961, p<0.0001). ECV correlated with histological CVF% by multibreath-hold ECV (r2= 0.589) but better by ShMOLLI ECV (r2= 0.685). Inter-study reproducibility demonstrated that ShMOLLI ECV trended towards greater reproducibility than the multibreath-hold ECV, although this did not reach statistical significance (95%CI -4.9% to 5.4% versus 95%CI -6.4% to 7.3% respectively, p=0.21).ConclusionsECV quantification by single breath-hold ShMOLLI T1 mapping can measure ECV by EQ-CMR across the spectrum of interstitial expansion. It is procedurally better tolerated, slightly more reproducible and better correlates with histology compared to the older multibreath-hold FLASH techniques.

【 授权许可】

Unknown   
© Fontana et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.