Comparison of T1 mapping techniques for ECV quantification. Histological validation and reproducibility of ShMOLLI versus multibreath-hold T1 quantification equilibrium contrast CMR.
Comparison of T1 mapping techniques for ECV quantification. Histological validation and reproducibility of ShMOLLI versus multibreath-hold T1 quantification equilibrium contrast CMR.
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DOI：
10.1186/1532-429x-14-88
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发表时间：
2012-12-28
期刊：
影响因子：
--
通讯作者：
Moon JC
中科院分区：
文献类型：
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作者：
Fontana M;White SK;Banypersad SM;Sado DM;Maestrini V;Flett AS;Piechnik SK;Neubauer S;Roberts N;Moon JC
心肌细胞外容积（ECV）在纤维化或浸润中升高，并且可以通过在足够的对比平衡下测量对比前后T1的红细胞压积来量化。平衡CMR（EQ-CMR），使用大剂量输注方案，已被证明可以提供强大的测量ECV使用多屏气T1脉冲序列。用于T1标测的更新、更快的序列有望覆盖整个心脏并提高临床实用性，但尚未得到验证。在平衡对比CMR中使用心率校正的多次屏气T1定量和使用缩短的修正Look-Inversion恢复（ShMOLLI）的单次屏气T1标测，以生成ECV值，并以3种方式进行比较。首先，两种技术在具有可变ECV扩张的疾病谱中进行比较（n=100，50名健康志愿者，12名肥厚型心肌病患者，18名重度主动脉瓣狭窄患者，20名淀粉样蛋白患者）。其次，两种技术均与人组织学胶原体积分数（CVF%，n=18，重度主动脉瓣狭窄活检）相关。第三，在具有广泛不同ECV的个体（n=10名健康志愿者，n=7名淀粉样蛋白患者）中，间隔1周进行2种CMR技术的测试：重测再现性的评估。更多的患者能够进行ShMOLLI比多屏气技术（6%无法屏气）。多次屏气T1和ShMOLLI计算的ECV显示出强相关性（r2=0.892）、小偏倚（偏倚-2.2%，95%CI-8.9%至4.6%）和良好的一致性（ICC 0.922，范围0.802至0.961，p<0.0001）。多屏气ECV与组织学CVF%相关（r2= 0.589），但ShMOLLI ECV更好（r2= 0.685）。研究间重现性表明，ShMOLLI ECV的重现性倾向于高于多次屏气ECV，尽管这未达到统计学显著性（95%CI分别为-4.9%至5.4%和-6.4%至7.3%，p=0.21）。通过单次屏气ShMOLLI T1标测的ECV量化可以通过EQ-CMR测量整个间质扩张谱的ECV。与旧的多次屏气FLASH技术相比，它在手术上耐受性更好，重现性略高，与组织学相关性更好。
Myocardial 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. Multibreathhold 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). More 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). ECV 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.