Ohyama Yoshiaki, Ambale-Venkatesh Bharath, Chamera Elzbieta, Shehata Monda L, Corona-Villalobos Celia P, Zimmerman Stefan L, Hassoun Paul M, Bluemke David A, Lima Joao A C
Division of Cardiology, Johns Hopkins University, Baltimore, MD, USA.
Mercy Catholic Medical Center, Philadelphia, PA, USA.
Int J Cardiol. 2015 Mar 1;182:342-348. doi: 10.1016/j.ijcard.2015.01.016. Epub 2015 Jan 6.
Pixel-based multimodality tissue tracking (MTT) is a new noninvasive method for the quantification of cardiac deformation from cine image of MRI. The aim of this study is to validate bi-ventricular strain measurement by MTT compared to strain-encoding (SENC) MRI and harmonic phase (HARP) MRI in pulmonary hypertension (PH) patients.
In 45 subjects (30 PH patients and 15 normal subjects), RV and LV peak global longitudinal strains (Ell) were measured from long axis 4 chamber view using MTT. LV peak global circumferential strains (Ecc) by MTT were measured from short axis. For validation, RV and LV Ell by MTT were compared to measures by SENC-MRI from short axis, and LV Ecc by MTT was compared to measures by short axis tagged MRI analysis (HARP). Reproducibility of MTT was also determined.
MTT quantified RV Ell correlated closely to those of SENC (r=0.72, p<0.001), with good limits of agreement. LV Ell quantified by MTT showed moderate correlation with SENC (r=0.57, p=0.001), and LV Ecc by MTT also showed moderate correlation with HARP (-16.9±4.1 vs -14.3±3.5, p<0.001 for all, r=0.60, p<0.001). RV Ell negatively correlated with RVEF (r=-0.53, p=0.001) and also positively correlated with mean PAP in PH patients (r=0.60, p=0.001). Strain measurement by MTT showed high reproducibility.
We demonstrate that MTT is a reproducible tool for quantification of cardiac deformation using cine images in PH patients. Hence, it could serve as a new rapid and comprehensive technique for clinical assessment of regional cardiac function.
基于像素的多模态组织追踪（MTT）是一种从MRI电影图像中定量心脏变形的新型非侵入性方法。本研究的目的是在肺动脉高压（PH）患者中，将MTT测量的双心室应变与应变编码（SENC）MRI和谐波相位（HARP）MRI进行比较，以验证MTT测量双心室应变的准确性。
对45名受试者（30名PH患者和15名正常受试者），采用MTT从四腔心长轴视图测量右心室（RV）和左心室（LV）的整体纵向应变峰值（Ell）。通过MTT从短轴测量LV的整体圆周应变峰值（Ecc）。为进行验证，将MTT测量的RV和LV的Ell与短轴SENC-MRI测量值进行比较，将MTT测量的LV Ecc与短轴标记MRI分析（HARP）测量值进行比较。还确定了MTT的可重复性。
MTT定量的RV Ell与SENC测量值密切相关（r = 0.72，p < 0.001），一致性界限良好。MTT定量的LV Ell与SENC显示出中度相关性（r = 0.57，p = 0.001），MTT测量的LV Ecc与HARP也显示出中度相关性（-16.9±4.1对-14.3±3.5，总体p < 0.001，r = 0.60，p < 0.001）。在PH患者中，RV Ell与右心室射血分数（RVEF）呈负相关（r = -0.53，p = 0.001），与平均肺动脉压呈正相关（r = 0.60，p = 0.001）。MTT测量应变具有高可重复性。
我们证明MTT是一种在PH患者中使用电影图像定量心脏变形的可重复工具。因此，它可作为一种新的快速且全面的技术用于区域心脏功能的临床评估。
