Sarnari Roberto, Blake Allison M, Ruh Alexander, Abbasi Muhannad A, Pathrose Ashitha, Blaisdell Julie, Dolan Ryan S, Ghafourian Kambiz, Wilcox Jane E, Khan Sadiya S, Vorovich Esther E, Rich Jonathan D, Anderson Allen S, Yancy Clyde W, Carr James C, Markl Michael
Department of Radiology, Cardiovascular Imaging, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA.
Department of Cardiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA.
J Magn Reson Imaging. 2020 Sep;52(3):920-929. doi: 10.1002/jmri.27091. Epub 2020 Feb 15.
Magnetic resonance tissue phase mapping (TPM) measures three-directional myocardial velocities of the left and right ventricle (LV, RV). This noninvasive technique may supplement endomyocardial biopsy (EMB) in monitoring grafts post-heart transplantation (HTx).
To assess biventricular myocardial velocity alterations in grafts and investigate the relationship between velocities and acute cellular rejection (ACR) episodes.
Prospective.
Twenty-seven patients within 1 year post-HTx (49 ± 13 years, 19 M) and 18 age-matched controls (49 ± 15 years, 12 M).
FIELD STRENGTH/SEQUENCE: 1.5T, 2D balanced steady-state free precession, and TPM.
Ventricular function: end-diastolic and end-systolic volumes, stroke volumes, ejection fraction (EF), and myocardial mass. TPM velocities: peak-systolic and peak-diastolic velocities, cardiac twist, and interventricular dyssynchrony. ACR rejection episodes: International Society for Heart and Lung Transplantation grading of EMB specimens.
The Lilliefors test for normality, unpaired t-tests, and Wilcoxon rank-sum tests for normally and nonnormally distributed data, respectively, were used, as well as multivariate regression for confounding variables and Pearson's correlation for associations between TPM velocities and global function.
Compared to controls, HTx patients demonstrated reduced biventricular systolic longitudinal velocities (LV: 5.2 ± 2.1 vs. 4.0 ± 1.5 cm/s, P < 0.05; RV: 4.2 ± 1.3 vs. 3.1 ± 1.2 cm/s, P < 0.01). Correlation analysis revealed significant positive relationships for biventricular EF with radial peak velocities of the same ventricle in both systole and diastole (LV systole: r = 0.48, P < 0.01; LV diastole: r = 0.28, P < 0.05; RV systole: r = 0.35, P < 0.01; RV diastole: r = 0.36, P < 0.01). Segmentally, longitudinal velocities were impaired in 7/16 LV segments and 5/10 RV segments in systole and 7/10 RV segments in diastole. TPM analysis in studies with >4 preceding ACR episodes showed globally reduced RV and LV systolic radial velocity, and segmentally reduced radial and longitudinal systolic velocities.
Biventricular global and segmental velocities were reduced in HTx patients. Patients with >4 rejection episodes showed reduced myocardial velocities. The TPM sequence may add functional information for monitoring graft dysfunction.
2 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:920-929.
磁共振组织相位映射（TPM）可测量左心室和右心室（LV，RV）的三维心肌速度。这种非侵入性技术可在心脏移植（HTx）后监测移植物时补充心内膜心肌活检（EMB）。
评估移植物中双心室心肌速度改变，并研究速度与急性细胞排斥反应（ACR）发作之间的关系。
前瞻性研究。
27例HTx术后1年内的患者（49±13岁，19例男性）和18例年龄匹配的对照者（49±15岁，12例男性）。
场强/序列：1.5T，二维平衡稳态自由进动序列以及TPM。
心室功能：舒张末期和收缩末期容积、每搏量、射血分数（EF）以及心肌质量。TPM速度：收缩期峰值速度和舒张期峰值速度、心脏扭转以及心室间不同步。ACR排斥反应发作：国际心肺移植学会对EMB标本的分级。
分别使用Lilliefors正态性检验、非配对t检验以及针对正态分布和非正态分布数据的Wilcoxon秩和检验，同时使用多变量回归分析混杂变量，并使用Pearson相关性分析TPM速度与整体功能之间的关联。
与对照组相比，HTx患者双心室收缩期纵向速度降低（左心室：5.2±2.1 vs. 4.0±1.5 cm/s，P<0.05；右心室：4.2±1.3 vs. 3.1±1.2 cm/s，P<0.01）。相关性分析显示，双心室EF与同一心室在收缩期和舒张期的径向峰值速度呈显著正相关（左心室收缩期：r = 0.48，P<0.01；左心室舒张期：r = 0.28，P<0.05；右心室收缩期：r = 0.35，P<0.01；右心室舒张期：r = 0.36，P<0.01）。节段性分析显示，收缩期左心室16个节段中的7个和右心室10个节段中的5个以及舒张期右心室10个节段中的7个纵向速度受损。在之前有>4次ACR发作的研究中，TPM分析显示右心室和左心室整体收缩期径向速度降低，节段性收缩期径向和纵向速度降低。
HTx患者双心室整体和节段性速度降低。有>4次排斥发作的患者心肌速度降低。TPM序列可为监测移植物功能障碍增加功能信息。
2 技术效能阶段：2 J.Magn.Reson.Imaging 2020;52:920 - 929。
