二维斑点追踪技术对甲状腺功能低下患儿左室纵向收缩功能的评价

发布时间：2018-03-23 06:10

本文选题：二维斑点追踪技术　切入点：先天性甲状腺功能低下　出处：《吉林大学》2013年硕士论文　论文类型：学位论文

【摘要】：先天性甲状腺功能低下(congenital hypothyroidism，CH，简称甲低)是目前一种儿科常见的内分泌疾病，临床表现为永久性或暂时性的甲状腺激素水平降低及出生后促甲状腺激素(TSH)水平升高。心脏是甲状腺激素作用的一个重要靶器官，甲状腺激素对维持心脏功能具有重要的意义。甲状腺激素可调节心肌细胞多种基因的转录，甲状腺激素T3与核受体结合促进蛋白质的合成，，从而影响氨基酸和糖类等在细胞膜上的运输，同时甲状腺激素也影响肌浆网对钙离子的吸收和膜钙ATP酶活性。此外，甲状腺激素还有核外作用，如短期内T3变化可以改变心脏钠、钙离子通道特性，改变细胞内钠、钙离子水平，从而影响心脏收缩及节律变化。甲状腺激素可以增加心肌细胞肾上腺素能受体的基因表达，增强交感-肾上腺素系统的敏感性；还可以降低外周血管阻力、提高心排血量。Heron MI等实验室研究表明，甲状腺激素对冠状动脉微小动脉生长有一定的影响，甲状腺功能减低时可抑制微小动脉生长，甲亢时，则相反。国内动物实验提示甲状腺激素减少可使新生大鼠心肌钙转运蛋白表达异常，直接抑制相关酶的活性，导致心肌细胞内Ca2+超载，从而引起心脏收缩和舒张功能下降。目的：探讨甲低患儿左室整体及局部收缩功能的改变，本研究应用二维斑点追踪技术对甲低患儿左室纵向收缩功能进行检测，并探讨其临床应用价值。方法：二维斑点追踪成像技术（two dimension speckle-trackingimaging,2D-STI）是在二维的基础上，在心脏室壁中选定一定范围的感兴趣区。随着心动周期，分析软件根据组织灰阶自动逐帧追踪上述感兴趣区内心肌组织像素的位置和运动，并与第一帧图像中的位置相比较，计算整个感兴趣区内各节段心肌的变形。2D-STI技术与传统超声技术相比,不受声束方向与室壁运动方向间夹角的影响，无角度依赖性，能更准确地反映心肌的局部收缩和舒张功能。研究中应用的自动功能成像(automated function imaging，AFI)是斑点追踪成像技术中的实用性分析软件，能迅速分析获取室壁运动异常的数据和牛眼图。本研究选取我院诊断为甲低的患儿35例及与患儿年龄相匹配的正常儿童30例。两组研究对象均排除其他疾病。应用AFI分析软件测量左室壁各节段收缩纵向峰值应变(longitudinal peak systolic strain,LPSS)、及该切面收缩期总应变（GLS）、平均总应变(GLS-Avg)、18节段的应变曲线及牛眼图。结果：（1）左室收缩功能常规参数比较:甲低组左室射血分数（LVEF）和左室短轴缩短率(LVFS%)与正常对照组比较，差异无统计学意义（P0.05）。(2)左室壁收缩期纵向峰值应变（LPSS）比较:与正常对照组相比甲低患儿左室前壁基底段，侧壁心尖段、室间隔基底段、中间段，后壁收缩期纵向峰值应变明显减低（P0.05）。(3)左室各切面收缩期总应变及平均总应变的比较:左室整体收缩期应变（GLS）明显低于正常组（P0.05）。结论：本研究中使用AFI技术能够准确、快速地检测心肌整体及局部收缩功能的改变，具有良好的可行性和准确性，是临床上评估左心室功能的有效手段。研究结果表明，甲低患儿存在左心室整体和局部的收缩功能改变，AFI技术可早期发现甲低患儿心脏功能的细微变化，及时反馈给临床，对指导临床用药具有重要意义。
[Abstract]:Congenital hypothyroidism (congenital, hypothyroidism, CH, referred to as CH) is currently a common pediatric endocrine disease, the clinical manifestations of thyroid hormone level in permanent or temporary decrease and postnatal thyroid stimulating hormone (TSH) levels. The heart is an important target organ of thyroid hormones, thyroid hormone an important role in maintaining cardiac function. Thyroid hormone can regulate transcription of many genes in myocardial cells, thyroid hormone nuclear receptor T3 and promote protein synthesis, thus affecting the amino acids and sugars on the cell membrane transport, and thyroid hormones also affect the absorption and membrane of sarcoplasmic reticulum calcium ATP enzyme activity. In addition, thyroid hormone has extranuclear effects, such as short term changes of T3 can change the cardiac sodium, calcium channel characteristics, the change of intracellular sodium, calcium levels, from The effect of cardiac systolic and rhythm. The expression of thyroid hormone can increase myocardial adrenergic receptor gene, enhance the sensitivity of sympathetic adrenergic system; also can reduce peripheral vascular resistance, improve cardiac output.Heron MI laboratory studies show that thyroid hormones have a certain effect on the growth of small coronary artery, thyroid dysfunction could inhibit the growth of small arteries, hyperthyroidism, on the contrary. The animal experiments indicated that thyroid hormone can reduce myocardial calcium transport protein in neonatal rats with abnormal expression, direct inhibition of enzyme activity, leading to Ca2+ overload in myocardial cells, resulting in decreased systolic and diastolic function.
Objective: To investigate the global and regional left ventricular systolic function in patients with hypothyroidism changes of left ventricular systolic function of children with hypothyroidism were detected in this study using two-dimensional speckle tracking, and to explore its clinical value.
Methods: two dimensional speckle tracking imaging (two dimension, speckle-trackingimaging, 2D-STI) is based on the two-dimensional and the region of interest selected a certain range in the heart wall in the cardiac cycle. With the analysis, location and movement of gray scale automatic frame by frame to track the ROI pixel according to the heart muscle tissue and compared with the software. The first frame image position, calculate the ROI segments of.2D-STI deformation compared with traditional ultrasonic technology, is not affected by the direction of acoustic beam and wall motion direction angle, angle dependence, can more accurately reflect left ventricular systolic and diastolic function. Automatic functional imaging studies the application of (automated function imaging, AFI) is a practical imaging analysis software can quickly obtain the speckle tracking analysis of abnormal wall motion data and bovine eye.
This study selected 30 cases in our hospital diagnosed 35 cases of hypothyroidism patients and matched with the age of children with normal children. Two subjects were excluded other diseases. The application of AFI analysis software of the measurement of left ventricular segmental longitudinal systolic peak strain (longitudinal peak systolic strain, LPSS), and the total systolic strain (section GLS), the average total strain (GLS-Avg), 18 segments of the strain curve and the bull's-eye map.
Results: (1) comparison of left ventricular systolic function parameters: conventional hypothyroidism group left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS%) compared with the normal control group, the difference was not statistically significant (P0.05). (2) left ventricular peak systolic longitudinal strain (LPSS). Compared with the normal control group children with hypothyroidism left ventricular anterior basal segment, the side wall of the apical segment, septal basal segment, middle segment, posterior wall peak systolic longitudinal strain was significantly decreased (P0.05). (3) compare the left ventricular systolic strain and the total section average total strain: left ventricular systolic strain (GLS) significantly compared with the normal group (P0.05).
Conclusion: AFI can accurately use technology in this research, the rapid detection myocardialsystolic function change, has good feasibility and accuracy, is a effective means for the assessment of left ventricular function in clinic. The results of the study show that children with hypothyroidism change of left ventricular global and regional systolic function, AFI can early detect subtle the changes of cardiac function in patients with hypothyroidism, timely feedback to the clinic, is of great significance to guide the clinical medication.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R445.1;R725.8

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