Objective To evaluate the clinic experimental value of quantitative tissue velocity imaging (QTVI) in early as-sessment of thoracic radiotherapy - induced myocardial damage. Methods There were 40 patients with thoracic radiotherapy and 20 healthy patients as control group in this study. Myocardial velocity gradient(MVG) and conventional echocardiographic param-eters were performed in 60 subjects. According to the process of radiotherapy, the 40 patients were divided into two groups: group A: radiotherapy time was 2.7 - 3.3 weeks, radiotherapy dose was 30 - 40 Gy; group B: radiotherapy time was 4.1 - 5.5 weeks, radiotherapy dose was 50 - 60 Gy. Off line profiles of the left ventricular regional diastolic velocity along long axis in the 40 pa-tients and 20 healthy subjects were analyzed by QTVI. Regional systolic and diastolic velocities ( Vs, Ve, Va) were measured at each segment of left ventricular basal, middle and apical levels. MVG were calculated respectively. Results ①Left ventricular inflow velocity index (E/A) of group A and group B was significantly lower than that in control group (P<0.05) ; There was significant difference of E/A ratio between group B and group A(P<0.05). ②MVG1 ,MVG2 of group A and group B in anteri-or, antero - septal walls in the period of systole or diastole were significantly lower than those in control group (P<0.05); MVG1 ,MVG2 of group B in anterior, antero - septal walls in the period of systole or diastole were lower than those in group A (P<0.05); MVG1, MVG2 of group B in posterior walls in the period of diastole were lower than those incontrol group (P< 0. 05); MVG1, MVG2 of group A and group B in left lateral, inferior, postero - septal walls in the period of systole or diastole in all groups had no significant difference (P>0.05). Conclu-sion The results in this study demonstrated that regional left ventricular systolic and diastolic function were decreased in patients with thoracic radiotherapy. MVG is more sensitive, reliable reduplicative index in estimating left ventricle myocardial function of thoracic radiotherapy patient.%目的 探讨定量组织速度成像心肌速度梯度技术在评价胸部放疗患者早期心肌损伤方面的临床应用价值. 方法 应用定量组织速度成像(QTVI)技术离线分析40例胸部肿瘤放疗患者和20例正常人左心室心肌各节段长轴方向上的速度曲线,并将40例胸部肿瘤放疗患者按照放疗进程分为两组:A组:2.7～3.3周、照射剂量30～40 Gy;B组:4.1～5.5周、照射剂量50～60 Gy;测量收缩期峰值速度(Vs)及舒张早期峰值速度(Ve)、晚期峰值速度(Va),并分别计算长轴方向上收缩期及舒张早期、晚期心肌速度梯度(MVG1、MVG2)等参数. 结果 ①A组、B组左室二尖瓣口血流速率(E/A)比值较对照组减低(P<0.05);B组的E/A比值较A组减低(P<0.05);②A组、B组前壁、前间隔各节段收缩期及舒张期MVG1、MVG2均较对照组明显减低(P<0.05);B组前壁、前间隔各节段收缩期及舒张期MVG1、MVG2较A组减低差异有统计学意义(P<0.05);B组后壁各节段舒张期MVG1、MVG2均较对照组明显减低差异有统计学意义(P<0.05);A组、B组侧壁、后间隔、下壁各节段收缩期及舒张期MVG1、MVG2在3组之间比较,差异均无统计学意义(P>0.05). 结论 胸部放疗患者左室长轴方向心肌局部收缩及舒张功能均存在一定程度的降低;心肌速度梯度为一项敏感、可靠、可重复的胸部放疗患者心肌功能评价的新指标.
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