论文标题:背向散射积分对风湿性二尖瓣狭窄患者左房血液状态的定量评估
Quantitative Evaluation of the Blood in Left Atrial Cavity of Patients with Rheumatic Mitral Stenosis by Integrated Backscatter
论文作者 侯永霞
论文导师 任卫东,论文学位 硕士,论文专业 影像医学与核医学
论文单位 中国医科大学,点击次数 80,论文页数 39页File Size2069k
2002-03-01论文网 http://www.lw23.com/lunwen_282049972/ 背向散射积分;经胸超声心动图;风湿性二尖瓣狭窄;左房血液
integrated backscatter;transthoracic echocardio-graphy;rheumatic mitral stenosis;blood in LA cavity
前言 目前，风湿性心脏瓣膜病的发生率虽有下降趋势，但在我国仍为常见疾病之一。风湿性二尖瓣狭窄患者继发房颤、左房和／或左心耳血栓的发生率均较高，且发生栓塞的危险性明显升高。部分患者的左房内可见到动态的云雾样回声——自发性显影回声(spontaneous echo contrast，SEC)。常规超声心动图能够确切诊断风湿性二尖瓣狭窄，并能提供左房内SEC及血栓等信息，但不能提供定量信息。 背向散射积分(integrated backscatter，IBS)是近年发展起来的一项新的超声组织定征(ultrasonic tissue characterization，UTC)技术，除了可以对正常和异常的心肌细胞成分进行定量评估，尚能够对血液的生理或病理状态进行定量分析。本研究通过经胸超声心动图用IBS技术对风湿性二尖瓣狭窄患者左房血液状态进行定量分析，研究影响风湿性二尖瓣狭窄病人左房内血液IBS的相关因素，为判定有无栓塞风险提供定量指标。 实验材料 研究对象：病例组56例，均为临床明确诊断为风湿性二尖瓣狭窄患者，根据左房内SEC的存在与否及其程度将其分为3组：①左房内无SEC组(A组)26例(男10例)，年龄21～55岁，平均47±14岁。有房颤(AF)者7例(27％)，均无左房血栓和血栓栓塞病史。②左房内轻度SEC组(B组)18例(男7例)，年龄35～71岁，平均52±11岁。有AF者14例(78％)，有左房血栓者4例(22％)，有血栓栓塞病史者3例(17％)。③左房内重度SEC组 ＊组）12例（男5例），年龄33－67岁，平均47 t 8岁。有AF者12例门00％入有左房血栓者7例K8％人有血栓栓塞病史者5例k％人对照组 30例，男 12例，女 18例，年龄 18－65岁，平均 44t13岁。 仪器：美国 HP SONOS 5500型相控阵超声显像仪（配置组织射频信号二维图像显示和声学定量分析系统软件及光盘存储器厂／。融合探头频率2－4MHZ。 实验方法 1．常规经胸超声心动图（刀【）检查：取左侧卧位，于标准胸骨旁左室长轴切面（LAX厂测量左房大小（LA人于心尖四腔心切面KCH厂记录二尖瓣口血流频谱，根据压差减半时间灯HT）估测H尖瓣口面积（AMV人采用Simpson法测定左室射血分数（LVEF）。 2．IBS参数的测定：应用AD一BS程序，根据仪器设置条件将各组进一步分为：①组1：总增益固定为45 dB，调整时间增益补偿（TGC）（起始设置为25dB，其后每档增加10dB，共增力8档）；②组 11：总增益固定为 50dB，调整 TGC（起始设置为 25dB，其后每档增加 10dB，共增加 8档入③组 Ill：总增益固定为 50dB，调整TGC（起始设置为35dB，其后每档增加 10dB，共增加8档人在实验过程中各条件保持不变。将感兴趣区（ROI）分别置于LAX的左房、左室内，分别采集左房和左室血液＊ 值。校正 IBS值，以左房与左室血液IBS值的差值来表示，单位为分贝uB人 3．统计学处理：应用 SPSS 8．0统计分析软件分析各组资料。 ·2· 实验结果 二．各组间临床指标、TYE参数的比较 四组间＊A、＊＊V人F的发生率有差别（P＜0．05）。C组的LA（64．89。8．80rum）明显大于 A8和 D组（分别为：44．of t 7．52mm、53．50 is．48mm和 30．56 t3．50rum），AMV（0．69 ic．20cm’）小于AJ和D组（分别为：互．66 i 0．61 Cm’、二．二互。0．29Cm’和4．39土0．81cm‘），AF的发生率（100％）明显高于 A、B和 D组（分别为：27％J 8％和0％人B人两组间左房血栓和栓塞病史的发生率无差异（分别为：22％j8％和17啪。8阮，P＞0．05人各组间研究对象的年龄、性别及L＊＊F无显著差别瞩＞0．05人 2．各组间 IBSb较 左房及左室内血液的IBS值无明显周期性变化。A在和C三组间的校正IBS 值（分别为：1．53。0．50dB、3．39。O．NdB和8．叩j．的血，P＜0．05）和LA因值（分另为：7．的土1．82昭、9．36土2．71＊ 和15．66上2．6＊B，P＜O．05）有差异。A山两组间校正IBS值和 LAIBS值无差异（分别为：1．53。0．50dB、1．43。0．96dB和7．46士二．82dB、6．4O土二．43dB，P＞O．05）。各组间LVmS值无差异（分别为 5．93。二．85、6．16。2．38、7．24。2．门和 5．50。互．32，P＞0．05）。校正1既值与＊＊V呈负相关（r＝－O．66o，P＜0．001），与邪C分级（r＝O．91O，P＜0．00且）、LA（r＝O．656，P＜o．001）、＊F的发生率（r＝o．533，P＜0．OO二）、左房血栓的发生率（r＝O．39O，P＜O．0二）及栓塞病史的发生率（r＝0．3 14，P＜O．05）呈正相关。与性别（r＝－0．＊1，P＞O．05）、年龄（r＝－o．06，P＞0．05）无相关性。 3．仪器不同设置条件下IBS值的比较 1．组I、组＊两组间比较，校正IBS值在两组间无显著差异河 ·3·＞O．05厂但两组间＊1既值和LV既值有显著差异河＜0．05X随着总增益的增大，LAIBS值和LVIBS值也随之增高。 2．组 11、组 Ill两组间比较，校K IBS值在两组间无差异u
PrefaceAlthough the incidence of rheumatic mitral valve disease has decreased recently, it is still one of the commonest valve diseases in our country. Mitral valve is prone to being involved in all valves. Incidence of atrial fibrillation ( AF) and left atrial thrombus is very high in patients with rheumatic mitral stenosis, which closely correlate with thromboembolic events. There exists left atrial spontaneous echo contrast (SEC) in some patients with rheumatic mitral stenosis. SEC refers to the dynamic, smoke - like pattern of blood echogenicity detected with echocardiography. Conventional echocardiography can not only diagnose rheumatic mitral stenosis but also provide information of left atrial SEC and thrombus. However, it cannot provide quantitative information for clinic diagnosis.Integrated backscatter (IBS) is a new technology for ultrasonic tissue characterization ( UTC ). Additional to characterizing normal and abnormal myocardial tissue, it also quantitatively assesses blood. This study w.as designed to quantify the blood in left atrial cavity of patients with rheumatic mitral stenosis using IBS in transthoracic echocardiography (TTE) and define correlated facts which influence left atrial SEC, therefore, provide echocardiographic predictors of thrombosis and thromboembolism for clinical physician.Materials86 adults were enrolled in this study. 56 patients ( males 22, females 34) with rheumatic mitral stenosis were divided into three subgroups regarding the absence or presence of left atrial SEC and its Qualitative grades. Group A ( no SEC) included 26 patients ( males 10: mean age 47 + 14 years, AF 7). Group B (mild SEC) included 18 patients (males 7: mean age 52 + 11 years, AF 14, left atrial thrombus 4, thromboembolic events 3 ) . Group C ( severe SEC ) included 12 patients (males 5: mean age 47 +8 years, AF 12, left atrial thrombus 7, thromboembolic events 5 ). No patients had moderate or severe mitral regurgitation. Group D included 30 healthy adults (males 12; mean age 44 + 13 years) as control group.All study data were acquired by using Hewlett - Packard Sonos 5500 ultrasonic system equipped with IBS analysis software with a 2 -4 MHz phased array transducer.MethodsConventional TTE; All study objects were in the left lateral de-cubitus position. Left atrial dimension (LA) in the anterior - posterior plane was measured in .parasternal left ventricle long axis view. Left ventricular ejection fraction (LVEF) was calculated with Simpson"s rule in apical 4 - chamber view (4CH). The mitral valve area (AMV) was determined by the Doppler pressure halftime ( PHT) method.Integrated backscatter system preset and data acquisition: Switc-hing on AD - IBS procedure, we preset the instrument settings as follows; (1)GroupI; Gain was fixed at 45 dB, time -gain -compensation (TGC) was initially fixed at 25dB (lOdB steps incrementally, total 8 steps). (2)GroupII: Gain was fixed at 50dB, TGC was initially fixed at25dB (10dB steps incrementally, total 8 steps). (3)GroupIII: Gain was fixed at 50dB, TGC was initially fixed at 35dB (10dB steps incrementally , total 8 steps). We respectively acquired digital integrated backscatter ( IBS) image sequences of the left atrial cavity and the left ventricular cavity from the parasternal long - axis view according to a-bove -mentioned machine settings. Left atrial IBS (LAIBS) intensity and left ventricular IBS (LVIBS) intensity were respectively measured by putting the region of interest ( ROI: 11x11 pixels) in left atrial and ventricle cavity. The corrected IBS intensity was defined as the difference between LAIBS intensity and LVIBS intensity.Statistical analysis; All data acquired was analyzed by SPSS 8.0 software.Results1. Clinical and TTE parametersThere was statistical difference in LA, AMV and incidence of AF among group A, B, C and D (P <0. 05). LA, AMV and incidence of AF of group C ( 64. 89 + 8. 80mm, 0. 69 + 0. 20cm2 and 100% , respectively) were obviously higher than others. There was no significant statistical di
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