^99Tc^m-替曲膦与^99Tc^m-MIBI心肌灌注显像诊断无症状心肌缺血的比较研究

A comparison between ^99 Tc^m.tetrOfOsmin and ^99 Tc^m.MIBI myocardial perfusion imaging in detection of silent myocardial ischemia

目的比较^99Tc^m-替曲膦（TF）与^99Tc^m-MIBI腺苷负荷-静息MPI在无症状心肌缺血（SMI）患者中的应用价值。方法选择符合WHO冠心病诊断标准的Ⅰ、Ⅱ、Ⅲ型SMI患者，分别为122、112和72例，各型SMI均按完全随机法分为2组，分别行^99Tc^m-MIBI及^99Tc^m腺苷负荷一静息MPI。306例患者的冠心病经心电图（46例）、动态心电图（219例）和CAG（41例）证实。比较2种显像方法的心肌缺血诊断灵敏度及原始图像质量。数据比较采用矿检验及方差分析。结果按照心肌缺血诊断标准（负荷显像节段性放射性稀疏或缺损处静息显像时明显填充），^99Tc^m-MIBI和^99Tc^m-TF心肌显像诊断心肌缺血的灵敏度分别为：Ⅰ型：57．38％（35／61）和60．66％（37／61），X^2=0．136，P〉0．05；Ⅱ型：69．64％（39／56）和64．29％（36／56），X^2=0．363，P〉0．05；Ⅱ型：83．33％（30／36）和88．89％（32／36），X^2=0．465，P〉0．05，3型SMI患者各2组间诊断心肌缺血的灵敏度差异均无统计学意义。原始图像质量方面，^99Tc^m-MIBI及^99Tc^m-TF显像图优（心肌影像清晰，无肝、肺、血本底干扰）者百分比分别为41．18％（63／153）和48．37％（74／153）,X^2=1．599，P=0．206；良（心肌影像尚清晰，但肝可见放射性，无明显血液本底）者百分比分别为45．10％（69／153）和34．64％（53／153）,X^2=3．489，P=0．062；中（心肌显影，肝放射性高，血液本底低）者百分比分别为13．72％（21／153）和16．99％（26／153），X^2=0．628，P=0．428，差异均无统计学意义。图像总体质量良好，无不合格图像。注射^99Tc^m-TF者较注射^99Tc^m-MIBI者肝、肺放射性清除陕，与心肌放射性摄取差异较大，对心脏下壁及心尖部显示影响较小，且至少缩短1h待检时间。结论^99Tc^m-TF可获得与^99Tc^m-MIBI同等的心肌缺血诊断显像效果，且肝、肺清除快，图像质量较好，可有效缩短患者待检时间，有很好的应用前景。

Objective To compare ^99Tc^m-tetrofosmin （TF） and ^99Tc^m-MIBI adenosine stress/rest- ing MPI in detection of silent myocardial isehemia （SMI）. Methods According to the WHO diagnostic criteria for coronary heart disease （CHD） , 306 SMI patients were classified to three groups as type Ⅰ （n = 122 ） , type Ⅱ （ n = 112） and type Ⅱ（ n = 72）. The subjects of each type were randomly divided into 2 sub- groups; one subgroup underwent adenosine stress/rest MPI with ^99Tc^m-MIBI and another subgroup with ^99Tc^m-TF. The clinical diagnosis of CHD was proven with electrocardiogram （46 cases） , dynamic electro- cardiogram （219 cases） or CAG （41 cases ）. Comparison factors between the two tracers included image quality and diagnostic efficacy. The image quality was graded into three classes ： excellent, good and moder- ate. X2 test and analysis of variance were used to analyze data. Results The sensitivities of detecting myo- cardial ischemia with 99Tcm-MIBI MPI and 99Tcm-TF MPI in group type Ⅰ were 57. 38% （35/61） vs 60. 66% （37/61） （X^2 = 0. 136, P 〉 0.05 ） ; in group type Ⅱ 69.64% （39/56） vs 64.29% （36/56） （X^2 = 0.363, P〉0.05） and in group type Ⅲ83.33% （30/36） vs88.89%（32/36） （X^2=0.465, P〉0.05）, respectively. There was no significant difference between the sensitivities of the two imaging modalities in all three types of SMI patients. In image quality grading, ^99Tc^m-MIBI and ^99Tc^m-TF demonstrated excellent im- ages with 41.18% （63/153） vs 48.37% （74/153） （X^2 = 1. 599, P =0. 206） , good with 45.10% （69/ 153） vs 34.64% （53/153） （X^2 = 3. 489, P = 0. 062） and moderate with 13.72% （21/153） vs 16.99%（26/153） （X^2 =0. 628, P =0. 428）. There was no unqualified image with either modality. ^99Tc^m-TF dis- played quicker radioactivity clearance in liver and lungs. Thereby there was less interference or pitfalls pres- ent in the ventricle base or inferior wall that may result from higher liver radioactivity retention. The waiting time between the tracer injection and imaging was at least 1 h shorter with ^99Tc^m-TF compared to ^99Tc^m-MIBI. Conclusions ^99Tc^m-TF is comparable with ^99Tc^m-MIBI in detection of silent myocardial ischemia as a MPI tracer. Meanwhile, ^99Tc^m-TF MPI may reduce MPI pitfalls and save time during the imaging protocol.