门控^99mTc—MIBI心肌断层显像诊断多支冠状动脉病变和心肌缺血

目的：评价门控心肌显像诊断冠心病（ＣＡＤ）的临床意义。方法：对３２例ＣＡＤ患者的＾９９ｍＴｃ－甲氨基异丁基异腈（ＭＩＢＩ）门控、非门控心肌断层显像和冠状动脉造影进行了比较，以及对４０例ＣＡＤ患者的门控与常规潘生丁－静息心肌断层显像也作了比较。结果：１．门控与非门控显像法诊断ＣＡＤ的灵敏度和特异性无差别，但前者对检测病变冠状动脉和诊断多支冠状动脉病变性ＣＡＤ的灵敏度高于后者，而特异性无差别。２．射血     

^99mTc-MIBI门控心肌断层显像的临床应用与冠状动脉造影对比分析

分析了６６例受试者~（９９ｍ）Ｔｃ－ＭＩＢＩ门控心肌断层显像的临床资料，并与冠状动脉造影进行比较。结果表明，门控心肌断层显像和非门心肌断层显像在冠心病诊断中有同样的高特异性，但前者较后者对于轻度冠状动脉病变所致微细的心肌灌注异常检出率有所提高。同时还分析了核素心肌显像可能出现假阴性和假阳性的原因以及有效防止假阳性率升高的手段。     

~（99m）Tc－MIBI门控心肌断层显像同时评价心肌灌注和左室功能

应用９９ｍＴｃ－甲氧基异丁基异腈（ＭＩＢＩ）门控心肌断层显像同时获得心肌血流灌注和左室功能状况，并将结果与１１５例冠状动脉造影和８４例门电路心室显像进行对比分析．表明对于诊断心绞痛门控心肌断层显像较非门控心肌断层显像有较高的灵敏度；由门控心肌断层显像计算的左室容积收缩分数与门电路心室显像测得的左室射血分数高度相关（Ｐ＜０．０１）．上述结果提示，９９ｍＴｃ－ＭＩＢＩ门控心肌断层显像有较大的临床实用价值．     

99m Tc-MIBI心肌显像对冠状动脉病变的定位研究

目的：探讨９９ｍＴｃ－ＭＩＢＩ心肌显像在检出冠心病病变心肌节段和病变血管定位上的价值。方法：对照分析２０例冠心病和５例对照组冠状动脉造影与９９ｍＴｃ－ＭＩＢＩ单光子发射断层显像（ＳＰＥＣＴ）的结果。结果：潘生丁负荷ＳＰＥＣＴ检出冠心病、病变血管和病变心肌节段的敏感性分别为９５．００％、６３．６４％和４３．６８％明显高于静息相的６０．００％、４２．４２％和２７．５９％（Ｐ＜０．０１）。与静息相比较,潘生丁负荷ＳＰＥＣＴ多发现３３．３３％的病变血管和３６．８４％的病变心肌节段。对病变血管的敏感性,ＬＡＤ高于ＲＣＡ和ＬＣＸ;对于病变心肌节段检测敏感性ＲＣＡ支配节段高于ＬＡＤ和ＬＣＸ,特异性均较高。结论：潘生丁ＳＰＥＣＴ能显著提高冠心病的检出,有效估计病变心肌范围和病变冠状动脉     

^99mTc—MIBI门控心肌断层显像同时评价心肌灌注和左室功能

应用＾９９ｍＴｃ－甲氧基异丁基异腈（ＭＩＢＩ）门控心肌断层获得心肌血流灌注和左室功能状况，并将结果与１１５例冠状动脉造影和８４例门电路心室显像进行对比分析，表明对于诊断心绞痛门控心肌断层显像较非门控心肌断层显像有较高的灵敏度，由门控心肌断层显像计算的左室容积收缩在与门电路心室显像测得的左室射血分数高度相关，上述结果提示，＾９９ｍＴｃ－ＭＩＢＩ门控心肌断层显像有较大的临床实用价值。     

扩张型心肌病和缺血性心肌病心肌灌注,代谢及功能的综合评价

目的 探讨核素显像在扩张性心肌病（ＤＣＭ）的缺血性心肌病（ＣＡＤ－ＤＭ）诊断及鉴别诊断中的作用。方法 对２８例ＤＣＭ和５５例ＣＡＤ－ＣＭ均行＾９９Ｔｃ＾ｍ－甲氧基异丁基异腈（ＭＩＢＩ）静息心肌灌注ＳＰＥＣＴ及＾１８Ｆ－脱氧葡萄糖（ＦＤＧ）心肌代谢ＰＥＴ显像，其中７３例行核素心室显像，６８例做冠状动脉造影。结果 心肌灌注显像２３例（８２％）ＤＣＭ为不呈节段分布的、散在的稀疏，４例（１４％）有灌注缺损     

静息门控~（99m）Tc－MIBI心肌断层显像定量分析在诊断心肌缺血中的临床价值

静息门控９９ｍＴｃ－甲氧基异丁基异腈心肌断层显像能同时评价局部心肌灌注与功能，对功能较好的心肌缺血节段的检测优于潘生丁负荷－静息心肌断层显像．此方法能预测９７％的无再分布、８１％的再分布和２９％的反向再分布灌注低下室壁节段．     

99 Tcm-MIBI门控与硝酸甘油介入心肌断层显像诊断冠心病

本研究通过对 5 6例患者行99Ｔｃｍ 甲氧基异丁基异腈 (ＭＩＢＩ)门电路和非门电路静息态及硝酸甘油介入心肌断层显像 ,并作半定量分析 ,探讨该方法对诊断冠心病和估测心肌存活的价值。一、资料与方法1.病例选择。 5 6例有临床典型病史、典型心肌酶学改变和典型心电图表现的心肌梗死患者 ,男 4 7例 ,女 9例 ,年龄 36～ 81岁 ,平均 5 6 .5岁。均行静息态非门控心肌断层显像 ,除 12例患有严重心律不齐的患者外 ,余患者均同时做了静息态门控心肌灌注断层显像。该 4 4例患者于静息显像 4 8ｈ后又行硝酸甘油介入门控和非门控心肌断层显像。2 .显…     

食道心房调搏心肌灌注断层显像对冠心病的诊断价值

对４６例冠心病（ＣＡＤ）患者和１５例正常人进行食道心房调搏（ＴＡＰ）９９ｍＴｃ－甲氧基异丁基异腈（ＭＩＢＩ）心肌灌注断层显像，并与运动心肌断层显像进行对比研究．结果表明：ＴＡＰ心肌灌注断层显像对ＣＡＤ诊断的灵敏度和特异性分别为８６．９６％与９３．３３％，与运动心肌断层显像结果相近；对ＣＡＤ心肌缺血的定位诊断与运动心肌断层显像密切相关，ｒ＝０．９５．提示ＴＡＰ心肌灌注断层显像对不能耐受运动心肌显像的早期ＣＡＤ和可疑ＣＡＤ患者具有较大的实用价值．     

静息门控99mTc—MIBI心肌断层显像定量分析在诊断心肌缺血中的临…

静息门控＾９９ｍＴｃ－甲氧基异丁基异腈心肌断层显像能同时评价局部心肌灌注与功能，对功能较好的心肌缺血节段的检测优于潘生丁负荷－静息心肌断层显像。此方法能预测９７％的无再分布、８１％的再分布和２９％的反应再分布灌注低下室壁节段。     

Incremental value of assessment of regional wall motion for detection of multivessel coronary artery disease in exercise (201)Tl gated myocardial perfusion imaging.

Assessment of reversible perfusion defects in exercise (201)Tl perfusion SPECT has low sensitivity and high specificity for detection of multivessel coronary artery disease (CAD). The goal of this study was to evaluate whether worsening of left ventricular regional wall motion assessed by an automated algorithm in exercise (201)Tl electrocardiography-gated SPECT had incremental diagnostic value over perfusion data for detection of multivessel CAD. METHODS: Two hundred one patients underwent exercise (201)Tl gated SPECT. Software that automatically analyzes left ventricular function was used to assess exercise and rest regional wall motion. Regional wall motion on initial images was compared with that on rest images, that is, delayed images for patients without reinjection images and reinjection images for patients with reinjection images. The left ventricle was divided into 9 segments, with individual segments assigned to 3 coronary territories. Worsening of wall motion was defined as worsening in any segment on initial images compared with rest images. RESULTS: Of 73 patients with multivessel CAD, 20 (27.4%) had reversible perfusion defects in multiple coronary territories, 26 (35.6%) exhibited worsening of regional wall motion in multiple territories, and 37 (50.7%) had reversible perfusion defects or worsening of regional wall motion in multiple territories. The sensitivity of the combination of reversible perfusion defect and worsening of regional wall motion was significantly higher than that of reversible perfusion defect alone for detection of multivessel CAD (50.7% vs. 27.4%, P < 0.05). The specificity of the combination of reversible perfusion defect and worsening of regional wall motion for detecting multivessel CAD did not differ from that of reversible perfusion defect alone and that of worsening of regional wall motion alone (94.5% vs. 99.2% and 97.7%, respectively, P = not statistically significant). CONCLUSION: Combined assessment of worsening of left ventricular regional wall motion by exercise and perfusion data in exercise (201)Tl gated myocardial SPECT was more sensitive, with acceptable specificity, than was assessment with perfusion data alone for detection of multivessel CAD.     

Gated Tc-99m sestamibi SPECT versus stress-rest SPECT in detecting coronary artery disease: correlation with coronary angiography in patients without myocardial infarction

PURPOSE: It is possible to simultaneously evaluate wall thickening and perfusion abnormalities with radionuclide techniques that use tracers such as Tc-99m MIBI. We presumed that detection of wall thickening by gated MIBI SPECT imaging in the presence of a stress-induced perfusion defect correlates with reversibility of that defect on resting images. Therefore, the aim of our study was to analyze, in patients without myocardial infarction, resting wall thickening and stress perfusion imaging as an alternative to conventional stress-rest imaging. METHODS AND RESULTS: The patients (n = 44) underwent an exercise (n = 37) or pharmacologic (n = 7) stress protocol. All patients had previous coronary angiography within 3 months. Stress-rest MIBI SPECT and gated MIBI SPECT studies were analyzed by visual scoring. The sensitivity and specificity of segmental analysis of both stress-rest MIBI SPECT perfusion and gated MIBI SPECT studies for the overall detection of coronary artery disease were, respectively, 71% and 96%. For patient evaluation for detection of coronary artery disease, stress-rest MIBI SPECT perfusion and gated MIBI SPECT studies showed a sensitivity rate of 96% for both and specificity rates of 84% and 79%, respectively. CONCLUSIONS: Our data revealed close agreement between reversible perfusion defects on stress-rest MIBI SPECT scans and significant wall thickening on gated MIBI SPECT stress images in patients without previous myocardial infarction (95%). Gated MIBI SPECT stress, without resting studies, which provide an assessment of wall motion and wall thickening, potentially allows stress defect reversibility to be evaluated in patients without previous myocardial infarction.     

Incremental value of left ventricular ejection fraction for detection of multivessel coronary artery disease in exercise (201)Tl gated myocardial perfusion imaging.

Assessment of reversible defects in exercise (201)Tl perfusion SPECT has low sensitivity and high specificity for detection of multivessel coronary artery disease (CAD). The goal of this study was to evaluate whether the left ventricular ejection fraction (LVEF) in exercise (201)Tl gated SPECT had incremental diagnostic value over perfusion data for detection of multivessel CAD. METHODS: One hundred eighty-two patients underwent exercise (201)Tl gated SPECT. Automated LV function analysis software was used for calculation of the postexercise and the rest LVEF. The best threshold between 0- to 1-vessel CAD and 2- to 3-vessel CAD was determined as the cutoff that on receiver-operating-characteristic analysis resulted in the best sensitivity for detection of multivessel CAD with an associated specificity of >90%. RESULTS: Only 18 (26.9%) of 67 patients with multivessel CAD had reversible defects in multiple territories. Sensitivities of the postexercise and the rest LVEF and the worsening of the LVEF by exercise did not differ from those of perfusion data alone. Sensitivities of the combination of perfusion data and the postexercise and rest LVEF did not differ from those of perfusion data alone, whereas the sensitivity of the combination of perfusion data and worsening of the LVEF (i.e., reversible defects in multiple territories or worsening of the LVEF >5.6% [or both]) was significantly greater than that of perfusion data alone (43.3% vs. 26.9%; P < 0.05), with an acceptable level of specificity (90.4%). CONCLUSION: The worsening of the LVEF by exercise has the potential to detect patients with multivessel CAD among those without multivessel patterns of reversible defects.     

Evaluation of left ventricular volumes and ejection fraction by gated myocardial perfusion SPECT versus cardiac MRI

It is stated that cardiac MRI imaging can provide accurate estimation of left ventricular (LV) volumes and ejection fraction (EF). The purpose of this study was to evaluate the accuracy of gated myocardial perfusion SPECT for assessment of LV end-diastolic volume (EDV), end-systolic volume (ESV) and EF, using cardiac MRI as the reference methods/(methodology). Gated myocardial perfusion SPECT images were analyzed with two different quantification software, QGS and 4D-MSPECT. Thirty-four consecutive patients were studied. Myocardial perfusion SPECT and cardiac MRI had excellent intra/interobserver reproducibility. Correlation between the results of gated myocardial perfusion SPECT and cardiac MRI were high for EDV and EF. However, ESV and EDV were significantly underestimated by gated myocardial perfusion SPECT compared to cardiac MRI. Moreover, gated myocardial perfusion SPECT overestimated EF for small heart. One reason for the difference in volumes and EF is the delineation of the endocardial border. Cardiac MRI has higher spatial resolution. We should understand the differences of volumes and EF as determined by gated myocardial perfusion SPECT and cardiac MRI.     

Post-stress end-systolic left ventricular dilation: a marker of endocardial post-ischemic stunning

Several studies have shown the accuracy of gated single photon emission computed tomography (SPECT) using thallium-201 and technetium tracers in the assessment of myocardial perfusion and function. Gated SPECT has been successfully utilized to detect post-stress left ventricular ejection fraction (LVEF) reduction resulting from post-ischemic stunning in patients with coronary obstruction. The aim of this study was to evaluate whether the post-stress LVEF impairment could be related to the post-stress end-systolic ventricular dilation resulting from post-ischemic endocardial stunning. Two hundred and eighty-two consecutive patients were studied by conventional diagnostic 2 day stress/rest gated SPECT following injection of 925 MBq of 99mTc-tetrofosmin using a dual-headed SPECT camera. One hundred and forty-seven of these patients (52%) showed reversible perfusion defects, 69 (24%) permanent defects and the remaining 66 (24%) had normal perfusion. One hundred and thirty-eight of these patients had a history of myocardial infarction (MI) and 19% underwent coronary angiography without an intervening cardiac event. Perfusion was analysed on ungated images using 20 segments scored on a five-point scale (0, normal; 4, no uptake), while wall thickening (WT) was assessed visually on stress/rest end-systolic images using a four-point score (0, normal; 3, absence of WT). LVEF and volumes were calculated using an automatic algorithm. The post-stress and rest ratios were determined for both end-diastolic (EDV) and end-systolic (ESV) volume. Normal values for all these parameters were obtained using data from 149 patients with a low likelihood (<5%) of coronary artery disease (CAD). In 50 of the 147 (34%) of patients with reversible perfusion defects, post-stress LVEF was >5% lower than rest values (stunned group), while the remaining 97 patients did not show a significant LVEF change (group 2A). The percentage of patients who developed exercise-induced angina, the percentage of patients who underwent coronary angiography and the segmental summed perfusion and WT scores were significantly higher in the stunned group compared with group 2A. Only ESV increased significantly post-stress, and this increase occurred only in stunned patients. Both EDV and ESV ratios were significantly higher in the stunned group compared with normal controls (P=0.008 and P<0.000001, respectively) and with the subgroup 2A (P=0.011 and P<10(-12), respectively). The ESV stress/rest ratio correlated significantly with the summed WT difference score by univariate analysis in stunned patients. It can be concluded that the post-stress ESV dilation, obtained by stress/rest gated SPECT, seems to be due to endocardial post-ischemic stunning. The stunned patients showed more severe clinical, angiographic, perfusion and function parameters.     

Overestimation of postischemic myocardial stunning on gated SPECT imaging: Correlation with echocardiography

Background  Postischemic global and regional left ventricular (LV) dysfunction on stressgated single photon emission computed tomography (SPECT) imaging is attributed widely to myocardial stunning. We sought to determine the specificity of gated SPECT for the detection of myocardial stunning after ischemic stress. Methods and Results  Twenty-seven patients with an ischemic response to stress on dual-isotope exercise SPECT were enrolled prospectively. Transthoracic echocardiography was performed just before stress gated SPECT for assessment of regional wall motion and quantitative LV ejection fraction (LVEF). The 17 myocardial segments for each patient were scored for myocardial perfusion by stress gated SPECT, and regional wall motion by stress gated SPECT and echo. Of the 459 myocardial segments, 41% had perfusion defects, 15% had stress gated SPECT regional wall motion abnormality, 4.8% had poststress echo regional wall motion abnormality, and 3.9% had baseline regional wall motion abnormality. Overall, a stress gated SPECT regional wall motion abnormality had a sensitivity of 100% and a specificity of 89%. Among reversible perfusion defects of moderate severity or more, a stress gated SPECT regional wall motion abnormality had a specificity of 41% and a positive predictive value of 8%. Stress gated SPECT LVEF was similar to poststress echo LVEF for all patients, but significantly lower in patients with reversible perfusion defects of moderate severity or more. Conclusion  Post-stress gated SPECT imaging overestimates global and regional myocardial stunning. Caution should be exercised in interpreting poststress global or regional LV function on stress gated SPECT in scans with reversible ischemia.     

Improvement of the diagnostic value of synchronous myocardial tomoscintigraphy in the assessment of regional myocardial perfusion]

INTRODUCTION: Gated SPECT using 99mTc-labeled flow tracers provides simultaneous assessment of global and regional myocardial function. PURPOSE: To investigate whether studying regional wall thickening after stress and at rest provides additional diagnostic information in coronary artery disease patients. METHODS: We examined 61 consecutive patients (40 men) who underwent conventional diagnostic dual day stress/rest Gated SPECT using a dual head SPECT camera, following injection of 925 MBq of 99mTc-Tetrofosmin. The mean age of these patients was 61 years (range: 23-73); 28 patients had a history of myocardial infarction. Perfusion was analyzed on both ungated and end-diastolic images using 20 segments scored on a 5-point scale (0 = normal, 4 = no uptake), while wall thickening and motion were assessed visually on stress/rest end-systolic images using a 4-point score (0 = normal, 3 = no wall thickening/motion). Twenty eight patients underwent coronary angiography. RESULTS AND DISCUSSION: 14/61 (23%) patients showed no segmental defects, while fixed equivocal defects, with preserved wall thickening, in 10/61 (16%) patients were considered artifactual. 11/61 (18%) showed true fixed defects. The remaining 26 patients showed al least one reversible defect. 14/61 (23%) patients with post-stress wall thinning and normal rest wall thickness, were considered stunned. The stunned subgroup showed a significant post-stress reduction in left ventricular ejection fraction. Finally, analyzing 1220 segments, we found an excellent agreement (k = .697) between the segmental score obtained by end-diastolic and ungated post-stress images: in fact, comparing the two sets of images, diagnostic accuracy was not significantly different. However the number of segments with fixed defects and normal wall thickening was lower with end-diastolic perfusion images than with ungated images, probably due to attenuation artifacts. This suggests a better accuracy of the former in the evaluation of regional myocardial perfusion. CONCLUSIONS: Although stress end-diastolic images do not seem to significantly improve diagnostic perfusion accuracy compared to ungated acquisitions, the simultaneous assessment of stress-rest wall thickening permits better characterization of a coronary artery disease population.     

Low-dose dobutamine nitrate-enhanced technetium 99m sestamibi gated spect versus low-dose dobutamine echocardiography for detecting reversible dysfunction in ischemic cardiomyopathy

BACKGROUND: The simultaneous assessment of perfusion and function with the use of technetium 99m sestamibi gated single photon emission computed tomography (SPECT) is helpful for the detection of myocardial viability, but its value in comparison with more established methods is not yet defined. METHODS AND RESULTS: This study compared low-dose dobutamine (LDD) nitrate-enhanced gated SPECT with LDD echocardiography for predicting recovery of regional ventricular function after revascularization in 25 patients with ischemic cardiomyopathy. In both studies, regional function (wall motion and thickening) at rest, during inotropic stimulation, and after revascularization was scored by a 4-point scale. In LDD echocardiography, the prediction of reversible dysfunction was based on the recognition of contractile reserve in asynergic (hypokinetic or a-dyskinetic) segments. In LDD gated sestamibi SPECT, reversible dysfunction was predicted on the basis of perfusion quantification (sestamibi uptake >or= 50%) in a-dyskinetic segments and on the basis of contractile reserve in hypokinetic segments. LDD echocardiography predicted reversible dysfunction with sensitivity, specificity, and global accuracy of 57%, 85%, and 75%, respectively. The sensitivity and specificity of LDD gated SPECT for identifying dysfunctional segments capable of functional recovery were 77% and 88%, respectively, with a diagnostic accuracy of 84% (P <.02 vs LDD echocardiography). CONCLUSIONS: The combined use of 2 different markers of viability, such as cellular integrity in a-dyskinetic segments and contractile reserve in hypokinetic segments, as permitted by LDD gated sestamibi SPECT, showed higher predictive accuracy for reversible dysfunction than the assessment of contractile reserve in all asynergic segments with LDD echocardiography.     

Usefulness of distinct activity thresholds according to baseline regional asynergy for predicting functional recovery in patients with chronic coronary artery disease and left ventricular dysfunction: A study with nitrate-enhanced sestamibi gated SPECT

BACKGROUND: The role of gated single photon emission computed tomography (SPECT) in improving viability detection with the use of perfusion imaging is uncertain. This study aimed to verify whether the classification of baseline regional dysfunction with gated SPECT helps to predict functional recovery with the use of quantitative perfusion imaging. METHODS AND RESULTS: Resting nitrate-enhanced sestamibi gated SPECT was performed in 31 patients with left ventricular dysfunction, who later underwent coronary revascularization. With the use of a 16-segment model, tracer activity was quantified, and wall motion and thickening were estimated with a 4-point scoring scheme. Reversible dysfunction was assessed with follow-up gated SPECT. According to receiver operating characteristic curve analysis, the best overall cutoff for predicting reversible dysfunction in asynergic segments was 50% of peak activity or greater, with 83% sensitivity, 54% specificity, and 64% accuracy. When the segments were divided according to wall motion in resting gated SPECT, the optimal activity cutoff was greater than 68% for hypokinetic and 50% or greater for adyskinetic segments. With the use of 2 thresholds, the overall sensitivity remained good (76%), whereas specificity increased to 73% (P <.0005) and accuracy to 74% (P <.02). CONCLUSIONS: Regional dysfunction assessment directly on perfusion images permits use of different activity thresholds with an improvement over a single cutoff for all asynergic segments. Therefore combining perfusion and functional data with nitrate-enhanced gated SPECT at rest appears to be a promising approach for viability detection.