99 Tcm-MIBI门控心肌显像ECTS软件测量左室射血分数

目的评价99Tcm-甲氧基异丁基异腈(MIBI)门控心肌显像Emory Cardiac Toolbox softwere (ECTS)处理软件测量左室射血分数(LVEF)的临床价值.方法 31例受检者,采用静息-多巴酚丁胺负荷一日法,行99Tcm-MIBI门控心肌断层显像,用ECTS软件测量LVEF,并于1周内完成平衡法心室显像,比较2种方法测量LVEF的相关性及一致性.结果①ECTS软件分析左室功能参数的重复性很好,变异系数(CV)均小于2%.②99Tcm-MIBI门控心肌显像ECTS软件测定LVEF值与平衡法心室显像测定值相关性良好(r=0.893,P<0.001).③ECTS软件测定的LVEF值[(57.3±2.93)%]较心室显像测定值[(46.6±2.86)%]高(t=7.76,P<0.001).结论 99Tcm-MIBI门控心肌显像ECTS软件与平衡法心室显像测定LVEF值具有较好的相关性,但前者测量值较后者高.99Tcm-MIBI门控心肌显像ECTS软件测定LVEF值能否完全取代平衡法心室显像测定,尚需进一步研究.     

门控心肌灌注断层显像与超声心动图评价左室功能和左室容积的比较

门控心肌灌注断层(GSPECT)显像可同步评价左室心肌血流灌注和左室功能状况,此技术所测的左室射血分数(LVEF)、舒张末期容积(EDV)和收缩末期容积(ESV)的准确性报道尚少。因此,使用不同的显像剂和显像方案行GSPECT显像,将其测定的结果与超声心动图(ECG)进行比较。方法:109例冠心病患者(男53例,女56例)于15d内分别行GSPECT显像和ECG检查。其中42例采用201　Tl负荷-再分布显像方案,55例行一天法99Tcm-甲氧基异丁基异腈(99Tcm-MIBI)或99Tcm-tetrofosmin负荷-静息显像方案,余12例行静息201　Tl-负荷99Tcm-MIBI显像方案。每个…     

201Tl定量门控心肌灌注体层显像与99mTc-红细胞门控心血池显像测定左心室射血分数的对比研究

目的 探讨201Tl定量门控心肌灌注体层显像与99mTc-红细胞门控心血池显像测量左心室射血分数(LVEF)的相关性.方法 72例受检者接受201Tl静息门控心肌灌注体层显像,用AUTOQUANT 4.21软件测量LVEF,并与24 h内的静息99mTc-红细胞平衡法门控心血池显像结果进行比较.结果 ①门控心肌灌注体层显像与门控心血池显像测量LVEF值的结果呈明显正相关(r=0.554,P=-0.000),两种方法无统计学差别(t=1.194,P＞0.05).②不同疾病组之间两种测量方法无统计学差异(P值均大于0.05).③门控心肌灌注体层显像及门控心血池显像测量的LVEF值分别为(64.68±10.77)%和(62.46±8.99)%,门控心肌灌注体层显像测量的LVEF值要比门控心血池显像高出3.55%.结论 201Tl门控心肌灌注体层显像与99mTc-红细胞门控心血池显像测量LVEF值的相关性好且结果准确,但门控心肌灌注体层显像的LVEF测量值要稍高于门控心血池显像.     

定量门控99Tcm-tetrofosmin心肌显像测量左室功能

目的探讨定量门控(QG)99Tcm-tetrofosmin心肌显像测量左室功能的临床应用价值.方法74例受试者进行了门控99Tcm-tetrofosmin心肌显像,采用QGSPECT专用分析程序全自动测量左室功能.其中36例同时进行静息门控心室显像,以比较两种方法测量左室功能的相关性.结果①74例99Tcm-tetrofosminQGSPECT全自动定量测定左室功能均获成功.②QGSPECT全自动测量36例受试者的静息左室射血分数(LVEF)、舒张末期容积(EDV)、收缩末期容积(ESV)分别与静息门控心室显像计算结果显著正相关(r分别为0.859,0.914,0.950,P均<0.001),重复性好.③心肌缺血组(n=28)静息LVEF与对照组(n=23)比较差异无显著性,而心肌梗死组(n=9)静息LVEF明显低于对照组(t=6.33,P<0.001).结论定量门控心肌显像99Tcm-tetrofosmin能准确评价左室功能.     

双核素心肌显像预测PCI术后心功能改善的评价

目的:探讨多巴酚丁胺201Tl负荷-再分布/硝酸甘油介入99Tcm-MIBI门控心肌灌注显像预测PCI术后心功能改善的作用.方法:69例临床怀疑有冠心病拟行经皮冠状动脉介入治疗(PCI)的病人进行多巴酚丁胺201 Tl负荷-再分布显像,显像结束后行硝酸甘油介入99Tcm-MIBI门控心肌灌注显像.心肌显像后2周内69例病人全部进行了经皮冠状动脉介入治疗.PCI术前及术后3个月心脏超声测定左室射血分数(LVEF).结果:①69例病人PCI术后左心室功能较术前有改善(△LVEF=4.78±2.4,t=2.02,P值<0.05).②左心室功能降低组术后心功能提高值明显高于左心室功能正常组(△LVEF=5.3±2.0对LVEF=3.1±2.9,t=2.83,P<0.05).③可逆性灌注缺损心肌节段数>3组术后心功能提高值明显高于可逆性灌注缺损心肌节段数≤3组(△LVEF=5.8±1.6对△LVEF=4.4±1.4,t=2.45,P<0.05).结论:多巴酚丁胺201Tl负荷-再分布/硝酸甘油介入99Tcm-MIBI门控心肌灌注显像能准确检出缺血且存活心肌,对PCI术后心功能改善有很好的预测价值.     

门控99Tcm-MIBI/18F-FDG双核素同时采集显像评价左心室功能

目的探讨门控99Tcm-甲氧基异丁基异腈(MIBI)/18F-脱氧葡萄糖(FDG)双核素同时采集(DISA)显像评价左心室功能的临床价值.方法 77例冠心病患者行门控DISA,其中53例行X线左心室造影(LVG),分别比较LVG心室射血分数(EF)值和DISA法门控99Tcm-MIBI和18F-FDG 同时显像所得EF值.局部室壁运动行Kappa值比较.结果门控99Tcm-MIBI和门控18F-FDG显像所得EF值间相关性高(r=0.90,P<0.001).两者与LVG EF值相关性均高(r分别为0.86和0.85,P均<0.001).门控99Tcm-MIBI和18F-FDG显像与LVG比较Kappa值分别为0.765和0.742.结论门控99Tcm-MIBI/18F-FDG DISA可同时了解左室心肌灌注、代谢及功能,提供左心室功能的重要信息,有重要的临床价值.     

定量门控~(99)Tc~m-tetrofosmin心肌显像测量左室功能

目的　探讨定量门控 (QG) 99Tcm tetrofosmin心肌显像测量左室功能的临床应用价值。方法　 74例受试者进行了门控99Tcm tetrofosmin心肌显像 ,采用QGSPECT专用分析程序全自动测量左室功能。其中 36例同时进行静息门控心室显像 ,以比较两种方法测量左室功能的相关性。结果　①74例99Tcm tetrofosminQGSPECT全自动定量测定左室功能均获成功。②QGSPECT全自动测量 36例受试者的静息左室射血分数 (LVEF)、舒张末期容积 (EDV)、收缩末期容积 (ESV)分别与静息门控心室显像计算结果显著正相关 (r分别为 0 .85 9,0 .914,0 .95 0 ,P均 <0 .0 0 1) ,重复性好。③心肌缺血组 (n =2 8)静息LVEF与对照组 (n =2 3)比较差异无显著性 ,而心肌梗死组 (n =9)静息LVEF明显低于对照组 (t=6 .33,P <0 .0 0 1)。结论　定量门控心肌显像99Tcm tetrofosmin能准确评价左室功能     

99 TcmN-NOEt门控心肌显像的临床应用

目的评价99Tcm-N-乙氧基,N-乙基氨荒酸钠(N-NOEt)门控心肌显像的临床应用价值,并与99Tcm-甲氧基异丁基异腈(MIBI)进行比较.方法 20例受检者分为2组,组1左室射血分数(LVEF)≥50%,共13例,平均年龄(49.9±14.7)岁;组2LVEF<50%,共7例,平均年龄(50.9±12.9)岁.受检者静脉注射99TcmN-NOEt 925 MBq后分别于30和120 min行静息门控心肌断层显像,并计算心/肺(H/L)比值.组2 6例、组1 1例在3 d内行99Tcm-MIBI门控心肌显像,将每例受检者的左室心肌分为9个节段,以常规4分法进行打分.结果组1 30及120 min H/L比值分别为1.47±0.47和1.59±0.53(t=0.31, P>0.05),2次显像的LVEF、舒张末期容积(EDV)和收缩末期容积(ESV)差异无显著性(P>0.05).组2 30和120 min H/L比值分别为0.72±0.11和0.89±0.11(t=2.93, P<0.05),2次显像的LVEF,EDV和ESV间差异无显著性(P>0.05).2组间的H/L比值和LVEF、EDV、ESV差异有显著性.NOEt与MIBI所得LVEF,EDV和ESV值基本一致(P>0.05),但NOEt的不正常节段数(21个)较MIBI(17个)为多,两者的一致性为93.65%, Kappa±s=0.87±0.12,得分分别为2.00±0.84(MIBI)和2.38±0.84(NOEt)(t=1.39, P>0.05).结论①左心功能受损时, 肺摄取99TcmN-NOEt增多.②99TcmN-NOEt与99Tcm-MIBI所测得的LVEF,EDV和ESV基本一致.③99TcmN-NOEt测得的心肌放射性缺损的范围及程度较MIBI广泛而严重.     

99m Tc-MIBI门控心肌灌注断层显像左心室射血分数与超声心动图相关性

目的:评价99mTc-MIBI门控心肌断层显像(GMPT)测量左心室射血分数(LVEF)与超声心动图的相关性。方法:175例确诊和疑诊冠心病(CAD)的患者同时进行静息GMPT和超声心动图检查,分别计算无心肌梗死和心肌梗死两组患者GMPT与超声心动图测量LVEF的相关系数。结果:无心肌梗死和心肌梗死组GMPT和超声心动图测量LVEF值均呈正相关(r=0.62,r=0.84)。结论:GMPT测量LVEF与超声心动图有较好的相关性。     

~(99)Tc~m-NOET门控心肌灌注SPECT评价冠心病的价值

目的 评价~(99)Tc~m-双(N-乙氧基,N-乙基-二硫代氨基甲酸酯)氮化锝(~(99)Tc~m-NOET)静息门控断层心肌灌注显像对冠心病患者的诊断价值.方法 疑诊为冠心病的45例患者注射925 MBq~(99)Tc~m-NOET后1h用SPECT行静息门控心肌灌注显像,获得舒张未期容积(EDV)、收缩未期容积(ESV)、左室射血分数(LVEF)等心功能参数和舒张末期容积灌注、局部射血分数、局部室壁活动和室壁增厚度4个靶心图.所有患者在1周内行冠状动脉造影,将冠状动脉狭窄≥50%定为病变血管.根据冠状动脉造影结果将其分为心肌梗死组、心肌缺血组和对照组三组.结果 ~(99)Tc~m-NOET静息门控SPECT诊断冠心病的灵敏度和特异度分别为68.42%和83.33%.心肌梗死组的心功能参数[EDV=(129.32±9.14)ml,ESV=(80.97±9.49)ml,LVEF=(40.15±3.28)%]与对照组[EDV=(80.91±3.12)ml,ESV=(30.12±1.79)ml,LVEF=(63.51±1.04)%]相比,统计学差异有显著性(EDV:F=22.103,ESV:F=32.277,LVEF:F=42.604,均为P＜0.01),心肌缺血组的心功能参数[(EDV=(70.83±3.46)ml,ESV=(25.13±2.85)ml,LVEF=(65.55±2.62)%]与对照组相比,统计学差异无显著性意义.心肌梗死组左室心肌共分为460个节段,其中209个节段局部灌注、局部射血分数、局部室壁活动和室壁增厚度4个靶心图均异常.局部灌注异常的节段共328个节段.伴有局部射血分数、局部室壁活动和室壁增厚度异常分别有250个、240个和276个节段.局部灌注异常的节段与局部射血分数、局部室壁活动和室壁增厚度异常的节段不完全匹配.结论 ~(99)Tc~m-NOET静息门控心肌灌注显像对冠心病的诊断有较大临床应用价值,所获得的整体心室功能参数在心肌梗死的评价中有优越性,但对心肌缺血的诊断价值不大.心肌梗死中存在有不少的局部灌注与心肌室壁功能异常节段的不匹配,对心肌存活的评价有帮助.     

Can the estimation of ejection fraction during gated single photon emission computed tomography at rest add information to the cardiac perfusion study?

Left ventricular function is an important prognostic indicator in patients with coronary artery disease. The electrocardiogram gated, myocardial, single photon emission tomography (SPECT) program is coming into wide use. This program permits measurement of end diastolic volume, end systolic volume, and ejection fraction. This study was designed to show whether the measurement of ejection fraction by using (99c)Tc tetrofosmin gated SPECT at rest could give additional information to the interpretation of perfusion. Exercise 99mTc tetrofosmin SPECT and gated (99c)Tc tetrofosmin SPECT at rest were performed in 33 patients with or suspected of having coronary artery disease. Left ventricular ejection fraction was calculated from reconstructed gated SPECT at rest with a software quantitative gated SPECT. The results showed a poor correlation between segmental ejection fraction and segmental perfusion in stress and rest. There was an increasing probability of reversibility as the ejection fraction increased, while there was a greater chance of a fixed defect as the ejection fraction decreased. It is concluded that gated SPECT using (99c)Tc tetrofosmin provides clinically satisfactory functional data that, in combination with the perfusion information, will improve diagnostic and prognostic accuracy without an increase in cost or radiation dose to patients.     

应用门控SPECT测量左心室功能的方法学研究

目的：试用门控心肌显像测定左室功能并与心血池显像结果比较。材料和方法：61例受检者进行了Tc-99m—MIBI门控心肌显像及心血池显像．结果：门控断层心肌显像的短轴中间部左室功能结果与平衡法心血池显像有良好的相关性(r=0．82）。结论：门控心肌断层显像测定的左室功能结果方法简便可靠．能同时反映心肌直流及左室功能。     

Reproducibility of Tl-201 and Tc-99m sestamibi gated myocardial perfusion SPECT measurement of myocardial function

BACKGROUND: We compared the reproducibility of thallium 201 and technetium 99m sestamibi (MIBI) gated single photon emission computed tomography (SPECT) measurement of myocardial function using the Germano algorithm (J Nucl Med 1995;36:2138-47). METHODS AND RESULTS: Gated SPECT acquisition was repeated in the same position in 30 patients who received Tl-201 and in 26 who received Tc-99m-MIBI. The quantification of end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) on Tl-201 and Tc-99m-MIBI gated SPECT was processed independently with Cedars-Sinai QGS (Quantitative Gated SPECT) software. The reproducibility of the measurement of ventricular function on Tl-201 gated SPECT was compared with that of Tc-99m-MIBI gated SPECT. Correlation between the 2 measurements for volumes and EF was excellent for the repeated gated SPECT studies of Tl-201 (r = 0.928 to 0.986, P <.05) and Tc-99m-MIBI (r = 0.979 to 0.997, P <.05). However, Bland-Altman analysis revealed the 95% limits of agreement (2 SDs) for volumes and EF were narrower by repeated Tc-99m-MIBI gated SPECT (EDV 14.1 mL, ESV 9.4 mL, EF 5.5%) than by repeated Tl-201 gated SPECT (EDV 24.1 mL, ESV 18.6 mL, EF 10.3%). The root-mean-square values of the coefficient of variation for volumes and EF were smaller by repeated Tc-99m-MIBI gated SPECT (EDV 2.1 mL, ESV 2.7 mL, EF 2.3%) than by repeated Tl-201 gated SPECT (EDV 3.2 mL, ESV 3.5 mL, EF 5.2%). CONCLUSIONS: QGS provides an excellent correlation between repeated gated SPECT with Tl-201 and Tc-99m-MIBI. However, Tc-99m-MIBI provides more reproducible volumes and EF than Tl-201. Tc-99m-MIBI gated SPECT is the preferable method for the clinical monitoring of ventricular function.     

Accuracy of the automated assessment of left ventricular function with gated perfusion SPECT in the presence of perfusion defects and left ventricular dysfunction: Correlation with equilibrium radionuclide ventriculography and echocardiography

BACKGROUND: Gated single photon emission computed tomography (SPECT) with automated methods allows the quantitative assessment of left ventricular function and perfusion; however, its accuracy must be defined for patients with large earlier infarctions and severe rest perfusion defects, in whom the estimation of endocardial and epicardial borders might be more difficult, even with automated edge-detection techniques. METHODS AND RESULTS: We prospectively compared the automated measurements of left ventricular ejection fraction (LVEF) and volumes from rest-injected gated Technetium 99m (Tc99m) perfusion SPECT with equilibrium radionuclide angiocardiography (ERNA) in 62 patients and the assessment of regional function with echocardiography in 22 patients. Forty-six patients had an earlier myocardial infarction (mean defect size, 34% of left ventricle; SD, 12.7%; range, 8% to 56%); 27 patients had large defects (> or = 20% of left ventricle; LVEF range, 8% to 75%). LVEF, as determined with Cedars-Sinai software (quantitative gated SPECT), correlated well with ERNA (r = 0.941; y = 1.003x + 1.15; P<.0001; SE of the estimate = 6.3%; mean difference -1.3% for LVEF) in the entire study population and in the subgroups of patients with an earlier infarction, severe defects, and large infarctions (> or = 20% of the left ventricle). A correlation existed between gated SPECT and ERNA volumes (r = 0.882, y = 1.040x - 14.7, P<.0001 for end-diastolic volume; r = 0.954, y = 1.147x - 13.9, P<.0001 for end-systolic volumes with the count-ratio technique), but with wider limits of agreement. The exact segmental score agreement between gated SPECT and echocardiography for regional function was 79.8% (281 of 352, kappa = 0.682). CONCLUSIONS: Automated gated SPECT provides an accurate assessment of ejection fraction and regional function, even in the presence of an earlier myocardial infarction with large perfusion defects and significant left ventricular dysfunction.     

Factors affecting left ventricular ejection fraction using automated quantitative gated SPECT

BACKGROUND: Factors affecting the accuracy of left ventricular ejection fraction (LVEF) quantification using automated quantitative gated SPECT have not been adequately investigated in patients in the clinical setting. Therefore, the authors studied the effect of defect size and Tc-99m tetrofosmin dose on the accuracy of LVEF calculation using the automated QGS program. MATERIALS AND METHODS: Thirty-two consecutive patients underwent gated rest and stress myocardial perfusion SPECT after administration of 8 and 27 mCi Tc-99m tetrofosmin, respectively. The LVEF was obtained for both the rest and stress studies using the QGS program and compared with the LVEF obtained using quantitative echocardiography performed within 2 weeks. Myocardial perfusion defects were recorded as scarring, ischemia, or mixed scarring and ischemia in 12 left ventricular segments. The defect size was evaluated by adding the number of affected segments. RESULTS: The mean LVEF calculated using high-dose stress QGS, low-dose rest QGS, and echocardiography was 49.2% +/- 15%, 46.2% +/- 17% and 48.7% +/- 16.9% respectively, with no statistically significant differences. The LVEF obtained using high-dose stress QGS correlated better with echocardiography than did that obtained using low-dose rest QGS (r = 0.86 versus 0.76). In addition, when the high-dose stress LVEF in the 14 patients with normal myocardial perfusion was compared with that in 11 patients who had one- or two-segment perfusion defects, and 7 patients who had perfusion defects in > or = three segments, there was good correlation with echocardiography in the three patient groups (r = 0.85, 0.88, and 0.91, respectively). CONCLUSIONS: Myocardial perfusion defects do not affect the accuracy of LVEF calculation using automated QGS. High-dose gated myocardial SPECT demonstrated better correlation with quantitative echocardiography LVEF results.     

Myocardial tracking, a new method to calculate ejection fraction with gated SPECT: validation with (201)Tl versus planar angiography.

Left ventricular ejection fraction (LVEF) and viability are essential variables for the prognosis of myocardial infarction and can be measured simultaneously by (201)Tl gated SPECT; however, most algorithms tend to underestimate LVEF. This study aimed to evaluate a new myocardial tracking algorithm, MyoTrack (MTK), for automatic LVEF calculation. METHODS: A rest/redistribution (20 min/4 h) (201)Tl gated SPECT protocol followed immediately by a (99m)Tc equilibrium radionuclide angiography (ERNA) was performed in 75 patients with history of myocardial infarction. Quality of myocardial uptake was evaluated from count statistics and automatic quantification of defect sizes and severities (CardioMatch). LVEFs were calculated both with Germano's quantitative gated SPECT (QGS) algorithm and with MTK. Briefly, the originality of this algorithm resides in the unique end-diastole segmentation, matching to a template and motion field tracking throughout the cardiac cycle. RESULTS: ERNA LVEF averaged 33% +/- 14%. QGS significantly underestimated this value at 20 min (30% +/- 13%, P < 0.001) and at 4 h (30% +/- 13%, P < 0.0001). By contrast, MTK did not miscalculate LVEF at 20 min (34% +/- 14%, probability value was not significant) though a similar underestimation occurred at 4 h (31% +/- 13%, P < 0.02). Individual differences between early and late gated SPECT values and differences between gated SPECT and ERNA values did not correlate with the extension of perfusion defects, count statistics, or heart rate. CONCLUSION: MTK algorithm accurately calculates LVEF on early/high-count images compared with ERNA [corrected], even in patients with severe perfusion defects, but tends to underestimate LVEF on delayed/low-contrast images, as other algorithms do.     

缺血心肌99Tcm-MIBI清除率变化的临床研究

目的 探讨缺血性心脏病（IHD）患者心肌99Tcm-甲氧基异丁基异腈（MIBI）早期、晚期清除率的变化及其评估缺血心肌细胞功能障碍的价值.方法 对临床诊断为IHD并满足冠状动脉三支主要分支狭窄均≥50%、除外心肌梗死的16例患者行99Tcm-MIBI静态平面及门控心肌灌注断层显像.用t检验比较99Tcm-MIBI早期（注药后90 min）、晚期（注药后4 h）清除率及左心室射血分数（LVEF）与健康对照组（10名）的差异,并对早期、晚期清除率与LVEF行直线相关分析.结果 IHD组早期、晚期心肌清除率及LVEF分别为（13.44±2.87）%、（19.24±4.71）%和（55.71±7.97）%,健康对照组分别为（17.32±4.92）%、（15.23±3.81）%和（67.75±5.43）%,2组相比差异均有统计学意义（t值分别为2.384,-2.246及-4.418,P均＜0.05）.早期及晚期清除率与LVEF不具有相关性,r值分别为-0.212（P＞0.05）及0.352（P＞0.05）.结论 IHD患者心肌99Tcm-MIBI清除率异常可反映缺血引起的细胞功能损伤.     

^99Tc^m—MIBI静息门控心肌灌注显像在心肌梗死干细胞移植治疗中的价值

目的用^99Tc^m-甲氧基异丁基异腈（MIBI）静息门控心肌灌注显像的方法,评价急性心肌梗死（AMI）患者自体骨髓间质干细胞（MSC）移植术治疗的疗效。方法AMI患者31例,均行经皮冠状动脉介入治疗（PCI）术,其中18例患者作为试验组,于PCI术后行自体MSC移植术治疗,PCI术后拒绝行细胞移植治疗的13例患者作为对照组。于PCI术前,术后1,3和6个月进行^99Tc^m-MIBI静息门控心肌灌注断层显像,评价心肌血流灌注及心功能改善程度。统计学处理采用SPSS11．0软件,行t检验。结果所有患者术后1个月放射性稀疏节段数明显减少,术后3个月和6个月放射性缺损节段数试验组（2．37±1．09和2．21±0．93）较对照组（3．24±0．93和3．21±1．05）明显减少（t=2．32,2．79,P均〈0．05）;与术前[（35．4±16．7）％和（32．8±15．9）％]相比,术后6个月试验组[（57．2±14．3）％]和对照组[（44．8±11．7）％]患者左心室射血分数（LVEF）均显著升高（t=4．27,2．18,P均〈0．05）,试验组患者LVEF明显高于对照组（t=2．58,P〈0．05）。结论心肌梗死患者自体MSC移植术后,应用^99Tc^m-MIBI静息门控心肌灌注显像随访和评价疗效有一定临床价值。     

201Tl and 99mTc-MIBI gated SPECT in patients with large perfusion defects and left ventricular dysfunction: comparison with equilibrium radionuclide angiography.

Left ventricular ejection fraction (LVEF) is a major prognostic factor in coronary artery disease and may be computed by 99mTc-methoxyisobutyl isonitrile (MIBI) gated SPECT. However, 201Tl remains widely used for assessing myocardial perfusion and viability. Therefore, we evaluated the feasibility and accuracy of both 99mTc-MIBI and 201Tl gated SPECT in assessing LVEF in patients with myocardial infarction, large perfusion defects and left ventricular (LV) dysfunction. METHODS: Fifty consecutive patients (43 men, 7 women; mean age 61 +/- 17 y) with a history of myocardial infarction (anterior, 26; inferior, 18; lateral, 6) were studied. All patients underwent equilibnum radionuclide angiography (ERNA) and rest myocardial gated SPECT, either 1 h after the injection of 1110 MBq 99mTc-MIBI (n = 19, group 1) or 4 h after the injection of 185-203 MBq 201Tl (n = 31, group 2) using a 90 degrees dual-head camera. After filtered backprojection (Butterworth filter: order 5, cutoff 0.25 99mTc or 0.20 201Tl), LVEF was calculated from reconstructed gated SPECT with a previously validated semiautomatic commercially available software quantitative gated SPECT (QGS). Perfusion defects were expressed as a percentage of the whole myocardium planimetered by bull's-eye polar map of composite nongated SPECT. RESULTS: Gated SPECT image quality was considered suitable for LVEF measurement in all patients. Mean perfusion defects were 36% +/- 18% (group 1), 33% +/- 17% (group 2), 34% +/- 17% (group 1 + group 2). LVEF was underestimated using gated SPECT compared with ERNA (34% +/- 12% and 39% +/- 12%, respectively; P = 0.0001). Correlations were high (group 1, r= 0.88; group 2, r = 0.76; group 1 + group 2, r = 0.82), and Bland-Altman plots showed a fair agreement between gated SPECT and ERNA. The difference between the two methods did not vary as LVEF, perfusion defect size or seventy increased or when the mitral valve plane was involved in the defect. CONCLUSION: LVEF measurement is feasible using myocardial gated SPECT with the QGS method in patients with large perfusion defects and LV dysfunction. However, both 201Tl and 99mTc-MIBI gated SPECT similarly and significantly underestimated LVEF in patients with LV dysfunction and large perfusion defects.