门控心肌显像和心血池显像联合检测左心室功能

目的应用99mTC-MIBI门控心肌显像和心血池显像来评价左心室功能.方法30例受检者,静脉注射99mTc-MIBI后,用SPECT行常规体位平面心肌显像,观察分析室壁运动和左心室收缩分数(LVCF).结果99mTc-MI3I门控心肌显像能清楚区分室壁边缘,在判断室壁运动上与心血池显像的完全符合节段达66%.用象素数表现左心室腔面积大小所计算的左心室收缩分数(LVCF)与左心室射血分数(LVEF)明显相关(r=0.09,P＜0.01).结论99mTc-MIBI门控心肌显像和心血池显像在冠心病的检查中具有重要价值,可作为常规检查之一应用于临床.     

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.     

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.     

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     

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.     

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。     

核素显像识别存活心肌的临床应用进展

存活心肌的判断对冠心病患者治疗方案的选择及预后十分重要。^201Tl再注射法、硝酸甘油介入的静息^99Tc^m-sestamibi法增强了心肌灌注核素体层显像对存活心肌的检测能力，门控SPECT技术能在评估心肌灌注的同时计算LVEF(左心室射血分数)、局部室壁运动和局部室壁增厚率，具有符合线路的SPECT可以进行心肌代谢显像及灌注显像，其对存活心肌的检测能力可能接近于PET，而检查费用可大大降低。     

核素显像识别存活心肌的临床应用进展

存活心肌的判断对冠心病患者治疗方案的选择及预后十分重要。201Tl再注射法、硝酸甘油介入的静息99Tcm-sestamibi法增强了心肌灌注核素体层显像对存活心肌的检测能力,门控SPECT技术能在评估心肌灌注的同时计算LVEF(左心室射血分数)、局部室壁运动和局部室壁增厚率,具有符合线路的SPECT可以进行心肌代谢显像及灌注显像,其对存活心肌的检测能力可能接近于PET,而检查费用可大大降低。     

用门控心肌显像评价重组腺病毒-肝细胞生长因子治疗缺血性心脏病

目的 探讨99Tcm-甲氧基异丁基异腈(MIBI)静息门控心肌灌注显像(G-MPI)评价重组腺病毒-肝细胞生长因子(Ad-HGF)心肌内直接注射对缺血性心脏病早期治疗的价值.方法 18例冠心病患者根据随机分组表分为小、中、大剂量Ad-HGF治疗组,分别接受5×108,1.5×109,5×109空斑形成单位(PFU)/点(均分10点注射)的Ad-HGF心肌内直接注射.所有患者于治疗前后分别行静息G-MPI,以评价心功能和注射部位心肌血流灌注的变化.采用Stata 7.0软件进行统计学处理.结果 (1)与治疗前相比,小剂量组中有3例、中剂量组中有5例、大剂量组中有6例患者于Ad-HGF注射区域出现心肌血流灌注的改善,改善情况与注射剂量有量-效关系(X2=4.34, P＜0.05).(2)18例患者治疗前静息左心室射血分数(LVEF)、左心室舒张末期容积(EDV)和收缩末期容积(ESV)分别为(50.1±6.4)%,(137.7±33.2)和(70.2±22.4)ml;治疗后分别为(58.7±5.6)%,(123.7±32.7)和(51.9±14.9)ml.LVEF治疗后较治疗前有增加(t=6.1, P＜0.01),EDV和ESV则明显降低(t值分别为5.9,6.4,P均＜0.01).(3)低、中、高剂量Ad-HGF治疗组治疗前LVEF为(50.3±4.9)%,(52.0±5.4)%和(47.8±8.8)%,治疗后LVEF为(54.7±4.1)%,(58.8±3.9)%和(62.5±6.3)%.治疗前后LVEF的差值分别为(4.3±1.2)%,(6.8±5.7)%和(8.6±5.9)%,各组治疗后LVEF均增加:其中高剂量组的增加幅度明显高于中、低剂量组(t=3.3, P＜0.05; t=4.3, P＜0.01),中、低剂量组之间差异无统计学意义(t=1.1, P＞0.05).治疗前后LVEF的变化幅度与注射Ad-HGF剂量有量-效关系(Spearman相关系数为0.67, P＜0.01).结论 G-MPI可用于评价Ad-HGF心肌内直接注射治疗缺血性心脏病早期疗效.     

定量门控99Tcm-MIBI/201Tl心肌显像左心室射血分数正常参考值的建立

目的：应用定量门控^99Tc^m－甲氧基异丁基异腈（MIBI）和^201T1心肌显像测量静息左心室射血分数（LVEF），建立其正常参考值。方法；对277例患冠心病（CAD）低风险概率（＜10％）受检者行运动负荷－静息门控心肌断层显像。受检者分^99Tc^m－MIBI组（110例）和^201T1组（167例），各组再分无高血压（HBP）亚组（^99Tc^m－MIBI组85例，^201T1组128例）和HBP不伴左室肥厚9LVH）亚组（^99Tc^m－MIBI组25例，^201T1组39例）。采用QGSPECT专用分析程序测量静息LVEF。结果：^99Tc^m－MIBI组和^201T1组中HBP亚组的静息LVEF值均明显高于无HBP亚组（P均＜0．05），无HBP男性患者的静息LVEF值明显低于女性患者（P＜0．01）；无HBP者的心率、年龄与静息LVEF值间无线性相关（P均＞0．05）。^99Tc^m－MIBI组和^201T1组静息LVEF值均呈正态分布，其静息LVEF正常参考值分别为≥45％和≥43％。考虑性别影响，则^99Tc^m－MIBI组男性≥45％，女性≥48％；^201T1组男性≥42％，女性≥47％。结论：LVEF正常参考值有潜在的临床价值。     

Left ventricular ejection fraction and volumes on rest gated 201Tl perfusion SPECT: comparison with two-dimensional echocardiography

BACKGROUND: Rest gated 201Tl images are considered to be of poor count statistics due to lower energy and low photon flux of 201Tl in addition to increased attenuation and low dose that can be administered. We compared the left ventricular ejection fraction (LVEF), end diastolic (EDV) and end systolic volume (ESV) obtained on 4 h gated rest 201Tl myocardial perfusion single photon emission computed tomography (SPECT) with those obtained by two-dimensional echocardiography (2-D ECHO) in patients with known or suspected coronary artery disease (CAD). METHODS: Eighty-two consecutive patients who underwent gated 201Tl stress-rest myocardial perfusion SPECT and 2-D ECHO were studied. The gated thallium images were processed with Siemens e-soft autocardiac processor and LVEF, EDV and ESV were evaluated using Emory Cardiac Toolbox. The same parameters were also assessed on the 2-D ECHO using the modified Simpson method for comparison. RESULTS: Out of 82 rest gated images, one study was excluded because of poor count statistics. In 81 (99%) patients there was good linear correlation with 2-D ECHO values and rest gated 201Tl SPECT images for EDV, ESV and LVEF. Pearson's correlation co-efficient (r value) for EDV, ESV and LVEF between the two methods was 0.78, 0.79 and 0.88, respectively. A Bland-Altman plot showed close agreement with LVEF but not for EDV and ESV. CONCLUSION: These results suggest that the 4 h rest gated 201Tl study gives a reliable value for the LVEF compared to 2-D ECHO and can be used in routine clinical practice.     

99Tcm-NOET门控心肌灌注SPECT评价冠心病的价值

目的评价99Tcm--双（N-乙氧基,N-乙基-二硫代氨基甲酸酯）氮化锝（99Tcm-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925MBq 99Tcm-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99Tcm-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=42．60：4,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）％1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99Tcm-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?     

静息/负荷82Rb PET门控心肌灌注显像定量分析的价值

目的 探讨门控和定量分析技术在82Rb PET心肌灌注显像中的应用价值.方法 对32例临床可疑冠心病患者进行静息/腺苷负荷82Rb PET门控心肌灌注显像.原始数据按常规处理成断层图像,再应用定量分析软件Emory Cardiac Toolbox(ECTb)进行定量分析.由3位有经验的核医学科医师分别对图像质量(优、良、一般、差、无法分析)、左心室射血分数(LVEF)的可信程度(同意、基本同意、不确定、基本不同意、不同意)、左心室功能的其他指标对诊断的价值(很有帮助、有帮助、不确定、基本无帮助、无帮助)进行评价.将观察指标分为肯定组和否定组,分别计算其百分率和90%可信区间.结果 192组分析结果中,图像质量优良者共计160组,占83.3%(160/192),其95%可信区间为78.1%～88.6%;图像质量为一般和差的共计32组,占16.7%(32/192),其95%可信区间为11.4%～21.9%.对LVEF的结果表示同意和基本同意者共计164组,占85.4%(164/192),其95%可信区间为80.4%～90.4%;认为不确定和基本不同意或不同意者共计28组,占14.6%(28/192),其95%可信区间为9.6%～19.6%.应用定量分析软件获得的除LVEF以外左心室功能的其他指标,认为很有帮助和有帮助者共计102组,占53.1%(102/192),其95%可信区间为46.1%～60.2%;不确定和基本无帮助或无帮助者90组,占46.9%(90/192),其95%可信区间为39.8%～53.9%.结论 门控和定量分析技术有助于PET图像阅片者作出更正确的诊断.     

~(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.     

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.     

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.     

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.     

Accuracy of left ventricular ejection fraction determined by gated myocardial perfusion SPECT with Tl-201 and Tc-99m sestamibi: Comparison with first-pass radionuclide angiography

BACKGROUND: We compared estimates of left ventricular ejection fraction (LVEF) assessed by gated single photon emission computed tomography (SPECT), using both technetium-99m sestamibi and thallium-201, with those obtained by first-pass radionuclide angiography (FPRNA) in patients with a broad spectrum of LVEF and perfusion abnormalities. METHODS: Sixty-three patients were randomly selected to undergo a dual isotope gated SPECT study (rest Tl-201 followed by adenosine Tc-99m sestamibi scintigraphy). Studies were processed by use of the Cedars quantitative gated SPECT software. FPRNA was acquired during an intravenous bolus injection of Tc-99m sestamibi and processed with a commercially available software. RESULTS: The estimates of LVEF were similar (P = NS) with Tl-201 gated SPECT (54% +/- 15%), Tc-99m gated SPECT (54% +/- 16%), and FPRNA (54% +/- 12%). There was an excellent correlation between Tc-99m and Tl-201 gated SPECT (Pearson's r = 0.92, P < .0001). There were also good linear correlations between Tc-99m sestamibi gated SPECT and FPRNA (Pearson's r = 0.85, P < .0001), as well as between Tl-201 gated SPECT and FPRNA (Pearson's r = 0.84, P < .0001). In the 16 patients with LVEF < 50%, Tc-99m sestamibi gated SPECT and FPRNA (Pearson's r = 0.84, P < .0001) and Tl-201 gated SPECT and FPRNA (Pearson's r = 0.92, P < .0001) correlated well. CONCLUSION: LVEF can be accurately assessed by gated SPECT with either Tc-99m sestamibi or Tl-201 in properly selected patients with normal or depressed left ventricular function.     

Assessment of ejection fraction with Tl-201 gated SPECT in myocardial infarction: Precision in a rest-redistribution study and accuracy versus planar angiography

BACKGROUND. Viability and left ventricular ejection fraction (LVEF) are essential measures for the assessment of myocardial infarction (MI). These 2 variables may be evaluated simultaneously by means of thallium-201 gated single photon emission computed tomography (SPECT); however, the precision and accuracy of LVEF measurements with this isotope remain controversial, particularly in cases of extended perfusion defects and poor count densities. METHODS AND RESULTS. Fifty patients with a history of MI underwent a 20-minute rest and a 4-hour redistribution Tl-201 gated SPECT viability protocol, immediately followed by a technetium-99m planar equilibrium radionuclide angiography (ERNA). On gated SPECT images, various count statistics were calculated, and perfusion was automatically quantified by means of CardioMatch, which provided both the size and severity of MI defects. Rest and redistribution LVEFs were determined from gated SPECT with Germano's algorithm, whereas LVEFs were calculated from ERNA using the manufacturer's software. Mean LVEF values calculated with rest gated SPECT, redistribution gated SPECT, and planar ERNA were 30% +/- 13%, 30% +/- 13% and 33% +/- 13%, respectively. Significant differences between repeated gated SPECT LVEFs were not shown by means of the paired t test. Correlation coefficients were high between 20-minute and 4-hour scans (r = 0.89) and between gated SPECT and ERNA (r = 0.88 and r = 0.92 at 20 minutes and 4 hours, respectively). Additionally, close agreement between gated SPECT and ERNA was shown by means of the Bland-Altman plot, despite an underestimation of 3 units. Finally, neither the technical conditions (count density, heart rate, lung uptake, etc) nor the perfusion alteration (size, severity, redistribution) appeared to interfere with the precision and accuracy of gated SPECT LVEF measurement. CONCLUSION. Tl-201 gated SPECT is a precise method for assessing LVEF within the same patient at 4-hour intervals, even with a substantial count decay, and it gives accurate results compared with planar ERNA, even in the case of large perfusion defects.     

A comparison and validation of blood-pool imaging and ECG-gated SPET myocardial perfusion imaging to assess left ventricular ejection fraction

The aim of this study was to validate the accuracy of left ventricular ejection fraction (LVEF) obtained by quantitative gated single photon emission tomography (QGS) perfusion imaging in comparison with gated blood-pool imaging. Resting gated myocardial perfusion imaging was performed in 269 patients with suspected or known coronary artery disease, and followed by equilibrium nuclear cardiac blood-pool imaging in one week. The later was considered as the reference standard. The LVEF from both methods were analyzed. The LVEF were calculated with QGS using Cedars Cardiac Quantification software. We found that LVEF from QGS and blood-pool (Bp)-LVEF were highly correlated (r=0.819, <0.001). Taken into consideration that QGS-LVEF was significantly different from Bp-LVEF (mean ± SD: 57.77% ± 19.28% vs 54.23% ± 15.41%, P<0.05), data were further analyzed by grouping participants based on end-systolic ventricular volume (ESV). QGS-LVEF was not significantly different from Bp-LVEF in the group where that ESV was larger than 15m, (mean ± SD: 52.71% ± 16.11% vs 51.83% ± 15.33%, P>0.05), whereas when ESV was smaller than 15 mL, QGS-LVEF was significantly higher than Bp-LVEF (mean ± SD: 80.53% ± 7.01%vs 65.06% ± 10.37%, P<0.05). Our findings demonstrate that when ESV values are larger than 15 mL, QGS- LVEF could replace Bp-LVEF. However, when ESV value is smaller than 15 mL, LVEF should be assessed in combination with blood-pool imaging.