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。     

~(18)F-FDG与~(201)Tl静息-再分布SPECT显像在识别存活心肌及预测再血管化术后心功能恢复中的价值比较

目的:比较18F-FDG和201　Tl静息-再分布的SPECT显像在预测再血管化术后左室局部功能改善中的价值。方法:对拟行再血管化手术并经超声心动检查确有局部室壁运动异常的24例冠心病患者在同一天内进行201　Tl静息-再分布及18F-FDGSPECT显像。用201　Tl静息-再分布SPECT显像的早期影像作为心肌灌注显像与18F-FDGSPECT显像比较;用极坐标靶心图对201　Tl静息-再分布显像资料进行半定量分析;采用13节段模型分析比较超声心动图与心肌断层影像。将18F-FDGSPECT显像示室壁运动异常节段中灌注影像正常或不匹配(灌注降低而18F-FDG摄…     

门控心肌灌注显像局部室壁运动异常判断冠状动脉狭窄程度的价值

目的 探讨_99mTc-甲氧基异丁基异腈(_99mTc-MIBI)门控心肌灌注显像出现的可逆性局部室壁运动异常(RWMA)在判断冠状动脉狭窄程度中的价值。方法 入选90例疑似冠心病患者,在门控心肌灌注显像的前后2周内进行冠状动脉造影检查。门控心肌SPECT检查应用9节段5分制进行室壁运动及增厚率评分。结果 心肌显像上可逆性RWMA判断≥75%的冠状动脉狭窄的灵敏度为64%,特异度为95%;用可逆性RWMA来区别严重冠状动脉狭窄(≥75%)和不严重的冠状动脉狭窄(<75%)有很高的阳性预测值(97%)。可逆性RWMA和濒危冠状动脉评分之间有良好的相关性。多因素分析显示,负荷室壁负荷总积分、室壁负荷差分值和心电图负荷试验阳性是濒危冠状动脉积分的独立危险因子。结论 根据_99mTc-MIBI门控心肌灌注显像上可逆性RWMA判断严重冠状动脉狭窄具有高度的特异性和阳性预测值。潘生丁负荷后及可逆性RWMA增强了心肌灌注显像对冠状动脉狭窄程度的评估。     

双核素心肌SPECT显像与PET显像检测存活心肌的对比研究

目的评价99Tcm-甲氧基异丁基异腈(MIBI)/18F-脱氧葡萄糖(FDG)双核素同时采集法(DISA)SPECT显像检测存活心肌的价值。方法对75例冠心病陈旧性心肌梗死患者进行了研究。采用双探头SPECT仪配备超高能准直器,行DISASPECT显像,同时行18F-FDGPET显像,用半定量法分析图像。结果75例患者中,99Tcm-MIBI心肌灌注显像有222个节段灌注减低,而DISA法FDG-SPECT显像有118个节段(53%)改善,FDG-PET显像有128个节段(58%)改善,即灌注/代谢不匹配,以存活心肌为主。DISA法FDG-SPECT有104个节段灌注/代谢匹配,FDG-PET显像有94个节段灌注/代谢匹配,为坏死心肌。FDG-SPECT与FDG-PET对存活心肌的检出率差异无显著性(χ2=0.863,P>0.05)。222个心肌灌注减低节段的FDG-SPECT与FDG-PET的得分符合率为91%。结论DISA法SPECT显像方法简便,费用较低,对检测存活心肌有重要价值。     

~(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.     

用双核素心肌断层显像评价Q波和非Q波心肌梗死存活心肌

目的利用^99Tc^m-甲氧基异丁基异腈(MIBI)/^18F-脱氧葡萄糖(FDG)双核素心肌断层显像评价Q波和非Q波心肌梗死(MI)患中存活心肌的情况。方法45例MI患分为无Q波MI(NQMI，n=17)和有Q波MI(QMI，n=28)2组。均行^99Tc^m-MIBI SPECT门控心肌灌注显像、^18F-FDG SPECT心肌代谢显像和冠状动脉造影。根据心肌血流灌注、代谢和门控信息等比较2组患存活心肌的情况。结果NQMI组的缺血存活心肌节段数明显高于QMI组，非存活心肌节段数明显低于QMI组(P值分别为0．001和0．005)；左室射血分数(LVEF)明显高于QMI组(t=4．603，P：0．000)。门控分析所得室壁增厚率和缺血存活心肌间存在良好相关性(r=0．671，P=0．000)，NQMI组室壁增厚率降低的节段数明显低于QMI组(t=4．183，P=0．000)。结论对NQMI患采取更积极的治疗策略有助于挽救更多的缺血存活心肌，改善其预后。     

99Tcm-MIBI与18F-FDG双核素同时采集法心肌显像检测存活心肌

目的 评价辨99Tcm-甲氧基异丁基异腈(MIBI)与18F-脱氧葡萄糖(FDG)双核素同时采集法心肌显像(DISA SPECT)检测存活心肌的临床价值.方法 21例经彩超检查证实存在左室壁节段运动障碍的冠心病患者,进行DISA SPECT、冠状动脉造影(CAG)及经皮冠状动脉介人治疗(PCI),对所有狭窄病变行完全血运重建术.参照美国超声心动图学会16节段划分法获得心肌各运动异常节段DISA SPECT图像,并对心肌存活情况进行判定.DISA SPECT图像用目测半定量法分析.术后1,3和6个月时复查心脏超声,以冠状动脉血运重建后室壁节段收缩功能改善为判断存活心肌的"金标准",根据诊断试验四格表评价DISA SPECT检测存活心肌的价值.结果 21例冠心病患者共获得符合条件的室壁运动异常节段156个,根据"金标准"判断其中105个为存活心肌,51个为非存活心肌,DISA SPECT检测存活心肌的灵敏度、特异性、阳性预测值、阴性预测值、准确性分别是93.3%(98/105)、82.4%(42/51)、91.6%(98/107)、85.7%(42/49)、89.7%(140/156).结论 DISASPECT目测半定量法检测存活心肌有较高的临床价值.     

18F-FDG PET显像和超声心动图检测心肌梗死面心肌存活

目的　比较1 8F 脱氧葡萄糖 (FDG)PET显像和超声心动图 (UCG)对心肌梗死面存活心肌检查的符合情况。方法　 4 0例心肌梗死患者 ,男 38例 ,女 2例 ,平均年龄 (5 6± 11)岁 ,分别行1 8F FDGPET显像及UCG检查。结果　PET显像检出坏死心肌 2 6 9个节段 ,UCG发现室壁节段运动异常2 15个节段 (检出率 79 9% )。PET显像检测心肌梗死面有无心肌存活与UCG观察室壁运动情况显著相关 (χ2 =4 9 5 3,P <0 0 0 1)。UCG室壁运动轻微异常的节段与PET显像示有部分心肌存活相关 ;而UCG室壁运动消失及矛盾运动的节段 ,与PET显像示心肌无存活相关 (χ2 =4 7 9,P <0 0 0 1)。同时PET显像在UCG室壁矛盾运动节段检出部分节段有心肌存活 (u =3 6 8,P <0 0 1)。结论　常规UCG检查观察心脏室壁运动可以初步筛选梗死累及部位的心肌存活情况 ;对UCG发现大面积室壁运动消失甚至室壁矛盾运动的患者 ,应行心肌PET显像。     

^99Tc^m—MIBI与^18F-FDG双核素同时采集法心肌显像检测存活心肌

目的评价^99Tc^m-甲氧基异丁基异腈（MIBI）与^18F-脱氧葡萄糖（FDG）双核素同时采集法心肌显像（DISA SPECT）检测存活心肌的临床价值。方法21例经彩超检查证实存在左室壁节段运动障碍的冠心病患者,进行DISA SPECT、冠状动脉造影（CAG）及经皮冠状动脉介入治疗（PCI）,对所有狭窄病变行完全血运重建术。参照美国超声心动图学会16节段划分法获得心肌各运动异常节段DISA SPECT图像,并对心肌存活情况进行判定。DISA SPECT图像用目测半定量法分析。术后1,3和6个月时复查心脏超声,以冠状动脉血运重建后室壁节段收缩功能改善为判断存活心肌的“金标准”,根据诊断试验四格表评价DISA SPECT检测存活心肌的价值。结果21例冠心病患者共获得符合条件的室壁运动异常节段156个,根据“金标准”判断其中105个为存活心肌,51个为非存活心肌,DISA SPECT检测存活心肌的灵敏度、特异性、阳性预测值、阴性预测值、准确性分别是93．3％（98／105）、82．4％（42／51）、91．6％（98／107）、85．7％（42／49）、89．7％（140／156）。结论D1SA SPECT目测半定量法检测存活心肌有较高的临床价值。     

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．     

核素心肌显像在冠状动脉旁路移植术中的应用

心肌存活的判断对于严重冠心病患者选择再血管化适应证、估测疗效和判断预后有着极其重要的临床意义。传统的201Tl静息-再分布显像能较好又经济地评估心肌活力,门控显像技术显示的室壁运动情况能帮助医师更准确地判断缺血心肌的活力,18F-氟代脱氧葡萄糖(18F-FDG)心肌代谢显像是迄今评估心肌活力最准确的方法。患者在冠状动脉旁路移植术后出现胸闷症状时,核素心肌显像也能准确地判断有无新发缺血灶或是原有病变术后再狭窄。     

Assessment of cardiac function and myocardial metabolism by nuclear medicine]

Simultaneous assessment of myocardial perfusion and cardiac function came to be possible by 99mTc myocardial perfusion agents. We can use ECG-gated SPECT and first pass radionuclide angiocardiography for it. ECG-gated SPECT made it possible to assess wall motion using wall thickening and QGS (quantitative gated SPECT) analysis, which are useful in various clinical situations. First pass radionuclide angiocardiography gives good assessment of cardiac function during stress, and supports the diagnosis of myocardial ischemia. On the other hand, the assessment of myocardial metabolism is another specific feature of nuclear cardiology. 123I-BMIPP SPECT is applicable to various cardiac diseases such as ischemic heart disease, and 18F-FDG PET has been considered as the gold standard of myocardial viability. Recently, gamma camera for 18F-FDG imaging has been developed, which may make FDG imaging more popular.     

Value of linsidomin in assessing myocardial viability with thallium-201 SPECT.

Myocardial viability can be assessed with rest/24 h redistribution (201)Tl myocardial single photon emission computed tomography (SPECT). The intravenous injection of vasodilators induces an early redistribution of (201)Tl and shortens the total examination time. The aim of this study was to compare the images after injection of linsidomin with the 24 h images. We studied 51 consecutive patients (38 males, 13 females), aged 66+/-11 years, referred for assessment of myocardial viability after acute myocardial infarction. SPECT acquisition at rest (30 projections over 180 degrees, 30 s per projection) was performed 20 min after injection of (201)Tl. A second acquisition (same parameters) was performed 2 min after intravenous injection of linsidomin (2 mg). A delayed acquisition was performed on the following day (50 s per step). Myocardial perfusion at rest was normal in 111 of 255 segments. For the 144 other segments, 24 h images were similar to the images acquired after the injection of linsidomin in 94% of cases (136 of 144 segments). The 24 h images showed partial redistribution that was not present after linsidomin in only eight segments (6%). Injection of linsidomin after rest acquisition can provide a reliable and more rapid assessment of myocardial viability. This very simple protocol (rest/linsidomin (201)Tl myocardial SPECT) can be performed in less than 1 h.     

Simultaneous assessment of wall motion and myocardial perfusion by technetium-99m methoxy isobutyl isonitrile

The aim of this study was to assess whether or not myocardial uptake of Technetium-99m methoxy isobutyl isonitrile (Tc-MIBI) indicated myocardial viability. We performed simultaneous Tc-MIBI angiography and myocardial SPECT at rest on 12 patients with suspected coronary artery disease. Left ventricle was divided into 3 segments, and regional wall motion was graded as normal, hypokinesis and akinesis/dyskinesis. Myocardial uptake of Tc-MIBI was assessed as normal, reduced and absent in each segment. In segments with normal and reduced Tc-MIBI uptake, 7% (2 of 28) and 33% (2 of 6) showed wall motion abnormalities of akinesis/dyskinesis, respectively. However, all segments with absent Tc-MIBI uptake had asynergy of akinesis/dyskinesis (2 of 2, 100%). Myocardial Tc-MIBI uptake at rest indicated wall motion abnormalities and was considered to be useful for the evaluation of myocardial viability. First-pass radionuclide angiography followed by myocardial SPECT with Tc-MIBI demonstrated to be useful for the simultaneous assessment of the left ventricular wall motion and myocardial perfusion.     

Detection of residual wall motion after sustained myocardial infarction by gated 99Tcm-tetrofosmin SPECT: a comparison with echocardiography

The differentiation of residual viability from necrotic myocardium in patients with a previously sustained myocardial infarction is important in deciding indications for revascularization. Myocardial viability can be assessed by studying perfusion and regional wall motion. With gated single photon emission computed tomography (SPECT), it is possible to augment SPECT perfusion data with ventricular functional data both at a global and regional level. The aim of the study was to analyse the concordance between wall motion score derived by gated SPECT and echocardiography. Furthermore, the agreement between myocardial perfusion and left ventricular wall motion was analysed with both techniques. We studied a homogenous group of 25 consecutive patients with a previous myocardial infarction (MI) using both gated SPECT 99Tcm-tetrofosmin myocardial perfusion imaging and two-dimensional echocardiography. Echocardiography was performed within 2 weeks of the gated SPECT study. Both for gated SPECT and for echocardiography the left ventricle was divided into seven regions per patient. For comparison, the gated SPECT regions were matched to the echocardiographic regions, resulting in a total of 175 regions. Prevalence of abnormal wall motion (akinetic or dyskinetic) was 23% (39/171) for echocardiography and 21% (36/175) for gated SPECT (P = NS). There was a high agreement in wall motion score between echocardiography and gated SPECT of 80% (136/171). The agreement between myocardial perfusion and myocardial wall motion was 82% (143/175) for gated SPECT and 76% (130/171) for echocardiography (P = NS). Nineteen (34%) of the 56 regions with severely diminished or absent myocardial perfusion showed normal or hypokinetic wall motion both by gated SPECT and echocardiography suggesting residual myocardial viability in malperfused regions. Our results suggest that, gated SPECT imaging is a reliable tool for the assessment of regional wall motion in post myocardial infarction patients. Furthermore, in patients with a previous myocardial infarction gated SPECT imaging has the potential to detect preserved wall motion in regions with fixed perfusion defects, which might be indicative of residual myocardial viability.     

The diagnostic and prognostic value of ECG-gated SPECT myocardial perfusion imaging.

Since the development of gated SPECT imaging approximately 10 y ago, this technique is now almost universally used as an adjunct for radionuclide perfusion imaging, enabling the assessment of perfusion along with determination of regional and global left ventricular function in the same examination. The gated SPECT determination of the left ventricular ejection fraction and volumes has been extensively validated. Additionally, this method allows for the improved identification of soft-tissue artifacts and enhances the detection of multivessel coronary artery disease. Furthermore, gated SPECT provides powerful information for the risk assessment of patients with known or suspected coronary artery disease and aids in the assessment of myocardial viability. Gated SPECT imaging has clearly become an integral part of radionuclide myocardial perfusion imaging.     

Myocardial viability assessment with gated SPECT Tc-99m tetrofosmin % wall thickening: Comparison with F-18 FDG-PET

OBJECT: This study was designed to assess the value of gated SPECT Tc-99m-tetrofosmin (TF) wall thickening (WT) in addition to TF exercise (Ex)/rest myocardial SPECT, in comparison with F-18 fluorodeoxyglucose (FDG)-PET. METHODS: The study population consisted of 33 patients with old myocardial infarction (27 men and 6 women; mean age, 62 +/- 8 years old). All patients underwent Ex/rest TF SPECT and glucose loading FDG-PET. Polar map images of Ex/rest TF were generated and divided into 24 segments for further analysis. We classified LV segments according to the exercise-rest perfusion scintigraphy. LV segments with less than 70% of the maximum TF activity on the exercise image were defined as stress-induced defects. Among these, the segments whose TF activity increased by 10% from exercise to rest images or exceeded 70% of the maximum uptake were defined as reversible (viable) defects. The remaining defects on the rest image were irreversible (non-viable) defect segments, and were considered for viability study on the basis of %WT. %WT was calculated according to the standard method: [(counts ES - counts ED)/counts ED] x 100. A viable segment on gated SPECT was defined as a segment whose %WT exceeded the lower limit of the normal value (mean - SD). PET viability was defined as FDG uptake exceeding 50% of the maximum count. RESULTS: Among the 792 segments evaluated in the 33 patients studied, there were 689 PET viable segments. Of the 689 segments analyzed, 198 (29%) were identified as having defects on Ex images. Among these defects, 55 (8%) were reversible or partially reversible, as evidenced by rest images, and 143 (21%) were irreversible. Of the irreversible segments on Ex/rest images, 106 (15%) demonstrated no apparent WT by gated TF SPECT, whereas 37 (6%) segments with irreversible defects did have apparent WT. Overall, the sensitivity of Ex/rest TF perfusion imaging was 79%. Sensitivity was improved from 79% to 85% by combining %WT and perfusion data, but specificity was reduced from 70% to 56%. CONCLUSION: %WT evaluated from gated TF imaging enhanced myocardial viability assessment in comparison with FDG-PET.     

F-18 fluoro deoxyglucose SPECT for assessment of myocardial viability

Identification of myocardial viability in hypokinetic segments is important in patients with ischemic cardiomyopathy because systolic dysfunction improves with revascularization. Positron emission tomography (PET) F-18 fluoro deoxyglucose (FDG) uptake has been demonstrated as an accurate indicator of metabolically active and thus viable myocardium. F-18 FDG single photon emission computed tomography (SPECT) has recently been introduced and offers a technically easier and less costly alternative to PET imaging for determination of myocardial viability. A body of literature demonstrates that F-18 FDG SPECT can reliably be performed with SPECT hardware equipped with 511-keV collimators, which provides an accurate assessment of myocardial viability. F-18 FDG SPECT offers data similar to those offered by F-18 FDG PET and compares favorably with other imaging modalities, including rest-redistribution and stress-reinjection thallium-201 myocardial perfusion imaging, gated technetium 99m SPECT, and low-dose dobutamine echocardiography.     

18FDG SPECT to assess myocardial viability: initial experience at a hospital remote from a cyclotron

18F-Fluorodeoxyglucose positron emission tomography (18FDG PET) is the recognized gold standard for the assessment of myocardial viability, but is not widely available in the UK. FDG imaging on a gamma camera with high-energy collimators (FDG SPECT) has been shown to have an accuracy comparable with that of FDG PET for the assessment of myocardial viability. This study was performed to assess the feasibility of introducing FDG SPECT for myocardial viability at a hospital a considerable distance away from a cyclotron (200 miles). Twenty-three patients, who were being actively considered for revascularization but had demonstrated fixed defects on stress/rest with nitrate tetrofosmin imaging, underwent FDG SPECT. Image quality was acceptable in all patients. Nine out of the 23 patients with defects classed as fixed on tetrofosmin imaging demonstrated viability on FDG SPECT. Six of these nine patients, reported to have some viable myocardium on FDG SPECT, underwent revascularization as a result. This study has demonstrated that FDG SPECT is feasible at a site some distance from a cyclotron.