~(99)Tcm-MIBI SPECT心肌灌注显像与磁共振成像心肌灌注延迟增强诊断冠心病的对比研究

目的评价99 Tcm-MIBI SPECT心肌灌注显像与磁共振成像心肌灌注延迟增强(DE-MRI)诊断冠心病(CAD)的临床价值,并比较两种方法的相关性。方法 72例临床诊断CAD病人,进行99 Tcm-MIBI SPECT心肌灌注显像、DE-MRI及冠状动脉造影(CAG)。左心室心肌节段划分采用17节段法,连续两个心肌节段灌注显像异常作为诊断CAD的标准,左心室各节段心肌延迟增强分级标准分为5级,1级~4级作为诊断CAD的标准,以CAG结果冠状动脉狭窄≥50%作为诊断CAD的金标准。结果 72例病人中经CAG诊断为CAD 61例,非CAD 11例;以CAG结果作为诊断CAD的金标准,99 Tcm-MIBI SPECT心肌灌注显像诊断CAD的灵敏性、特异性、准确性分别是88.5%、63.6%、84.7%;DE-MRI诊断CAD的灵敏性、特异性、准确性分别是78.7%、81.8%、79.2%。两种方法诊断CAD相关性良好。结论 99 Tcm-MIBI SPECT心肌灌注显像和DE-MRI诊断CAD具有较高的临床价值,二者相关性较好。     

实时心肌超声造影与磁共振心肌灌注延迟增强检测存活心肌的比较

目的评价实时心肌超声造影(RT-MCE)与磁共振心肌灌注延迟增强(DE-MRI)检测存活心肌的临床价值。方法入选2012年7月至2013年12月徐州矿务集团总医院(徐州医学院第二附属医院)心内科收治入院的冠状动脉粥样硬化性心脏病(冠心病)患者27例,男性16例,女性11例,平均年龄62.5岁。所有患者行RT-MCE、DE-MRI、冠状动脉造影(CAG)及冠状动脉介入治疗(PCI)。对患者的RT-MCE图像分析采用目测半定量法,判定存活心肌;对心肌灌注延迟增强情况进行分级,根据分级结果对心肌存活情况进行判定。术后1、3、6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。结果 RT-MCE目测半定量法检测存活心肌的灵敏性、特异性及准确度分别是70.9%、85.7%、76.3%;DE-MRI法检测存活心肌的灵敏性、特异性及准确度分别是72.7%、76.2%、74.0%,RT-MCE目测半定量法检测存活心肌较DE-MRI法具有较高的特异度(76.2%vs.85.7%,P0.05)。两种检测方法的相关性良好。结论 RT-MCE目测半定量法与DE-MRI法检测存活心肌具有较高的临床价值,RT-MCE目测半定量法具有更高的特异性。     

小剂量多巴酚丁胺超声心动图与硝酸甘油介入~(99m)Tc-MIBI的心肌灌注显像估测存活心肌

目的　探讨小剂量多巴酚丁胺超声心动图 (LDDE)与含服硝酸甘油 (NTG)介入99mTc 甲氧基异丁基异睛 (MIBI)的心肌灌注显像在心肌存活估测中的价值。方法　对 17例心肌梗死患者分别行静息 NTG介入99mTc MIBI和小剂量多巴酚丁胺超声心动图的检查 ,经皮冠状动脉腔内成形术或冠状动脉旁路移植术后一个月重复基础超声心动检查 ,并进行对比分析。结果　 17例患者于基础超声心动检查 ,共有 94个心肌节段运动异常 ,在其中 5 0个低动力心肌节段中 ,两种方法一致性节段 2 9个 (5 8% ,P >0 .0 5 ) ;在 44个无动力心肌节段中两种方法一致性节段 16个 (36 % ,P<0 .0 5 )。两种方法对低动力心肌节段功能恢复的预测差异无显著性意义 (P>0 .0 5 ) ;而对无动力心肌节段 ,LDDE较NTG介入 99m　Tc MIBI心肌灌注显像有较高的特异性 (90 .9%vs 6 4.7% ,P <0 .0 5 )和较低的敏感性 (6 3.6 %vs88.9% ,P <0 .0 5 )。对整个运动障碍节段功能恢复的预测 ,LDDE较NTG介入99mTc MIBI心肌灌注显像有较高的特异性 (87.2 %vs 6 8.2 % ,P <0 .0 5 )。结论　两种方法对低动力心肌节段的预测有良好的一致性 ,LDDE对整个运动障碍节段功能恢复的预测有较高的特异性。     

硝酸甘油99mTc-甲氧基异丁基异晴心肌灌注显像技术对冠心病诊断及其估测心肌存活性的价值

目的评价硝酸甘油99mTc-甲氧基异丁基异晴(MIBI)心肌灌注显像技术对冠心病的诊断及其估测心肌存活性的价值。方法48例可疑冠心病患者,于冠状动脉造影(CAG)术前1周内行静息、硝酸甘油介入99mTc-MIBI心肌灌注显像(SPECT)检查,以CAG为金标准,观察SPECT诊断冠心病的准确性。对于25例成功行经皮冠脉介入治疗(PCI)的冠心病患者,以PCI术后3个月室壁运动改善为检验标准,评价SPECT检测存活心肌的应用价值。结果SPECT诊断冠心病的敏感性、特异性和准确性分别为86.7%、72.2%和81.3%,评价存活心肌的敏感性为91.8%,准确性为84.9%。结论硝酸甘油99mTc-MIBI心肌灌注显像技术在诊断冠心病及其估测心肌存活性方面有较高的临床应用价值。     

不同小剂量多巴酚丁胺超声心动图与18F-脱氧葡萄糖心肌代谢显像对比检测冠心病左心室收缩功能严重受损患者存活心肌

目的 :与18F 脱氧葡萄糖单光子发射计算机断层摄影术 (SPECT)心肌代谢显像对比 ,评价不同小剂量多巴酚丁胺超声心动图 ,检测冠心病左心室收缩功能严重受损患者存活心肌的准确性和安全性。方法 :冠心病心肌梗死伴左心室收缩功能严重受损 (平均左心室射血分数 0 3 8± 0 0 5 )的患者 3 3例 ,1周内分别进行不同小剂量多巴酚丁胺 [3、5、10 μg/(kg·min) ]超声心动图和99m锝 甲氧基异丁基、18F 脱氧葡萄糖SPECT心肌灌注及代谢显像。图像分析均采用 16节段半定量法。以18F 脱氧葡萄糖SPECT检测结果为标准 ,评价不同小剂量多巴酚丁胺超声心动图检测存活心肌的敏感性、特异性、准确性和安全性。结果 :3 3例患者的 3 65个运动异常节段中存活心肌检出率 :18F 脱氧葡萄糖SPECT心肌代谢显像检出的存活心肌节段为 67 4% ,多巴酚丁胺 3、5和 10 μg/(kg·min)分别为 3 8 9%、61 4%和 70 4%。多巴酚丁胺 3 μg/(kg·min)检出的存活心肌节段显著低于18F 脱氧葡萄糖SPECT心肌代谢显像检出的存活心肌节段 (P <0 0 0 1)。多巴酚丁胺 3、5、10μg/(kg·min)超声心动图检出存活心肌的敏感性分别为 5 1 6%、82 9%和 91 8% ,准确性分别为 63 6%、81 6%和87 8% ,均显著递增 (P <0 0 5～ 0 0 0 1) ;副作用发生率分别     

双核素心肌灌注显像对存活心肌判断

目的 :观察二硝酸异山梨醇酯 (isoket)介入后铊 2 0 1(2 0 1TI)和99mTc 甲氧基异丁基异腈 (MIBI)双核素心肌断层显像检测梗死后存活心肌的敏感性及两种核素间显像结果的一致性。方法 :将 4 0例陈旧性心肌梗死(OMI)患者 ,分为A(12例 )、B(16例 )及C(12例 )三组 ,A、B组分别进行isoket介入后2 0 1TI和99mTc MIBI单核素显像 ,C组进行isoket介入后2 0 1TI及99mTc MIBI双核素心肌显像。结果 :A组摄取2 0 1TI后出现不同程度的灌注异常节段共 6 5个 ,平均得分为 9.7± 1.2。B组摄取99mTc MIBI后出现不同程度的灌注异常节段共 87个 ,平均得分 10 .8± 1.6。C组以不同核素能窗双核素显像后结果2 0 1TI心肌显像检出灌注异常节段共 4 2个 ,平均得分 5 .8± 0 .6 ;99mTc MIBI心肌显像检出灌注异常节段共 4 8个 ,平均得分 6 .1± 0 .8。A组与B及C组两种结果比较 ,均P >0 .0 5。结论 :两种核素对梗死后心肌存活力的评估一致性良好 ;双核素心肌断层显像对梗死后心肌存活力的评估与单核素心肌断层显像是一致的 ,两种显像的结合可提高诊断的准确性     

DECT心肌灌注显像诊断缺血性心肌的效能及其与SPECT/CT结果的相关性

目的评价双能源CT(DECT)心肌灌注显像诊断缺血性心肌的价值及其与单光子发射型计算机扫描(SPECT)心肌灌注显像结果的相关性。方法选取2013年1月~2015年12月于新乡中心医院就诊的疑似缺血性心肌病患者79例,其中男性56例,女性23例,平均年龄(54.72±11.18)岁。在一周内相继行DECT和SPECT/CT心肌灌注显像。以SPECT/CT为"金标准",对DECT的检测结果进行评价。结果 1343个心肌节段中DECT识别正常心肌1187个(88.4%),异常心肌156个(11.6%),诊断缺血性心肌的灵敏度、特异度分别为82.6%、95.0%;阳性预测值、阴性预测值和准确度分别为60.9%、98.3%和94.0%;ROC曲线下面积为0.98。DECT心肌显像与SPECT/CT结果之间相关系数Kappa值为0.68。结论 DECT心肌灌注显像诊断缺血性心肌有较高的效能,与SPECT/CT心肌灌注显像结果一致性好。     

~(99m)Tc-MIBI+~(18)F-FDG心肌灌注-代谢显像评价心肌梗死后存活心肌对心功能的影响

目的~(99m)Tc-MIBI+~(18)F-FDG静态心肌血流灌注-代谢显像评价心肌梗死后,患者有无存活心肌以及存活心肌对左心功能的影响。方法本组受检心肌梗死患者60例,根据超声心动图左心室射血分数(LVEF)分为心功能不全组33例,心功能正常组27例,行~(99m)Tc-MIBI+~(18)F-FDG静态心肌血流灌注-代谢显像。结果心功能不全组静态心肌灌注缺损102节段,代谢缺损82节段。心功能正常组静态心肌灌注缺损67节段,代谢缺损32节段。心功能不全组灌注代谢匹配45%(15/33例);灌注代谢不匹配55%(18/33例);心功能正常组灌注代谢匹配30%(8/27例),灌注代谢不匹配70%(19/27例)。心功能不全组灌注记分(SPS)平均25.34±13.17,代谢记分(SMS)平均21.97±9.63,严重度记分(SSS)平均1005.25±596.01;心功能正常组SPS平均19.95±9.51,SMS平均14.35±8.97,SSS平均525±350.46。2组的LVEF与心肌灌注缺损的节段数、代谢缺损的节段数以及半定量SPS、SMS和SSS均呈负相关关系。LVEF与病变冠状动脉的支数无明显相关关系。结论心功能不全组的梗死区存活心肌明显少于心功能正常组。心肌梗死后有无存活心肌对心功能有较大影响。     

硝酸甘油介入~(99m)Tc-甲氧基异丁基异腈心肌灌注断层显像评估存活心肌

目的　评估静息及硝酸甘油介入99mTc 甲氧基异丁基异腈 (99mTc MIBI)心肌灌注断层显像在存活心肌检测中的应用价值。方法　对心肌梗死 2 0例于血管重建术前分别行静态及硝酸甘油介入显像 ,血管重建术后 1个月重复静息心肌显像并进行对比分析。结果　 2 0例共有 1 4 4个异常灌注的心肌节段 ,硝酸甘油介入后有 72个心肌节段灌注改善 ,血管重建术后有 77个心肌节段灌注改善。硝酸甘油介入改善的 72个节段术后有 62个节段改善 ;而术前无改善的 72个节段术后只有 1 5个节段改善 ,硝酸甘油介入99mTc MIBI心肌灌注显像对存活心肌预测的阳性预测值为 86 .1 % ,阴性预测值为 79.2 % ,预测准确率为 82 .6%。结论　硝酸甘油介入99mTc MIBI心肌灌注断层显像是可供临床检测心肌存活的安全、有价值的方法     

小剂量腺苷负荷超声心动图试验与双核素心肌显像检测急性心肌梗死后患者存活心肌比较

目的:比较小剂量腺苷负荷超声心动图试验(LDASE)与99mTc-甲氧基异丁腈(MIBI)/18F-脱氧葡萄糖(FDG)双核素同时采集法(DISA)单光子发射断层显像(SPECT)对急性心肌梗死(AMI)患者早期存活心肌检出的准确性.方法:对36例AMI患者于发病后3～10 d内行LDASE与DISA-SPECT.所有患者在LDASE前后接受经皮冠状动脉介入治疗术.AMI后3个月随访二维超声心动图,以局部室壁运动改善作为心肌存活的金标准,比较2种方法检测存活心肌的敏感性和特异性.结果:LDASE检出存活心肌敏感性为90.3%,特异性为80.8%,阳性预测值与阴性预测值分别为84.8%和87.5%,准确性为86.0%;DISA-SPECT检出存活心肌敏感性81.2%,特异性78.3%,阳性预测值81.1%,阴性预测值83.1%,准确性80.2%.2种方法对运动异常节段存活心肌检出一致性为72.6%,差异无统计学意义.结论:对AMI后患者,LDASE与DISA-SPECT均为检出存活心肌较敏感和特异的技术.     

Myocardial viability in chronic ischemic heart disease: comparison of contrast-enhanced magnetic resonance imaging with (18)F-fluorodeoxyglucose positron emission tomography

OBJECTIVES: We sought to compare contrast-enhanced magnetic resonance imaging (ceMRI) with nuclear metabolic imaging for the assessment of myocardial viability in patients with chronic ischemic heart disease and left ventricular (LV) dysfunction. BACKGROUND: Contrast-enhanced MRI has been shown to identify scar tissue in ischemically damaged myocardium. METHODS: Twenty-six patients with chronic coronary artery disease and LV dysfunction (mean ejection fraction 31 +/- 11%) underwent (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET), technetium-99m tetrofosmin single-photon emission computed tomography (SPECT), and ceMRI. In a 17-segment model, the segmental extent of hyperenhancement (SEH) by ceMRI, defined as the relative amount of contrast-enhanced tissue per myocardial segment, was compared with segmental FDG and tetrofosmin uptake by PET and SPECT. RESULTS: In severely dysfunctional segments (n = 165), SEH was 9 +/- 14%, 33 +/- 25% (p < 0.05), and 80 +/- 23% (p < 0.05) in segments with normal metabolism/perfusion, metabolism/perfusion mismatch, and matched defects, respectively. Segmental glucose uptake by PET was inversely correlated to SEH (r = -0.86, p < 0.001). By receiver operator characteristic curve analysis, the area under the curve was 0.95 for the differentiation between viable and non-viable segments. At a cutoff value of 37%, SEH optimally differentiated viable from non-viable segments defined by PET. Using this threshold, the sensitivity and specificity of ceMRI to detect non-viable myocardium as defined by PET were 96% and 84%, respectively. CONCLUSIONS: Contrast-enhanced MRI allows assessment of myocardial viability with a high accuracy, compared with FDG-PET, in patients with chronic ischemic heart disease and LV dysfunction.     

Multislice computed tomography and magnetic resonance imaging for the assessment of reperfused acute myocardial infarction.

OBJECTIVES: We evaluated the accuracy of in vivo delayed-enhancement multislice computed tomography (DE-MSCT) and delayed-enhancement magnetic resonance imaging (DE-MRI) for the assessment of myocardial infarct size using postmortem triphenyltetrazolium chloride (TTC) pathology as standard of reference. BACKGROUND: The diagnostic value of DE-MSCT for the assessment of acute reperfused myocardial infarction is currently unclear. METHODS: In 10 domestic pigs (25 to 30 kg), the circumflex coronary artery was balloon-occluded for 2 h followed by reperfusion. After 5 days (3 to 7 days), DE-MRI (1.5-T) was performed 15 min after administration of 0.2 mmol/kg gadolinium-DTPA using an inversion recovery gradient echo technique. On the same day, DE-MSCT (64-slice) was performed 15 min after administration of 1 gI/kg of iodinated contrast material. One day after imaging, hearts were excised, sectioned in 8 mm short-axis slices, and stained with TTC. Infarct size was defined as the hyperenhanced area on DE-MSCT and DE-MRI images and the TTC-negative area on TTC pathology slices. Infarct size was expressed as percentage of total slice area. RESULTS: Infarct size determined by DE-MSCT and DE-MRI showed a good correlation with infarct size assessed with TTC pathology (R2 = 0.96 [p < 0.001] and R(2) = 0.93 [p < 0.001], respectively). The correlation between DE-MSCT and DE-MRI was also good (R2 = 0.96; p < 0.001). The relative difference in CT attenuation value of infarcted myocardium compared to remote myocardium was 191 +/- 18%. The relative MR signal intensity between infarcted myocardium and remote myocardium was 554 +/- 156%. CONCLUSIONS: We demonstrated that DE-MSCT can assess acute reperfused myocardial infarction in good agreement with in vivo DE-MRI and TTC pathology.     

Clinical validity of longitudinal pre-ejectional myocardial velocity for identifying the transmural extent of viable myocardium: early after reperfusion of an infarct-related coronary artery.

BACKGROUND: Positive longitudinal pre-ejectional velocity (+PEVL) was recently reported to be a reliable index of myocardial recovery early after successful revascularization in myocardial infarction (MI); that is, it recognizes the transmural extent of viable myocardium. The applicability of PEVL in the real-world clinical setting for identifying the transmural extent of viable myocardium in reperfused recent MI was assessed. METHODS AND RESULTS: Using tissue Doppler imaging, the resting basal and mid myocardial PEVLs were determined within 3 days after revascularization in 41 consecutive patients with recent MI. Infarct thickness was semi-quantified using delayed gadolinium-enhanced magnetic resonance imaging (MRI) at baseline and at 6-month follow up to differentiate transmural from nontransmural MI. The proportion of segments showing the presence of +PEVL was not significantly changed as infarct thickness increased (p=0.2), with 66.2% having +PEVL even in segments involving >75% transmural infarction. Moreover, +PEVL was found in a large fraction of segments with akinesia (70.4%). Specificity and negative predictive value of +PEVL for assessing infarct nontransmurality were disappointingly low (32.0% and 26.9%, respectively). All of these results were not altered when the 6-month follow-up MRI was done. CONCLUSIONS: +PEVL cannot be regarded as a reliable marker for predicting the transmural extent of viable myocardium in recent MI.     

Exercise four hour redistribution thallium-201 single photon emission computed tomography and exercise induced ST segment elevation in detecting the viable myocardium in patients with acute myocardial infarction

OBJECTIVE: To investigate the specificity and sensitivity of the combination of redistribution in exercise thallium-201 single photon emission computed tomography (SPECT) and exercise induced ST elevation for detecting the viable myocardium in patients with acute myocardial infarction. DESIGN: 37 patients were studied within seven weeks of onset of Q wave myocardial infarction (anterior in 22, inferior in 15). All patients underwent exercise four hour redistribution thallium-201 SPECT and positron emission tomography using fluorine-18-fluorodeoxyglucose (FDG) and nitrogen-13 ammonia under fasting conditions. RESULTS: Sixteen patients showed exercise induced ST elevation >/= 1.5 mm, and 15 of these had increased FDG uptake in the infarct region. Eleven of 16 patients (10 of 11 patients with anterior infarctions) with irreversible thallium-201 defects and increased FDG uptake showed exercise induced ST elevation. The sensitivity, specificity, and predictive accuracy of redistribution, exercise induced ST segment elevation, or both for detecting increased FDG uptake were 82%, 75%, and 67% (94%, 75%, and 91% for anterior infarctions), respectively. CONCLUSIONS: In patients with acute Q wave myocardial infarction, the combination of redistribution in exercise thallium-201 SPECT and exercise induced ST elevation can detect the viable myocardium in the infarct region with high sensitivity and specificity, especially in patients with anterior infarctions.     

Magnetic resonance tomography image of transmural myocardial infarct in comparison with 99mTc-methoxyisobutylisonitrile SPECT]

To assess the ability of magnetic resonance imaging (MRI) to identify morphologic and functional abnormalities associated with transmural anterior and inferior myocardial infarction, 18 patients with anterior myocardial infarcts and 11 patients with inferior myocardial infarcts confirmed by ECG and cine-ventriculography underwent gradient-echo MRI of transverse and short-axis imaging planes. Myocardial perfusion of corresponding imaging planes was measured by 99mTc-methoxyisobutyl-isonitrile single-photon emission computed tomography (MIBI-SPECT). Transmural scar by MRI was defined as diastolic wall thickness 2.5 SD below corresponding normal values of a healthy control group (n = 21). MIBI-SPECT scar was defined as a MIBI uptake less than 2.5 SD below mean values of a healthy control group (n = 11). By MIBI-SPECT, 231 segments contained normal tissue and 161 contained scarred myocardium. In 352/392 (90%) segments gradings based on diastolic wall thickness and MIBI-SPECT gradings were identical. Diastolic wall thickness was significantly higher in normal than in scarred MIBI-SPECT segments (10.3 +/- 1.5 vs 5.2 +/- 2 mm, p less than 0.0001). Additionally, normal segments by MIBI-SPECT showed significantly higher systolic wall thickening than scar segments (5.5 +/- 1.5 vs 0.6 +/- 1.6 mm, p less than 0.0001). The correlation between MRI and MIBI-SPECT assessed infarct size was r = 0.91 for anterior and r = 0.77 for inferior myocardial infarcts. The agreement between MIBI-SPECT perfusion defect size and regions with reduced diastolic wall thickness on MRI tomograms was significantly better for anterior myocardial infarcts than for inferior myocardial infarcts.(ABSTRACT TRUNCATED AT 250 WORDS)     

Early prediction of infarct size by strain Doppler echocardiography after coronary reperfusion.

OBJECTIVES: The objective of this study was to investigate whether strain Doppler echocardiography performed immediately after revascularization by percutaneous coronary intervention could predict the extent of myocardial scar, determined by contrast-enhanced magnetic resonance imaging (MRI). BACKGROUND: There is considerable variability in survival rate after percutaneous coronary intervention, and accurate early risk stratification is therefore of major clinical importance. METHODS: Thirty individuals with acute anterior myocardial infarction were examined with longitudinal strain by Doppler 1.5 h after revascularization. The extent of scarring 9 months later was analyzed by MRI in 16 corresponding myocardial segments. Strain in all left ventricular segments was averaged to obtain a global value. Infarct size was estimated by clinical parameters and cardiac markers. RESULTS: A good correlation was found between the global strain and total infarct size (R = 0.77, p < 0.00001). A multivariate regression analysis showed that global peak strain and serum glutamic oxaloacetic transaminase correlated with the infarct size measured by MRI (p = 0.0001 and p = 0.001, respectively). Furthermore, a clear inverse relationship was found between the segmental strain and the transmural extent of infarction in each segment (R = 0.67, p < 0.0001). CONCLUSIONS: This study demonstrates that assessment of regional and global strain at 1.5 h after reperfusion therapy correlates with size and transmural extent of myocardial infarction as determined by contrast-enhanced MRI. The novel global strain parameter is a valuable predictor of the total extent of myocardial infarction and may therefore be an important clinical tool for risk stratification in the acute phase of myocardial infarction.     

药物负荷超声心动图与双核素心肌显像对比检测存活心肌

目的　比较99mTc 甲氧基异丁腈(MIBI) /18F 脱氧葡萄糖(FDG)双核素同时采集法(DISA)单光子发射型断层显像(SPECT)和药物负荷二维超声心动图(2DE)试验,识别冠心病左心室收缩功能严重减低患者[左室射血分数(LVEF)≤45% ]存活心肌的准确性。方法　陈旧性心肌梗死患者26例,平均LVEF(38. 6±4 .9 )%,在一周内分别进行小剂量多巴酚丁胺10μg·kg-1·min-1(Dob10μg)、亚硝酸异山梨酯合用Dob5μg·kg-1·min-1 (ISDN Dob5μg)的2DE试验,以及DISASPECT心肌显像。所有患者在冠状动脉血管重建(CRV)术后(6 .8±2 .9)个月完成了2DE复查。采用16节段半定量法分别分析图像,以CRV术后收缩功能改善节段为存活标准,比较两种方法检测存活心肌的敏感性、特异性和准确性。结果　26例患者272个运动异常节段中,术后156个( 57. 4% )有收缩运动改善。DISASPECT检测出72 .4% (134 /254)存活心肌节段,显著高于术后实际改善率(P<0 .001)。Dob10μg2DE的存活心肌检出率为65 5% (163 /249 ),ISDN Dob5μg2DE的为65 .7%(176 /268),均与术后实际改善率一致(P均>0 .05)。DISASPECT检测存活心肌的敏感性、特异性和准确性分别为93%, 55%和76. 8%;Dob10μg2DE的分别为88 .6%, 64 .2%和77. 9%,两种方法检测效果相当(P均>0 .05)。ISDN Dob5μg     

MRI for the assessment of myocardial viability

Accurate distinction between viable and infarcted myocardium is important for assessment of patients who have cardiac dysfunction. Through the technique of delayed-enhancement MRI (DE-MRI), viable and infarcted myocardium can be simultaneously identified in a manner that closely correlates with histopathology findings. This article provides an overview of experimental data establishing the physiologic basis of DE-MRI-evidenced hyperenhancement as a tissue-specific marker of myocardial infarction. Clinical data concerning the utility of transmural extent of hyperenhancement for predicting response to medical and revascularization therapy are reviewed. Studies directly comparing DE-MRI to other viability imaging techniques are presented, and emerging applications for DE-MRI are discussed.     

The usefulness of delayed enhancement magnetic resonance imaging for diagnosis and evaluation of cardiac function in patients with cardiac sarcoidosis

OBJECTIVES: Cardiac involvement is an important prognostic factor in patients with sarcoidosis. We evaluated the usefulness of delayed enhancement MRI (DE-MRI) for diagnosing cardiac sarcoidosis by comparing with nuclear imaging and studying the correlation between DE area and left ventricular (LV) function. METHODS: Twelve patients (male:female 3:9) diagnosed as having sarcoidosis underwent Gd-MRI, myocardial perfusion SPECT (Tl-201, Tc-99m sestamibi), Ga-67 scintigraphy, and/or F-18 FDG-PET. RESULTS: DE was observed in 5 patients, and was positive in 39 (39%) of 100 LV segments. The corresponding perfusion defects in myocardial perfusion SPECT were undetectable in 14 (36%) segments. DE distributed mainly in mid- to epi-myocardium, and the lack of perfusion defects in myocardial perfusion SPECT was more prominent in less transmural DE segments. Two patients with diffuse DE and 1 case with focal DE exhibited positive cardiac uptake in Ga-67 scintigraphy, and 2 other cases with focal DE showed cardiac uptake in F-18 FDG-PET. In 7 patients without DE, there were no significant findings in nuclear imaging. Both LV end-diastolic and end-systolic volume were positively and LV ejection fraction was negatively correlated with the extent of DE area. Four patients treated with corticosteroid showed improvement in nuclear imaging and slight decreases in DE area but no recovery in LV function. CONCLUSIONS: DE-MRI is useful to diagnose the cardiac involvement of sarcoidosis and to evaluate cardiac function. It is likely that the distribution of DE in mid- to epi-myocardium is the characteristic of cardiac sarcoidosis, and the larger DE area may be correlated with poor LV function.     

Positron emission tomography--usefulness in assessing myocardial viability.

Positron emission tomography (PET) using N-13 ammonia and F-18 fluorodeoxyglucose (FDG) has been used to evaluate myocardial viability in comparison with thallium-201 single photon emission computed tomography (SPECT), and left ventricular wall motion in comparison with contrast ventriculography. Forty patients with anterior myocardial infarction underwent stress and delayed resting perfusion imaging using Tl-201 SPECT and ammonia PET, a glucose metabolism study using FDG PET, and wall motion assessment with left ventriculography. Out of a total of 600 segments of left ventricular imaging, SPECT demonstrated 197 fixed perfusion defects, 99 with redistribution on delayed imaging and 304 normal segments. Of 197 segments with fixed defects, 24 (12%) were normal and 71 (36%) ischemic according to PET criteria. Nineteen of 28 with infarction and all of 12 with non-Q wave infarction showed a viable myocardium. Left ventricular wall motion was significantly better in patients with normal PET findings compared with those with ischemia or scar on PET. Post-PTCA PET revealed improved ammonia PET in 6 of 11 patients but reduced FDG uptake was noted only in 3. These data suggests that Tl-201 SPECT significantly underestimates myocardial viability and that PET imaging is a promising tool for assessing the presence of salvaged myocardium.