低负荷201Tl/静息99Tcm-MIBI双核素心肌断层显像诊断冠心病

目的探讨低负荷-再分布201Tl/静息99Tcm-甲氧基异丁基异腈(MIBI)双核素心肌断层显像在冠心病诊断中的临床价值.方法对101例临床怀疑有冠心病的患者进行低剂量多巴酚丁胺负荷-再分布201Tl/静息99Tcm-MIBI同时心肌断层显像,图像断层重建后进行定量靶心图测定,并与正常数据进行对照,由2位以上有经验的核医学科医师进行图像分析.断层显像后2周内101例患者均行冠状动脉造影,其中54例冠状动脉造影正常,26例有1支动脉病变,15例有2支动脉病变,6例有3支动脉病变.结果①多巴酚丁胺负荷试验,每节段负荷时间维持约2 min,负荷后心率仅达到目标心率的(72±17)%.②以动脉狭窄>50%作为冠心病的判断标准,低负荷-再分布201Tl/静息99Tcm-MIBI同时心肌断层显像法诊断冠心病的灵敏度、特异性、准确性分别为93.62%、85.19%和89.11%.③对狭窄动脉检出率由高到低依次为左前降支(LAD)、左回旋支(LCX)、右冠状动脉(RCA),其灵敏度、特异性、准确性分别为91.89%、82.81%、86.14%;80.00%、82.72%、82.18%和76.47%、82.14%、81.19%.④74支病变冠状动脉中21支为不可逆性放射性缺损,53支为可逆性放射性再分布.⑤53支可逆性放射性再分布的病变动脉中,8支负荷201Tl显像和静息99Tcm-MIBI显像示放射性稀疏缺损,而再分布或再注射201Tl显像见放射性填充,提示存在"冬眠心肌".结论在较低多巴酚丁胺负荷状态下,负荷-再分布201Tl/静息99Tcm-MIBI同时心肌断层显像法仍是一种有效的诊断冠心病及检出病变冠状动脉的方法.     

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.     

冠心病患者201Tl和99Tcm-MIBI双核素心肌灌注显像

目的探讨静息201Tl/负荷99Tcm-甲氧基异丁基异腈(MIBI)双核素心肌SPECT显像在冠心病诊断中的价值.方法对36例冠心病患者行201Tl负荷-延迟再分布心肌SPECT显像;常规潘生丁药物负荷高峰时,静脉注射201Tl 111～148 MBq,15 min后进行心肌显像.对23例冠心病患者和9例正常人行静息201Tl负荷、99Tcm-MIBI双核素心肌SPECT显像,静息状态注射201Tl 111～148 MBq,注射后5 min给予潘生丁药物负荷,高峰时注射99Tcm-MIBI 925 MBq.1 h后行双核素显像.结果 36例冠心病患者201Tl负荷-延迟再分布心肌显像的阳性率为83.33%,23例冠心病患者双核素心肌显像的阳性率为100%,两组阳性率比较差异有显著性(χ2=4.267,P=0.043).9例正常受检者均为阴性.结论双核素心肌显像对冠心病的检出率较高,省时、安全并可获得高质量图像,对冠心病诊断有较高临床价值.     

多巴酚丁胺负荷用于猪缺血心肌18F-FDG代谢显像的价值

目的 探讨多巴酚丁胺负荷情况下实验猪缺血心肌对18F-脱氧葡萄糖(FDG)的摄取情况.方法 15头中华小型猪,于冠状动脉左前降支近中段放置动脉环,造成慢性冠状动脉狭窄.分别在静息和多巴酚丁胺负荷试验时,进行99Tcm-甲氧基异丁基异腈(MIBI)心肌灌注和18F-FDG心肌代谢SPECT显像.99Tcm-MIBI心肌血流灌注图像用17段4分法进行半定量分析,通过测量心肌短轴感兴趣区(ROI)放射性计数,对缺损的可逆程度进行定量分析.18F-FDG心肌代谢图像分析通过在原始投影数据上勾画ROI,计算心脏与肝脏的平均放射性比值(H/Li)、心脏与右肺尖的平均放射性比值(H/L).所有实验猪均行冠状动脉造影检查.结果 冠状动脉造影发现,所有实验猪的冠状动脉左前降支狭窄均大于50%.99Tcm-MIBI药物负荷和静息显像时的心肌血流灌注半定量评分分别为(9.5±8.3)和(8.3±8.4)分,两者差异有显著性(P＜0.05).缺损可逆程度比值为1.17±0.14.18F-FDG图像分析发现在静息情况下,H/Li比值为1.06±0.10,H/L比值为1.40±0.18;而在多巴酚丁胺负荷情况下,心脏对18F-FDG的摄取相对增加H/Li比值为1.25±0.15(P＜0.0001),与缺血可逆程度呈明显正相关(r=0.64,P=0.007),H/L比值为1.77±0.33(P=0.001),与缺血可逆程度呈明显正相关(r=0.51,P＜0.05).结论多巴酚丁胺负荷可使缺血心肌增加对18F-FDG的摄取.     

放射性核素显像估价心肌活力

负荷试验、3~4小时再分布201Tl心肌显像明显低估缺血、但存活的心肌的范围,与之相比,18~24小时延迟再分布和静态再注射201Tl心肌显像增强了对缺血、但存活的心肌的检测,静态再注射201Tl心肌显像被认为是一种相对理想、实用的方法。18F-FDG正电子断层显像是目前被公认的估价心肌活力的最可靠的方法,但因为费用昂贵,它的临床应用很有限,静态99mTc-MIBI心肌显像明显低估缺血、但存活的心肌的范围。     

探测心肌活力的技术进展

心肌活力的评估十分重要,它有助于了解心肌病变患者的预后和选择治疗方式。评估心肌活力的方法包括核医学和其他临床上常见的方法,其中核医学上的方法有18F-FDG PET、18F-FDG SPECT、201Tl SPECT、99Tcm-MIBI SPECT和脂肪酸显像,其他显像技术包括多巴酚丁胺负荷超声,MRI(核磁共振显像)等。     

多巴酚丁胺负荷试验^99mTc—MIBI心肌断层显像诊断冠心病的应用

为探讨多巴酚丁胺药物负荷试验替代运动试验进行核素心肌断层显像的临床价值，４０例患者通过微量输液泵静脉给予多巴酚丁胺，逐渐加量，至高峰时注射＾９９ｍＴｃ－甲氧基异丁基异腈，之后行心肌图像采集，４８小时再行静息达心肌显像。３１例冠心病患者中３０例多巴酚丁胺负荷试验阳性，９例非冠心病患者中２例阳性，其特异性为７７．８％，灵敏度为９６．８％，无１例因多巴酚丁胺副作用而停止试验，因此，多巴酚丁胺试验核素心肌     

^201Tl与^13N—NH3、^18F—PDG PET心肌显像判断存活心肌的对比研究

目的 比较再注射^201Tl心肌显像与联合应用^13N-NH3及^18F-脱氧葡萄糖（FDG）心肌PET显像判断存活心肌的临床价值。方法 20例心肌梗死患者，行^201Tl SPECT负荷、再分布、再注射显像及^13N-NH3`^18F-FDG PET心肌显像。将左室分成9个节段，以视觉评价法对放射性分布进行4级评分。获得^201Tl SPECT再分布、再注射像及^18F-FDG PET显像的局部心肌摄取率（％ID）。结果 PET判定为存活心肌的48个节段中，45个节段（93．8％）^201Tl再注射像也判定为存活心肌。在^201Tl再分布像示放射性分布严重低下的24个节段，^201Tl再注射像与PET显像判定存活心肌的一致率为87．5％，其中37．5％为存活心肌节段，50％为地存活心肌节段。2种显像方法的％ID无明显差异，且呈显著正相关（r=0.722)。结论 再注射^201Tl心肌显像判断存活心肌的准确性与PET心肌显像相似，有较大的临床应用价值。     

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…     

扩张型心肌病患者双嘧达莫负荷心肌^201Tl SPECT显像分析

目的 观察扩张型心肌病患者的双嘧达莫负荷心肌201Tl SPECT显像表现.方法 2008年8月至2009年12月临床符合扩张型心肌病诊断标准的住院患者30例,按体质量0.56 mg/kg给予其双嘧达莫,于4 min内静脉注射,2 min后注射201Tl,注射完后10及240 min分别进行双嘧达莫负荷心肌201Tl SPECT显像,图像经三维重建后由2位以上有经验的核医学科医师进行分析.结果 27例（90.00%）患者的双嘧达莫负荷201Tl图像（10 min）显示左心室心肌放射性分布异常.延迟（240 min）显像时所有患者均出现左室心肌放射性分布异常,其中6例患者出现＂反向再分布＂.结论 双嘧达莫负荷心肌201Tl SPECT显像对指导扩张型心肌病的诊治具有一定的临床意义.     

Nitrate-augmented myocardial imaging for assessment of myocardial viability

²⁰¹Tl myocardial perfusion imaging is presently done by several possible strategies. Stress/delayed redistribution, stress/redistribution/reinjection, and rest/redistribution imaging can be useful in the clinical assessment of myocardial viability. Unfortunately, the extent of myocardial viability may still be underestimated even by ²⁰¹Tl reinjection imaging, compared with ¹⁸F-fluorodeoxyglucose positron emission tomography. ^99mTc-labeled sestamibi imaging provides results similar to those of ²⁰¹Tl imaging in the detection of coronary artery disease, but several previous studies suggest that stress/rest ^99mTc-labeled sestamibi imaging significantly underestimates myocardial viability. Recently it has been reported that the administration of nitrates, before ²⁰¹Tl reinjection, improves detection of defect reversibility. Several studies also suggested that administration of nitrates before the injection of ^99mTc-labeled sestamibi significantly improved detection of reversibility with this agent, whereas additional studies showed further that this combination improves the predictive accuracy for recovery of left ventricular function and perfusion after coronary revascularization, compared with a standard rest ^99mTc-labeled sestamibi study. Nitrate administration before the injection of ²⁰¹Tl and ^99mTc-labeled sestamibi may thus be a potentially attractive alternative for the evaluation of myocardial viability. Although the available results are encouraging, further studies are needed to evaluate the clinical value of ²⁰¹Tl and ^99mTc-labeled sestamibi imaging, in combination with nitrates, for predicting recovery of left ventricular dysfunction.     

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.     

A new algorithm for the quantitation of myocardial perfusion SPECT. I: technical principles and reproducibility.

We have developed a new, completely automatic 3-dimensional software approach to quantitative perfusion SPECT. The main features of the software are myocardial sampling based on an ellipsoid model; use of the entire count profile between the endocardial and epicardial surfaces; independence of the algorithm from myocardial shape, size, and orientation and establishment of a standard 3-dimensional point-to-point correspondence among all sampled myocardial regions; automatic generation of quantitative measurements and 5-point semiquantitative scores for each of 20 myocardial segments and automatic derivation of summed perfusion scores; and automatic generation of normal limits for any given patient population on the basis of data fractionally normalized to minimize hot spot artifacts. METHODS: The new algorithm was tested on the tomographic images of 420 patients studied with a rest 201TI (111-167 MBq, 35 s/projection)-stress 99mTc-sestamibi (925-1480 MBq, 25 s/projection) separate dual-isotope protocol on a single-detector camera, a dual-detector 90 degrees camera, and a triple-detector camera. RESULTS: The algorithm was successful in 397 of 420 patients (94.5%) and 816 of 840 image datasets (97.1%), with a statistically significant difference between the success rates of the 201TI images (399/ 420, or 95.0%) and the 99mTc images (417/420, or 99.3%; P < 0.001). Algorithm failure was caused by extracardiac uptake (10/24, or 41.7%) or inaccurate identification of the valve plane because of low count statistics (14/24, or 58.3%) and was obviated by simply limiting the image volume in which the software operates. Reproducibility of measurements of summed perfusion scores (r = 0.999 and 1 for stress and rest, respectively), global defect extent (r = 0.999 and 1 for stress and rest, respectively), and segmental perfusion scores (exact agreement = 99.9%, kappa = 0.998 for stress and 0.997 for rest) was extremely high. CONCLUSION: Automatic 3-dimensional quantitation of perfusion from 201Tl and 99mTc-sestamibi images is feasible and reproducible. The described software, because it is based on the same sampling scheme used for gated SPECT analysis, ensures intrinsically perfect registration of quantitative perfusion with quantitative regional wall motion and thickening information, if gated SPECT is used.     

Utility of reinjection method in stress Tl-201 myocardial scintigraphy to assess viability of the infarcted myocardium

To assess viability of the infarcted myocardium, we performed stress Tl-201 myocardial scintigraphy using reinjection method in 37 patients with old myocardial infarction, and in 13 patients of them, Tl myocardial imagings were performed in resting state on the other day within 4 weeks after this examination. In this method, 111 MBq (3 mCi) of thallium was injected at the peak of exercise and initial and delayed images were acquired, then additionally 37 MBq (1 mCi) of thallium was injected after delayed scanning (reinjection) and we obtained post-reinjection images. Delayed images showed redistribution in 15 patients (41%), and no redistribution in 22 patients (59%). In post-reinjection images, 7 (19%) of 15 patients with redistribution and 3 (8%) of 22 patients without redistribution showed improvement of thallium uptake, in total 10 patients (27%) had additional thallium uptake in infarcted regions. And the degree of thallium uptake in post-reinjection images were almost equal to that in resting images. In conclusion, myocardial imaging using thallium reinjection method may be useful for the assessment of viability of the infarcted myocardium.     

Identification of viable myocardium in patients with chronic coronary artery disease: comparison of thallium-201 scintigraphy with reinjection and technetium-99m-methoxyisobutyl isonitrile.

We compared the results of 201Tl reinjection and those of 99mTc-methoxyisobutyl isonitrile (MIBI) in identifying viable myocardium in 20 male patients with angiographically proven coronary artery disease (CAD) and left ventricular dysfunction (ejection fraction 30% +/- 8%). All patients had irreversible defects on standard exercise-redistribution thallium imaging. Thallium was reinjected immediately after the redistribution study, and images were reacquired. The patients also underwent stress and rest 99mTc-MIBI myocardial scintigraphy (2-day protocol). A total of 300 myocardial regions were analyzed, of which 122 (41%) had irreversible thallium defects on redistribution images before reinjection. Of the 122 myocardial regions with irreversible defects on standard stress-redistribution thallium cardiac imaging, 65 (53%) did not change at reinjection and 57 (47%) demonstrated enhanced uptake of thallium after reinjection. Of the same 122 irreversible defects on stress-redistribution thallium, 100 (82%) appeared as fixed defects and 22 (18%) were reversible on 99mTc-MIBI myocardial scintigraphy. These data indicate that 201Tl cardiac imaging with rest reinjection is superior to 99mTc-MIBI myocardial scintigraphy in identifying viable myocardium in patients with chronic CAD, suggesting that regions with severe reduction of 99mTc-MIBI uptake both on stress and rest images may contain viable myocardium.     

201Tl与13N-NH3、18F-FDG PET心肌显像判断存活心肌的对比研究

目的　比较再注射2 0 1T1心肌显像与联合应用13 N NH3 及18F 脱氧葡萄糖 (FDG)心肌PET显像判断存活心肌的临床价值。方法　 2 0例心肌梗死患者 ,行2 0 1T1SPECT负荷、再分布、再注射显像及13 N NH3 、18F FDGPET心肌显像。将左室分成 9个节段 ,以视觉评价法对放射性分布进行 4级评分。获得2 0 1T1SPECT再分布、再注射像及18F FDGPET显像的局部心肌摄取率 (%ID)。结果　PET判定为存活心肌的 48个节段中 ,45个节段 (93.8% ) 2 0 1T1再注射像也判定为存活心肌。在2 0 1T1再分布像示放射性分布严重低下的 2 4个节段 ,2 0 1T1再注射像与PET显像判定存活心肌的一致率为 87.5 % ,其中 37.5 %为存活心肌节段 ,5 0 %为无存活心肌节段。 2种显像方法的 %ID无明显差异 ,且呈显著正相关 (r=0 .72 2 )。结论　再注射2 0 1T1心肌显像判断存活心肌的准确性与PET心肌显像相似 ,有较大的临床应用价值。     

扩张型心肌病患者双嘧达莫负荷心肌201Tl SPECT显像分析

目的 观察扩张型心肌病患者的双嘧达莫负荷心肌201Tl SPECT显像表现.方法 2008年8月至2009年12月临床符合扩张型心肌病诊断标准的住院患者30例,按体质量0.56 mg/kg给予其双嘧达莫,于4 min内静脉注射,2 min后注射201Tl,注射完后10及240 min分别进行双嘧达莫负荷心肌201Tl SPECT显像,图像经三维重建后由2位以上有经验的核医学科医师进行分析.结果 27例(90.00%)患者的双嘧达莫负荷201Tl图像(10 min)显示左心室心肌放射性分布异常.延迟(240 min)显像时所有患者均出现左室心肌放射性分布异常,其中6例患者出现"反向再分布".结论 双嘧达莫负荷心肌201Tl SPECT显像对指导扩张型心肌病的诊治具有一定的临床意义.     

Assessment of myocardial viability by resting 201Tl SPECT image

The aim of this study was to assess whether resting 201Tl scintigraphy is superior in detecting viable myocardium than previous conventional methods. We performed not only stress 201Tl SPECT but also resting 201Tl SPECT within one month in 65 patients with coronary artery disease. Resting 201Tl images were quantitatively compared with 4 hour late images of stress study using a polar map. In stress study, redistribution was recognized on 83% (25/30) of non-MI SEGs with perfusion defect in the stress 201Tl image, and on 39% (18/46) of infarcted SEGs. The agreement of resting 201Tl study with 4 hour late images of stress study was shown on 93% (28/30) of non-MI SEGs and on 52% (24/46) of MI SEGs. The increased uptake of 201Tl in resting study, however, was found on 13 (46%) of 28 MI SEGs showing fixed defects in stress study. In stress delayed image with fixed defect, the %Tl uptake of improved SEGs was higher than that of unchanged SEGs (59 +/- 10% vs 48 +/- 11%; p greater than 0.05). There was no viable myocardium which had %Tl uptake less than 40% at stress delayed image. In conclusion, the resting 201Tl imaging will give an important information as for the myocardial viability showing fixed defects, if more than 40% Tl uptake is observed.     

Feasibility of simultaneous stress 99mTc-sestamibi/rest 201Tl dual-isotope myocardial perfusion SPECT in the detection of coronary artery disease.

This study assesses feasibility and diagnostic accuracy of simultaneous stress 99mTc-sestamibi/rest 201 TI dual-isotope myocardial perfusion SPECT with Moore's correction method, in which contamination originating from lead x-rays produced in a collimator was subtracted in the 201TI windows. METHODS: Eighty-one patients with suspected coronary artery disease received exercise 99mTc-sestamibi injection, followed by rest 201TI injection 50 min later, and dual-isotope SPECT was performed (group 1). These results were compared with coronary angiographic findings. Furthermore, to estimate the accuracy of Moore's correction method, 201TI crosstalk into the 99mTc acquisition window (group 2A, n = 20) and 99mTc crosstalk into the 201TI acquisition windows (group 2B, n = 20) were studied. For group 2A, stress 99mTc-sestamibi SPECT (single 99mTc-sestamibi SPECT) was performed, followed by 201TI injection at rest and dual-isotope SPECT acquisition 50 min later. For group 2B, rest 201TI SPECT (single 201TI SPECT) was performed, followed by 99mTc-sestamibi injection at rest and dual-isotope SPECT acquisition 30 min later. RESULTS: Sensitivity and specificity in group 1 were 83% and 99%, respectively, when > or =75% coronary artery narrowing was considered significant. In groups 2A and 2B, SPECT images were divided into 24 segments, and relative regional uptake in each segment was obtained. In group 2A, relative regional uptake of single 99mTc-sestamibi SPECT correlated well with that of dual-isotope SPECT (r = 0.942). In group 2B, relative regional uptake of single 201TI SPECT correlated well with that of dual-isotope SPECT (r = 0.935). Furthermore, in low 201TI uptake segments with relative regional uptake in both single- and dual-isotope SPECT of < or =70%, the degree of concordance between single- and dual-rest 201TI was considered to be high with Bland-Altman analysis and the kappa statistic. Comparison of perfusion defect type demonstrated that, of 22 stress defects within infarct zones, 95% were irreversible and 5% were reversible. In contrast, of 28 stress defects within stenosed vessel zones in noninfarct zones, 89% were reversible and 11% were irreversible (P < 0.0001 versus infarct zones). CONCLUSION: Simultaneous dual-isotope imaging with Moore's correction method is feasible, with acceptable accuracy for detection of coronary artery disease and a small amount of crosstalk into each window.