Clinical evaluation of the 99mTc-CPI myocardial perfusion imaging

^99mTc-CPI myocardial perfusion scintigraphy including planar images in 35 patients and SPECT images in 16 patients has been studied. Scintigraphic data revealed that high quality ^99mTc-CPI myocardial perfusion images were obtained. The sensitivity and specificity of ^99mTc-CPI planar images in detecting CAD was 92% and 80% respectively. There was no significant difference in sensitivity for detecting CAD between planar and SPECT. However, the specificity of SPECT was much better than that of planar imaging.     

99mTc-MIBI myocardial perfusion imaging in myocarditis

Myocardial perfusion imaging with technetium-99m-labelled methoxyisobutyl isonitrile single photon emission computed tomography (99mTc-MIBI SPECT) has proven to be an important clinical procedure in assessing the severity of myocardial ischaemia. The uptake and clearance of 99mTc-MIBI by the myocardium is affected by cell viability and membrane integrity. Consequently, infectious diseases, such as myocarditis, may also affect myocardial perfusion by inducing local inflammation and necrosis. We compared 99mTc-MIBI myocardial perfusion imaging with other heart monitoring methods in order to assess its value in the diagnosis of children with Coxsackie viral myocarditis. We examined 46 patients (age, 3-12 years) with Coxsackie viral myocarditis using 99mTc-MIBI myocardial perfusion imaging and compared the perfusion data with myocardial enzymes, electrocardiographic findings and echocardiography. Regions of hypoperfusion were found in all 46 patients. Seventeen patients (37%) showed two or more areas of diminished perfusion. Myocardial hypoperfusion was mild-to-moderate (<30%) in 33 (72%) patients and severe (>30%) in 13 (28%) patients. Characteristic creatine-kinase isoenzyme (CK-MB) increases, ST-T segment changes and diminished heart function were significantly correlated with reduced myocardial perfusion (all comparisons P<0.05). The results of this study suggest that the presence of myocardial uptake of 99mTc-MIBI may be a marker of myocardial inflammation and necrosis. All 46 patients with Coxsackie viral myocarditis showed a certain degree of reduced perfusion. When the perfusion findings were compared with other parameters, it was shown that myocardial enzyme levels, ST-T segment changes and left ventricular function correlated well with the 99mTc-MIBI-established perfusion defect severity. 99mTc-MIBI SPECT imaging is therefore helpful in providing additional diagnostic information in patients with Coxsackie viral myocarditis.     

^99Tc^m—MIBI心肌灌注显像评价代谢综合征患者心肌血流

目的应用MPI评价代谢综合征（MS）患者心肌血流灌注情况。方法选择确诊或疑似冠心病患者342例行常规门控运动＋静息MPI;根据代谢指标异常情况分为4组,组1：无代谢指标异常;组2：具有1个代谢指标异常;组3：具有2个代谢指标异常;组4：具有3个或3个以上代谢指标异常。分析代谢指标异常数量与MPI的关系。对符合中华医学会糖尿病分会MS诊断标准、在显像前后1个月内行CAG检查的103例患者的MPI结果,以CAG结果为标准,分析2种方法间诊断的一致性。采用SPSS13．0软件,组间心肌灌注异常的发生率比较采用x。检验,方法间的一致性分析用Kappa检验。结果（1）与CAG比较,MPI诊断冠心病的灵敏度为80．5％（33／41）,特异性85．5％（53／62）,阳性预测值78．6％（33／42）,阴性预测值86．9％（53／61）,诊断准确性为83．5％（86／103）,惭值为0．657,P〈0．001。（2）随代谢指标异常数量增加,心肌灌注异常的发生率增加：组1为23．3％（10／43）,组2为32．9％（26／79）,组3为54．4％（56／103）,组4为57．3％（67／117）,X2：23．22,P〈0．001。结论MPI可以应用于IS患者的心肌血流评估;代谢指标异常数量增加,心肌灌注异常的发生率增加。     

心肌灌注显像剂:99Tcm-N-NOET

99Tcm-N-NOET{双[N-乙氧,N-乙基(二硫代氨基甲酸脂)氮化锝](V)}是一种锝标记中性亲脂性心肌灌注显像剂,具有心肌首过摄取率高、心肌滞留时间长之优点.其心肌摄取部位在细胞膜,且摄取不依赖于能量.L型钙通道阻滞剂能影响其心肌摄取.99Tcm-N-NOET不仅具有201Tl类似的心肌再分布,而且其心肌灌注显像在诊断冠状动脉疾病的敏感性和特异性方面与201Tl类似.     

Technetium-99m labeled myocardial perfusion imaging agents

99mTc labeled myocardial perfusion tracers have significantly advanced the field of noninvasive diagnostic evaluation and risk stratification of patients with known or suspected coronary artery disease by providing comprehensive information about myocardial perfusion and function from a single study. Of various currently available invasive and noninvasive test modalities, myocardial perfusion imaging provides the most powerful prognostic information that is incremental to the information obtained from invasive evaluation. Future research should focus on the development of perfusion tracers that linearly track myocardial blood flow over a wide range and have minimal splanchnic uptake. Availability of an effective attenuation and scatter correction program would further eliminate some of the current limitations of this technique.     

99Tcm-MIBI心肌灌注显像对代谢综合征患者并发冠心病的评价

目的 探讨核素心肌灌注显像对代谢综合征患者并发冠心病的诊断价值.方法 回顾性分析251例[男179例,女72例,年龄(59±10)岁]代谢综合征患者99Tcm-甲氧基异丁基异腈(MIBI)心肌灌注显像的结果,与冠状动脉造影进行比较,计算99Tc-MIBI心肌灌注显像诊断冠心病的灵敏度、特异性和准确性.结果 在251例代谢综合征患者中,163例(65%)患者冠状动脉造影示有狭窄病变,99Tcm-MIBI心肌灌注显像检出心肌缺血或心肌梗死116例;88例冠状动脉造影阴性患者中,82例心肌灌注显像结果正常;99Tcm-MIBI心肌灌注显像诊断冠心病的灵敏度为71%(116/163),特异性为93%(82/88),阳性预测值为95%(116/122),阴性预测值为64%(82/129),准确性为79%(198/251).诊断单支、双支和三支冠状动脉病变患者的灵敏度分别为58%(36/61),61%(22/36)和87%(57/66).结论 99Tcm-MIBI心肌灌注显像对检测代谢综合征患者有无并发冠心病有重要的应用价值.     

肌聚糖病的99Tc^m—MIBI门控心肌灌注断层显像评价

目的探讨99Tc^m一MIBIG—MPI评价肌聚糖病患者心肌受损的价值。方法临床、分子病理确诊的肌聚糖病患者8例（男3例,女5例,年龄10—30岁）、对照者4名均接受99TcmMIBIG—MPI。原始数据按常规处理成断层图像,再应用定量门控分析软件（QGS）进行左室功能定量分析。采用将左心室分为7个节段、20个亚段的5分制（0—4分）半定量方法,用于评估心肌受损的程度。结果8例患者99Tcm-MIBIG—MPI阳性7例。7例阳性患者140个心肌亚段中共检出59个亚段异常。按病变累及室壁节段（7个节段）分为：单一室壁节段异常1例,2个室壁节段异常2例,3个及3个以上室壁节段异常、病灶呈散在性分布4例。8例肌聚糖患者中5例患者左心室扩大,其中3例左室射血分数为（43．1±2．8）％。结论99Tcm-MIBIG—MPI能直观探测肌聚糖病患者的心肌损害,可作为肌聚糖病患者心肌损害早期诊断和远期随访的辅助诊断方法。     

99Tcm-替曲膦与99Tcm-MIBI门控心肌灌注显像的对比研究

目的 对比99Tcm-替曲膦(TF)和99Tcm-MIBI G-MPI的左室心肌灌注及左室心功能参数结果,探讨99 Tcm-TF能否作为临床G-MPI常规显像剂.方法 99Tcm标记TF和MIBI并进行放化纯测定.选取2011年12月至2012年5月间既往健康、排除严重心律不齐及临床拟诊为心肌炎、心肌病的112例受试者(研究经医院伦理委员会批准,患者签署知情同意书),采用简单随机抽样法将其随机分成2组,分别行一日法99Tcm-TF(47例,运动负荷状态下注射显像剂370 MBq,静息状态下注射显像剂740 MBq)G-MPI和两日法99Tcm-MIBI(65例,注射剂量均为555 MBq)G-MPI,所有受试者均于1周内行CAG和UCG检查.利用Cedars定量门控SPECT(QGS)软件获得左室心功能参数,包括LVEF、EDV、ESV、峰充盈率(PFR)、峰射血率(PER)及相位标准差(SD).采用SPSS 17.0软件进行x2检验、两独立样本r检验、配对r检验及直线相关分析.结果 99 Tcm-TF和99Tcm-MIBI放化纯分别为(97.5±0.4)％和(99.1±0.2)％.与CAG结果对比,99Tcm-MIBI心肌灌注结果符合率为90.5％(57/63),99Tcm-TF为88.9％(40/45),两者差异无统计学意义(x2=0.389,P＞0.05).99Tcm-TF和99Tcm-MIBIG-MPI获得的左室心功能参数差异也无统计学意义[LVEF:(62.60±±13.56)％与(60.52±7.08)％,r=0.940;EDV:(103.31±17.29) ml与(98.52±19.37) ml,t=1.348;ESV:(41.73±12.69) ml与(46.05±10.81) ml,t=0.851;PER:(2.73±0.67) EDV/s与(2.61±1.04) EDV/s,t =0.725;PFR:(2.13±0.80) EDV/s与(2.07±1.09) EDV/s,t=0.339;相位SD:(5.58±4.16).与(5.97±4.64).,t=0.450,均P＞0.05].两者G-MPI获得的左室心功能参数与UCG结果差异无统计学意义[LVEF:(61.39±10.28)％与(62.13±8.51)％,t=0.991;EDV:(100.50±18.61) ml与(101.70±18.34) ml,t=1.806;ESV:(44.25±11.77) ml与(43.94±11.28)ml,t=0.658;均P＞0.05],且与UCG结果呈正相关(r=0.673、0.710和0.452,均P＜0.05).结论 99Tcm-TF可作为G-MPI显像剂常规用于临床,同时评价左室心肌灌注情况和左室功能.     

Simultaneous technetium-99m MIBI angiography and myocardial perfusion imaging

Resting first-pass radionuclide angiography (FPRNA) was performed with the myocardial perfusion agent technetium-99m MIBI. In 27 patients, it was compared with technetium-99m diethylenetriamine pentaacetic acid FPRNA. A significant correlation was present in left (r = 0.93, p less than 0.001) as well as right (r = 0.92, p less than 0.001) ventricular ejection fraction measured with both radiopharmaceuticals. In 13 patients, MIBI derived segmental wall motion was compared with contrast ventriculography. A high correlation was present (p less than 0.001), and qualitative agreement was found in 38/52 segments. In 19 patients with myocardial infarction a significant correlation was present between MIBI segmental wall motion and perfusion scores (p less than 0.001). In ten patients with a history of myocardial infarction, 18 myocardial segments demonstrated diseased coronary vessels and impaired wall motion at contrast angiography. These segments were all identified by the MIBI wall motion and perfusion study. We conclude that MIBI is a promising agent for simultaneous evaluation of cardiac function and myocardial perfusion at rest.     

99mTc-MIBI心肌灌注显像在心肌缺血治疗中的指导意义

目的确定~(99m)Tc-MIBI心肌灌注显像在心肌缺血治疗中的指导意义。方法利用美国GE公司生产的双探头可变角SPECT检查了86例冠状动脉供血不足引起的心肌缺血患者,并对其中48例心肌灌注治疗前后的缺损填充或改善情况进行了观察。结果43例(89.6%)患者显像缺损填充或有明显改善,仅1例缺损填充不佳。结论~(99m)Tc-MIBI心肌灌注显像在心肌缺血治疗中有重要指导意义。     

Incidental pathologic extracardiac uptake of 99mTc-tetrofosmin in myocardial perfusion imaging

Technetium-99m-tetrofosmin ((99m)Tc-TF) myocardial perfusion studies have incidentally detected various extracardiac abnormalities. The interpretation of these findings may be essential for early diagnosis and treatment of important diseases. We present a rare case of a mediastinal thymoma incidently detected during myocardial perfusion imaging. A 60 year-old woman, with precardiac symptoms of possible myocardial ischemia, underwent a (99m)Tc-TF stress-rest single photon emission tomography test. Intense uptake of the radiotracer in the left paracardiac area, was observed. The computerized tomography and the magnetic resonance imaging tests revealed a mass in the left lower anterior mediastinal area. Biopsy and subsequent histology showed that this mass was a thymoma.     

Clinical evaluation of the 99mTc-labeled myocardial imaging agent,hexakis (t-butylisonitrile)-technetium

^99mTc-TBI myocardial perfusion imaging has been studied in 7 normal subjects and 24 patients with coronary artery disease. Scintigraphic data revealed that ^99mTc-TBI myocardial perfusion imaging is more sensitive than ECG in detecting myocardial infarction. In comparing ^99mTc-TBI imaging with contrast angiography, its' sensitivity for the diagnosis of coronary artery disease was 91.7%.     

Tc-99m-N-MPO: Novel cationic Tc-99m radiotracer for myocardial perfusion imaging

Background. Technetium 99m-N-MPO ([Tc-99m-N(mpo)(PNP5)]⁺) is a cationic Tc-99m nitrido complex. The objective of this study is to evaluate its potential as a new radiotracer for myocardial perfusion imaging. Methods and Results. Biodistribution studies were performed in Sprague-Dawley rats and guinea pigs to compare the myocardial uptake and excretion kinetics of Tc-99m-N-MPO from noncardiac organs, such as the liver and lungs, with those of the known cationic Tc-99m radiotracers: Tc-99m-N-DBODC5 and Tc-99m-sestamibi. Planar imaging was performed in Sprague-Dawley rats to evaluate the utility of Tc-99m-N-MPO as a myocardial perfusion imaging agent. Metabolism studies were carried out by use of both Sprague-Dawley rats and guinea pigs. In general, the heart uptake of Tc-99m-N-MPO was between that of Tc-99msestamibi and Tc-99m-N-DBODC5 over the 2-hour study period. However, the heart-liver ratio of Tc-99m-N-MPO (12.75±3.34) at 30 minutes after injection was more than twice that of Tc-99m-N-DBODC5 (6.01±1.45) and approximately 4 times higher than that of Tc-99msestamibi (2.90±0.22). The heart uptake and heart-liver ratio of Tc-99m-N-MPO and Tc-99m-sestamibi in guinea pigs were significantly lower than those obtained in Sprague-Dawley rats. The metabolism studies demonstrated no detectable Tc-99m-N-MPO metabolites in the urine and feces samples of the Sprague-Dawley rats at 120 minutes after injection. In guinea pigs no Tc-99m-N-MPO metabolites were detected in the urine at 120 minutes, but only approximately 60% of Tc-99m-N-MPO remained intact in the feces samples. In contrast, there was no intact Tc-99m-sestamibi detected in urine samples, and less than 15% of Tc-99m-sestamibi remained intact in the feces samples. Planar imaging studies indicated that clinically useful images of the heart may be obtained as early as 15 minutes after injection of Tc-99m-N-MPO. Conclusion. The combination of favorable organ biodistribution and myocardial uptake with rapid liver clearance makes Tc-99m-N-MPO a very promising myocardial perfusion radiotracer worthy of further evaluation in various preclinical animal models. This work was supported, in part, by Purdue University and the following research grants: R01 CA115883 A2 (S.L.) from the National Cancer Institute, BCTR0503947 (S.L.) from the Susan G. Komen Breast Cancer Foundation, AHA0555659Z (S.L.) from the Greater Midwest Affiliate of the American Heart Association, R21 EB003419-02 (S.L.) from the National Institute of Biomedical Imaging and Bioengineering, and R21 HL083961-01 from the National Heart, Lung, and Blood Institute.     

Technetium-99m teboroxime scintigraphy. Clinical experience in patients referred for myocardial perfusion evaluation

In order to evaluate the clinical value of a new myocardial perfusion tracer, a series of 30 patients (25 male, 5 female, mean age 56 years) referred for thallium 201 stress/redistribution scintigraphy has been studied using stress/rest (n = 7) or rest/stress (n = 23) protocols with technetium 99m teboroxime (Cardiotec SQUIBB). In all cases coronary artery disease was known or highly probable, with a history of myocardial infarction in 18 cases. Medical treatment was not discontinued at the time of stress testing, and coronary angiography was available in 27 patients. Exercise tests for both tracers were carried out on a bicycle ergometer during the same day, and the levels of exercise achieved for the 201Tl study were very similar to those achieved for 99mTc-teboroxime. Studies performed in three planar projections were evaluated using a model with four territories: septal and anterior assumed to correspond to the left anterior descending artery, lateral and latero-posterior (left circonflex), inferior and posterior (right coronary artery) and apex. Classification of results was: normal, ischaemic, infarcted and infarcted with ischaemia. On comparison with the 201Tl results, agreement was found in 86% (37/43) of normal regions and in 82% (63/77) of abnormal regions. Relative to documented coronary artery lesions (27 patients), sensitivity and specificity of 201Tl and 99mTc-teboroxime for exact correspondence between arteries and territories were respectively: 201Tl: sensitivity 64%, specificity 60%; 99mTc-teboroxime: sensitivity 62%, specificity 77%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Focal pulmonary uptake during Tc-99m myocardial perfusion SPECT imaging

PURPOSE: To evaluate the incidence and origin of abnormal focal pulmonary uptake during myocardial perfusion SPECT imaging (MSPECT). METHODS: For evaluation of chest pain, 790 men and 581 women (mean age, 56 +/- 13 years) underwent MSPECT. All of them received adenosine for pharmacologic stress and Tc-99m tetrofosmin (TF, n = 817) or Tc-99m sestamibi (MIBI, n = 554) for myocardial perfusion imaging. RESULTS: Review of chest radiography with or without computed tomography revealed 111 (8.1%) focal pulmonary diseases. Among them, 38 (34.2%) showed focal pulmonary uptake (TF, 22; MIBI, 16); 27 (30.7%) of 88 showed previous pulmonary tuberculosis; 2 of 10 (20%) benign pulmonary nodules; 4 of 5 (80%) metastatic lung cancers; 2 of 4 (50%) primary lung cancers; and 3 of 4 (75%) pneumonias. No difference in uptake was noted for the two imaging agents. Intensity of uptake did not vary with origin of the uptake. Focal abnormal pulmonary uptake was found in 2.8% of patients undergoing MSPECT and in 34.2% of patients in whom radiological examinations showed regional pulmonary disease. In patients with abnormal pulmonary uptake on MSPECT, 16% had a malignant lesion, whereas 75% of patients with a pulmonary nodule shown on radiography and focal pulmonary uptake on MSPECT had a malignant lesion. CONCLUSIONS: Although the incidence of abnormal pulmonary uptake during MSPECT was very low, the incidence of malignant lesions in the patients with nodular pulmonary uptake was relatively high.     

Blinded evaluation of planar technetium-99m-sestamibi myocardial perfusion studies.

Sestamibi planar myocardial perfusion studies were performed at Hotel-Dieu de Montreal on 28 patients with documented coronary artery disease and 16 normal subjects. Stress and rest studies were performed on separate days. These studies were sent to Virginia for interpretation while blinded as to age, sex, and other clinical information. Studies were quantitated independently by two operators (using a computer program modified for Sestamibi), and interpreted independently by two experienced interpreters. Computer quantitation of 2816 segments gave an average interoperator deviation of 2.2%. Pure quantitative criteria were applied for computer interpretation. By varying the detection threshold, we produced the entire ROC curve relating sensitivity and specificity as a function of detection threshold. Using only computer criteria for normal or abnormal, interoperator agreement by patient was 98% and 93% by view. The computer could achieve equal positive and negative predictive accuracy of 87%. Interpreters, allowed both quantitative and subjective judgment, agreed on 91% of 44 patients, 90% of 132 views, and 92% of 660 segments. Interpreters averaged 94% positive and 86% negative predictive accuracy.     

Clinical evaluation of 99mTc-pyrophosphate myocardial emission computed tomography: comparison with planar imaging

To depict the three-dimensional distribution of 99mTc-pyrophosphate in the heart, emission computed tomography (ECT) was performed, following the conventional planar imaging, in 32 cases with suspected acute myocardial infarction (AMI). There were 23 cases with evidence of AMI, 7 with unstable angina (UA), and 2 with dilated cardiomyopathy (DCM). While the planar images showed discrete cardiac activity in only 11 of the 23 cases (48%) with AMI, the ECT images delineated focal myocardial uptake clearly in 20 of them (87%). On the other hand, the ECT images revealed cardiac blood-pool activity without significant myocardial uptake in all cases with UA and DCM in which the planar images showed diffuse activity. Thus, the ECT imaging of 99mTc-pyrophosphate seems to be a valuable technique for assessing the presence and localization of myocardial necrosis, especially in cases showing diffuse cardiac activity in the planar imaging.