A comparison of planar and tomographic thallium scintigraphy in patients with coronary artery disease

Planar and tomographic scans from 57 patient are compared and related to coronary arteriographic results. Tomography identified inferior and septal defects not seen on planar imaging. Planar imaging better identified apical defects. Lesions of the left circumflex were poorly defined by both techniques.     

A comparison of planar and tomographic thallium scintigraphy in patients with coronary artery disease

Planar and tomographic scans from 57 patients are compared and related to coronary arteriographic results. Tomography identified inferior and septal defects not seen on planar imaging. Planar imaging better identified apical defects. Lesions of the left circumflex were poorly defined by both techniques.     

Exercise gated planar myocardial perfusion imaging using technetium-99m sestamibi for the diagnosis of coronary artery disease: an alternative to exercise tomographic imaging

Single-photon emission tomography (SPET) using technetium-99m labelled myocardial tracers (e.g.^99mTc-sestamibi) has become one of the most popular myocardial imaging methods for the diagnosis of coronary artery disease (CAD). This prospective study was designed to evaluate the diagnostic performance of^99mTc-sestamibi exercise gated planar myocardial imaging by comparison with both visual and quantitative analyses of SPET. The study was conducted in 115 consecutive patients with known or suspected CAD, including 54 patients with a previous myocardial infarction (MI), referred for exercise testing prior to coronary angiography. Multi-gated planar imaging and SPET were performed after bicycle exercise. The end-diastolic (ED) and SPET images were visually scored (SVi). Myocardial uptake was quantitated on SPET slices using maximum count circumferential profiles (SQu) and defect extent was measured by comparison with gender-matched data sets obtained from 27 controls (<5% likelihood of CAD). CAD was defined as coronary artery stenosis >50% and/or regional wall motion abnormality. The cut-off criteria for positivity of the three procedures were determined from receiver operating characteristic (ROC) curves derived from the data of patients without previous MI. The area under the ROC curves was similar for ED, SVi and SQu. This was confirmed by the analysis of sensitivity performed using the ROC curve-derived cut-off criteria, in patients with or without previous MI. SVi was more sensitive than ED in identifying the diseased vessel(s) (ED: 41% vs SVi: 80%;P<0.0005) but ED was more specific in this respect (ED: 79% vs SVi: 61%;P<0.0005). We conclude that visual analysis of ED images obtained from gated^99mTc-sestamibi stress planar imaging is a valuable alternative to SPET imaging for the diagnosis of CAD. SPET is, however, more accurate for the evaluation of the disease extent and localization and therefore remains the method of choice for the assessment of myocardial perfusion.     

Prognostic value of tomographic rest-redistribution thallium 201 imaging in medically treated patients with coronary artery disease and left ventricular dysfunction

Background

Previous studies show that rest-redistribution thallium imaging is useful in the assessment of myocardial viability. The impact of such studies on patient outcome is not well defined. This study examined the prognostic value of tomographic rest-redistribution ²⁰¹TI imaging in 81 medically treated patients with coronary artery disease and left ventricular dysfunction.

Methods and Results

Rest-redistribution single-photon emission computed tomographic images were obtained and analyzed quantitatively. The segmental thallium uptake (20 segments per patient) was interpreted as normal, reversible defect, mild to moderate fixed defect, or severe fixed defect. The thallium images were abnormal in 80 patients. The left ventricular ejection fraction was 27%±8% in patients with no redistribution and 26%±7% in patients with redistribution (difference not significant). In patients with no ischemia, there were 7±5 severe fixed defects and 5±4 mild to moderate fixed defects per patient. In patients with ischemia there were 7±4 reversible defects, 3±3 mild to moderate fixed defects, and 5±4 severe fixed defects per patient. The number of any abnormal segments was 11±5 in patients with no ischemia and 14±4 in patients with ischemia (p=0.03). During a mean follow-up of 31±24 months, there were 11 cardiac deaths in patients with no ischemia (26%) and 22 in patients with ischemia (58%); the survival rate was worse in patients with than without ischemia (p<0.05). Multivariate Cox survival analysis on important clinical, angiographic, and thallium variables showed that the presence of redistribution was an independent predictor of death (x ²=5; p=0.03).

Conclusions

Patients with left ventricular dysfunction and redistribution on rest thallium imaging, a marker of hibernating myocardium, have a higher mortality rate with medical therapy than do patients with a comparable degree of left ventricular dysfunction but with fixed defects only. Thus observations similar to those made with positron emission tomography can be made in a much more straightforward, simple, and probably cost-effective manner with single-photon emission computed tomography.     

Detection of coronary artery disease by dynamic planar and single photon emission tomographic imaging with technetium-99m teboroxime

To test the clinical significance of technetium-99m teboroxime regional myocardial clearance in the detection of coronary artery disease, 25 patients underwent dynamic planar or single-photon emission tomographic (SPET) myocardial imaging with ^99mTc-teboroxime after exercise and again 2 h later at rest. All patients underwent both thallium-201 exercise and redistribution SPET and coronary arteriography. The early phases of exercise ^99mTc-teboroxime myocardial clearance determined by dynamic planar imaging showed a significant difference between normal and post-stenotic myocardial regions (clearance rate constant k: 0.047±0.005 min' versus 0.034±0.003 min^–1, P <0.001). Reflecting this differential clearance between myocardial regions, an early redistribution-like phenomenon was observed in a significant number of myocaridal segments by comparing serially acquired post-exercise ^99mTc-teboroxime SPET images. These results indicated that the analysis of ^99mTc-teboroxime myocardial clearance was of potential use in the detection of coronary artery disease, yielding additional information to that provided by the tracer distribution analysis. Although the early redistribution-like phenomenon of ^99mTc-teboroxime could be the source of underestimation of ischaemia if acquisition of the initial post-exercise image were delayed, it could also prove useful in the early differentiation of ischaemia from scar because when the phenomenon was observed in delayed post-exercise images, the rest study could be omitted under some circumstances.     

Prognostic value of adenosine single-photon emission computed tomographic thallium imaging in medically treated patients with angiographic evidence of coronary artery disease

Background  

This study examined the prognostic value of adenosine single-photon emission computed tomographic thallium imaging in medically treated patients with angiographic evidence of coronary artery disease (CAD).     

Segmental coronary artery disease: detection by rotating slant-hole collimator tomography and planar thallium 201 myocardial scintigraphy

Normal quantitative circumferential profile limits were established for a 30 degrees bilateral rotating slant-hole (RSH) collimator tomographic system. This system's value in detecting segmental coronary artery disease was assessed in a study evaluating 196 patients by thallium 201 myocardial scintigraphy and coronary arteriography. Profile curves were calculated from images of 20 healthy patients and used to identify significant coronary artery disease (greater than or equal to 70% diameter narrowing) in the left anterior descending (LAD), the right, and the left circumflex (LCx) coronary arteries. In a group of 86 patients, an abnormality on the apical or middle plane optimally identified segmental coronary artery disease. When such abnormalities were prospectively evaluated in a test group of 110 patients, the sensitivity and specificity were 79% and 93% for LAD, 90% and 90% for right, and 83% and 83% for LCx coronary artery disease. Compared with qualitative interpretation of the planar and tomographic images, quantitative tomography significantly improved the sensitivity of T1-201 imaging in detecting LAD, right, and LCx coronary artery disease (P less than .001) in patients with or without previous myocardial infarction.     

Early thallium imaging after percutaneous transluminal coronary angioplasty: tomographic evaluation during adenosine-induced coronary hyperemia.

This study examined the immediate results of 201Tl imaging during adenosine-induced coronary hyperemia in 25 patients with one-vessel coronary artery disease, 4 +/- 3 days after percutaneous transluminal coronary angioplasty (PTCA). There were special features in our study: use of quantitative angiography and single-photon emission computed tomography (SPECT); a homogeneous group of patients (one-vessel disease) and a uniform stress (adenosine infusion). As a group, quantitative coronary angiography showed a decrease in percent diameter stenosis from 72% +/- 12% to 23% +/- 14%, p < 0.001. The thallium images were normal in 17 patients and abnormal in eight patients. However, of the eight patients, four had residual stenosis either in a secondary branch or downstream; one patient had local dissection (the residual stenosis could not be assessed reliably), two patients had > 50% residual diameter stenosis, and one patient had previous Q-wave myocardial infarction with a corresponding fixed thallium defect. In each of the eight patients with an abnormal image, a logical explanation could be identified. Thus, our results suggest that maximum reactive coronary hyperemia returns to normal immediately after PTCA, and that abnormal thallium results are due to inadequate dilatation or associated lesions.     

CT冠状动脉成像在冠心病诊断中的应用

目的:研究CT冠状动脉成像在冠心病早期诊断冠状动脉狭窄定性定量判读的作用。方法:对34例临床未发生急性冠脉综合征的冠心病患者,先后进行冠状动脉造影、128排双源CT冠状动脉成像。以冠状动脉造影为"金标准",计算CT冠状动脉成像敏感性、特异性、阳性预测值、阴性预测值。结果:①与冠状动脉造影相比,CT冠状动脉成像的敏感性为68%,特异性为97%,阳性预测值为89%,阴性预测值为90%。②CT冠状动脉成像有65个血管段图像质量差,约占12%,造成图像质量差的原因主要为钙化,心跳、呼吸伪影,少部分为管腔显示不良。结论:冠心病早期诊断中,CT冠状动脉成像可用作冠状动脉造影前筛选,CT冠状动脉成像阴性的患者不必行冠状动脉造影检查;CT冠状动脉成像阳性的患者,可行冠状动脉造影进一步确认病变。     

The detection of coronary artery disease: a comparison of exercise thallium imaging and exercise equilibrium radionuclide ventriculography

This study compared the accuracy of rest and exercise gated equilibrium technetium ventriculography with exercise thallium imaging in 50 consecutive male patients undergoing routine coronary angiography for the evaluation of chest pain. No patients were excluded on the basis of prior myocardial infarction, nature of angiographically defined coronary disease or symptoms. Antianginal therapy was continued in all patients. Eight patients had normal coronary arteries, 9 had single vessel, disease, 20 had double vessel disease and 13 had triple vessel disease. Sixteen patients had previously documented myocardial infarction. Using exercise radionuclide ventriculography, 34 patients with coronary disease were detected resulting in a sensitivity of 81%; 6 patients with normal coronary arteries had normal scans, a specificity of 75%, with a predictive accuracy of 80%. In comparison, thallium imaging detected 42 patients with coronary disease resulting in a sensitivity of 100%. Six patients with normal coronary arteries had normal thallium images resulting in a specificity of 75% and a predictive accuracy of 96%. These results suggest that exercise thallium imaging is a more accurate investigation than exercise equilibrium radio-nuclide ventriculography and is the investigation of choice in the noninvasive detection of coronary artery disease.     

The detection of coronary artery disease: A comparison of exercise thallium imaging and exercise equilibrium radionuclide ventriculography

This study compared the accuracy of rest and exercise gated equilibrium technetium ventriculography with exercise thallium imaging in 50 consecutive male patients undergoing routine coronary angiography for the evaluation of chest pain. No patients were excluded on the basis of prior myocardial infarction, nature of angiographically defined coronary disease or symptoms. Antianginal therapy was continued in all patients. Eight patients had normal coronary arteries, 9 had single vessel, disease, 20 had double vessel disease and 13 had triple vessel disease. Sixteen patients had previously documented myocardial infarction. Using exercise radionuclide ventriculography, 34 patients with coronary disease were detected resulting in a sensitivity of 81%; 6 patients with normal coronary arteries had normal scans, a specificity of 75%, with a predictive accuracy of 80%. In comparison, thallium imaging detected 42 patients with coronary disease resulting in a sensitivity of 100%. Six patients with normal coronary arteries had normal thallium images resulting in a specificity of 75% and a predictive accuracy of 96%. These results suggest that exercise thallium imaging is a more accurate investigation than exercise equilibrium radio-nuclide ventriculography and is the investigation of choice in the noninvasive detection of coronary artey disease.     

Flow-mediated vasodilation predicts the presence and extent of coronary artery disease assessed by stress thallium imaging

BACKGROUND: Endothelial function can be measured by flow-mediated vasodilation (FMD) of the brachial artery and has been associated with cardiac risk factors (RF) and angiographically defined coronary artery disease (CAD). Stress single photon emission computed tomography (SPECT) imaging is commonly used to study patients with CAD. We sought to study the relationship between endothelial dysfunction by FMD and stress thallium SPECT to detect CAD. METHODS AND RESULTS: Fifty-five consecutive patients with chest pain syndrome referred for stress SPECT and eleven healthy control subjects had FMD measured on the brachial artery by standard techniques. The main outcome was the percent of brachial artery diameter dilation from baseline and the number of perfusion defects by SPECT. In subjects with no RF, those with RF but no defects, and those with defects, the mean FMD was 18.88% +/- 2.31%, 7.85% +/- 1.66%, and 5.91% +/- 1.07%, respectively (P < .05). A significant correlation was found between the number of thallium defects and degree of FMD impairment (r = -0.40, P < .01). An FMD cutoff value of less than 7.5% had a 72.5% sensitivity and 73.1% specificity in predicting the presence of any thallium defects. After RF adjustment, FMD remained as the strongest predictor of scintigraphic CAD (odds ratio, 10.96; 95% confidence interval, 2.82-57.31). CONCLUSION: FMD independently predicts the presence and extent of scintigraphic CAD.     

Comparison between dipyridamole and adenosine as pharmacologic coronary vasodilators in detection of coronary artery disease with thallium 201 imaging

Background

Both dipyridamole and adenosine are widely used as pharmacologic stressors with ²⁰¹Tl imaging for detection of coronary artery disease. The purpose of this study was to compare dipyridamole and adenosine ²⁰¹Tl imaging directly in patients with angiographically proved coronary artery disease.

Methods and Results

Fifty-four patients were submitted to two planar ²⁰¹Tl studies: one with dipyridamole and the other with adenosine. The interval between the two studies varied from 2 to 7 days and the order was assigned randomly. Three standard planar views were obtained 10 minutes and 4 hours after the injection of 3.0 mCi ²⁰¹Tl. Administration of dipyridamole was as follows: 0.142 mg/kg/min during 4 minutes, followed by a slight exercise and ²⁰¹Tl injection. The infusion of adenosine was as follows: 0.140 mg/kg/min during 6 minutes with injection of ²⁰¹Tl after the third minute of infusion. Patients were asked to give their preference considering the number type, severity, and duration of side effects on a scale from 0 (worst) to 5 (best). Reading was done by two experienced observers. The heart was divided into three segments per view. The change in systolic blood pressure was-12±11 mm Hg for adenosine and-5±10 mm Hg for dipyridamole (p<0.001), and the change in heart rate was 18±10 beats/min for adenosine and 8±7 beats/min for dipyridamole (p<0.001). With regions of interest, ischemic/normal wall ratios were determined: 0.78 ± 0.06 for adenosine and 0.83±0.08 for dipyridamole (p<0.001). Adenosine detected 295 normal, 170 ischemic, and 21 scar segments, whereas dipyridamole detected 326, 135, and 25 segments, respectively. Patients preferred adenosine (4.3±1.0 for adenosine vs 3.8±1.5 for dipyridamole; p<0.04) mainly because of the short duration of side effects.

Conclusion

This study shows that the use of adenosine with ²⁰¹Tl imaging may have some advantages over dipyridamole.     

Detection of coronary artery disease using MR imaging with dipyridamole infusion

Exercise testing in the magnetic resonance (MR) scanner is difficult because of space restriction and movement artefact, which limit its use in the investigation of patients with suspected coronary artery disease. Pharmacological stress, however, can be used as a substitute for exercise. Therefore, a patient with angina underwent MR ventricular wall motion studies before and after intravenous dipyridamole. Reversible abnormal regional contraction of the myocardium was demonstrated and correlated with a reversible perfusion defect on subsequent thallium myocardial perfusion imaging and a blocked artery at coronary angiography. A clinically useful investigative procedure may be developed.     

Planar and tomographic imaging with technetium 99m-labeled tetrofosmin: Correlation with thallium 201 and coronary angiography

This study compared the results of planar and single-photon emission computed tomographic (SPECT) imaging with tetrofosmin with those of²⁰¹Tl and coronary angiography. In three normal volunteers the images were normal by both²⁰¹Tl and tetrofosmin (planar and SPECT). In 23 patients with coronary artery disease, the images were abnormal in 20 patients by SPECT tetrofosmin, in 19 by planar tetrofosmin, in 20 by SPECT thallium, and in 18 by planar thallium (difference not significant). Both planar and SPECT images were divided into five segments per patient. There were 58 perfusion defects by SPECT tetrofosmin, 50 by planar tetrofosmin (difference not significant), 47 by SPECT thallium, and 42 by planar thallium (difference not significant). Perfusion defects were reversible in 47 segments (36%) by SPECT tetrofosmin, 35 (27%) by planar tetrofosmin, 31 (24%) by SPECT thallium (p<0.05 vs SPECT tetrofosmin), and 31 (24%) by planar thallium (difference not significant). Among the 23 patients with coronary artery disease, 19 underwent coronary angiography. In these patients there were 32 diseased coronary arteries. Perfusion defects were present in 21 territories (66%) by SPECT tetrofosmin, 19 (59%) by planar tetrofosmin, 20 (63%) by SPECT thallium, and 18 (56%) by planar thallium. There was agreement between thallium and tetrofosmin in 108 of 130 segments (κ statistics=0.69±0.06). The images, especially with SPECT, are better with tetrofosmin than with²⁰¹Tl. Thus myocardial imaging with tetrofosmin provides results that are at least as good as those of²⁰¹Tl. Slightly more abnormal segments and more reversible defects are detected by tetrofosmin than by thallium imaging, especially with SPECT imaging. Supported in part by Mediphysics, Inc., Arlington Heights, Ill.     

Improved detection of coronary artery disease by estimated myocardial thallium uptake

Myocardial thallium uptake has been assessed at the time of thallium scanning in a group of 50 male patients undeergoing coronary arteriography and 10 young healthy volunteers. The net thallium dose injected was obtained by counting the dose prior to injection using the gamma camera and counting the syringe and IV cannula after injection. Significantly higher levels of myocardial thallium uptake were obtained in both the volunteers and patients with normal coronary anatomy (1.36%±0.32%, n=10 and 0.93%±0.26%, n=9, respectively) compared to patients with single, double or triple vessel coronary artery disease (0.63%±0.19%, n=11; 0.70%±0.20%, n=15; 0.67±0.18, n=15, respectively). Exercise tests were positive in 46% of patients with coronary artery disease with an overall predictive accuracy of 56%. Thallium scans were positive in 68% of patients at a specificity of 89%. If the range of myocardial thallium uptake from the patients with normal coronary arteries is used to define a lower limit of normal, then the sensitivity of the thallium scan with thallium uptake is 90% with a predictive accuracy of 90% in the detection of significant coronary artery disease in this group of patients. Thus, estimation of total % thallium uptake is a simple index which yields useful diagnostic clinical information.     

Improved detection of coronary artery disease by estimated myocardial thallium uptake

Myocardial thallium uptake has been assessed at the time of thallium scanning in a group of 50 male patients undergoing coronary arteriography and 10 young healthy volunteers. The net thallium dose injected was obtained by counting the dose prior to injection using the gamma camera and counting the syringe and IV cannula after injection. Significantly higher levels of myocardial thallium uptake were obtained in both the volunteers and patients with normal coronary anatomy (1.36% +/- 0.32%, n = 10 and 0.93% +/- 0.26%, n = 9, respectively) compared to patients with single, double or triple vessel coronary artery disease (0.63% +/- 0.19%, n = 11; 0.70% +/- 0.20%, n = 15; 0.67 +/- 0.18, n = 15, respectively). Exercise tests were positive in 46% of patients with coronary artery disease with an overall predictive accuracy of 56%. Thallium scans were positive in 68% of patients at a specificity of 89%. If the range of myocardial thallium uptake from the patients with normal coronary arteries is used to define a lower limit of normal, then the sensitivity of the thallium scan with thallium uptake is 90% with a predictive accuracy of 90% in the detection of significant coronary artery disease in this group of patients. Thus, estimation of total % thallium uptake is a simple index which yields useful diagnostic clinical information.     

Radionuclide imaging in coronary artery disease

The utility and limitations of radionuclide imaging in coronary artery disease are presented. Rationale for its usage is discussed in terms of pathophysiologic alterations of the heart and how the pharmacologic properties of these radiopharmaceutical agents can be used advantageously for assessment of such alterations.     

CT冠状动脉成像对男性吸烟冠心病患者斑块量化特征的评价

目的:探讨吸烟者和非吸烟者64排CT冠状动脉成像(coronary CT angiography,CCTA)斑块量化特征的区别。方法:拟诊冠心病行64排CCTA检查且证实有斑块者354例,比较吸烟组121例和非吸烟组233例的冠状动脉粥样硬化斑块的最大横截面积、体积、斑块负荷、重构指数和厚度长度比。结果:2组年龄、体质量指数、糖尿病、高血压、高血脂发病率差异均无统计学意义(均P0.05)。吸烟组斑块的最大横截面积、体积、斑块负荷、重构指数、厚度长度比分别为(7.03±3.51)mm2、(28.31±14.03)mm3、(49.52±16.07)%、1.29±0.36、0.35±0.13,均显著高于非吸烟组的(5.81±2.43)mm2、(13.67±5.00)mm3、(35.34±10.12)%、1.08±0.27、0.25±0.15(均P0.05)。结论 :64排CT能够有效测量斑块,吸烟患者的斑块体积、面积及斑块负荷、重构指数、厚度长度比均显著大于非吸烟患者。     

冠状动脉斑块量化特征预测急性冠状动脉综合征的价值

目的 :探讨64排CT冠状动脉成像斑块量化特征预测急性冠状动脉综合征(acute coronary syndrome,ACS)的价值。方法:随访830例经64排CT证实的冠状动脉斑块患者2~33个月,随访终点事件为ACS,经冠状动脉造影及心电图、负荷心肌缺血实验确定罪犯斑块,比较罪犯斑块与非罪犯斑块的最大横截面积、体积、斑块负荷、重构指数、厚度长度比,并绘制各指标预测ACS的ROC曲线,选取最佳截断点,计算灵敏度、特异度、阳性预测值、阴性预测值。结果:最终793例作为研究对象,其中,27例随访期发生ACS,检出罪犯斑块27个,非罪犯斑块59个。在未发生ACS的患者中随机选取100例作为对照组,共检出非罪犯斑块275个。2组非罪犯斑块共334个,罪犯斑块27个。罪犯斑块的最大横截面积(平均5.20 mm2)、体积(22.89 mm3)、斑块负荷(40.5%)、重构指数(1.32)、厚度长度比(0.33)均显著高于非罪犯斑块(分别为3.71 mm2、11.80 mm3、31.40%、1.04、0.25)(均P0.05),以上指标预测ACS的ROC曲线下面积分别为0.87、0.73、0.78、0.73、0.71。结论:64排CT显示的斑块最大横截面积、体积、斑块负荷、重构指数、厚度长度比在一定程度上能够预测ACS的发生。