Evaluation of Cardiovascular Disease in Patients with Diabetes Mellitus Using Myocardial Perfusion SPECT / 임상당뇨병

The number of patients with diabetes mellitus increases every year. Compared with the nondiabetic population, diabetic patients have an increased risk of developing cardiovascular disease and an increased risk for death from myocardial infarction or congestive heart failure. In diabetic patients, compared with people without diabetes, coronary artery disease is often silent, more advanced at diagnosis, and associated with an unfavorable prognosis. To maximize the effect of appropriate treatment, it is important to stratify patients according to their risk of future clinical events as early as possible. Commonly used noninvasive tests in coronary artery disease include exercise ECG, stress echocardiography, coronary CT and MRI, and stress myocardial perfusion SPECT. The generally used radioisotopes for myocardial perfusion SPECT are 201Tl and technetium-based agents such as 99mTc-MIBI and 99mTc-tetrofosmin. Stress myocardial perfusion SPECT provides information on perfusion and function including wall motion, ejection fraction, and myocardial viability. Also, the hemodynamic significance of coronary artery stenosis can be assessed. Stress myocardial perfusion SPECT provides quantifiable data and identifies patients with diabetes who are at low and high risk for future adverse cardiovascular events. These risk stratification data are useful in planning appropriate treatment strategies for patients with diabetes.

Current Status and Future Perspective of Nuclear Cardiology / 핵의학분자영상

Coronary artery disease is on the rise over the world. Myocardial perfusion SPECT is a well established technique to detect coronary artery disease and to assess left ventricular function. In addition, it has the unique ability to predict the prognosis of the patients. Moreover, the application of ECG-gated images provided the quantitatve data and improved the accuracy. This approach has been proved to be cost-effective and suitable for the emerging economies as well as developed countries. However, the utilization of nuclear cardiology procedures vary widely considering the different countries and region of the world. Korea exits 2-3 times less utilization than Japan, and 20 times than the United States. Recently, with the emerging of new technology, namely cardiac CT, cardiac MR and stress echocardiography, the clinical usefulness of nuclear cardiology has been called in question and its role has been redefined. For the proper promotion of nuclear cardiology, special educations should be conducted since the nuclear cardiology has the contact points between nuclear medicine and cardiology. Several innovations are in horizon which will impact the diagnostic accuracy as well as imaging time and cost savings. Development of new tracers, gamma camera technology and hybrid systems will open the new avenue in cardiac imaging. The future of nuclear cardiology based on molecular imaging is very exciting. The newly defined biologic targets involving atherosclerosis and vascular vulnerability will allow the answers for the key clinical questions. Hybrid techniques including SPECT/CT indicate the direction in which clinical nuclear cardiology may be headed in the immediate future. To what extent nuclear cardiology will be passively absorbed by other modalities, or will actively incorporate other modalities, is up to the present and next generation of nuclear cardiologists.

Value of 99mTc-NOET and 99mTc-MIBI GSPECT in the diagnosis, treatment and prognosis of coronary artery disease / 中国介入影像与治疗学

Objective To predict the value of 99mTc-NOET gated myocardial perfusion SPECT imaging (GSPECT) in detecting coronary artery disease (CAD) and the theraputic effect of percutaneous transluminal coronary angioplasty (PTCA). Methods First, 70 patients suspected of CAD underwent 99mTc-NOET (group NOET1) or 99mTc-MIBI (group MIBI1) rest GSPECT and coronary angiography (CAG) was performed within 1 week after GSPECT. Second, 53 patients with CAD underwent 99mTc-NOET (group NOET2) or 99mTc-MIBI (group MIBI2) rest GSPECT before and 1, 3 and 6 months after PTCA and/or stent treatment. Results The sensitivity and specificity had no difference between group NOET1 and MIBI1 in detecting CAD. Comparison of group NOET 2 and MIBI 2: ①59.29%, 64.60% and 66.37% of the abnormal myocardial segment was improved in group NOET2.1, 3 and 6 months after PTCA, while 20.35%, 55.10% and 61.22% respectively in group MIBI2;②There was no difference of the incidence of clinical events and the myocardial function parameters before and after PTCA in group NOET2 and MIBI2. Conclusion Compared with 99mTc-MIBI, 99mTc-NOET has a greater clinical value for CAD diagnosis, PTCA efficacy and observation of the clinical events incidence.

Consideration of Normal Variation of Perfusion Measurements in the Quantitative Analysis of Myocardial Perfusion SPECT: Usefulness in Assessment of Viable Myocardium / 핵의학분자영상

PURPOSE: Although automatic quantification software of myocardial perfusion SPECT provides highly objective and reproducible quantitative measurements, there is still some limitation in the direct use of quantitative measurements. In this study we derived parameters using normal variation of perfusion measurements, and tried to test the usefulness of these parameters. Materials and METHODS: In order to calculate normal variation of perfusion measurements on myocardial perfusion SPECT, 55 patients (M:F=28:27) of low-likelihood for coronary artery disease were enrolled and (201)Tl rest / (99m)Tc-MIBI stress SPECT studies were performed. Using 20-segment model, mean (m) and standard deviation (SD) of perfusion were calculated in each segment. As a myocardial viability assessment group, another 48 patients with known coronary artery disease, who underwent coronary artery bypass graft surgery (CABG) were enrolled. (201)Tl rest / (99m)Tc-MIBI stress / (201)Tl 24-hr delayed SPECT was performed before CABG and SPECT was followed up 3 months after CABG. From the preoperative 24-hr delayed SPECT, Q(delay) (perfusion measurement), delta(delay) (Q(delay)-m) and Z(delay) ((Q(delay)-m)/SD) were defined and diagnostic performances of them for myocardial viability were evaluated using area under curve (AUC) on receiver operating characteristic (ROC) curve analysis. RESULTS: Segmental perfusion measurements showed considerable normal variations among segments. In men, the lowest segmental perfusion measurement was 51.8+/-6.5 and the highest segmental perfusion was 87.0+/-5.9, and they are 58.7+/-8.1 and 87.3+/-6.0, respectively in women. In the viability assessment, Q(delay) showed AUC of 0.633, while those for delta(delay) and Z(delay) were 0.735 and 0.716, respectively. The AUCs of delta(delay) and Z(delay) were significantly higher than that of Q(delay) (p=0.001 and 0.018, respectively). The diagnostic performance of delta(delay), which showed highest AUC, was 85% of sensitivity and 53% of specificity at the optimal cutoff of -24.7. CONCLUSION: On automatic quantification of myocardial perfusion SPECT, the normal variation of perfusion measurements were considerable among segments. In the viability assessment, the parameters considering normal variation showed better diagnostic performance than the direct perfusion measurement. This study suggests that consideration of normal variation is important in the analysis of measurements on quantitative myocardial perfusion SPECT.

Analysis of Myocardial Function Using Gated Myocardial SPECT : Comparison of QGS, 4D-MSPECT Software and Echocardiography / 핵의학분자영상

PURPOSE: Gated myocardial perfusion SPECT provides not only myocardial perfusion status but also various functional parameters of left ventricle. We compared left ventricular ejection fraction, end-diastolic volume, LV mass by cardiac SPECT using Quantitative Gated SPECT (QGS), 4D-MSPECT software and standard 2D-echocardiography. MATERIALS AND METHODS: One hundred fourteen patients (male 51, female 63; 29-85 years old, mean 61.3+/-13.3 years old) with normal perfusion status on Tc-99m tetrofosmin gated myocardial perfusion SPECT were analyzed retrospectively. Ejection fraction (LVEF), End-diastolic volume (LVED), LV mass (LVM) were calculated using QGS, 4D-MSPECT, and LVEF, LVM using 2D-echocardiography. Statistical analysis including Bland-Altman plot was performed using MedCalc(R) (MedCalc software, Mariakerke, Belgium). RESULTS: The correlation of LVEF between methods was good: 0.95/0.96 (stress/rest) between QGS and 4D-MSPECT, 0.79 between QGS and echocardiography, 0.79 between 4D-MSPECT and echocardiography (p<0.001). Using Bland-Altman plot, the 95% confidence interval of agreement between QGS and 4D-MSPECT ranged from -12.7% to 7.3% / from -12.2% to 6.5% (stress/rest). The agreement between QGS and echocardiography, 4D-MSPECT and echocardiography ranged from -17.4% to 24.0%, and -14.8% to 27.0% respectively. The correlation of LVM between methods was also good: 0.95 between QGS and 4D-MSPECT, 0.76 between QGS and echocardiography, 0.73 between 4D-MSPECT and echocardiography (p<0.001). The 95% confidence interval of agreement between QGS and 4D-MSPECT ranged from -33.8 g to 14.1 g (stress/rest). The 95% confidence interval of agreement between QGS and echocardiography, 4D-MSPECT and echocardiography ranged from -148.7 g to 21.8. g, and -142.8 g to 35.5 g, respectively. CONCLUSION: There was a good correlation for LVEF, LVED, LVM among methods (QGS, 4D-MSPECT, echocardiography), but the variance between methods was big. Therefore, the functional parameters by each method cannot be used interchangeably.

Myocardial Tracer Uptake in SPECT Images after Direct Intracoronary Injection Of Tl-201: Comparison with Stress-Reinjection Images / 핵의학분자영상

PURPOSE: To investigate the feasibility of Tl-201 SPECT with intracoronary injection (IC-I) in the detection of viable myocardium, we have performed SPECT imaging after direct intracoronary injection of Tl-201 and images were compared with those of stress-reinjection (Re-I) SPECT. METHODS: Fourteen coronary artery disease patients (male 11, mean age 54 years) who had myocardial infarction or demonstrated left ventricular wall motion abnormality on echocardiography were enrolled. Three mCi of Tl-201 was injected into both coronary arteries during angiography and images were acquired between 6- and 24-hour after injection. Reinjection imaging with 1 mCi of Tl-201 was performed at 4-hour after adenosine stress imaging with 3 mCi of Tl-201. Images were interpreted according to 4-grade visual scoring system (grade 0-3). Segments with mild to moderated uptake (< or=grade 1), and upgraded more than one score with reinjection, and were defined as viable myocardium. RESULTS: Image quality was poor in two cases with IC-I. Numbers of non-viable segments were 60 (23.8%) with IC-I, and 38 (15.1%) with Re-I, respectively. Overall agreement for perfusion grade per myocardial segment in each IC-I and Re-I was 76.5%. Overall agreement for viable segment between IC-I and Re-I was 90.5%. Only one out of 38 segments interpreted as non-viable with Re-I were interpretated as viable with IC-I. And 23 out of 214 segments interpreted as viable with Re-I were interpreted as non-viable with IC-I. CONCLUSION: Intracoronary Tl-201 SPECT seemed to be not advantageous over stress-rest reinjection imaging in the assessment of myocardial viability, mainly due to low count statistics at 6-hour or 24-hour delayed time points. The feasibility of intracoronary Tl-201 SPECT is considered to be limited.

Myocardial Tracer Uptake in SPECT Images after Direct Intracoronary Injection Of Tl-201: Comparison with Stress-Reinjection Images / 핵의학분자영상

PURPOSE: To investigate the feasibility of Tl-201 SPECT with intracoronary injection (IC-I) in the detection of viable myocardium, we have performed SPECT imaging after direct intracoronary injection of Tl-201 and images were compared with those of stress-reinjection (Re-I) SPECT. METHODS: Fourteen coronary artery disease patients (male 11, mean age 54 years) who had myocardial infarction or demonstrated left ventricular wall motion abnormality on echocardiography were enrolled. Three mCi of Tl-201 was injected into both coronary arteries during angiography and images were acquired between 6- and 24-hour after injection. Reinjection imaging with 1 mCi of Tl-201 was performed at 4-hour after adenosine stress imaging with 3 mCi of Tl-201. Images were interpreted according to 4-grade visual scoring system (grade 0-3). Segments with mild to moderated uptake (< or=grade 1), and upgraded more than one score with reinjection, and were defined as viable myocardium. RESULTS: Image quality was poor in two cases with IC-I. Numbers of non-viable segments were 60 (23.8%) with IC-I, and 38 (15.1%) with Re-I, respectively. Overall agreement for perfusion grade per myocardial segment in each IC-I and Re-I was 76.5%. Overall agreement for viable segment between IC-I and Re-I was 90.5%. Only one out of 38 segments interpreted as non-viable with Re-I were interpretated as viable with IC-I. And 23 out of 214 segments interpreted as viable with Re-I were interpreted as non-viable with IC-I. CONCLUSION: Intracoronary Tl-201 SPECT seemed to be not advantageous over stress-rest reinjection imaging in the assessment of myocardial viability, mainly due to low count statistics at 6-hour or 24-hour delayed time points. The feasibility of intracoronary Tl-201 SPECT is considered to be limited.

Diagnosis of Coronary Artery Disease using Myocardial Perfusion SPECT in Patients with Diabetes Mellitus: Analysis of Risk Factors / 핵의학분자영상

PURPOSE: Diabetes mellitus (DM) is a critical disease with higher rates of cardiovascular morbidity and mortality due to myocardial ischemia and infarction. There is growing interest in how to determine high-risk patients who are candidates for screening testing. This study was performed to evaluate the incidence of coronary artery disease (CAD) in diabetic patients detected by Tc-99m MIBI myocardial perfusion SPECT (MPS) and to assess risk factors of CAD and cardiac hard events. SUBJECTS AND METHODS: 203 diabetic patients (64 male, mean age 64.1+/-9.0 years) who underwent MPS were included between Jan 2000 and July 2004. Cardiac death and nonfatal myocardial infarction (MI) were considered as hard events, and coronary angioplasty and bypass surgery >60 days after testing were considered as soft events. The mean follow-up period was 36+/-18 months. Patients underwent exercise (n=6) or adenosine stress (n=197) myocardial perfusion SPECT. RESULTS: Perfusion defects on MPS were detected in 28.6% (58/203) of the patients. There was no cardiac death but 11 hard events were observed. The annual cardiac hard event rate was 1.1%. In univariate analysis of clinical factors, typical anginal pain, peripheral vascular disease, peripheral polyneuropathy, and resting ECG abnormality were significantly associated with the ocurrence of hard events. Anginal pain, peripheral vascular disease, and resting ECG abnormality remained independent predictors of nonfatal MIs with multivariate analysis. Abnormal SPECT results were significantly associated with high prevalence of hard events but not independent predictors on uni- and multivariate analyses. CONCLUSION: Patients who were male, had longer diabetes duration (especially over 20 years), peripheral vascular disease, peripheral polyneuropathy, or resting ECG abnormality had higher incidence of CAD. Among clinical factors in diabetic patients, typical angina, peripheral vascular disease, peripheral polyneuropathy, and resting ECG abnormality were strong predictors of hard events.

Abnormal Perfusion on Myocardial Perfusion SPECT in Patients with Wolff-Parkinson-White Syndrome / 대한핵의학회잡지

PURPOSE: Abnormal myocardial perfusion may be caused by ventricular preexcitation, but its location, extent, severity and correlation with accessory pathway (AP) are not established. We evaluated perfusion patterns on myocardial perfusion SPECT and location of AP in patients with WPW (Wolff-Parkinson-White) syndrome. MATERIALS AND METHODS: Adenosine Tc-99m MIBI or Tl-201 myocardial perfusion SPECT was performed in 11 patients with WPW syndrome. Perfusion defects (PD) were compared to AP location based on ECG with Fitzpatrick's algorithm or electrophysiologic study and radiofrequency catheter ablation. RESULTS: Patients had atypical chest discomfort or no symptom. Risk of coronary artery disease (CAD) was below 0.1 in 11 patients using the nomogram to estimate the probability of CAD. Coronary angiography was performed in 4 patients (mid-LAD 50% in one, normal in others). In 4 patients, AP localization was done by electrophysiologic study and radiofrequency catheter ablation (RFCA). Small to large extent (11.0 +/- 8.5%, range: 3~35%) and mild to moderate severity (-71 +/- 42.7%, range: -217~-39%) of reversible (n=9) or fixed (n=1) perfusion defects were noted. One patient with right free wall (right lateral) AP showed normal. PD locations were variable following the location of AP. One patient with left lateral wall AP was followed 6 weeks after RFCA and showed significantly decreased PD on SPECT with successful ablation. CONCLUSION: Myocardial perfusion defect showed variable extent, severity and location in patients with WPW syndrome. Abnormal perfusion defect showed in most of all patients, but it did not seem to be correlated specifically with location of accessory pathway and coronary artery disease. Therefore myocardial perfusion SPECT should be interpreted carefully in patients with WPW syndrome.

The clinical significance of the differernce in left ventricular ejection fraction between rest and stress on gated myocardial perfusion SPECT / 대한내과학회지

BACKGROUND: Gated myocardial perfusion SPECT improved diagnostic accuracy of coronary artery disease and enabled us to observe motion and thickening of myocardial walls, ejection fraction as well as myocardial perfusion. Many studies suggested that there was a decrease of left ventricular ejection fraction (LVEF) at post-stress compared with that at rest gated myocardial perfusion SPECT (stunning). The objective of this retrospective study is to evaluate the clinical significance of the decrease of LVEF at post-stress gated myocardial perfusion SPECT by correlating with coronary angiographic finding. METHODS: Authors selected 41 patients who underwent exercise electrocardiography and gated myocardial perfusion SPECT between May, 2001 and May, 2002. The patients underwent coronary angiography within 6 months. The patients were divided into two groups, 16 patients in whom post-stress LVEF was >or=5% lower than rest (stunning group) and 25 patients in whom LVEF was not >or=5% lower than rest (non-stunning group). RESULTS: The number of patients with hyperlipidemia was higher in stunning group than in non-stunning group (50% vs 4%, p=0.001). The number of patients with angiographic stenoses >90% was significantly higher in stunning group than in non-stunning group (75% vs 28%, p=0.04). The number of patients with multi-vessel disease was also significantly higher in stunning group than in non-stunning group (75% vs 36%, p=0.015). CONCLUSION: The patients who had a decreased LVEF after stress (stunning) showed more severe coronary artery stenosis. This finding suggests that stunning may be an important additional indicator of underlying myocardial ischemia.

Accuracy of Ventricular Volume and Ejection Fraction Measured by Gated Tl-201 Perfusion Single Photon Emission Tomography / 대한핵의학회잡지

Electrocardiogram-gated single photon emission computed tomography (SPECT) provides valuable information in the assessment of both myocardial perfusion and ventricular function. Tl-201 is a suboptimal isotope for gating. Tl-201 images are more blurred compared with Tc-99m tracers due to the increased amount of scattered photons and use of a smooth filter. The average myocardial count densities are approximately one-half those of conventional technetium tracers. However, Tl-201 is still widely used because of its well-established utility for assessing myocardial perfusion, viability and risk stratification. Gated SPECT with Tl-201 enables us to assess both post-stress and rest left ventricular volume and function. Previous studies with gated Tl-201 SPECT measurements of ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV) have shown high correlation with first-pass radionuclide angiography, gated blood pool scan, Tc-99m-MIBI gated SPECT, contrast ventriculography, echocardiography, and 3-dimensional magnetic resonance imaging. However, problems related to these studies include few agreement data of EDV and ESV, use of a reference method that is likely to have the same systemic errors (gated Tc-99m-MIBI SPECT), and other technical factors related to the count density of gated SPECT. With optimization of gated imaging protocols and more validation studies, gated Tl-201 SPECT would be an accurate method to provide perfusion and function information in patients with coronary artery disease.

The Effect of Attenuation Correction with CT on the Interpretation of Myocardial Perfusion SPECT: in Patients with Normal Coronary Angiogram / 대한핵의학회잡지

PURPOSE: There has been many reports for the effect of attenuation correction on myocardial perfusion SPECT. We studied the effect of attenuation correction with CT (computed tomography) in patients with normal coronary angiography. MATERIALS AND METHODS: Fifteen patients with normal coronary artery on angiography and low likelihood of coronary artery disease were enrolled in this study (male: 6, female: 9, mean age: 58+/-8 year). Myocardial perfusion SPECT was done with Millennium VG with Hawkeye device (GE, SPECT/CT camera). A visual analysis and polar map quantification (Emory tool box) was performed. In quantitative analysis, percent uptake of each myocardial wall on polar map (percent of maximal uptake) was compared between non-corrected (NC) and corrected (AC) images. RESULTS: Visual analysis showed AC images led to an increase of uptake in the inferior wall, but decrease of uptake in the anterior wall, apex and septum. Liver activity is also increased in AC images. In quantitative analysis, the percent uptake is decreased in the anterior wall, apex and septum, but increased in the inferior wall. It is helpful to interpret the images in the inferior wall after AC, but difficult in the apex and anterior wall after AC. CONCLUSION: AC is helpful in the inferior wall. But in the apex or anterior wall, AC must be carefully applied to normal perfused myocardium.

Reference Values of Functional Parameters in Gated Myocardial Perfusion SPECT: Comparison with QGS (R) and 4DM (R) Program / 대한핵의학회잡지

PURPOSE: The objectives of this study were - First, to determine the normal range of left ventricular end diastolic volume (EDV), end systolic volume (ESV) and ejection fraction (EF) from gated myocardial perfusion SPECT for Quantitative Gated SPECT (QGS) and 4D-MSPECT (4DM), respectively. Second, to evaluate the relationships between values produced by both software packages. MATERIALS AND METHODS: Tc-99m MIBI gated myocardial perfusion SPECT were performed for 77 patients (mean age: 49.6+/-13.7y, n=37 (M), 40 (F) ) with a low likelihood ( 0.05). In 4DM, the mean EDV, ESV and EF for all patients were 89.1+/-26.4ml, 29.1+/-12.8ml and 68.5+/-6.7% at stress test. Most cases in 4DM, there was no significant difference statistically between stress and rest test (p> 0.05). But statistically significant difference was found in EF (68.5+/-6.7% at stress vs 70.9+/-8.0% at rest, p< 0.05). Correlation coefficients between the methods for EDV, ESV and EF were comparatively high (0.95, 0.93, 0.71 at stress test and 0.95, 0.90, 0.69 at rest test, respectively). However, Bland-Altman plots showed a large range of the limit value of agreement for EDV, ESV and EF between both methods (-30ml 10ml, -12ml 8ml, -14% 11% at stress test and -32ml 5ml, -13ml 13ml, -18% 12% at rest test). CONCLUSION: We found the normal ranges of EDV, ESV and EF for patients with a low likelihood of CAD in both methods. We expect these values will be a good reference to interpret gated myocardial perfusion SPECT. Although good correlation was observed between both methods, they should not be used interchangeably. Therefore, when both programs are used at the same site, it will be important to apply normal limits specific to each method.

Characteristic Findings of Exercise ECG Test, Perfusion SPECT and Coronary Angiography in Patients with Exercise Induced Myocardial Stunning / 대한핵의학회잡지

PURPOSE: Transient wall motion abnormality and contractile dysfunction of the left ventricle (LV) can be observed in patients with coronary artery disease due to post-stress myocardial stunning. To understand clinical characteristics of stress induced LV dysfunction, we have compared the findings of exercise stress test, myocardial perfusion SPECT and coronary angiography between subjects with and without post-stress LV dysfunction. MATERIALS AND METHODS: Among subjects who underwent exercise stress test, myocardial perfusion SPECT and coronary angiography within a month of interval, we enrolled 36 patients with post-stress LV ejection fraction (LVEF) was > or=5% lower than rest (stunning group) and 16 patients with difference of post-stress and rest LVEF was lesser than 1% (non-stunning group) for this study. Treadmill exercise stress gated myocardial perfusion SPECT was performed with dual head SPECT camera using 740 MBq Tc-99m MIBI and coronary angiography was also performed by conventional Judkins method. RESULTS: Stunning group had a significantly higher incidence of hypercholesterolemia than non-stunning group (45.5 vs. 7.1%, p=0.01). Stunning group also had higher incidence of diabetes mellitus and lower incidence of hypertension, but these were not statistically significant. Stunning group had larger and more severe perfusion defect in stress perfusion myocardial SPECT than non-stunning group (extent 18.2 vs. 9.2%, p=0.029; severity 13.5 vs. 6.9, p=0.040). Stunning group also had higher degree of reversibility of perfusion defect, higher incidence of positive exercise stress test and higher incidence of having severe stenosis (80~99%) in coronary angiography than non-stunning group, but these were not statistically significant. In stunning group, all of 4 patients without perfusion defect had significant coronary artery stenosis and had received revascularization treatment. CONCLUSION: Patients with post-stress LV dysfunction had larger and more severe perfusion defect and severe coronary artery stenosis than patients without post-stress LV dysfunction. All of the patients without perfusion defect in stunning group had significant coronary artery stenosis and needed revascularization. Therefore, we suggest that invasive diagnostic procedures and therapeutic interventions might be needed in patients with post-stress LV dysfunction.

Comparison of Regional Myocardial Perfusion, Left Ventricular Volume and Ejection Fraction between 8- and 16-Frame Gated SPECT / 대한핵의학회잡지

No abstract available.

Prediction of Salvaged Myocardium in Patients with Acute Myocardial Infarction after Primary Percutaneous Coronary Angioplasty using early Thallium-201 Redistribution Myocardial Perfusion Imaging / 대한핵의학회잡지

PURPOSE: The amount of salvaged myocardium is an important prognostic factor in patients with acute myocardial infarction (MI). We investigated if early Tl-201 SPECT imaging could be used to predict the salvaged myocardium and functional recovery in acute MI after primary PTCA. MATERIALS AND METHODS: In 36 patients with first acute MI treated with primary PTCA, serial echocardiography and Tl-201 SPECT imaging (5.8+/-2.1 days after PTCA) were performed. Regional wall motion and perfusion were quantified with on 16-segment myocardial model with 5-point and 4-point scaling system, respectively. RESULTS: Wall motion was improved in 78 of the 212 dyssynergic segments on 1 month follow-up echocardiography and 97 on 7 months follow-up echocardiography, which were proved to be salvaged myocardium. The areas under receiver operating characteristic curves of Tl-201 perfusion score for detecting salvaged myocardial segments were 0.79 for 1 month follow-up and 0.83 for 7 months follow-up. The sensitivity and specificity of Tl-201 redistribution images with optimum cutoff of 40% of peak thallium activity for detecting salvaged myocardium were 84.6% and 55.2% for 1 month follow-up, and 87.6% and 64.3% for 7 months follow-up, respectively. There was a linear relationship between the percentage of peak thallium activity on early redistribution imaging and the likelihood of segmental functional improvement 7 months after reperfusion. CONCLUSION: Tl-201 myocardial perfusion SPECT imaging performed early within 10 days after reperfusion can be used to predict the salvaged myocardium and functional recovery with high sensitivity during the 7 months following primary PTCA in patients with acute MI.

Dipyridamole Induced Transient Left Ventricular Dysfunction in the Tl-201 Gated Myocardial SPECT / 대한핵의학회잡지

PURPOSE: Recently the occurrence of dipyridamole stress-induced short term stunning was proven and it is reported that Bland Altman analysis by repeated acquisition Tl-201 gated myocardial SPECT (gSPECT) revealed the 95% limit of agreement for LVEF was 10.3 %. The purpose of this study was to investigate the clinical value of dipyridamole induced transient LV dysfunction on Tl-201 gSPECT. MATERIALS AND METHODS: Total 93 patients were included and coronary angiography was performed in all patients less than 2 month from gSPECT. The patients with myocardial infarction were excluded. All patients underwent both dipyridamole stress and 4-h redistribution Tl-201 gSPECT. Forty nine patients of total 93 showed normal coronary arteries (Group 1) and the remaining 44 patients had coronary artery disease (Group 2). We compared LV EF, EDV and ESV during post-stress and 4-h redistribution period calculated by gSPECT using quantitative gated SPECT software and the incidence of dipyridamole induced transient LV dysfunction between group 1 and 2. The criteria for transient LV dysfunction was defined more decrease > or =11% of LVEF during post-stress than 4-h redistribution according to previous reported Bland Altman analysis. RESULTS: During post-stress and 4-h redistribution average of 3.1% increment in LVEF, 6.6% increment in LVEDV and 0.7% decrement in LVESV were shown after stress in Group 1, whereas 4.1% decrement, 9.7% increment and 7.2% increment in Group 2 respectively. Dipyridamole induced transient LV dysfunction was only detected in group 2 (18.2%) and not in group 1. It was more frequently observed in triple vessel disease and left main disease (31.8%, N=22) than one and two vessel disease (4.5%, N=22). CONCLUSION: As with Tc-99m myocardial agent post-stress LV dysfunction was observed in dipyridamole Tl-201 gSPECT. It was only detected in CAD and more frequently occurred in multivessel disease. Thus this finding seems to provide additional information in the diagnosis of coronary artery disease and prediction of prognosis.

Cost-effectiveness of Myocardial Perfusion SPECT for Diagnosis of Coronary Artery Disease in Korea: Comparison with Exercise ECG and Coronary Angiography / 대한핵의학회잡지

PURPOSE: Cost-effectiveness of myocardial SPECT f'or the diagniosis of coronary artery disease was investigated considering the present and amended costs of myocardial SPECT and exercise ECG in Korea. MATERIALS AND METHODS: Four diagnostic tactics such as 1) coronary angiography (CAG) after exercise ECG, 2) CAG after myocardial SPECT, 3) direct CAG, and 4) CAG after myocardial SPECT following exercise ECG were chosen. Costs were calculated using the present costs of various tests and effects represented by Quality Adjusted Life Year (QALY) were estimated. Difference of QALY (deltaQALY) was calculated by subtracting QALY of diagnosed/treated cases from QALY of undiagnosed cases, Cost/delta QALY was calculated and compared between four different tactics according to pre-test probability, RESULTS: When pre-test probability was equal to or larger than 0.6, direct CAG was the most cost-effective. When pre-test probability was between 0.2 and 0.6, CAG after myocardial SPECT following exercise ECG was the most cost-effective. CAG after myocardial SPECT was the second most cost-effective. Cost-effectiveness was similar when the costs of exercise ECG were doubled or quadrupled. CAG after exercise ECG was always the least cost-effective, CONCLUSION: Myocardial SPECT with or without preceding exercise ECG was the most cost-effective method to diagnose coronary artery disease in the present or expected amended cost system.

Left Ventricular Ejection Fraetion Determmed by Cated Tl-201 Perfusion SPECT and Quantitative Software / 대한핵의학회잡지

PURPOSE: We compared estimates of ejection fraction (EF) determined by gated Tl-201 perfusion SPECT (g-TI-SPECT) with those by gated blood pool (GBP) scan. MATERIALS AND METHODS: Eighteen subjects underwent g-TI-SPECT and GBP scan. After reconstruction of g-TI-SPECT, we measured EF with Cedars software. The comparison of the EF with g-TI-SPECT and GHP scan was assessed by correlation analysis and Bland Altman plot. RESULTS: The estimates of EF were significantly different (p<0.05) with g-TI-SPECT (40%+/-14%) and GBP scan (43%+/-14%). There was an excellent correlation of EF between e-TI-SPECT and GBP scan (r=0.94, p<0.001). The mean difference of EF between GRP scan and g-TI- SPECT was +3.2%, Ninety-five percent limits of agreement were +9,8%. EF between g-TI-SPECT and GBP scan were in poor agreement. CONCLUSION: The estimates of EF by g-TI-SPECT was well correlated with those by GBP scan. However, EF of g-TI-SPECT doesn't agree with EF of GBP scan. EF of g-TI-SPECT cant be used interchangeably with EF of GBP scan.

Assessment of Ischemic Heart Disease in Patients with Stroke Using Myocardial Perfusion SPECT: Preliminary report

OBJECTIVE: The purpose of this study was to investigate cardiac events and ischemic heart disease in patients with stroke. The patients were studied by myocardial perfusion SPECT (single photon emission computed tomography) and evaluated the functional outcome after rehabilitation. METHOD: Subjects were 31 patients with stroke who had myocardial perfusion SPECT for abnormal findings on the electrocardiography. There were eighteen patients with ischemic stroke: 12 patients with hemorrhagic stroke; and one patient with both ischemic and hemorrhagic stroke. We screened the patients for the hypertension, diabetes mellitus, previous history of stroke, smoking, alcohol use, and hyperlipidemia as risk factors of ischemic stroke and ischemic heart disease. For the dichotomous classification of positive or negative myocardial perfusion SPECT, reversible and persistent defects were considered as positive. We investigated the functional outcomes on the admission and discharge using the Modified Rankin scale (MRS) and functional independence measure (FIM) scores. Cardiac events in patients with stroke were investigated. RESULTS: The myocardial perfusion SPECT was positive in 10 of 18 patients (55.6%) with ischemic stroke. Four out of ten patients with ischemic stroke had cardiac events. Positive myocardial perfusion SPECT was significantly associated with cardiac events (p0.05). CONCLUSION: The results of our study suggested that myocardial perfusion SPECT is useful in the screening of silent ischemic heart disease in patients with ischemic stroke and to assess future cardiac events of them.