• The Korean Journal of Nuclear Medicine
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• v.33 no.3
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• pp.273-281
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• 1999

Purpose: We investigated whether myocardial SPECT had additional usefulness to clinical, functional or surgical indices for the preoperative evaluation of cardiac risks in noncardiac surgery. Materials and Methods: 118 patients (M: F=66: 52, $62.7{\pm}10.5$ years) were studied retrospectively. Eighteen underwent vascular surgeries and 100 nonvascular surgeries. Rest T1-20l/ stress Tc-99m-MIBI SPECT was performed before operation and cardiac events (hard event: cardiac death and myocardial infarction; soft event: ischemic ECG change, congestive heart failure and unstable angina) were surveyed through perioperative periods ($14.6{\pm}5.6$ days). Clinical risk indices, functional capacity, surgery procedures and SPECT findings were tested for their predictive values of perioperative cardiac events. Results: Perioperative cardiac events occurred in 25 patients (3 hard events and 22 soft events). Clinical risk indices, surgical procedure risks and SPECT findings but functional capacity were predictive of cardiac events. Reversible perfusion decrease was a better predictor than persistent decrease, Multivariate analysis sorted out surgical procedure risk (p=0.0018) and SPECT findings (p=0.0001) as significant risk factors. SPECT could re-stratify perioperative cardiac risks in patients ranked with surgical procedures. Conclusion : We conclude that myocardial SPECT provides additional predictive value to surgical type risks as well as clinical indexes or functional capacity for the prediction of preoperative cardiac events in noncardiac surgery.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.4
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• pp.285-291
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• 2008

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 $^{201}TI$ 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. $^{201}TI$ rest/$^{99m}Tc$-MIBI stress / $^{201}TI$ 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 $51.8{\pm}6.5$ and the highest segmental perfusion was $87.0{\pm}5.9$, and they are $58.7{\pm}8.1$ and $87.3{\pm}6.0$, 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.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.49-56
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• 2012

Purpose : Gated myocardial perfusion SPECT provides not only myocardial perfusion status, but various functional parameters of left ventricle (LV). The purpose of this study was to analyze ejection fraction (EF) for correlation and difference between $^{201}Tl$ gated myocardial perfusion SPECT and echocardiography depending on extent of perfusion defect, gender and LV volumes. Materials and Methods : From April 2011 to May 2012, we analyzed 291 patients (male:female =165:126; mean: $64.6{\pm}10.8$ years) who were examined both $^{201}Tl$ gated myocardial perfusion SPECT and echocardiography at less than 7 days apart in our hospital. 101 patients showed perfusion defect and the rest of the people without any defect. We applied automatic analysis (Quantitative gated SPECT, QGS), and calculated EF, End-diastolic volume (EDV) and End-systolic volume (ESV) from Stress (G-Stress) and Rest (G-Rest) studies. And we analyzed the correlation and difference for EF between $^{201}Tl$ gated SPECT and echocardiography. Results : The correlation of LVEF among G-Stress, G-Rest and echocardiography was quite a good (G-Stress vs. G-Rest: r=0.909, G-Stress vs. echocardiography: r=0.833, G-Rest vs. echocardiography: r=0.825). And there were significant differences in EDV, ESV and EF in total patients (p<0.01). The normal group showed significant difference in EF (p<0.01) and the group with perfusion defect also demonstrated significant difference (a group with reversible defect: p<0.01, fixed defect: p<0.01) depending on extent of perfusion defect. We analyzed difference in normal group by gender. In normal group, there was no significant difference (p>0.05) in EF from men. However, there was a significant difference (p<0.01) from women. When we classified two groups by average size of EDV in Korean women, there was no significant difference in a group of above average size of EDV (p>0.05). Conclusion : When compared among Stress and Rest of $^{201}Tl$ gated SPECT and echocardiography, we confirmed that there was a good correlation for LVEF. But there were significant differences among three studies. And extent of perfusion defect, gender and LV volumes are independent determinants of the accuracy of LVEF. So, it is hard to compare and interchange quantitative indices among modalities. We should take additional researches to prove results of our study.

• Journal of Chest Surgery
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• v.30 no.11
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• pp.1083-1091
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• 1997

This study was purposed to assess the result of coronary artery bypass graft surgery by analyzing and comparing the pre and postoperative myocardial perfusion state quantitatively by using myocardial SPECT. Twenty patients who received coronary artery bypass graft surgery since 1993 underwent both preoperative and postoperative myocardial SPECT and the result were analyzed. The mean age was 56.4$\pm$9.0 years, and the patients were composed of thirteen males and seven females. For quantitative analysis, we used polar maps of SPECT generated by Cedars-Sin i Medical Center program and we calculated perfusion scores, ischemic myocardial area ratios and reperfusion scores from polar maps. Preoperative mean stressfrest perfusion score was 7.3$\pm$ 1.117.7$\pm$ 1.0 and postoperative score was 8.1 $\pm$ 1 118.3$\pm$ 1.1. Preoperative mean stress ischemic myocardial area ratio was 0.32$\pm$0.2 and postoperative ratio was 0.15 $\pm$0.1. Postoperative mean perfusion score was significantly increased but, on the other hand, mean ischemic myocardial area ratio was significantly decreased as compared with preoperative values(p<0.01). Preoperative mean perfusion score of patients with postoperative roper(usion score more than 1.5 was significantly higher(p<0.01) than that of patients with postoperative reperfusion score less than 1.5. Preoperative perfusion scores of coronary artery territories that had fixed perfusion defect at myocardial SPECT were significantly low(4.3 $\pm$0.514.6$\pm$0.6, stresslrest), nevertheless it proved quantitatively that there was improvement in myocardial perfusion after surgery by showing improved perfusion scores postoperatively. In conclusion, myocardial SPECT is useful method for quantitative analysis of the myocardial perfusion state after coronary artery bypass grafting surgery.

• The Korean Journal of Nuclear Medicine
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• v.32 no.3
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• pp.259-265
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• 1998

Purpose: We studied early rest/24 hour delay T1-201 perfusion SPECT for prediction of wall motion improvement after reperfusion in patients with acute myocardial infarction. Materials and Methods: Among 17 patients (male/female= 11/6, age: $59{\pm}13$) with acute myocardial infarction, 15 patients were treated with percutaneous transcoronary angioplasty (direct:2, delay: 11) and intravenous urokinase (2). Spontaneous resolution occurred in infarct-related arteries of 2 patients. We confirmed TIMI 3 flow of infarct-related artery after reperfusion in all patients with coronary angiography. We performed rest T1-201 perfusion SPECT less then 6 hours after reperfusion and delay T1-201 perfusion SPECT next day. T1-201 uptake was visually graded as 4 point score from normal (0) to severe defect (3). Rest T1-201 uptake ${\le}2$ or combination of rest T1-201 uptake ${\le}2$ or late reversibility were considered to be viable. Myocardial wall motion was graded as 5 point score from normal (1) to dyskinesia (5). Myocardial wall motion was considered to be improved when a segment showed an improvement ${\ge} 1$ grade in follow up echo compared with the baseline values. Results: Among 98 segments with wall motion abnormality, the severity of myocardial wall motion decrease was as follow: mild hypokinesia: 18/98 (18%), severe hypokinesia: 28/98 (29%), akinesia: 51/98 (52%), dyskinesia: 1/98 (1%). The wall motion improved in 85%. Redistribution (13%), and reverse redistribution (4%) were observed in 24 hour delay SPECT. Positive predictive value (PPV) and negative predictive value (NPV) of combination of late reversibility and rest T1-201 uptake were 99%, and 54%. PPV and NPV of rest T1-201 uptake were 100% and 52% respectively. Predictive values of combination of rest T1-201 uptake and late reversibility were not significantly different compared with predictive values of rest T1-201 uptake only. Conclusion: We conclude that early T1-201 perfusion SPECT predict myocardial wall motion improvement with excellent positive but relatively low negative predictive values in patients with acute myocardial infarction after reperfusion.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.6
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• pp.435-443
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• 2008

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 $61.3\;{\pm}\;13.3$ 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 -33.8g to 14.1g (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, LVEO, 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.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.6
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• pp.513-518
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• 2009

Purpose: Integration of the functional information of myocardial perfusion SPECT (MPS) and the morphoanatomical information of coronary CT angiography (CTA) may provide useful additional diagnostic information of the spatial relationship between perfusion defects and coronary stenosis. We studied to know the added value of three dimensional cardiac SPECT/CTA fusion imaging (fusion image) by comparing between fusion image and MPS. Materials and Methods: Forty-eight patients (M:F=26:22, Age: $63.3{\pm}10.4$ years) with a reversible perfusion defect on MPS (adenosine stress/rest SPECT with Tc-99m sestamibi or tetrofosmin) and CTA were included. Fusion images were molded and compared with the findings from the MPS. Invasive coronary angiography served as a reference standard for fusion image and MPS. Results: Total 144 coronary arteries in 48 patients were analyzed; Fusion image yielded the sensitivity, specificity, negative and positive predictive value for the detection of hemodynamically significant stenosis per coronary artery 82.5%, 79.3%, 76.7% and 84.6%, respectively. Respective values for the MPS were 68.8%, 70.7%, 62.1% and 76.4%. And fusion image also could detect more multi-vessel disease. Conclusion: Fused three dimensional volume-rendered SPECT/CTA imaging provides intuitive convincing information about hemodynamic relevant lesion and could improved diagnostic accuracy.

• The Korean Journal of Nuclear Medicine
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• v.30 no.1
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• pp.86-94
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• 1996

Coronary angiography should be performed to verify the patency of bypass graft if coronary artery disease is said to be surgically corrected. Rest/stress myocardial SPECT could be used as a noninvasive alternative to prove patency of bypass graft and functional significance of graft patency by showing improvement of rest perfusion and perfusion reserve after operation. We evaluated the outcome of coronary artery bypass graft surgery by comparing rest/dipyridamole-stress myocardial SPECT before and after operation. Myocardial SPECT were performed $19{\pm}23$ days before and $108{\pm}19$ days after operation in 44 patients(M:F=25:19). Segmental perfusion were scored with 0(normal) to 3(defect) independently for each image set of rest and stress. Perfusion scores were compared between pre and postoperative images. Rest/stress images of pre and post-operative SPECT were compared in paired sets. Postoperative change of perfusion was determined as no change, improvement or aggravation for each artery territory. Postoperative outcome of patients were analyzed. Overall, 74%(158 segments) of 215 segments which had perfusion decrease before operation showed improvement. Among 60 artery territories, 37 territories(62%) improved. Among 42 patients with perfusion decrease in preoperative SPECT, 21 patients(47%) improved after operation. Severe persistent defects improved in 43%(6/14). We concluded that bypass surgery improved myocardial perfusion in dipyridamole stress induced or persistent decrease and that rest/stress myocardial SPECT could be used as a guide for which artery should be operated.

• The Korean Journal of Nuclear Medicine
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• v.34 no.1
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• pp.30-38
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• 2000

Purpose: We investigated the role of myocardial perfusion SPECT in prediction of ventricular dilatation and the role of revascularization including thrombolytic therapy and PTCA in prevention of ventricular dilatation after an acute myocardial infarction (AMI). Materials and Methods: We performed dipyridamole stress, 4 hour redistribution, and 24 hour reinjection Tl-201 SPECT in 16 patients with AMI two to nine days after attack. Perfusion and wall motion abnormalities were quantified by perfusion index (PI) and wall motion index (WMI). Left ventricular ejection fraction (LVEF), WMI and ventricular volume were measured within 1 week of AMI and after average of 6 months. According to serial changes of left ventricular end-diastolic volume (LVEDV), patients were divided into two groups. We compared WMI, PI and LVEF between the two groups. Relationships among degree of volume, stress-rest PI, WMI, CKMB, Q wave, LVEF and revascularization were analysed using multivariate analysis. Results: Only initial rest perfusion index was significantly different between the two groups (p<0.05). While initial LVEF, stress PI, CKMB, trial of revascularization procedure, presence of Q wave and WMI were not significantly different between the two groups. Eight of 16 patients (50%) showed LV dilatation on follow-up echocardiography. Three of 3 patients (100%) who did not undergo revascualrization procedure documented LV dilatation. And only 5 (38%) of the remaining 13 patients who underwent revascularization revealed LV dilatation. There was no difference in infarct location between the two groups. By multivariate linear regression analysis in patients only undergoing revascularization, rest perfusion index was the only significant factor. Conclusion: Myocardial perfusion SPECT performed prior to revascularization was useful in prediction of LV dilatation after an AMI. Rest perfusion index on myocardial perfusion plays as a significant predictor of left ventricular dilatation after AMI. And revascularization appears to be a valuable procedure in alleviating LV dilatation after AMI with or without viable myocardium in a limited number of patients studied retrospectively.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.65-71
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• 2011

Purpose: The recently adopted multiple confocal SPECT SYSTEM (hereinafter called IQ SPECT$^{TM}$) has a high difference from the conventional myocardial perfusion SPECT in the collimator form, image capture method, and image reconstruction method. This study was conducted to compare this novice equipment with the conventional one to design a protocol meeting the IQ SPECT, and also determine the characteristics and usefulness of IQ SPECT. Materials and Methods: 1. For the objects of LEHR (Low energy high resolution) collimator and Multiple confocal collimator, $^{99m}Tc$ 37MBq was put in the acrylic dish then each sensitivity ($cpm/{\mu}Ci$) was measured at the distance of 5 cm, 10 cm, 20 cm, 30 cm, and 40 cm respectively. 2. Based on the sensitivity measure results, IQ SPECT Protocol was designed according to the conventional general myocardial SPECT, then respectively 278 kBq/mL, 7.4 kBq/mL, and 48 kBq/mL of $^{99m}Tc$ were injected into the myocardial and soft tissues and liver site by using the anthropomorphic torso phantom then the myocardial perfusion SPECT was run. 3. For the comparison of FWHMs (Full Width at Half Maximum) resulted from the image reconstruction of LEHR collimator, the FWHMs (mm) were measured with only algorithms changed, in the case of the FBP (Filtered Back projection) method- a reconstruction method of conventional myocardial perfusion SPECT, and the 3D OSEM (Ordered subsets expectation maximization) method of IQ SPECT, by using $^{99m}Tc$ Line source. Results: 1. The values of IQ SPECT collimator sensitivity ($cpm/{\mu}Ci$) were 302, 382, 655, 816, 1178, and those of LEHR collimator were measured as 204, 204, 202, 201, 198, both at the distance of 5 cm, 10 cm, 20 cm, 30 cm, and 40 cm respectively. It was found the difference of sensitivity increases up to 4 times at the distance of 30 cm in the cases of IQ SPECT and LEHR. 2. The myocardial perfusion SPECT Protocol was designed according to the geometric characteristics of IQ SPECT based on the sensitivity results, then the phantom test for the aforesaid protocol was conducted. As a result, it was found the examination time can be reduced 1/4 compared to the past. 3. In the comparison of FWHMs according to the reconstructed algorithm in the FBP method and 3D OSEM method followed after the SEPCT test using a LEHR collimator, the result was obtained that FWHM rose around twice in the 3D OSEM method. Conclusion : The IQ SPECT uses the Multiple confocal collimator for the myocardial perfusion SPECT to enhance the sensitivity and also reduces examination time and contributes to improvement of visual screen quality through the myocardial-specific geometric image capture method and image reconstruction method. Due to such benefits, it is expected patients will receive more comfortable and more accurate examinations and it is considered a further study is required using additional clinical materials.