• The Korean Journal of Nuclear Medicine
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• v.36 no.6
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• pp.381-391
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• 2002

Purpose: The presence of perfusion defect may influence the left ventricular mass (LVM) measurement by quantitative gated myocardial perfusion SPECT (QGS), and ischemic myocardium, usually showing perfusion defect may produce post-stress LV dysfunction. This study was aimed to evaluate the effects of extent and reversibility of perfusion defect on the automatic measurement of LVM by QGS and to investigate the effect of reversibility of perfusion defect on post-stress LV dysfunction. Subjects and Methods: Forty-six patients (male/female=34:12, mean age=64years) with perfusion defect on myocardial perfusion SPECT underwent rest and post-stress QGS. Forty patients (87%) showed reversible defect. End-diastolic volume (EDV), end-systolic volume (ESV), LV ejection fraction (EF), and LV myocardial volume were obtained from QGS by AutoQUANT program, and LVM was calculated by multiplying the LV myocardial volume by the specific gravity of myocardium. Results: LVMs measured at rest and post-stress QGS showed good correlation, and higher correlation was founded in the subjects with fixed perfusion defect and with small defect (smaller than 20%). There were no significant differences in EDVs, ESVs and EFs between obtained by rest and post-stress QGS un patients with fixed myocardial defect. Whereas, EF obtained by post-stress QGS was lower than that by rest QGS in patients with reversible defect and 10 (25%) of them showed decreases in EF more than 5% in post-stress QGS, as compared to that of rest QGS. Excellent correlations of EDVs, ESVs, EFs between rest and post-stress QGS were noted. Patients with fixed defect had higher correlation between EDVs, ESVs, EFs than patients with reversible defect. Conclusion: These results suggest that perfusion defect can affect LVM measurement by QGS and patients with reversible defect shows post-stress LV dysfunction more frequently than patients with fixed perfusion defect.

• 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.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.82-82
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• 1993

허혈-재관류손상 심근세포의 DNA에서 8-hydroxydeoxyguanosine (8-OHdG) 생성을 검토하였다. 흰쥐 적출심장의 Langendorff 관류 표본에서 대동맥 차단에 의한 60분 허혈후 산소가 포화된 Kredb-Henseleit용액으로 30분간 재관류 하므로서 허혈-재관류 손상을 유도하였다. 재관류 후 심근세포에서 DNA를 추출하고 HPLC(EC detector)를 이용하여 8-OHdG를 측정하였다. 실험결과 허혈-재관류 심근세포의 DNA에서 8-OHdG 함량이 증가하였으며 이는 $O_2$ 제거물질인 superoxide dismutase와 OH 제거물질인 mannitol에 의하여 방지되었다. Xanthine oxidase외 경쟁적 길항약인 allopurinol도 8-OHdG 생성을 억제하였으며 단백분해효소 억제제인 phenylsulfonylfluoride 그리고 관류액에서 칼슘의 제거 또한 허혈-재관류 심근 DNA의 생성을 방지하였다. 이상의 결과 허혈심근의 재관류시 8-OHdG 생성이 증가하며 이는 재관류 손상과 같은 산화성 심근손상을 평가하는 좋은 Index가 될 수 있을 것으로 여겨진다.

• 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.

• The Korean Journal of Nuclear Medicine
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• v.37 no.5
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• pp.269-277
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• 2003

목적: 게이트 심근관류 스펙트는 심근의 관류와 좌심실 기능을 동시에 평가할 수 있는 유용한 방법이다. 현재, 게이트 영상 획득시 8 단위영상이 널리 사용되지만, 아직 가장 적절한 단위영상의 수에 대해서는 논의의 여지가 있다. 본 연구는 동일한 환자에서 8 단위영상과 16 단위영상으로 게이트 심근관류 스펙트를 2회 연속적으로 시행하여 국소적 심근관류, 좌심실 용적과 구혈률등을 비교하였다. 대상 및 방법: 42명(평균 연령: 55세, 남: 녀=26: 16)의 관상동맥 질환이 의심되거나 알려진 환자를 대상으로 안정시 Tc-99m MIBI를 이용한 게이트 스펙트를 8 단위영상과 16 단위영상으로 2회 연속하여 시행하였다. 좌심실의 확장기말 용적, 수축기말 용적과 구혈률을 각각 얻었으며 확장기말의 단층영상을 18 분절로 나누고 각 분절마다 심근의 관류정도를 4등급으로 나누어 국소적 심근관류를 평가하였다. 결과: 8 단위영상과 16 단위영상 게이트 스펙트에서 국소적 심근관류의 일치도는 85.7% (tau-b=0.786, p<0.001)로 우수하였다. 두 방법간에 1등급의 차이는 100 분절(13.2%), 2등급 차이는 8 분절(1.1 %)이 있었고 3등급 차이는 없었다. 좌심실의 확장기말 용적, 수축기말 용적, 구혈률은 두 방법간에 높은 상관성을 보였으며(r=0.993, 0.989, 0.935), 좌심실 구혈률은 8 단위영상을 사용할 때 평균 1.8% 낮게 측정되어 통계적인 유의성은 있었으나(p<0.05), 그 차이는 크지 않았다. 결론: 8 단위영상과 16 단위영상을 사용한 게이트 심근관류 스펙트에서 국소적 심근관류의 일치도는 우수하였으며, 좌심실의 기능적 계수의 차이도 크지 않았다. 비록 높은 단위영상을 사용했을 때 더 정확하고 자세한 정보를 얻을 수 있다 하더라도, 구혈률과 용적 등을 얻는 일상적인 임상검사에는 8 단위영상 또한 그 역할을 충분히 할 수 있을 것으로 사료된다.

• 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.

• Journal of Yeungnam Medical Science
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• v.5 no.2
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• pp.59-69
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• 1988

This study was designed to investigate the effect of substitution of strontium for calcium on mechanical activity in isolated perfused spontaneously beating rat hearts. The mechanical activity of the hearts of Langendorff's preparation in conditions of low calcium and strontium-substitution for calcium was compared. The effect of norepinephrine and verapamil were also observed in those conditions. The results were as follows : 1. In low calcium, the mechanical activity of the heart preparation was significantly reduced, but when the equimolar strontium was substituted for the reduced calcium, the activity was kept at similar level to the normal condition. 2. When equimolar strontium was substituted for the total calcium in perfusate, the heart preparation stopped its beating, and it was not restored in spite of reperfusion with normal calcium perfusate. 3. Norepinephrine-induced positive inotropic effect was inhibited in low-calcium condition especially with low concentration of norepinephrine, but not in strontium-substitution for calcium. 4. Verapamil reduced the activity of the heart both in low-calcium and strontium-substitution as well as in normal calcium conditions. From above results, it was concluded that strontium served as a substitute of calcium in maintaining mechanical activity and in responsiveness to norepinephrine, and the influx of strontium through cell membrane is inhibited by verapamil as the influx of calcium.

• 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.31 no.10
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• pp.924-927
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• 1998

Background: Myocardial cell death after myocardial infarction or reperfusion is classified into necrosis and apoptosis. Bcl-2 protein is a cytoplasmic protein, which inhibits apoptosis and is expressed in acute stage of myocardial infarction but not in normal heart. This study was performed to investigate whether Bcl-2 protein was expressed respectively to the reperfusion time. Materials and methods: Thirty nine New Zealand white rabbits weighing 1.5-4.8 kg (mean, 2.9kg) were alloted into 7 groups (n=5 in each group) which underwent left anterior descending coronary artery(LAD) occlusion for 30 minutes, followed by reperfusion. The animals were sacrificed at 1, 4, 8, 12, 24 hours, and 3, 7 days after occlusion. Ventricle was excised immediately after intervention. Tissues were fixed in 10% buffured formalin and embedded in paraffin. Bcl-2 protein was detected by immunohistochemical stain with using monoclonal antibody against Bcl-2 protein. Results: The positive immunohistochemical reactivity for Bcl-2 protein was observed in 12, 24 hours, and 3 days reperfusion groups. Bcl-2 protein was detected in salvaged myocytes surrounding the infarcted area. Conclusions: Bcl-2 protein is expressed at the late acute stage of infarct. Therefore, the expression of Bcl-2 protein may not protect acute cell death, but may play a role in the prevention of late cell death after myocardial is chemia-reperfusion.