• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.51-57
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• 2011

Purpose: The aim of this study is to identify clinical usefulness of Wide Beam Reconstruction (WBR) which is called Xpress.cardiac$^{TM}$ to confirm the agreement between segmental perfusion and regional wall motion in myocardium compared to conventional OSEM method. Materials and Methods: Subjects were separated two groups. First group was composed of 20 normal control group. Second group was composed of 10 patients (abnormal group) who had coronary artery disease. Subjects underwent myocardial perfusion SPECT ($^{201}Tl$ rest and $^{99m}Tc$-MIBI stress). Image acquisition and reconstruction were that rest stage was each step per 30, 15 seconds and stress stage was each step per 25, 13 seconds, OSEM and WBR methods were applied. Segmental perfusion and regional wall motion were applied 20-segment model of QPS, QGS algorithm in AutoQuant. Status of perfusion was composed of 5 point scoring system (0=normal, 1=mild, 2=moderate, 3=severe hypokinesia, 4=dyskinesia). Status of regional wall motion was also composed of 5 point scoring (0=normal, 1=mild, 2=moderate, 3=severe hypokinesia, 4=dyskinesia). We evaluated the agreement between conventional OSEM and WBR through automatic quantification value. Results: The agreement of rest segmental perfusion between conventional OSEM and WBR in normal patients was 99% (396/400, k=0.662, p<0.0001) and one of rest regional wall motion was 83.8% (335/400, k=0.283), the agreement of stress segmental perfusion was 95.8%(383/400, k=0.656), one of stress regional wall motion was 87.3% (349/400, k=0.390). The match rate of rest segmental perfusion in abnormal patients was 83% (166/200, k=0.605, p<0.0001) and one of rest regional wall motion was 55.5% (111/200, k=0.385), the agreement of stress segmental perfusion was 79.5% (159/200, k=0.682), one of stress regional wall motion was 63.5% (127/200, k=0.486). Conclusion: Compared to conventional OSEM, WBR method had a good agreement of segmental perfusion in myocardium in normal and abnormal groups. However regional wall motion showed meaningful low agreement. Although WBR offers high resolution and contrast ratio, it is not useful method for gated myocardial perfusion SPECT.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.3
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• pp.159-164
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• 2009

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 ECC-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.

• 대한핵의학회:학술대회논문집
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• 2004.11a
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• pp.414.2-414.2
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• 2004

• The Korean Journal of Nuclear Medicine
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• v.36 no.5
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• pp.288-297
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• 2002

Purpose: Soft tissue attenuation and scattering are major methodological limitations of myocardial perfusion SPECT. To overcome these limitations, algorithms for attenuation, scatter correction and resolution recovery (ASCRR) is being developed, while quantitative myocardial SPECT has also become available. In this study, we investigated the efficacy of an ASCRR-corrected quantitative myocardial SPECT method for the diagnosis of coronary artery disease (CAD). Materials and Methods: Seventy-five patients (M:F=51:24, $61.0{\pm}8.9$ years old) suspected of CAD who underwent coronary angiography (CAG) within $7{\pm}12$ days of SPECT(Group-I) and 20 subjects (M:F=10:10, age $40.6{\pm}9.4$) with a low likelihood of coronary artery disease (Group-II) were enrolled. Tl-201 rest/ dipyridamole-stress Tc-99m-MIBI gated myocardial SPECT was performed. ASCRR correction was peformed using a Gd-153 line source and automatic software (Vantage-Pro; ADAC Labs, USA). Using a 20-segment model, segmental perfusion was automatically quantified on both the ASCRR-corrected and uncorrected images using an automatic quantifying software (AutoQUANT; ADAC Labs.). Using these quantified values, CAD was diagnosed in each of the 3 coronary arterial territories. The diagnostic performance of ASCRR-corrected SPECT was compared with that of non-corrected SPECT. Results: Among the 75 patients of Group-I, 9 patients had normal CAG while the remaining 66 patients had 155 arterial lesions; 61 left anterior descending (LAD), 48 left circumflex (LCX) and 46 right coronary (RCA) arterial lesions. For the LAD and LCX lesions, there was no significant difference in diagnostic performance. In Group-II patients, the overall normalcy rate improved but this improvement was not statistically significant (p=0.07). However, for RCA lesions, specificity improved significantly but sensitivity worsened significantly with ASCRR correction (both p<0.05). Overall accuracy was the same. Conclusion: The ASCRR correction did not improve diagnostic performance significantly although the diagnostic specificity for RCA lesions improved on quantitative myocardial SPECT. The clinical application of the ASC-RR correction requires more discretion regarding cost and efficacy.

• 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.35 no.6
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• pp.364-370
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• 2001

Purpose: In the revascuarization of ischemic dysfunctional myocardium, stunned myocardium was reported to recover function earlier than hibernating myocardium. It was also suggested that stunning and hibernation could be discriminated by reversibility of perfusion impairment on myocardial SPECT. In this study, we investigated the time course of functional recover after CABG according to reversibility of perfusion impairment. Materials and Methods: In 92 patients with coronary artery disease, Tl-201 rest/dipyridamole stress Tc-99m-MIBI gated SPECT was performed before, 3 months after, and 17 months after CABG. Using a 20-segment model, segmental perfusion and systolic thickening were automatically quantified. Perfusion-impaired segments with abnormal thickening were classified by reversibility into reversible (REV) and irreversible (IRREV) groups. The proportions of function-recovered segments were compared between groups and also between 3 months and 17 months in each group. Results: A total of 129 segments were Included In the analysis, and 76 were REV and 53 were IRREV. At 3 months after CABG, 61 segments (80%) in REV group showed functional recovery while 28 segments (53%) in IRREV group did (p<0.001). However, at 17 months after CABG, 60 segments (79%) in REV group and 37 segments (70%) un IRREV group showed functional recovery (p=n.s.). When comparing 3 months and 17 months in each group, REV group showed no difference, while IRREV group showed significant further improvement (p<0.05). Conclusion: In viable myocardium with ischemic myocardial dysfunction, the segments with reversible perfusion impairment recover function earlier after revascularization than irreversible segments.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.122-127
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• 2010

Purpose: The Xpress3.$cardiac^{TM}$ which is a kind of wide beam reconstruction (WBR) method developed by UltraSPECT (Haifa, Israel) enables the acquisition of at quarter time while maintaining image quality. The purpose of this study is to investigate the usefulness of WBR method for decreasing scan times and to compare to it with filtered back projection (FBP), which is the method routinely used. Materials and Methods: Phantom and clinical studies were performed. The anthropomorphic torso phantom was made on an equality with counts from patient's body. The Tl-201 concentrations in the compartments were 74 kBq (2 ${\mu}Ci$)/cc in myocardium, 11.1 kBq (0.3 ${\mu}Ci$)/cc in soft tissue, and 2.59 kBq (0.07 ${\mu}Ci$)/cc in lung. The non-gated Tl-201 myocardial perfusion SPECT data were acquired with the phantom. The former study was scanned for 50 seconds per frame with FBP method, and the latter study was acquired for 13 seconds per frame with WBR method. Using the Xeleris ver. 2.0551, full width at half maximum (FWHM) and average image contrast were compared. In clinical studies, we analyzed the 30 patients who were examined by Tl-201 gated myocardial perfusion SPECT in department of nuclear medicine at Asan Medical Center from January to April 2010. The patients were imaged at full time (50 second per frame) with FBP algorithm and again quarter-time (13 second per frame) with the WBR algorithm. Using the 4D MSPECT (4DM), Quantitative Perfusion SPECT (QPS), and Quantitative Gated SPECT (QGS) software, the summed stress score (SSS), summed rest score (SRS), summed difference score, end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) were analyzed for their correlations and statistical comparison by paired t-test. Results: As a result of the phantom study, the WBR method improved FWHM more than about 30% compared with FBP method (WBR data 5.47 mm, FBP data 7.07 mm). And the WBR method's average image contrast was also higher than FBP method's. However, in result of quantitative indices, SSS, SDS, SRS, EDV, ESV, EF, there were statistically significant differences from WBR and FBP(p<0.01). In the correlation of SSS, SDS, SRS, there were significant differences for WBR and FBP (0.18, 0.34, 0.08). But EDV, ESV, EF showed good correlation with WBR and FBP (0.88, 0.89, 0.71). Conclusion: From phantom study results, we confirmed that the WBR method reduces an acquisition time while improving an image quality compared with FBP method. However, we should consider significant differences in quantitative indices. And it needs to take an evaluation test to apply clinical study to find a cause of differences out between phantom and clinical results.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.150-154
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• 2010

Purpose: Ejection fraction (EF) is one of the most important factors that evaluate heart function. Recently, according to echocardiography and myocardial perfusion SPECT, the number of gated blood pool scan (planar GBP) is declining. Measurement of left ventricular ejection fraction using gated blood pool SPECT (GBPS) is known as relatively correspond with echocardiography. We compared EF derived from plnar GBP, GBPS and echocadiography using modified simpson method to determine the accuracy. Materials and Methods: From January 2007 to June 2010, planar GBP and GBPS were performed on 34 patients who admitted to Pusan National University Hospital (men 23, women 11, mean age $52.6{\pm}27.2$). Each patient was injected with $^{99m}{TcO_4}^-$ of 20 mCi after pyrophosphate injection and then scanned using both planar GBP and GBPS techniques. For image analysis, we use ADAC Laboratories, Ver. 4.20 software. The result analyzed was processed by SPSS 17.0 Win statistic program and statistical method applied in data analysis is one-way anova, Tukey's post hoc test, pearson correlation test. Results: One-way anova test show no significant difference (planar GBP $56.3{\pm}13.9%$; GBPS $60.4{\pm}16.0%$; echocardiography $59.1{\pm}14.4%$, p=0.486, p>0.05). Tukey's post hoc test show no significant difference (planar GBP-echocardiography p=0.697; GBPS-echocardiography p=0.928; planar GBP-GBPS p=0.469, p>0.05). Values for EF obtained with planar GBP and GBPS correlated well with those obtained with echocardiography (planar-echocardiography r=0.697; GBPS-echocardiography r=0.928; planar GBP-GBPS r=0.469). Conclusion: The problems of accuracy and reproducibility for planar GBP still remain. But planar GBP is a safe and non-invasive method. In addition, planar GBP is useful to evaluate patient with low resolution echocardiography images. GBPS is not appicated clinically. but GBPS can be obtain various left ventricular functional parameters. planar GBP, GBPS and echocardiography show a good correlation between each other. Therefore, planar GBP and GBPS are useful for evaluating left ventricular ejection fraction.

• The Korean Journal of Nuclear Medicine
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• v.30 no.4
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• pp.493-501
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• 1996

To assess contribution of T1-201 rest-24 hour delay redistribution in detection of viable myocardium, we studied the predictive value of this redistribution in 17 patients who peformed rest-24 hour delay perfusion SPECT before bypass surgery. Regional wall motion was compared with gated SPECT in 10 patients and echocardiography in 7 patients before and after bypass surgery. Rest and 24 hour delayed uptakes were scored from 0 (normal perfusion) to 3 (defect). In rest SPECT, 56 segments showed perfusion decrease. Thirty four segments(61%) improved after surgery and were defined as viable Nineteen(34%) segments had more uptake of T1-201 at 24 hour delay, and the other 37 segments did not. In 81%(25/31) of segments with mildly decreased perfusion, wall motion after bypass surgery improved, 57% (8/14) of segments with severely decreased perfusion improved, and 9%(1/11) of segments with defects improved. In 14 among 19 segments which had more T1-201 uptakes at 24 hour delay, wall motion was improved(positive predictive value of redistribution: 74%). 20 among 37 segments which had persistent decreases in rest-24 hour redistribution improved and 17 did not(negative predictive value: 46%). Segments having severe perfusion decrease or defects showed improved wall motion after surgery in 64%(7/11), if it had redistribution at delay. Segments with either mildly decreased uptake in resting or rest-delayed redistribution showed improved wall motion in 76%(32/42). Among the 14 segments which showed improvement in wall motion, 10 had partial reversibility in stress-rest images and the other 4 had persistent perfusion defects in stress-rest images. These 4 segments were found viable only with rest-24 hour delayed perfusion SPECT. We concluded that rest T1-201 uptake or redistribution at 24 hour delay should be referred as an evidence to warrant postoperative improvement of abnormal wall motion and we could predict myocardial viability with preoperative rest-24 hour delay perfusion SPECT in the segments with rest perfusion decreases.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.122-126
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• 2014

Purpose: The new reconstruction algorithms (NRA) provided by vendor aim to shorten the acquisition scan time. Whereas depending on the installed version AutoQuant program used for myocardial SPECT quantitative analysis did not contain the normal data that NRA is applied. Thus, the purpose of this paper is to compare the results according to AutoQuant versions in myocardial SPECT applied NRA and half-time scan (HT). Materials and Methods: Rest Tl and stress MIBI data of total 80 (40 men, 40 women) patients were gathered. Data were applied HT acquisition and ASTONISH (Philips) software which is NRA. Modified autoquant of SNUH and old version of AutoQuant (full-time scan) provided by company were compared. Comparison groups were classified as coronary artery disease (CAD), 24 hrs delay and almost normal patients who have a simple pain patient. Perfusion distribution aspect, summed stress score (SSS), summed rest score (SRS), extent and total perfusion deficit (TPD) of each 25 patient who have above diseases were compared and evaluated. Results: The case of CAD, when using re-edited AutoQuant (HT) SSS and SRS showed about 30% reduction (P<0.0001), Extent showed about 38% reduction and TPD showed about 30% reduction in the tendency (P<0.0001). In the score of the perfusion, especially on the part of infero-medium, infero-apical, lateral-medium and lateral-apical regions were the biggest change. The case of the 24 hrs delay patient SRS (P=0.042), Extent (P=0.018) and TPD (P=0.0024) showed about 13-18% reduction. And the case of simple pain patient, comparison of 4 results showed about 5-7% reduction. Conclusion: This study was started based on expectation that results could be affected by normal patient data. Normal patient data is possible to change by race and gender. It was proved that combination of new reconstruction algorithm for reducing scan time and analysis program according to scan protocol with NRA could also be affected to results. Clinical usefulness of gated myocardial SPECT is possibly increased if each hospital properly collects normal patient data for their scan acquisition protocol.