알쯔하이머병에서 양전자방출단층촬영을 이용한 국소뇌포도당대사의 변화에 관한 연구

김병태(Byung Tae Kim),김상은(Sang Eun Kim),최용(Yong Choi),이경한(Kyung Han Lee),최연성(Yearn Seong Choe),나덕렬(Duk Lyul Na),이정림(Jeong Rim Lee),김도관(Doh Kwan Kim),이광호(Kwang Ho Lee),김승태(Seung Tai Kim) 대한핵의학회 1996 핵의학 분자영상 Vol.30 No.3

N/A The purpose of the present study was to validate the use of tissue radioactivity ratios instead of regional metabolic rates for the assessment of regional metabolic changes in Alzheimer's disease(AD) with [18F]FDG PET and to examine the correlation of ratio indices with the severity of cognitive impairment in AD. Thirty-seven AD patients(age 68±9 yrs, mean±s.d.; 36 probable and 1 definite AD), 28 patients with dementia of non-Alzheimer type(age 66±7 yrs), and 17 healthy controls(age 66±4 yrs) underwent [18F]FDG PET imaging. Two simplified radioactivity ratio indices were calculated from 37-66 min image: region-to-cerebellar radioactivity-ratio(RCR) and a composite radioactivity ratio(a ratio of radioactivity in the most typically affected regions over the least typically affected regions: CRR). Local cerebral metabolic rate for glucose(LCMRglu) was also measured using a three-compartment, five-parameter tracer kinetic model. The ratio indices were significantly lower in AD patients than in controls(RCR in temporoparietal cortex, 0.949±8.136 vs. 1.238±0.129, p=0.0004; PCR in frontal cortex, 1.027±0.128 vs. 1.361±0.151, p〈0.0001; CRR, 0.886±0.096 vs. 1.032±0.042: p=0.0024). On the RCR analysis, 86% of AD patients showed a pattern of bilateral temporoparietal hypometabolism with or without frontal involvement; hypometabolism was unilateral in 11% of the patients. When bilateral temporoparietal hypometabolism was considered to be suggestive of AD, the sensitivity and specificity of the RCR was analysis for the differential diagnosis of AD were 86% and 73%, respectively. The RCR was correlated significantly with the macroparameter K [K1k3/(k2+k3)] (r=0.775, p〈0.0001) and LCMRglu(r=0.633, p=0.0002) measured using the kinetic model. In patients with AD, both average RCR of cortical association areas and CRR were correlated with Mini-Mental Status Examination(r=0.565, p=0.0145; r=0.642, p=0.0031, respectively), Clinical Dementia Rating(r=-0.576, p=0.0124; r=-0.591, p=0.0077), and total score of Mattis Dementia Rating Scale (r=0.574, p=0.0648; r=0.737, p=0.0096). There were also significant correlations between memory and language impairments and corresponding regionl RCRs. The results suggest that the [18F]FDG PET ratio indices, RCR and CRR, reflect global and regional metabolic rates and correlate with the severity of cognitive impairment in AD. The simplified ratio analysis may be clinically useful for the differential diagnosis and seral monitoring of the disease.

CT상 악성여부가 불명확한 단일 폐결절에서의 양전자방출단층촬열술의 유용성

김병태(Byung Tae Kim),김상은(Sang Eun Kim),최용(Yong Choi),이경한(Kyung Han Lee),최연성(Yearn Seong Choe),윤석부(Seok Boo Yoon),최준영(Joon Young Choi),김선정(Sun Jung Kim),권오정(O Jung Kwon),이경수(Kyung Soo Lee) 대한핵의학회 1997 핵의학 분자영상 Vol.31 No.1

N/A About one-third of radiologically indeterminate solitary pulmonary nodules (SPN) are eventually turned out to be malignant. It is very important to noninvasively determine whether the SPN is malignant or not for the decision of its way of management. PET imaging is highlighted by its unique ability of imaging the function and metabolism of cells. Glucose metabolism is increased in malignant transformed cells. We performed FDG-PET studies in patients who ha radiologi- cally indeterminate SPN and compared the findings with histologic diagnoses to assess the diagnostic accuracy in the detection of malignancy and to decide which parameter is the most suitable for clinical practice among peak SUV (pSUV), average SUV (aSUV), 50/10 ratio, and time-activity curve (TAC). Thirty patients were included in this study and the most useful parameter was pSUV. The sensitivity and specificity in the detection of malignant SPN using 3.5 as a cut off pSUV were both 87%. Interestingly, all 2 false-negative cases were bronch- ioloalveolar carcinoma on histologic examination. If these cases, which could be strongly suspected by CT findings, were excluded, the sensitivity of pSUV was 100%. In conclusion, PET imaging is very helpful for determining malignancy in indeterminate SPN and pSUV is a conveniently measurable parameter which is valuable for interpretation.

최근 핵의학 영상 기기 발전 동향

김병태(Byung Tae Kim),김상은(Sang Eun Kim),김준영(Joon Young Kim),최용(Yong Choi),이경한(Kyung Han Lee),최연성(Yearn Seong Choe),김종호(Jong Ho Kim),임기천(Ki Chun Im) 대한핵의학회 1998 핵의학 분자영상 Vol.32 No.6

The goals of developments in nuclear medicine instrumentation are to offer a higher-quality image and to aid diagnosis, prognosis assessment or treatment planning and monitoring. It is necessary for physicists and engineers to improve or design new instrumentation and technique, and to implement, validate, and apply these new approaches in the practice of nuclear medicine. The researches in physical properties of detectors and crystal materials and advance in image analysis technology have improved quantitative and diagnostic accuracy of nuclear medicine images. This review article presents recent developments in nuclear medicine instrumentation, including scatter and attenuation correction, new detector technology, tomographic image reconstruction methods, 511 keV imaging, dual modality imaging device, small gamma camera, PET developments, image display and analysis methods.

N - 13 암모니아와 양전자방출단층촬영 동적영상을 이용하여 심근혈류량을 정량화하는 새로운 방법 개발에 관한 연구

김병태(Byung Tae Kim),김상은(Sang Eun Kim),김준영(Joon Young Kim),최용(Yong Choi),이경한(Kyung Han Lee),최연성(Yearn Seong Choe),주희경(Hee Kyung Ju),김영진(Yong Jin Kim) 대한핵의학회 1997 핵의학 분자영상 Vol.31 No.1

N/A Regional myocardial blood flow (rMBF) can be noninvasively quantified using N-13 ammonia and dynamic positron emission tomography (PET). The quantitative accuracy of the rMBF values, however, is affected by the distortion of myocardial PET images caused by finite PET image resolution and cardiac motion. Although different methods have been developed to correct the distortion typically classified as partial volume effect and spillover, the methods are too complex to employ in a routine clinical environment. We have developed a refined method incorporating a geometric model of the volume representation of a region-of-interest (ROI) into the two- compartment N-13 ammonia model. In the refined model, partial volume effect and spillover are conveniently corrected by an additional parameter in the mathematical model. To examine the accuracy of this approach, studies were performed in 9 coronary artery disease patients. Dynamic transaxial images (16 frames) were acquired with a GE AdvanceTM PET scanner simultaneous with intravenous injection of 20 mCi N-13 ammonia. rMBF was examined at rest and during pharmacologically (dipyridamole) induced coronary hyperemia. Three sectorial myocardium (septum, anterior wall and lateral wall) and blood pool time-activity curves were generated using dynamic images from manually drawn ROIs. The accuracy of rMBF values estimated by the refined method was examined by comparing to the values estimated using the conventional two-compartment model without partial volume effect correction. rMBF values obtained by the refined method linearly correlated with rMBF values obtained by the conventional method (108 myocardial segments, correlation coefficient (r)=0.88). Additionally, underestimated rMBF values by the conventional method due to partial volume effect were corrected by theoretically predicted amount in the refined method (slope(m)=1.57). Spillover fraction estimated by the two methods agreed well (r=1.00, m=0.98). In conclusion, accurate rMBF values can be efficiently quantified by t

소형 감마카메라 제작에 사용되는 NaI(TI)- 광전자증배관 검출기의 민감도와 위치 분해능 특성 연구를 위한 몬테카를로 시뮬레이션

김종호,최용,김준영,임기천,김상은,최연성,주관식,김영진,김병태,Kim, Jong-Ho,Choi, Yong,Kim, Jun-Young,Im, Ki-Chun,Kim, Sang-Eun,Choi, Yeon-Sung,Joo, Kwan-Sik,Kim, Young-Jin,Kim, Byung-Tae 한국의학물리학회 1997 의학물리 Vol.8 No.2

본 연구에서는 유방암 진단용 감마카메라 제작 시에 고려되어야 하는 섬광체의 크기와 섬광체 면의 적절한 표면처리가 카메라의 민감도와 위치 분해능에 미치는 영향을 연구하기 위하여 섬광의 광학적 특성을 몬테카를로(Monte Carlo) 시뮬레이션 방법을 이용하여 고찰하였다. 섬광체는 NaI(TI) 결정체로 크기가 60 mm $\times$ 60 mm $\times$ 6 mm이며, 발생한 섬광이 광전자증배관의 광음극에 도달할 때까지를 시뮬레이션 하였다. 섬광체 표면 처리를(5가지 : Ground,. Polished, Metal-0.95RC(반사계수), Polished-0.98RC, Painted-0.98RC) 변화시켜 민감도를 계산하였다. 섬광체와 광전자증배관 (photomultiplier tube, PMT)의 접합면에 사용되는 물질의 굴절률 변화에 따른 민감도와 NaI(TI) 섬광체 창으로 많이 사용되고 있는 유리의 두께 변화에 따른 민감도를 조사하였다. 또한 섬광 결정체의 내인성 위치 분해능(intrinsic position resolution)을 섬광이 발생된 후 섬광 퍼짐(light spread) 정도를 시뮬레이션 함으로써 고찰하였다. 감마선의 입사면을 각각 Ground, Polished, Metal-0.95RC, Polished-0.98RC, Painted-0.98RC로 표면처리 하였을 때 민감도가 70.9%, 73.9%, 78.6%, 80.1%, 85.2%로 나타나 Painted-0.98RC일 때 민감도가 가장 우수하였다. 섬광체와 광전자증배관의 접합에 사용된 물질의 굴절률이 증가할수록 민감도가 증가하였으며 매질이 두꺼울수록 민감도는 저하되었다. 디자인된 검출기의 내인성 위치분해능은 수직, 수평 방향으로 약 1.2 mm로 예측되었다. 이 연구에서는 감마카메라의 성능에 직접적인 영향을 미치는 NaI (Tl)-PMT의 민감도와 위치 분해능을 몬테카를로 시뮬레이션을 통해 예견할 수 있었으며, 본 연구결과 NaI(TI)-PMT를 이용한 검출기가 고민감도ㆍ고해상력이 요구되는 유방암 진단용 소형 감마카메라 제작에 적합하다고 판단된다. We studied optical behavior of scintillation light generated in NaI(TI) crystal using Monte Carlo simulation method. The simulation was performed for the model of NaI(TI) scintillator (size: 60 mm ${\times}$ 60 mm ${\times}$ 6 mm) using an optical tracking code. The sensitivity as a function of surface treatment (Ground, Polished, Metal-0.95RC, Polished-0.98RC, Painted- 0.98RC) of the incident surface of the scintillator was compared. The effects of NaI(TI) scintillator thickness and the refractive index of light guide optically coupling between the NaI(TI) scintillator and photomultiplier tube (PMT) were simulated. We also evaluated intrinsic position resolution of the system by calculating the spread of scintillation light generated. The sensitivities of the system having the surface treatment of Ground, Polished, Metal-0.95RC, Polished-0.98RC and Painted-0.98RC were 70.9%, 73.9%, 78.6%, 80.1% and 85.2%, respectively, and the surface treatment of Painted-0.98RC allowed the highest sensitivity. As increasing the thickness of scintillation crystal and light guide, the sensitivity of the system was decreased. As the refractive index of light guide increases, the sensitivity was increased. The intrinsic position resolution of the system was estimated to be 1.2 mm in horizontal and vertical directions. In this study, the performance of NaI(TI)-PMT detector system was evaluated using Monte Carlo simulation. Based on the results, we concluded that the NaI(TI)-PMT detector array is a favorable configuration for small gamma camera imaging breast tumor using Tc-99m labeled radiopharmaceuticals.

NaI ( T1 ) 섬광결정과 위치민감형 광전자증배관을 이용한 유방암 진단용 소형 감마카메라 개발

김종호,최용,권홍성,김희중,김상은,최연성,이경한,김문회,주관식,김병태 ( Jong Ho Kim,Yong Choi,Hong Seong Kwon,Hee Joung Kim,Sang Eun Kim,Yearn Seong Choe,Kyung Han Lee,Moon Hae Kim,Koan Sik Joo,Byung Tae Kim ) 대한핵의학회 1998 핵의학 분자영상 Vol.32 No.4

Purpose: The conventional gamma camera is not ideal for scintimammography because of its large detector size ( 500 mm in width) causing high cost and low image quality. We are developing a small gamma camera dedicated for breast imaging. Materils and Methods: The small gamma camera system consists of a NaI (Tl) crystal (60 mm X60 mm X6 mm) coupled with a Hamamatsu R3941 Position Sensitive Photomultiplier Tube (PSPMT), a resister chain circuit, preamplifiers, nuclear instrument modules, an analog to digital converter and a personal computer for control and display. The PSPMT was read out using a standard resistive charge division which multiplexes the 34 cross wire anode channels into 4 signals (X, X, Y, Y ). Those signals were individually amplified by four preamplifers and then, shaped and amplified by amplifiers. The signals were discriminated and digitized via triggering signal and used to localize the position of an event by applying the Anger logic. Results: The intrinsic sensitivity of the system was approximately 8,000 counts/.'ec/pCi. High quality flood and hole mask images were obtained. Breast phantom containing 2-7 mm diameter spheres was successfully imaged with a parallel hole collimator. The image displayed accurate size and activity distribution over the imaging field of view. Conclusion: We have succesfully developed a small gamma camera using NaI(T1)-PSPMT and nuclear instrument modules. The small gamma camera developed in this study might imprnve the diagnostic accuracy of scintimammography by optimally imaging the breast. (Korean J Nucl Med 1998;32:365-73)

누드마우스에 이식된 인체대장암에서 I - 131 표지 항태아성암항원 단일클론항체를 이용한 방사면역치료법 : 치료성적에 관계되는 인자분석

김병태(Byung Tae Kim),고창순(Chang Soon Koh),이명철(Myung Chul Lee),정준기(June Key Chung),김상은(Sang Eun Kim),최용(Yong Choi),이경한(Kyung Han Lee),지대윤(Dae Yoon Chi),정홍근(Hong Keun Chung) 대한핵의학회 1995 핵의학 분자영상 Vol.29 No.3

N/A This study was designed to evaluate the effects of various factors on the therapeutic effect of the I-l3l labeled anti-carcinoembryonic antigen monoclonal antibody(anti-CEA antibody). Tetrazolium-based colorimetric assay (MTT) was used to compare in vitro cytotoxicity of 3 Korean colon cancer cell lines (SNU-C2A, SNU-C4, SNU-C5) for selection of proper 2 cell lines in this study. The changes of the size of tumor which was xenografted to nude mice (balb/c nu/nu) were compared in 4 groups (group treated I-131 labeled anti-CEA antibody, group treated with non-radiolabeled anti-CEA antibody, group treated with I-131. labeled anti-human chorionic gonadotropin monoclonal antibody (anti-hCG antibody) as nonspecific antibody, and group injected with normal saline as a control). Immunohistochemical staining and in vivo autoradiography were performed after excision of the xenografted tumor. The results were as below mentioned. The in vitro cytotoxic effect of I-131 labeled anti-CEA antibody is most prominent in SNU-C5 cell line between 3 cancer cell lines. The changes of xenografted tumor size in both SNU-C4 and SNU-C5 cell tumors at the thirteenth day after injection of the antibodies were smallest in the group treated with I-131 labeled anti-CEA antibody (SNU-C4/SNU-C5; 324/342%) comparing with other groups, group treated with anti-CEA antibody (622/660%), group treated with I-131 anti-hCG antibody (538/546%), and control group(1030/724%) (p〈0.02 in SNU-C4 and p〈0.1in SNU-C5 at the 13th day after injection of antibodies). On the thirteenth day after injection of the antibodies nude mice were sacreficed to count the radiouptake of tumor and to check the changes of tumor size. Correlations between radiouptake and change of tumor size were calculated in each groups and significant negative correlation was only obtained in the group treated with I-131 anti-CEA antibody (p〈0.05). There were no correlations between antigenic expression of carcinoembryonic antigen and distribution of anti-CEA antibody in both SNU-C4 and SNU-C5-cell tumors on immunoperoxidase staining Qn in vivo autoradiography the distributions of anti-CEA antibody were heterogeneous and the intensities of binding were various in SNU-C4 and SNU-C5 cell tumors. It is concluded that I-131 labeled tumor-specific monoclonal antibody, anti-CEA antibody is effective in suppressing the xenografted tumor growth and the effect is influenced by sensitivity of tumor cell itself to the radiolabeled antibody and other local factors instead of specificity of antibody.

FDG - PET을 이용한 악성과 양성 연부조직 병변의 감별 : 반정량적 지표간의 비교

김병태(Byung Tae Kim),김상은(Sang Eun Kim),이경한(Kyung Han Lee),최준영(Joon Young Choi),최용(Yearn Seong Choe),최연성(Yong Choi),서재곤(Jai Gon Seo) 대한핵의학회 1997 핵의학 분자영상 Vol.31 No.1

N/A The purpose of this study is to evaluate the diagnostic accuracy of various quantitative indices for the differentiation of benign from malignant primary soft tissue tumors by FDG-PET. A series of 32 patients with a variety of histologically or clinically confirmed benign (20) or malignant (12) soft tissue lesions were evaluated with emission whole body (5min/bed position) PET after injection of [18F]FDG. Regional 20min transmission scan for the attenuation correction and calculation of SUV was performed in 16 patients (10 benign, 6malignant) followed by dynamic acquisition for 56min. Postinjection transmission scan for the attenuation correction and calculation of SUV was executed in the other 16 patients (10 benign, 6 malignant). The following indices were obtained : the peak and average SUV (pSUV, aSUV) of lesions, tumor-to-background ratio acquired at images of 51 min p.i. (TBR51), tumor-to-background ratio of areas under time-activity curves (TBRarea) and the ratio between the activities of tumor ROI at 51 min p.i. and at the time which background ROI reaches maximum activity on the time-activity curves (T51/Tmax). The pSUV, aSUV, TBR51, and TBRarea, in malignant lesions were significantly higher than those in benign lesions. We set the cut-off values of pSUV, aSUV, TBR51, TBRarea and T51/Tmax for the differentiation of benign and malignant lesions at 3.5, 2.8, 5.1, 4.3 and 1.55, respectively. The sensitivity, specificity and accuracy were 91.7%, 80.0%, 84.4% by pSUV and aSUV, 83.3%, 85.0%, 84.4% by TBR51, 83.3%, 100%, 93.8% by TBRarea and 66.7%, 70.0%, 68.8% by Tsl/Tmax. The time-activity curves did not give additional information compared to SUV or TBR. The one false negative was a case with low-grade fibrosarcoma and all four false positives were cases with inflammatory change on histology. The visual analysis of FDG-PET also detected the metastatic lesions in malignant cases with comparable accuracy. In conclusion, all pSUV, aSUV, TBR51, and TBRarea are useful metabolic semi-quantitative indices with good accuracy for the differentiation of benign from malignant soft-tissue lesions.

철운단백질 포화정도에 따른 Gallium-67 체내분포의 변화

김병태(Byung Tae Kim),김상은(Sang Eun Kim),이경한(Kyung Han Lee),최준영(Joon Young Choi) 대한핵의학회 1998 핵의학 분자영상 Vol.32 No.1

We present a case of a young female patient with fulminant hepatitis who showed an altered biodistribution of Ga-67, after being scanned twice at 10 month intevals. On initial scan, uptake of Ga-67 was increased in the liver, kidneys, and skeletons. Increased hepatic Ga-67 uptake may be explained by increased transferrin unbound Ga-67 that was taken up by the inflamed liver. The saturation of iron-binding proteins due to multiple transfusions may lead to increased renal and skeletal Ga-67 uptake. On follow-up scan hepatic Ga-67 uptake was markedly increased. Also increased Ga-67 uptake in the axial skeleton and normalized renal uptake were shown. The findings were consistent with iron deficiency anemia. This case demonstrates altered Ga-67 biodistribution associated with multiple transfusions, fulminant hepatitis, and iron deficiency anemia.

생쥐 간 S9 분획을 이용한 방사성추적자 대사물질의 새로운 체외 측정방법

류은경 ( Eun Kyoung Ryu ),최연성 ( Yearn Seong Choe ),김동현 ( Dong Hyun Kim ),이상윤 ( Sang Yoon Lee ),최용 ( Yong Choi ),이경한 ( Kyung Han Lee ),김병태 ( Byung Tae Kim ) 대한핵의학회 2004 핵의학 분자영상 Vol.38 No.4