신장 방사선 섭취량 결정을 위한 Conjugate View 방법에 대한 평가

봉정균 ( Jung Kyun Bong ),윤미진 ( Mi Jin Yun ),이종두 ( Jong Doo Lee ),김희중 ( Hee Joung Kim ),손혜경 ( Hye Kyung Son ),권윤영 ( Yun Young Kwon ),박해정 ( Hae Jeong Park ),김유선 ( Yu Seun Kim ) 대한핵의학회 2005 핵의학 분자영상 Vol.39 No.3

SPECT 영상 산란보정 개선: 몬테칼로 시뮬레이션 연구

봉정균 ( Jung Kyun Bong ),김희중 ( Hee Joung Kim ),손혜경 ( Hye Kyung Son ),이종두 ( Jong Doo Lee ),정해조 ( Hae Jo Jung ) 대한핵의학회 2005 핵의학 분자영상 Vol.39 No.3

< Tc-99m > TRODAT-1과 < I-123 > IST SPECT를 이용한 도파민 운반체의 영상화 및 정량분석 비교

이희경(Hee Kyung Lee),김희중(Hee Joung Kim),봉정균(Jung Kyun Bong) 대한핵의학회 1998 핵의학 분자영상 Vol.32 No.1

N/A The SPECT radiopharmaceuticals labeled with I-123 for dopamine transporter imaging have been used to measure dopamine transporters in patients with movement disorders. However, a cyclotron produced I-123 limits its availiability and ease of use as a radioisotope to be labeled with pharmaceuticals in routine clinical diagnostic procedures. Recently, new radiopharmaceuticals for Tc-99m which has optimal characteristic for SPECT imaging have been developed to overcome the limits of using I-123. The purpose of this study was to compare the quality of [Tc-99m]TRODAT-1 with [I-123]IPT SPECT data and then to evaluate the usefulness of [Tc-99m]TRODAT-I SPECT by using three noninvasive simplified quantitative methods. TRODAT-1 labeled with Tc-99m(15.93±0.82 mCi) and IPT labeled with I-123(6.60±0.11 mCi) were injected into five normal controls. Dynamic [Tc-99m] TRODAT-I SPECT scans of brain were performed for 10 minutes each over 180 minnutes, and for 20 minutes at 4 hrs and 5 hrs. [I-123IPT SPECT scans were performed for 5 minutes each over 120 minutes. Time activity curves were generated for the left basal ganglia(LBG), right basal ganglia(RBG), and occipital cortex(OCC). Dopamine transporter parameters were obtained using (BG-OCC)/OCC, graphical method(Rv), and area ratio method(RA). TRODAT-1 and IPT SPECT imaging showed high uptake at the level of the basal ganglia. (BG-OCC)/OCC ratios for TRODAT-1 and IPT were 0.80±0.14, and 3.22±0.81, Rvs were 0.62±0.12, and 2.30±0.35, and RAs were 0.37±0.08 and 1.73±0.31, respectively. In conclusion, further improvement of [Tc-99m]TRODAT-I imaging characteris- tics may be required to estimate the dopamine transporter concentrations in human brains although it shows clear BG localization.

GE AdvanceTM 양전자방출단층촬영기의 표준 성능평가

정하규(Ha Kyu Jeong),김희중(Hee Joung Kim),손혜경(Hye Kyung Son),봉정균(Jung Kyun Bong),정해조(Hai Jo Jung),전태주(Tae Joo Jeon),김재삼(Jae Sam Kim),이종두(Jong Doo Lee),유형식(Hyung Sik Yoo) 대한핵의학회 2001 핵의학 분자영상 Vol.35 No.2

N/A Purpose: The purpose of this study was to establish optimal imaging acquisition conditions for the GE AdvanceTM PET imaging system by performing the acceptance tests designed by National Electrical Manufacturers Association (NEMA) protocol and General Electric Medical Systems (GEMS) test procedures. Materials and Methods: Performance tests were carried out with 18FDG radioactivity source and phantoms by using a standard acquisition mode. Transaxial resolution and scatter fraction tests were performed with a line source and axial resolution with a point source, respectively. A cylindrical phantom made of polymethylmethacrylate (PMMA) was used to measure sensitivity, count rate losses and randoms, uniformity correction, and attenuation inserts were added to measure remaining tests. The test results were acquired in a diagnostic acquisition mode and analyzed mainly on high sensitivity mode. Results: Transaxial resolution and axial resolution were measured as average of 4.65 mm and 3.98 mm at 0 cm, and 6.02 mm and 6.71 mm at 20 cm on high sensitivity mode, respectively. Average scatter fraction was 9.87%, and sensitivity was 225.8 kcps/ Ci/cc of trues. Activity at 50% deadtime was 4.6 Ci/cc, and the error of count rate correction at that activity was from 1.49% to 3.83%. Average nonuniformity for total slice was 8.37%. The accuracy of scatter correction was -0.95%. The accuracies of attenuation correction were 5.68% for air, 0.04% for water and -6.51% for polytetrafluoroethylene (PTFE). Conclusion: The results satisfied most acceptance criteria, indicating that the GE AdvanceTM PET system can be optimally used for clinical applications. (Korean J Nucl Med 2001;35:100-112)

[ I - 123 ] IPT SPECt를 이용한 정상인과 파킨슨환자의 도파민 운반체의 영상화 및 단순화된 정량분석 방법들의 비교연구

문대혁(Dae Hyuk Moon),양승오(Seoung Oh Yang),이희경(Hee Kyung Lee),김희중(Hee Joung Kim),류진숙(Jin Sook Ryu),천준홍(Jun Hong Cheon),임주혁(Joo Hyuck Im),봉정균(Jung Kyun Bong),남기표(Ki Pyo Nam),권수일(Soo Il Kwon) 대한핵의학회 1996 핵의학 분자영상 Vol.30 No.3

N/A The purpose of this study was to compare the specific binding ratio method with model based methods in estimating the transporter parameter k3/k4 in normal controls and Parkinson's patients with [I-123]IPT SPECT and to evaluate the usefulness of [I-123]IPT SPECT. 6.5±1.1 mCi (239.0±40.3 MBq) of [123]IPT was intravenouly injected as a bolus into six normal controls(age:45±13) and seventeen patients(age:55±8) with Pakinson's disease(PD). The transporter parameter k3/k4 was derived using the Ichise's graphical method(Rv) and Lassen's area ratio method(RA) for the dynamic IPT SPECT data without blood samples. Then, the relationships between the transporter parameter Rv, RA and the ratio of (BG-OCC)/OCC at 115 minutes were evaluated by linear regression analysis. Rvs by Ichise's graphical method for NC and PD were 2.08±0.29 and 0.78±0.31, respectively. RAs by Lassen's area ratio method for NC and PD were 1.48±0.16 and 0.65±0.24, respectively. The correlation coefficients between (BG-OCC)/OCC and Rv, (BG-OCC)/OCC and RA, and RV, and RA were 0.93, 0.90, 0.99 and their corresponding slopes were 0.54, 0.34, and 0.65,respectively. The Rv and RA of NC were significantly higher than the ones of PD. That is, the k3/k4 Of NC was clearly separated from the one of PD. k3/k4 showed a good correlation with the ratio of (BG-OCC)/OCC. The results indicate that the noninvasive simplified quantitative methods may be useful to measure the transporter parameter k3/k4 and the specific binding ratio method can be used for quantitative studies of dopamine transporter with [I-123]IPT SPECT in humans brains.

Increase of Tc-99m TBC SPECT Sensitivity for Small Liver Hemangioma using Ordered Subset Expectation Maximization Techique

Jeon, Tae Joo,Bong, Jung Kyun,Kim, Hee Joung,Kim, Myung Jin,Lee, Jong Doo 대한핵의학회 2002 핵의학 분자영상 Vol.36 No.6

목적: 적혈구 혈액 풀 SPECT는 높은 특이도로 인하여, 간의 대표적인 양성 종양인 혈관종의 진단에 널리 사용되어 왔지만 해상도가 이 검사의 단점 중 하나였다. 최근 들어 ordered subset expectation maximization(OSEM이라는 기술이 임상 핵의학 분야에서 단층영상의 재구성에 도입되고 있는 바, 저자들은 간 혈관종을 대상으로 기존의 역투사방식과 새로운 수정된 반복영상구성법인 OSEM을 비교하고자 하였다. 대상 및 방법: 24명의 간 혈관종 환자의 28개의 병변들 각각으로부터 이중 헤드 감마 카메라를 이용하여 단층영상 재구성을 위한 64개의 투사 영상으로 얻었다. 이들 raw data는 LINYX운영체계의 개인용 컴퓨터에 보내서, 각각의 header file을 interfile로 대체하여 OSEM프로그램이 인식할 수 있도록 하였다. 최상의 영상을 구성하는 조건을 알아보기 위하여 다양한 subset 수(1, 2, 4, 8, 16 그리고 32) 및 반복계산 수 (1, 2, 4, 8, 그리고 16)하에서 재구성을 시도하여 4번의 반복계산과 16개의 subset일 때를 최적 조건으로 선택하였다. 이후 이 조건 하에서 OSEM과 역투사 방법으로 각각 모든 대상을 재구성한 후에 3명의 핵의학 및 방사선과 전문의가 특별한 정보없이 모든 영상을 검토하였다. 결과: 28개의 병변을 맹검한 결과, 거의 모든 중례에서 OSEM이 역투사에 비교하여 최소한 대등하거나 우수한 영상의 질을 보여주었다. 비록 3 ㎝이상의 큰 병변의 검출에는 차이가 없었으나 1.5-3 ㎝ 크기의 병변 5개는 OSEM을 통하여서만 발견되었다. 하지만 1.5 ㎝ 미만의 작은 병변 4개는 양쪽 모두에서 검출되지 않았다. 결론: OSEM은 작은 크기의 간 혈관종을 발견하는데 보다 높은 민감도를 보였으며 전체적인 영상의 질에 있어서도 보다 좋은 대조도와 윤곽을 보여주었다. OSEM은 이와 같은 장점 뿐만 아니라 높은 사양의 컴퓨터를 요하지않고 계산시간이 길지 않기 때문에 임상에서 간 혈관종의 진단을 위한 적혈구 혈액풀 SPECT에 쉽게 적용될 수 있는 좋은 방법으로 사료된다. (대한핵의학회지 2002;36;344-56) Purpose: RBC blood pool SPECT has been used to diagnose focal liver lesion such as hemangioma owing to its high specificity. However, low spatial resolution is a major limitation of this modality. Recently, ordered subset expectation maximization (OSEM) has been introduced to obtain tomographic images for clinical application. We compared this new modified iterative reconstruction method, OSEM with conventional filtered back projection (FBP) in imaging of liver hemangioma. Materials and Methods: Sixty four projection data were acquired suing dual head gamma camera in 28 lesions of 24 patients with cavernous hemangioma of liver and these raw data were transferred to LINUX based personal computer. After the replacement of header file as interfile, OSEM was performed under various conditions of subsets (1,2,4,8,16, and 32) and iteration numbers (1,2,4,8, and 16) to obtain the best setting for liver imaging. The best condition for imaging in our investigation was considered to be 4 iterations and 16subsets. After the, all the images were processed by both FBP and OSEM. Three experts reviewed these images without any information. Results: According to blind review of 28 lesions, OSEM images revealed at least same or better image quality than those of FBP in nearly all cases. Although there showed no significant difference in detection of large lesions more than 3 ㎝, 5 lesions with 1.5 to 3 ㎝ in diameter were detected by OSEM only. However, both techniques failed to depict 4 cases of small lesions less than 1.5 ㎝. Conclusion: OSEM revealed better contrast and define in depiction of liver hemangioma as well as higher sensitivity in detection of small lesions. Furthermore this reconstruction method dose not require high performance computer system or long reconstruction time, therefore OSEM is supposed to be good method that can be applied to RBC blood pool SPECT for the diagnosis of liver hemangioma.

감마프로브용 전단증폭기와 주증폭기의 개발과 성능 평가

이종두,김희중,봉정균,권수일 대한핵의학회 1999 핵의학 분자영상 Vol.33 No.1

Purpose: Preamplifier and amplifier are very important parts for developing a portable counting or imaging gamma probe. They can be used for analyzing pulses containing energy and position information for the emitted radiations. The commercial Nuclear Instrument Modules (NIMs) can be used for processing these pulses. However, it may be improper to use NIMs in developing a portable gamma probe, because of its size and high price. The purpose of this study was to develop both preamplifier and amplifier and measure their performance characteristics. Materials and Methodes: The preamplifier and amplifier were designed as a charge sensitive device and a capacitor resistor-rsistor capacitor (CR-RC) electronic circuit, respectively, and they were mounted on a print circuit board (PCB). We acquired and analyzed energy spectra for Tc-99m and Cs-137 using both PCB and NIMs. Multichannel analyzer (Accuspec/A, Caberra Industries Inc., Meriden Connecticut, U.S.A) and scintillation detectors (EP-047 (Bicron Saint-Gobain/Norton Industrial EP-047 (Ceramics Co., Ohio, U.S.A) with 2″×2″ NaI (T1) crystal and R1535 (Hamamatsu Photonics K.K., Electron Tube Center, Shizuoka-ken, Japan) with 1″×1″NaI (T1) crystal) were used for acquiring the energy spectra. Results: Using PCB, energy resolutions or EP-047 detectors for Tc-99m and Cs-137 were 12.92% and 5.01%, respectively, whereas R1535 showed 13.75% and 5.19% of energy resolution. Using the NIM devices, energy resolutions of EP-047 detector for Tc-99m and Cs-137 were measured as 14.6% and 7.58%, respectively. However, reliable energy spectrum of R1535 detector could not be acquired, since its photomultiplier tube (PMT) requires a specific type of preamplifier. Conclusion: We developed a special preamplifier and amplifier suitable for a small sized gamma probe that showed good energy resolutions independent of PMT types. The results indicate that the PCB can be used in developing both counting and imaging gamma probe.