Recent Advances in Nuclear Cardiology

Lee, Won Woo The Korea Society of Nuclear Medicine 2016 핵의학 분자영상 Vol.50 No.3

Nuclear cardiology is one of the major fields of nuclear medicine practice. Myocardial perfusion studies using single-photon emission computed tomography (SPECT) have played a crucial role in the management of coronary artery diseases. Positron emission tomography (PET) has also been considered an important tool for the assessment of myocardial viability and perfusion. However, the recent development of computed tomography (CT)/magnetic resonance imaging (MRI) technologies and growing concerns about the radiation exposure of patients remain serious challenges for nuclear cardiology. In response to these challenges, remarkable achievements and improvements are currently in progress in the field of myocardial perfusion imaging regarding the applicable software and hardware. Additionally, myocardial perfusion positron emission tomography (PET) is receiving increasing attention owing to its unique capability of absolute myocardial blood flow estimation. An F-18-labeled perfusion agent for PET is under clinical trial with promising interim results. The applications of F-18 fluorodeoxyglucose (FDG) and F-18 sodium fluoride (NaF) to cardiovascular diseases have revealed details on the basic pathophysiology of ischemic heart diseases. PET/MRI seems to be particularly promising for nuclear cardiology in the future. Restrictive diseases, such as cardiac sarcoidosis and amyloidosis, are effectively evaluated using a variety of nuclear imaging tools. Considering these advances, the current challenges of nuclear cardiology will become opportunities if more collaborative efforts are devoted to this exciting field of nuclear medicine.

Tc-99m Ciprofloxacin SPECT of Pulmonary Tuberculosis

Lee, Min-Kyung,Yoon, Min-Ki,Hwang, Kyung-Hoon,Choe, Won-Sick The Korea Society of Nuclear Medicine 2010 핵의학 분자영상 Vol.44 No.2

Purpose Tc-99m ciprofloxacin is available for imaging infection. However, there has been no study on employing single photon emission computed tomography (SPECT) with using Tc-99m ciprofloxacin to image active pulmonary tuberculosis. Therefore, we conducted this study to assess the efficacy of Tc-99m ciprofloxacin SPECT for imaging active pulmonary tuberculosis. Methods Twenty-one participants were enrolled in this prospective study. They were divided into two groups according to the clinical and radiological assessment. Group one (Gr. 1) consisted of five normal volunteers and six patients with inactive pulmonary tuberculosis. Group two (Gr. 2) consisted of ten patients with active pulmonary tuberculosis. SPECT was performed 3 h after injecting 555 MBq (15 mCi) of Tc-99m ciprofloxacin. The findings of Tc-99m ciprofloxacin SPECT were interpreted by a nuclear medicine specialist and then the results were analyzed according to the patients' clinical and radiological classifications. Results The results of Tc-99m ciprofloxacin SPECT were as follows: eight true-positive cases, ten true-negative cases, one false-positive case and two false-negative cases. The sensitivity and specificity was 80.0% and 90.9%, respectively. The positive predictive value was 88.9% and the negative predictive value was 83.3%. Conclusions Tc-99m ciprofloxacin SPECT is feasible for imaging active pulmonary tuberculosis. It is a useful nuclear-imaging method for discriminating between the active and inactive tuberculosis states in patients with a past medical history of pulmonary tuberculosis.

EDITORIAL : Molecular Pain Imaging by Nuclear Medicine: Where Does It Stand and Where Is It Going?

Min, Jung-Joon The Korea Society of Nuclear Medicine 2016 핵의학 분자영상 Vol.50 No.4

The Current Status and Future Perspectives of Nuclear Medicine in Korea

Lee, Myung-Chul,Oh, So-Won,Chung, June-Key,Lee, Dong-Soo The Korea Society of Nuclear Medicine 2010 핵의학 분자영상 Vol.44 No.2

Since the introduction of nuclear medicine in 1959, Korea accomplished a brilliant development in terms of both clinical practice and research activities, which was mainly due to the dedication of nuclear medicine specialists, consisting of physicians, technicians, and scientists, and strong support from the Korean Government. Now, Korea has 150 medical institutes, performing approximately 561,000 nuclear imaging procedures and 11.6 million in vitro studies in 2008, and ranked fourth in the number of presentations at the Annual Meeting of the Society of Nuclear Medicine (SNM) in 2008. The successful progress in this field has allowed Korea to focus on the international promotion of nuclear medicine, especially in the developing and underdeveloped countries. In consequence, the Asian Regional Cooperative Council for Nuclear Medicine (ARCCNM) was established in 2001, and Seoul hosted the 9th Congress of the World Federation of Nuclear Medicine and Biology (WFNMB) in 2006. In the future, Korea will strive to sustain its rate of advancement in the field and make every effort to share its progress and promote the exchange of scientific information at the international level.

Clinical Implication of PET/MR Imaging in Preoperative Esophageal Cancer Staging: Comparison with PET/CT, Endoscopic Ultrasonography, and CT

Lee, Geewon,I, Hoseok,Kim, Seong-Jang,Jeong, Yeon Joo,Kim, In Joo,Pak, Kyoungjune,Park, Do Yun,Kim, Gwang Ha Society of Nuclear Medicine 2014 The Journal of nuclear medicine Vol.55 No.8

<P>This was a study to compare the diagnostic efficacies of endoscopic ultrasonography (EUS), CT, PET/MR imaging, and PET/CT for the preoperative local and regional staging of esophageal cancer, with postoperative pathologic stage used as the reference standard. <B>Methods:</B> During 1 y, 19 patients with resectable esophageal cancer were enrolled and underwent preoperative EUS, CT, PET/CT, and PET/MR imaging. A chest radiologist and nuclear medicine physician retrospectively reviewed the images and assigned tumor and lymph node stages according to the seventh version of the TNM system and the American Joint Committee on Cancer staging system. Four patients who were treated nonsurgically were excluded from data analysis. The efficacies of EUS, CT, PET/CT, and PET/MR imaging were compared. <B>Results:</B> Primary tumors were correctly staged in 13 (86.7%), 10 (66.7%), and 5 (33.3%) patients at EUS, PET/MR imaging, and CT, respectively (<I>P</I> value ranging from 0.021 to 0.375). The accuracy of determining T1 lesions was 86.7%, 80.0%, and 46.7% for EUS, PET/MR imaging, and CT, respectively. For distinguishing T3 lesions, the accuracy was 93.3% for EUS and 86.7% for both PET/MR imaging and CT. For lymph node staging, the accuracy was 83.3%, 75.0%, 66.7%, and 50.0% for PET/MR imaging, EUS, PET/CT, and CT, respectively. In addition, area-under-the-curve values were 0.800, 0.700, 0.629, and 0.543 for PET/MR imaging, EUS, PET/CT, and CT, respectively. <B>Conclusion:</B> PET/MR imaging demonstrated acceptable accuracy for T staging compared with EUS and, although not statistically significant, even higher accuracy than EUS and PET/CT for prediction of N staging. With adjustments in protocols, PET/MR imaging may provide an important role in preoperative esophageal cancer staging in the future.</P>

Whole-Body Voxel-Based Personalized Dosimetry: The Multiple Voxel S-Value Approach for Heterogeneous Media with Nonuniform Activity Distributions

Lee, Min Sun,Kim, Joong Hyun,Paeng, Jin Chul,Kang, Keon Wook,Jeong, Jae Min,Lee, Dong Soo,Lee, Jae Sung Society of Nuclear Medicine 2018 The Journal of nuclear medicine Vol.59 No.7

<P>Personalized dosimetry with high accuracy is becoming more important because of the growing interest in personalized medicine and targeted radionuclide therapy. Voxel-based dosimetry using dose point kernel or voxel S-value (VSV) convolution is available. However, these approaches do not consider the heterogeneity of the medium. Here, we propose a new method for whole-body voxel-based personalized dosimetry in heterogeneous media with nonuniform activity distributions—a method we refer to as the multiple VSV approach. Instead of using only a single VSV, as found in water, the method uses multiple numbers (<I>N</I>) of VSVs to cover media of various density ranges, as found in the whole body. <B>Methods:</B> The VSVs were precalculated using GATE Monte Carlo simulation and were convoluted with the time-integrated activity to generate density-specific dose maps. CT-based segmentation was performed to generate a binary mask image for each density region. The final dose map was acquired by the summation of <I>N</I> segmented density-specific dose maps. We tested several sets of VSVs with different densities: <I>N</I> = 1 (single water VSV), 4, 6, 8, 10, and 20. To validate the proposed method, phantom and patient studies were conducted and compared with the direct Monte Carlo approach, which was considered the ground truth. Finally, dosimetry on 10 patients was performed using the multiple VSV approach and compared with the single VSV and organ-based approaches. Errors at the voxel and organ levels were reported for 8 organs. <B>Results:</B> In the phantom and patient studies, the multiple VSV approach showed significant decreases in voxel-level errors, especially for the lung and bone regions. As the number of VSVs increased, voxel-level errors decreased, although some overestimations were observed at the lung boundaries. For the multiple VSVs (<I>N</I> = 8), we achieved a voxel-level error of 2.06%. In the dosimetry study, our proposed method showed greatly improved results compared with single VSV and organ-based dosimetry. Errors at the organ level were −6.71%, 2.17%, and 227.46% for single VSV, multiple VSV, and organ-based dosimetry, respectively. <B>Conclusion:</B> The multiple VSV approach for heterogeneous media with nonuniform activity distributions offers fast personalized dosimetry at the whole-body level, yielding results comparable to those of the direct Monte Carlo approach.</P>

Hepatocyte-Targeted Nuclear Imaging Using ^99mTc-Galactosylated Chitosan: Conjugation, Targeting, and Biodistribution

Kim, E.-M.,Jeong, H.-J.,Park, I.-K.,Cho, C.-S.,Kim, C.-G.,Bom, H.-S. THE SOCIETY OF NUCLEAR MEDICINE INC 2005 The Journal of nuclear medicine Vol.46 No.1

The Comparison of Image Quality Using Body Contour and Circular Method with L-mode in Myocardial Perfusion SPECT

김성환,남기표,류재광,윤순상,Kim, Sung-Hwan,Nam, Ki-Pyo,Ryu, Jae-Kwang,Yoon, Soon-Sang The Korean Society of Nuclear Medicine Technology 2012 핵의학 기술 Vol.16 No.1

심근관류 SPECT의 영상획득 방법에는 Body contour와 Circular 방식이 있고, 환자와 검출기 사이의 거리를 줄이기 위해 Body contour 방식을 주로 사용한다. 그러나 이중(Dual) 검출기 장비에서 수직방식으로 검출기를 설정하여 영상을 획득하는 경우에는 환자와 검출기 사이의 거리가 Body contour 방식이 Circular 방식에 비해 더 증가하는 경향이 있다. 본 연구의 목적은 이중 검출기 장비에서 수직방식으로 검출기를 설정하여 영상을 획득하는 경우, Body contour 방식과 Circular 방식에서 환자와 검출기 사이의 거리를 비교하고, 거리에 따라 영상에 미치는 영향을 파악하여 영상의 질을 높이기 위한 방안을 제시하고자 시행하였다. 실험에 사용된 장비는 GE INFINIA Gamma Camera와 Anthropomorphic torso 모형에 심장 모형을 삽입하여 영상을 획득하였고, 2011년 8월 본원에서 심근관류 SPECT를 시행한 환자 40명을 대상으로 하였다. 모형 제작은 실제 환자조건과 동일하게 하기 위하여 심근에 74 kBq (0.22 mCi)/cc, 폐에 2.59 kBq ($60{\mu}Ci$)/cc, 연부조직에 11.1 kBq (2.2 mCi)/cc의 201-Tl을 주입하여 제작하였고, 영상획득 조건은 회전각 $6^{\circ}$, 50 sec/frame으로 환자와 동일한 조건으로 하였다. 영상획득 방식에 따른 차이를 확인하기 위해 Body contour와 Circular 방식으로 영상을 획득하여 환자와 검출기 사이의 거리를 각각 측정하여 비교하였고, 정상군과 비 정상군의 영상을 육안 분석하였다. 거리에 따라 영상에 미치는 영향을 확인하기 위해, 모형 실험에서 Circular 방식으로 회전반경을 18.8, 21.8, 23.8, 25.8, 28.8 cm 로 다르게 설정하여 영상을 획득하였고, 각 영상에서 심첨(Apex)에 관심영역을 설정하여 반치폭을 비교하였다. 모형 실험 결과, Body contour를 이용한 실험에서 산출된 반치폭은 6.23 mm이고, Circular mode에서 18.8, 21.8, 23.8, 25.8, 28.8 cm의 회전반경으로 산출된 반치폭은 각각 5.41, 6.24, 6.33, 6.42, 6.93 mm이다. 환자 데이터에서 Body contour의 회전반경이 -3.5 cm ~ 9.5 cm으로 차이를 보였고, Circular mode에 비해 평균 2.5 cm 더 큰 차이를 보였다. 본 연구를 통해, INFINIA 장비에서 Circular mode가 Body contour를 사용한 영상 획득 방법보다 낮은 반치폭을 보였다. 비록 INFINIA장비의 두 가지 영상 획득 방식에 대한 비교였지만, INFINIA장비를 이용한 심근관류 검사에서는 Circular mode 의 영상 획득 방식이 더 적합하다고 사료된다. Purpose : In myocardial perfusion SPECT, the type of orbit (circular vs. body contouring) that affect the image quality is still on the debate. Presently in the nuclear medicine field, the body contouring orbit acquisition is widely used to improve the image quality on the myocardial perfusion SPECT. But in case of body contouring acquisition using the vertical method with dual detect machine, there is a tendency of increasing the radius. In this research, we compared body contouring orbit acquisition with circular orbit acquisition, so we suggest ideal method that reduces the radius for improving image quality. Materials and Methods : Phantom and clinical studies were performed. The anthropomorphic torso phantom was made on equally with counts from patient's body. The study was performed under six different conditions. To compare image quality according to the radius, we increased radius sequentially per step during circular orbit acquisition. On the other hand, sensors that protect a collision and reduce the radius automatically were used to acquire image during body contouring orbit acquisition. So we compared FWHM value of apex. In clinical studies, we analyzed the 40 patients who were examined by Tl-201 gated myocardial perfusion SPECT in department of nuclear medicine at Asan Medical Center in August 2011. To acknowledge the differences according to the radius, we acquired the results two times using circular orbit acquisition and body contouring orbit acquisition. Results : In phantom study, we analyzed that increase of radius resulted in changes of FWHM value. It was 5.41, 6.24, 6.33, 6.42, 6.93 mm. On the other hand, using the body contouring orbit acquisition, FWHM value was 6.23 mm. In clinical study, difference of average radius between two methods was 2.5 cm (circular orbit acquisition was more close to patients). Conclusion : Through the experiments using Anthropomorphic torso phantom and patients data, we found that FWHM value of circular orbit acquisition was lower than body contouring orbit acquisition. As a result, if the difference of average radius exists approximately 3 cm, circular orbit type acquisition is better than body contouring type acquisition. But clinical investigation is only aimed to average radius, so it needs more investigation in comparison of patient's image.

Hospital Radiation Safety and Radioactive Waste Management (Radiation Protection in Nuclear Medicine - What's our role ? -)

Watanabe, Hiroshi The Korean Society of Nuclear Medicine Technology 2008 핵의학 기술 Vol.12 No.2

PET-Based Molecular Nuclear Neuro-Imaging

Kim, Jong-Ho The Korea Society of Nuclear Medicine 2004 핵의학 분자영상 Vol.37 No.5

분자영상은 살아있는 개체의 몸 속에서 일어나는 생물학적 반응이나 특정한 표적분자를 비관혈적이며 반복적으로 영상화하는 기술이다. 이를 위해서는 두 가지 기본 요소가 요구되는 바 하나는 관심 생물현상에 의해 농도나 분광특성이 변하는 분자영상용 추적자이며 다른 하나는 이런 추적자를 모니터링하는 장비이다. 분자 핵의학 영상기술은 이제 신경과학분야에서도 활발히 적용되고 있으며 신경관련 기초연구나 뇌질환 관련 신약개발에 이미 중요한 역할을 하고 있다. 최근에는 살아있는 개체에서 약제 투여가 뇌에 미치는 약물학적, 생리적 영향을 조사하는 데에도 이용되고 있다. 다가오는 미래에는 각종 뇌질환에서 특이적 표적을 공략하는 새로운 분자치료가 개발되어 뇌질환 치료에 혁명적인 변화를 가져올 것으로 예상되고 있다. 그 예로, 파킨슨씨 병과 같은 퇴행성 신경질환에 줄기세포를 이용한 자가수선, 신경보호, 약물분비 치료, 성장인자와의 병행치료 등이 개발되고, 유전자 치료도 이용될 것으로 보인다. 신경 분자 핵의학 영상은 이와 같은 새로운 뇌질환 치료기술의 개발에 있어서 뇌 안에서 일어나는 분자수준의 변화를 실시간으로 모니터링함으로써 관련연구에 크게 기여할 것으로 기대된다. Molecular Nuclear Neuro-Imaging in "CNS" drug discovery and development tan be divided into four categories that are clearly inter-related.(1) Neuroreceptor mapping to examine the involvement of specific neurotransmitter system in CNS diseases, drug occupancy characteristics and perhaps examine mechanisms of action;(2) Structural and spectroscopic imaging to examine morphological changes and their consequences;(3) Metabolic mapping to provide evidence of central activity and "CNS fingerprinting" the neuroanatomy of drug effects;(4) Functional mapping to examing disease-drug interactions. In addition, targeted delivery of therapeutic agents could be achieved by modifying stem cells to release specific drugs at the site of transplantation('stem cell pharmacology'). Future exploitation of stem cell biology, including enhanced release of therapeutic factors through genetic stem cell engineering, might thus constitute promising pharmaceutical approaches to treating diseases of the nervous system. With continued improvements in instrumentation, identification of better imaging probes by innovative chemistry, molecular nuclear neuro-imaging promise to play increasingly important roles in disease diagnosis and therapy.