• BMB Reports
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• v.55 no.6
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• pp.267-274
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• 2022

Molecular imaging is used to improve the disease diagnosis, prognosis, monitoring of treatment in living subjects. Numerous molecular targets have been developed for various cellular and molecular processes in genetic, metabolic, proteomic, and cellular biologic level. Molecular imaging modalities such as Optical Imaging, Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT), and Computed Tomography (CT) can be used to visualize anatomic, genetic, biochemical, and physiologic changes in vivo. For in vivo cell imaging, certain cells such as cancer cells, immune cells, stem cells could be labeled by direct and indirect labeling methods to monitor cell migration, cell activity, and cell effects in cell-based therapy. In case of cancer, it could be used to investigate biological processes such as cancer metastasis and to analyze the drug treatment process. In addition, transplanted stem cells and immune cells in cell-based therapy could be visualized and tracked to confirm the fate, activity, and function of cells. In conventional molecular imaging, cells can be monitored in vivo in bulk non-invasively with optical imaging, MRI, PET, and SPECT imaging. However, single cell imaging in vivo has been a great challenge due to an extremely high sensitive detection of single cell. Recently, there has been great attention for in vivo single cell imaging due to the development of single cell study. In vivo single imaging could analyze the survival or death, movement direction, and characteristics of a single cell in live subjects. In this article, we reviewed basic principle of in vivo molecular imaging and introduced recent studies for in vivo single cell imaging based on the concept of in vivo molecular imaging.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10057-10059
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• 2015

Positron emission tomography (PET) as the functional component of current hybrid imaging (like PET/CT or PET/MRI) seems to dominate the horizon of medical imaging in coming decades. $^{18}$Flourodeoxyglucose ($^{18}FDG$) is the most commonly used probe in oncology and also in cardiology and neurology around the globe. However, the major capital cost and exorbitant running expenditure of low to medium energy cyclotrons (about 20 MeV) and radiochemistry units are the seminal reasons of low number of cyclotrons but mushroom growth pattern of PET scanners. This fact and longer half-life of $^{18}F$ (110 minutes) have paved the path of a centralized model in which $^{18}FDG$ is produced by commercial PET radiopharmacies and the finished product (multi-dose vial with tungsten shielding) is dispensed to customers having only PET scanners. This indeed reduced the cost but has limitations of dependence upon timely arrival of daily shipments as delay caused by any reason results in cancellation or rescheduling of the PET procedures. In recent years, industry and academia have taken a step forward by producing low energy, table top cyclotrons with compact and automated radiochemistry units (Lab-on-Chip). This decentralized strategy enables the users to produce on-demand doses of PET probe themselves at reasonably low cost using an automated and user-friendly technology. This technological development would indeed provide a real impetus to the availability of complete set up of PET based molecular imaging at an affordable cost to the developing countries.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2215-2217
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• 2015

Background: This systemic analysis was conducted to to evaluate the application value of positron emission tomography/computed tomography (PET/CT) in early diagnosis of lung cancer. Methods: Clinical studies evaluating the application value of PET/CT for patients underwent PET/CT imaging. The histological diagnosis served as the standard of truth. Results: Four clinical studies which including 1330 patients with pulmonary spaceoccupying lesions were considered eligible for inclusion. Systemic analysis suggested that, in all 1330 patients, pooled sensitivity was 98.7% (1313.2/1330) and specificity was 58.2%(276.85/476). Conclusion: This systemic analysis suggests that integrated PET/CT imaging provides high sensitivity, and reasonably high specificity, and could be applied for early diagnosis of lung cancer.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.sup1
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• pp.134-136
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• 2008

Neuroblastoma is the most common extracranial solid tumor in children. In diagnostic assessment of neuroblastoma, $^{18}F-FDG$ PET has been reported to have high diagnostic performance, especially, very high sensitivity in staging, restaging, and assessment of therapeutic efficacy. In comparison with conventional diagnostic imaging modalities including a, bone scan, and MIBG scan, $^{18}F-FDG$ PET showed better diagnostic performance. According to clinical research data hitherto, $^{18}F-FDG$ PET is expected to be an effective diagnostic tool in the management of neuroblastoma.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.6
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• pp.570-573
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• 2007

We present a case of infected abdominal aortic aneurysm due to salmonella enteritidis. F-18 FDG PET/CT was performed to diagnosis and during follow-up after antibiotic treatment. Computed tomography (CT) is considered to be the best diagnostic imaging modality in infected aortic lesions. In this case, a combination of CT and FDG PET/CT provided accurate information for the diagnosis of infected abdominal aortic aneurysm. Moreover, FDG PET/CT made an important contribution to monitoring disease activity during antibiotic treatment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.7
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• pp.2191-2208
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• 2022

Motion blur in PET (Positron emission tomography) images induced by respiratory motion will reduce the quality of imaging. Although exiting methods have positive performance for respiratory motion correction in medical practice, there are still many aspects that can be improved. In this paper, an improved 3D unsupervised framework, Res-Voxel based on U-Net network was proposed for the motion correction. The Res-Voxel with multiple residual structure may improve the ability of predicting deformation field, and use a smaller convolution kernel to reduce the parameters of the model and decrease the amount of computation required. The proposed is tested on the simulated PET imaging data and the clinical data. Experimental results demonstrate that the proposed achieved Dice indices 93.81%, 81.75% and 75.10% on the simulated geometric phantom data, voxel phantom data and the clinical data respectively. It is demonstrated that the proposed method can improve the registration and correction performance of PET image.

• Korean Journal of Radiology
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• v.22 no.5
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• pp.714-724
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• 2021

Objective: To evaluate the value of ¹⁸F-fluorodeoxyglucose PET/MRI added to contrast-enhanced CT (CECT) in initial staging, assessment of resectability, and postoperative follow-up of biliary tract cancer. Materials and Methods: This retrospective study included 100 patients (initial workup [n = 65] and postoperative follow-up [n = 35]) who had undergone PET/MRI and CECT for bile duct or gallbladder lesions between January 2013 and March 2020. Two radiologists independently reviewed the CECT imaging set and CECT plus PET/MRI set to determine the likelihood of malignancy, local and overall resectability, and distant metastasis in the initial workup group, and local recurrence and distant metastasis in the follow-up group. Diagnostic performances of the two imaging sets were compared using clinical-surgical-pathologic findings as standards of reference. Results: The diagnostic performance of CECT significantly improved after the addition of PET/MRI for liver metastasis (area under the receiver operating characteristic curve [A_z]: 0.77 vs. 0.91 [p = 0.027] for reviewer 1; 0.76 vs. 0.92 [p = 0.021] for reviewer 2), lymph node metastasis (0.73 vs. 0.92 [p = 0.004]; 0.81 vs. 0.92 [p = 0.023]), and overall resectability (0.79 vs. 0.92 [p = 0.007]; 0.82 vs. 0.94 [p = 0.021]) in the initial workup group. In the follow-up group, the diagnostic performance of CECT plus PET/MRI was significantly higher than that of CECT imaging for local recurrence (0.81 vs. 1.00 [p = 0.029]; 0.82 vs. 0.94 [p = 0.045]). Conclusion: PET/MRI may add value to CECT in patients with biliary tract cancer both in the initial workup for staging and determination of overall resectability and in follow-up for local recurrence.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.4
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• pp.301-308
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• 2009

Purpose: The aim of this study was to evaluate the usefulness of FDG-PET/CT as follow up imaging tool in patients with endometrial cancer after therapy. Material and Methods: One hundred one patients with endometrial cancer who underwent FDG PET/CT after the treatment of this disease were included in this study population (25-79 yr old, Mean age 50.6 yr old) and all these patients also performed various laboratory and imaging studies such as serum tumor marker, CT or MRI. The lesions having increased focal FDG uptake were classified into benign, equivocal, and malignant one according to their pattern and activity. Tumor recurrence was confirmed by histopathological results and other clinical and imaging data. Results: Among the 19 patients with 30 malignant or equivocal hot uptakes, 11 of 14 patients supposed to be malignant finding in PET/CT were proved to be tumor recurrence, while one of 5 patients with equivocal lesions were recurred malignancy, Two false negative cases were turned out to be peritoneal carcinomatosis, Estimated sensitivity, specificity and accuracy of PET/CT for diagnosis of recurrence in endometrial carcinoma after treatment were 86 %, 92 % and 91 %, respectively. Positive and negative predictive values in the same issue were 63% and 98%, respectively. Conclusion: FDG-PET/CT is useful for regular work up of endometrial carcinoma after the treatment because of its high negative predictive value as well as high sensitivity and specificity.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.3
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• pp.174-178
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• 2009

Many radiopharmaceuticals have been developed and wildy used in the imaging cardiac function. Myocardial perfusion imaging (MPI) is a well established noninvasive method of assessing coronary blood flow and has been widely used in patients diagnosed or suspected with coronary artery diseases. The innovation of radiopharmaceuticals used in the cardiac imaging is one of the most important contributors to the development of nuclear cardiology. Thallium-201 and various technetium-99m agents have been globally used for myocardial perfusion SPEG, and N-13 ammonia (13NH3), rubidium-82 (82Rb), 0-15 water (H2150) for myocardial perfusion PET. As well as the cardiac perfusion studies, new radiopharmaceuticals that visualize fat metabolism or receptors of the sympathetic nervous system have successfully been applied to clinical practice. Useful information can be obtained for diagnosing coronary artery disease, evaluating patients' condition, or assessing therapeutic effects. In this review, we describe the characteristics and clinical usefulness of radiopharmaceuticals used for cardiac SPEG and PET.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.2
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• pp.88-97
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• 2008

In this review paper, basic configurations of gamma detectors in SPECT and PET systems were reviewed together with key performance parameters of the imaging system, such as the detection efficiency, the spatial resolution, the contrast resolution, and the data acquisition time for quick understanding of the system-component relationship and future design of advanced systems. Also key elements of SPECT and PET detectors, such as collimators, gamma detectors were discussed in conjunction with their current and future trend. Especially development trend of new scintillation crystals, innovative silicon-based photo-sensors and futuristic room-temperature semiconductor detectors were reviewed for researchers who are interested in the development of future nuclear medical imaging instruments.