• Nuclear Engineering and Technology
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• v.38 no.5
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• pp.399-404
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• 2006

Noninvasive molecular targeting in living subjects is highly demanded for better understanding of such diverse topics as the efficient delivery of drugs, genes, or radionuclides for the diagnosis or treatment of diseases. Progress in molecular biology, genetic engineering and polymer chemistry provides various tools to target molecules and cells in vivo. We used chitosan as a polymer, and $^{99m}Tc$ as a radionuclide. We developed $^{99m}Tc-galactosylated$ chitosan to target asialoglycoprotein receptors for nuclear imaging. We also developed $^{99m}Tc-HYNIC-chitosan-transferrin$ to target inflammatory cells, which was more effective than $^{67}Ga-citrate$ for imaging inflammatory lesions. For an effective delivery of molecules, a longer circulation time is needed. We found that around 10% PEGylation was most effective to prolong the circulation time of liposomes for nuclear imaging of $^{99m}Tc-HMPAO-labeled$ liposomes in rats. Using various characteristics of molecules, we can deliver drugs into targets more effectively. We found that $^{99m}Tc-labeled$ biodegradable pullulan-derivatives are retained in tumor tissue in response to extracellular ion-strength. For the trafficking of various cells or bacteria in an intact animal, we used optical imaging techniques or radiolabeled cells. We monitored tumor-targeting bacteria by bioluminescent imaging techniques, dentritic cells by radiolabeling and neuronal stem cells by sodium-iodide symporter reporter gene imaging. In summary, we introduced recent achievements of molecular nuclear imaging technologies in targeting receptors for hepatocyte or inflammatory cells and in trafficking bacterial, immune and stem cells using molecular nuclear imaging techniques.

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2640-2645
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• 2021

We report the development of a gamma-ray imaging device, named Large-Area Hybrid Gamma Imager (LAHGI), featuring high imaging sensitivity and good imaging resolution over a broad energy range. A hybrid collimation method, which combines mechanical and electronic collimation, is employed for a stable imaging performance based on large-area scintillation detectors for high imaging sensitivity. The system comprises two monolithic position-sensitive NaI(Tl) scintillation detectors with a crystal area of 27 × 27 cm² and a tungsten coded aperture mask with a modified uniformly redundant array (MURA) pattern. The performance of the system was evaluated under several source conditions. The system showed good imaging resolution (i.e., 6.0-8.9° FWHM) for the entire energy range of 59.5-1330 keV considered in the present study. It also showed very high imaging sensitivity, successfully imaging a 253 µCi ¹³⁷Cs source located 15 m away in 1 min; this performance is notable considering that the dose rate at the front surface of the system, due to the existence of the ¹³⁷Cs source, was only 0.003 µSv/h, which corresponds to ~3% of the background level.

• The Korean Journal of Nuclear Medicine
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• v.38 no.2
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• pp.171-174
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• 2004

Angiogenesis, the formation of new capillaries from existing vessels, increases oxygenation and nutrient supply to ischemic tissue and allows tumor growth and metastasis. As such, angiogenesis targeting provides a novel approach for cancer treatment with easier drug delivery and less drug resistance. Therapeutic anti-angiogenesis has shown impressive effects in animal tumor models and are now entering clinical trials. However, the successful clinical introduction of this new therapeutic approach requires diagnostic tools that can reliably measure angiogenesis in a noninvasive and repetitive manner. Molecular imaging is emerging as an exciting new discipline that deals with imaging of disease on a cellular or genetic level. Angiogenesis imaging is an important area for molecular imaging research, and the use of radiotracers offers a particularly promising technique for its development. While current perfusion and metabolism radiotracers can provide useful information related to tissue vascularity, recent endeavors are focused on the development of novel radioprobes that specifically and directly target angiogenic vessels. Presently available proges include RGD sequence containing peptides that target ${\alpha}_v\;{\beta}_3$ integrin, endothelial growth factors such as VEGF or FGF, metalloptoteinase inhibitors, and specific antiangiogenic drugs. It is now clear that nuclear medicine techniques have a remarkable potential for angiogenesis imaging, and efforts are currently continuing to develop new radioprobes with superior imaging properties. With future identification of novel targets, design of better probes, and improvements in instrumentation, radiotracer angiogenesis imaging promises to play an increasingly important role in the diagnostic evaluation and treatment of cancer and other angiogenesis related diseases.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.4
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• pp.344-351
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• 2009

Purpose: Optical imaging is providing great advance and improvement in genetic and molecular imaging of animals and humans. Optical imaging system consists of optical imaging devices, which carry out major function for monitoring, tracing, and imaging in most of molecular in-vivo researches. In bio-luminescent imaging, small animals containing luciferase gene locally irradiate light, and emitted photons transmitted through skin of the small animals are imaged by using a high sensitive charged coupled device (CCD) camera. In this paper, we introduced optical imaging system for the image acquisition of bio-luminescent signals emitted from small animals. Materials and Methods: In the system, Nikon lens and four LED light sources were mounted at the inside of a dark box. A cooled CCD camera equipped with a control module was used. Results: We tested the performance of the optical imaging system using effendorf tube and light emitting bacteria which injected intravenously into CT26 tumor bearing nude mouse. The performance of implemented optical imaging system for bio-luminescence imaging was demonstrated and the feasibility of the system in small animal imaging application was proved. Conclusion: We anticipate this system could be a useful tool for the molecular imaging of small animals adaptable for various experimental conditions in future.

• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1460-1471
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• 2024

2D and 3D ultrasonic imaging has so far not been demonstrated in pure molten lead in the open literature. In this study the development of such an ultrasonic device for imaging is outlined and results from testing at 380 ℃ in lead are presented. The main difficulties were found to be achieving then maintaining suitable wetting while ensuring suitable durability of the device, both due to the harsh nature of molten lead and the elevated temperatures. The successful detection and imaging (2D and 3D), of differently shaped targets, where the features were above the size of the transmitted ultrasound beam was demonstrated.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.7 no.2
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• pp.133-140
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• 2021

Various iron oxide nanoparticle-based radiomaterials(IO-NRM) can be used for multimodal imaging of magnetic resonance imaging and molecular imaging, can be easily sized, can be easily functionalized, and have biocompatibility, making them a very good platform for molecular imaging. Based on the previously revealed molecular imaging technology of iron oxide nanoparticles, this paper introduces the in vivo distribution and use in various diseases through iron oxide nanoparticles-based radiolabeled compounds for diagnosis and treatment of iron oxide nanoparticles-based molecular imaging platforms. We would like to look forward to its potential as a radiopharmaceutical.

• Nuclear Engineering and Technology
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• v.48 no.3
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• pp.597-607
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• 2016

Personalized medicine is tailored medical treatment that targets the individual characteristics of each patient. Theragnosis, combining diagnosis and therapy, plays an important role in selecting appropriate patients. Noninvasive in vivo imaging can trace small molecules, antibodies, peptides, nanoparticles, and cells in the body. Recently, imaging methods have been able to reveal molecular events in cells and tissues. Molecular imaging is useful not only for clinical studies but also for developing new drugs and new treatment modalities. Preclinical and early clinical molecular imaging shows biodistribution, pharmacokinetics, mechanisms of action, and efficacy. When therapeutic materials are labeled using radioisotopes, nuclear imaging with positron emission tomography or gamma camera can be used to treat diseases and monitor therapy simultaneously. Such nuclear medicine technology is defined as radiation theragnosis. We review the current development of drugs and technology for radiation theragnosis using peptides, albumin, nanoparticles, and cells.

• 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.6
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• pp.425-434
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• 2008

Dopamine transporter imaging is useful in the diagnosis of Parkinson's disease and the most successful technique in the clinical use of neuroreceptor imaging. Recently, several radiopharmaceuticals including I-123 FP-CIT, Tc-99m TRODAT, and F-18 FP-CIT for dopamine transporter imaging have been approved for the routine clinical use in several European countries, Taiwan and Korea, respectively. This review summarized the practical issue for the routine clinical examination of dopamine transporter imaging.

• The Korean Journal of Nuclear Medicine
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• v.32 no.3
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• pp.211-224
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• 1998

The role of scintigraphic imaging has moved from the detection of lesions to the tissue-specific characterization of lesions over the past 2 decades. Major advances in nuclear medicine imaging include: 1) positron imaging, 2) improved instrumentation, such as the use of multidetector (dual or triple head) gamma cameras for single photon emission computed tomography, and 3) development of numerous new radiopharmaceuticals for positron or single photon imaging (labeled glucose analogue, amino acids, fatty acids, hormones, drugs, receptor ligands, monoclonal antibodies, etc). These advances have resulted in a significantly improved efficacy of radionuclide techniques for the evaluation of various tumors, including those within the liver. The current role of nuclear medicine in the evaluation of focal hepatic tumors is reviewed in this article with an emphasis on the clinical applications of various tracer studies and imaging findings.