• The Korean Journal of Nuclear Medicine
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• v.20 no.1
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• pp.17-24
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• 1986

Authors enumerate various malignant and benign cases which showed soft tissue uptake of $^{99m}Tc-MDP$. We hope it might be a help in understanding and interpreting bone scans. Among 10,361 $^{99m}Tc-MDP$ bone scans underwent from April, 1981 to March, 1986, 344 (3.3%) showed abnormal soft tissue uptake, which included 126 malignancies, 5 benign tumors, and 153 nontumorous diseases. Neuroblastoma(23.3%) and malignant fibrous histiocytoma(22.2%) showed highest positive uptake rate among various malignancies. We also illustrated typical cases according to possible mechanisms.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.4
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• pp.366-367
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• 2009

Ga-67 scintigraphy demonstrated increased uptake in the lungs and stomach in a 26-year-old man with hypercalcemia. A primitive neuroectodermal tumor was confirmed by bone marrow examination. Tc-99m MDP uptake in the same locations as Ga-67 revealed by bone scintigraphy was consistent with metastatic calcification. Although the mechanism of Ga-67 uptake in metastatic calcification is not understood, the presence of an inflammatory process is suggested.

• The Korean Journal of Nuclear Medicine
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• v.39 no.3
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• pp.151-162
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• 2005

Hemangioma is the most common benign tumor of the liver, with a prevalence estimated as high as 7%. Tc-99m red blood cell (RBC) hepatic blood pool scan with single photon omission computed tomography (SPECT) imaging is extremely useful for the confirmation or exclusion of hepatic hemangiomas. The classic finding of absent or decreased perfusion and increased blood pooling ("perfusion/blood pool mismatch") is the key diagnostic element in the diagnosis of hemangiomas. The combination of early arterial flow and delayed blood pooling ("perfusion/blood pool match") is shown uncommonly. In giant hemangioma, filling with radioactivity appears first in the periphery, with progressive central fill-in on sequential RBC blood pool scan. However, the reverse filling pattern, which begins first in the center with progressive peripheral filling, is also rarely seen. Studies with false-positive blood pooling have been reported infrequently in nonhemangiomas, including hemangiosarcoma, hepatocellular carcinoma, hepatic adenoma, and metastatic carcinomas (adenocarcinoma of the colon, small cell carcinoma of the lung, neruroendocrine carcinoma). False-negative results have been also reported rarely except for small hemagniomas that are below the limits of spatial resolution of gamma camera.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1517-1523
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• 2020

The widely used medical isotope technetium-99 m (^99mTc) is a daughter of Molybdenum-99 (⁹⁹Mo), which is mainly produced using dedicated research reactors from the nuclear fission of uranium-235 (²³⁵U). ^99mTc has been used for several decades, which covers about 80% of the all the nuclear diagnostics procedures. Recently, the instability of the supply has become an important topic throughout the international radioisotope communities. The aging of major ⁹⁹Mo production reactors has also caused frequent shutdowns. It has triggered movements to establish new research reactors for ⁹⁹Mo production, as well as the development of various ⁹⁹Mo production technologies. In this context, a new research reactor project was launched in 2012 in Korea. At the same time, the development of fission-based ⁹⁹Mo production process was initiated by Korea Atomic Energy Research Institute (KAERI) in 2012 in order to be implemented by the new research reactor. The KAERI process is based on the caustic dissolution of plate-type LEU (low enriched uranium) dispersion targets, followed by the separation and purification using a series of columns. The development of proper waste treatment technologies for the gaseous, liquid, and solid radioactive wastes also took place. The first stage of this process development was completed in 2018. In this paper, the results of the hot test production of fission ⁹⁹Mo using HANARO, KAERI's 30 MW research reactor, was described.

• The Korean Journal of Nuclear Medicine
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• v.33 no.6
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• pp.484-492
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• 1999

Purpose: This study was to evaluate the clinical usefulness of $^{99m}Tc$-MDP bone scintigraphy for assessing vascular ingrowth into the ocular implants after enucleation or evisceration. Materials and Methods: Twenty-four patients (M:F=7:17, mean age: 36 years), who buried a coralline hydroxyapatite after uncomplicated enucleation or evisceration surgery were studied. Dynamic and static scintigraphy on the orbit fossa were obtained after injection of 740 MBq $^{99m}Tc$-MDP to evaluate the status of vascularization. The study was performed from the 3 to 33 weeks after surgery. According to the visual analysis, activity greater than nasal bridge was graded as 4, equal to the nasal bridge as 3, less than nasal bridge but greater than normal orbit as 2, greater than normal orbit but less than grade 2 as 1. Uptake ratio was also calculated by measuring the implants activity (H) and contralateral orbit activity (N). Grading score and uptake ratio were compared with clinical outcome of vascularization. Additionally, we also analyzed the vascularization status as time lapse between primary surgery and scintigraphic study and surgical methods. Results: Twenty-one patients who had bone scintigraphy at 11 weeks after surgery showed increased uptake above grade 2 and greater H/N ratio than 1.16. Of these, 19 patients who had drilling surgery for permanent peg application showed adequate bleeding during the procedure. The activity grade and uptake ratio were inversely correlated with vascular ingrowth. Higher than grade 2 or greater than 1.56 in H/N ratio seemed to be an indicator for better prognosis. Accomplishment of vascularization was not affected by the surgical way such as enucleation or evisceration. Conclusion: $^{99m}Tc$-MDP bone scintigraphy can be a useful method to evaluate the vascularized status of implants. Adequate time for $^{99m}Tc$-MDP bone scintigraphy may be 11-20 weeks after enucleation or evisceration.

• The Korean Journal of Nuclear Medicine
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• v.33 no.3
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• pp.262-272
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• 1999

Purpose: Interictal F-18-fluorodeoxyglucose (FDG) PET and ictal Tc-99m-HMPAO SPECT are found to be useful in localizing epileptogenic zones in neocortical lateral temporal or frontal lobe epilepsy. We investigated whether interictal F-18-FDG PET or ictal Tc-99m-HMPAO SPECT was useful to find epileptogenic Bones in occipital lobe epilepsy (OLE). Materials and Methods: We reviewed patterns of hypometabolism in interictal F-18-FDG PET and of hyperperfusion in ictal Tc-99m-HMPAO SPECT in 17 OLE patients (mean age=$27{\pm}6.8$ year, M:F= 10:7, injection time= $30{\pm}17$ sec). OLE was diagnosed based on invasive electroencephalography (EEG) study, surgery and post-surgical outcome (Engel class I in all for average 14 months). Results: Epileptogenic zones were correctly localized in 9 (60%) out of 15 patients by interictal F-18-FDG PET. Epiletogenic hemispheres were correctly lateralized in 14 patients (93%). By ictal Tc-99m-HMPAO SPECT, epileptogenic hemispheres were correctly lateralized in 13 patients (76%), but localization was possible only in 3 patients (18%). Among patients who showed no abnormality with MR imaging and no correct localization with ictal Tc-99m-HMPAO SPECT, interictal F-18-FDG PET was helpful in 2 patients. Conclusion: Ictal Tc-99m-HMPAO SPECT was helpful in lateralization but not in localization in OLE. Interictal F-18-FDG PET was helpful for localization of epileptogenic zones even in patients with ambiguous MR or ictal SPECT findings.

• 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.

• The Korean Journal of Nuclear Medicine
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• v.22 no.2
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• pp.163-170
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• 1988

8 patients of delayed CO sequelae were evaluated using Brain CT and $^{99m}Tc-HMPAO$ SPECT. The results were as follows; 1) CT findings of delayed CO sequleae were bilateral low density lesion in globus pallidus (l pt.), diffuse low density in white matter with bilateral low density in white matter (l pt.), diffuse low density in white matter with bilateral low density in globus pallidus (l pt.), diffuse low density in white matter with cortical atrophy (l pt.), bilateral low density in globus pallidus and diffuse low density in white matter with cortical atrophy (l pt.) and normal in 3 pts. 2) $^{99m}Tc-HMPAO$ Brain SPECT findings of delayed CO sequelae were decreased regional cerebral blood flow (rCBF) in frontal (1 among 8 pts.), frontal and basal ganglia (3 among 8 pts.), and diffuse patch decreased rCBF pattern (4 among 8 pts.) 3) $^{99m}Tc-HMPAO$ Brain SPECT study was well correlated with neurologic symptoms and signs in delayed CO sequelae. Our results may suggest that reduced cerebral blood flow contributes to the development of delayed CO sequelae.

• The Korean Journal of Nuclear Medicine
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• v.26 no.1
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• pp.26-32
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• 1992

Minimal deterioration of cerebral perfusion or microanatomical changes were undetectable on conventional Brain CT or MRI. So evaluation of focal functional changes of the brain parenchyme is essential in chronic head injury patients, who did not show focal anatomical changes on these radiological studies. However, the patients who had longstanding neurologic sequelae following head injury, there had been no available imaging modalities for evaluating these patients precisely. Therefore we tried to detect the focal functional changes on the brain parenchyme using $^{99m}Tc-HMPAO$ Brain SPECT on the patients of chronic head injuries. Twenty three patients who had suffered from headache, memory dysfunction, personality change and insomnia lasting more than six months fellowing head injury were included in our cases, which showed no anatomical abnormalities on Brain CT or MRI. At first they underwent psychological test whether the symptoms were organic or not. Also we were able to evaluate the cerebral perfusion changes with $^{99m}Tc-HMPAO$ Brain SPECT in 22 patients among the 23, which five patients were focal and 17 patients were nonfocally diffuse perfusion changes. Thus we can predict the perfusion changes such as local vascular deterioration or functional defects using $^{99m}Tc-HMPAO$ Brain SPECT in the patients who had suffered from post-traumatic sequelae, which changes were undetectable on Brain CT or MRI.

• The Korean Journal of Nuclear Medicine
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• v.27 no.2
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• pp.309-314
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• 1993

We report a case of 33-year-old man with a transient splenic uptake who had traumatic multiple rib fractures and hernoperitoneum combined with underlying liver cirrhosis, liver cirrhosis with liver bed laceration and splenomegaly without any other demonstrable splenic lesion due to traffic accident was found by abdominal ultrasound and surgery. Incidentally, $^{99m}Tc$-MDP Bone scan showed whole prominent splenic uptake, spleen was also visible on $^{99m}Tc$ Tin colloid liver scan. We suggest the splenic uptake of the radionuclide temporary splenic infarct to the transient total splenic infarction or unknown traumatic effect.