• Investigative Magnetic Resonance Imaging
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• v.13 no.2
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• pp.213-217
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• 2009

Solitary necrotic nodule (SNN) of the liver is a very uncommon benign lesion, and it is detected incidentally as a rule. It is important to differentiate SNN radiologically from various single hepatic nodules because SNN mimics hepatic metastasis, especially in staging work up of known primary malignancy. The reported imaging findings of SNN are well-defined nodule without enhancement or with subtle peripheral enhancement. There has been no report about the target-like SNN of the liver and about the imaging finding of 3T magnetic resonance imaging and positron emission tomography. We report a case of targetlike SNN of the liver, mimicking hepatic metastasis, with findings of various imaging modalities and try to find a cause of this nodule according to the pathologic and literature review.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.2
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• pp.166-171
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• 2007

GABA is primary an inhibitory neurotransmitter that is localized in inhibitory interneurons. GABA is released from presynaptic terminals and functions by binding to GABA receptors. There are two types of GABA receptors, $GABA_{A}-receptor$ that allows chloride to pass through a ligand gated ion channel and $GABA_{B}-receptor$ that uses G-proteins for signaling. The $GABA_{A}$-receptor has a GABA binding site as well as a benzodiazepine binding sites, which modulate $GABA_{A}$-receptor function. Benzodiazepine GABAA receptor imaging can be accomplished by radiolabeling derivates that activates benzodiazepine binding sites. There has been much research on flumazenil (FMZ) labeled with $^{11}C-FMZ$, a benzodiazepine derivate that is a selective, reversible antagonist to GABAA receptors. Recently, $^{18}F-fluoroflumazenil$ (FFMZ) has been developed to overcome $^{11}C's$ short half-life. $^{18}F-FFMZ$ shows high selective affinity and good pharmacodynamics, and is a promising PET agent with better central benzodiazepine receptor imaging capabilities. In an epileptic focus, because the GABA/benzodiazepine receptor amount is decreased, using $^{11}C-FMZ$ PET instead of $^{18}F-FDG$ PET, restrict the foci better and may also help find lesions better than high resolution MR. $GABA_{A}$ receptors are widely distributed in the cerebral cortex, and can be used as an viable neuronal marker. Therefore it can be used as a neuronal cell viability marker in cerebral ischemia. Also, GABA-receptors decrease in areas where neuronal plasticity develops, therefore, $GAB_{A}$ imaging can be used to evaluate plasticity. Besides these usages, GABA receptors are related with psychological diseases, especially depression and schizophrenia as well as cerebral palsy, a motor-related disorder, so further in-depth studies are needed for these areas.

• The Korean Journal of Nuclear Medicine Technology
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• v.26 no.2
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• pp.37-42
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• 2022

Purpose Since 1985, the Korean society of nuclear medicine technology (KSNMT) has been engaged in academic activities related to nuclear medicine imaging. From 2017 to 2021, the papers published in the journal were classified by the specific fields to examine the trends in the research and the direction of nuclear medicine in comparison with the papers submitted to the Korean Society of Nuclear Medicine (KSNM) during the same period. Materials and Methods From 2017 to 2021, papers submitted to KSNMT and KSNM were classified and databaseization using the Excel program by submission type, examination equipment, and examination field. Through this data, the number of papers published in journals by year, the number of papers submitted by detailed fields, and key words by era were analyzed and compared. Results The papers included by journal was 57 KSNMT and 280 KSNM. The major large classification of equipment, PET, Planar and SPECT was 26.3%, 21.1%, 19.3% in the KSNMT, KSNM was 49.6%, 6.4%, and 9.3%, with 66.7% and 65.3%, respectively. the major medium classification of equipment, industrial safety, urogenital system, nervous system, and quality control accounted for 54.4% of the total papers of the total ratio in the KSNMT, while the medium classification of oncology, endocrine system, urogenital system, therapy, and nervous system accounted for 61.1% of KSNM. In the major small classification of image acquisition, improvement effect, and exposure management accounted for 70.2% in KSNMT, while the items of image acquisition, report, and improvement effect accounted for 60.7% in KSNM. The major keywords except for equipment-related keywords such as PET/CT, PET/MR, and SPECT were SUV, Planar Image, and Respiration Gating Method in KSNMT and Ga68, Thyroid, and Lymphoma in the KSNM. Conclusion When checking the last 5 years of submissions, we can see that KSNMT is mainly concerned with image acquisition using existing radiotracers, while KSNM has focused on new radiotracers such as ⁶⁸Ga, ¹⁷⁷Lu, etc., and new medical technologies of theranostic. It has been confirmed that more PET-related papers than other examination equipment will account for a greater number of papers, and it is believed that future submissions will also account for a higher proportion of PET-related papers than other equipment.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.11
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• pp.171-172
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• 1995

In this paper, an anatomical labeling system for assisting localization of region of interest on human brain imaging is represented. Model image for labeling anatomical name on the other image is Atlas. Object image to be labeled, such as CT, MR, and PET, is registered onto Atlas. And then, anatomical name for region of interest is appeared on a window by clicking mouse button on object image. The same part named anatomically on that region is labeled and drawn on object image.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.301-303
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• 1996

A platform is developed for fast and effective functional mapping of human brain, which can allow semi-automatically the whole processes of an image segmentation, a fusion of MR and PET images, and 3-D rendering of volumetric data, including DICOM-based image transfers from PACS archiver within a short period of time.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.2
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• pp.3-8
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• 2016

Purpose SUV is one of the parameters that assist diagnosis in origin, metastasis and staging of cancer. Specially, it is important to compare SUV before and after chemo or radiation therapy to find out effectiveness of treatment. Storing PET data which has no quantitative change is needed for SUV comparison. However, there is a possibility to loss the data in external hard drive or MINIpacs that are managed by department of nuclear medicine. The aim of this study is to evaluate SUV and metabolic tumor volume (MTV) among reconstructed data (R-D) in workstation, R-D and re-sliced data (S-D) in PACS. Materials and Methods Data of 20 patients (aged $60.5{\pm}8.3y$) underwent $^{18}F-FDG$ PET (Biograph truepoint 40, mCT 40, mCT 64, mMR, Siemens) study were analysed. $SUV_{max}$, $SUV_{peak}$ and MTV were measured in liver, aorta and tumor after sending R-D in workstation, R-D and S-D in PACS to syngo.via software. Results R-D of workstation and PACS showed the same value as mean $SUV_{max}$ in liver, aorta and tumor were $2.95{\pm}0.59$, $2.35{\pm}0.61$, $10.36{\pm}6.15$ and $SUV_{peak}$ were $2.70{\pm}0.51$, $2.07{\pm}0.43$, $7.67{\pm}3.73$(p>0.05) respectively. Mean $SUV_{max}$ of S-D in PACS were decreased by 5.18%, 7.22%, 12.11% and $SUV_{peak}$ 2.61%, 3.63%, 10.07%(p<0.05). Correlation between R-D and S-D were $SUV_{max}$ 0.99, 0.96, 0.99 and $SUV_{peak}$ 0.99, 0.99, 0.99. And 2SD in balnd-altman analysis were $SUV_{max}$ 0.125, 0.290, 1.864 and $SUV_{peak}$ 0.053, 0.103, 0.826. MTV of R-D in workstation and PACS show the same value as $14.21{\pm}12.72cm^3$(p>0.05). MTV in PACS was decreased by 0.12% compared to R-D(p>0.05). Correlation and 2SD between R-D and S-D were 0.99 and 2.243. Conclusion $SUV_{max}$, $SUV_{peak}$, MTV showed the same value in both of R-D in workstation and PACS. However, there was statistically difference in $SUV_{max}$, $SUV_{peak}$ of S-D compare to R-D despite of high correlation. It is possible to analyse reliable pre and post SUV if storing R-D in main hospital PACS system.

• Investigative Magnetic Resonance Imaging
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• v.21 no.3
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• pp.162-170
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• 2017

Purpose: To evaluate the imaging findings of desmoid tumors using various imaging modalities and to evaluate whether diffusion-weighted imaging (DWI) can help differentiate between desmoid and malignant tumors. Materials and Methods: The study included 27 patients with pathologically confirmed desmoid tumors. Two radiologists reviewed 23 computed tomography (CT), 12 magnetic resonance imaging (MRI) and 8 positron emission tomography-computed tomography (PET-CT) scans of desmoid tumors and recorded data regarding the shape, multiplicity, size, location, degree of enhancement, and presence or absence of calcification or hemorrhage. The signal intensity of masses on T1- and T2-weighted imaging and the presence or absence of whirling or band-like low signal intensity on T2-weighted imaging were recorded. The apparent diffusion coefficient (ADC) values of the desmoid tumors in nine patients with DWIs were compared with the ADC values of 32 malignant tumors. The maximum standardized uptake value ($SUV_{max}$) on PET-CT images was measured in 8 patients who underwent a PET-CT. Results: The mean size of the 27 tumors was 6.77 cm (range, 2.5-26 cm) and four tumors exhibited multiplicity. The desmoid tumors were classified by shape as either mass forming (n = 18), infiltrative (n = 4), or combined (n = 5). The location of the tumors was either intra-abdominal (n = 15), within the abdominal wall (n = 8) or extra-abdominal (n = 4). Among the 27 tumors, 21 showed moderate to marked enhancement and 22 showed homogeneous enhancement. Two tumors showed calcifications and one displayed hemorrhage. Eleven of the 12 MR T2-weighted images showed whirling or band-like low signal intensity areas in the mass. The mean ADC value of the desmoid tumors ($1493{\times}10^{-6}mm^2/s$) was significantly higher than the mean of the malignant soft tissue tumors ($873{\times}10^{-6}mm^2/s$, P < 0.001). On the PET-CT images, all tumors exhibited an intermediate $SUV_{max}$ (mean, 3.7; range, 2.3-4.5). Conclusion: Desmoids tumors showed homogenous, moderate to marked enhancement on CT and MRI scans and a characteristic whirling or band-like pattern on T2-weighted images. DWI can be useful for the differentiation of desmoid tumors from malignant soft tissue tumors.

• Journal of the Korea Society of Computer and Information
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• v.18 no.12
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• pp.21-26
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• 2013

In this paper, We are suggested methods of feature extraction in molecular images. The result of image transform DWT examination by suggested method, we are obtained as follows. 1-level and 2-levels of decomposition results showed the composition of the low frequency region. But, 3-level decomposition results did not appear in the data component is almost. Observed not with the naked eye is not, but the 3-level output data values of the results were decomposed. We are printed the horizontal and vertical directions of low-frequency region of the data, the high frequency region of the horizontal and vertical data, and diagonal high frequency region of the horizontal and vertical directions data. If the output data using molecular imaging and CT, PET, MR imaging will be compared with the data.

• Journal of the Korean Society of Radiology
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• v.82 no.4
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• pp.936-942
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• 2021

Langerhans cell histiocytosis (LCH) is a rare condition that usually occurs in children and commonly affects the skeletal system. It is extremely rare in adults, especially in the clavicles. In this report, we describe a pathologically confirmed case of LCH in the clavicle of a 50-year-old male. We report various radiological findings, such as plain radiography, CT, MR, and PET-CT, along with a review of the literature.

• The Korean Journal of Nuclear Medicine
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• v.32 no.6
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• pp.490-496
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• 1998

Purpose: We evaluated brain perfusion SPECT findings of MELAS syndrome and mitochondrial myopathy in correlation with MR imaging in search of specific imaging features. Materials and Methods: Subjects were five patients (four females and one male; age range, 1 to 25 year) who presented with repeated stroke-like episodes, seizures or developmental delay or asymptomatic but had elevated lactic acid in CSF and serum. Conventional non-contrast MR imaging and Tc-99m-ethyl cysteinate dimer (ECD) brain perfusion SPECT were Performed and imaging features were analyzed. Results: MRI demonstrated increased T2 signal intensities in the affected areas of gray and white matters mainly in the parietal (4/5) and occipital lobes (4/5) and in the basal ganglia (1/5), which were not restricted to a specific vascular territory. SPECT demonstrated decreased perfusion in the corresponding regions of MRI lesions. In addition, there were perfusion defects in parietal (1 patient), temporal (2), and frontal (1) lobes and basal ganglia (1) and thalami (2). In a patient with mitochondrial myopathy who had normal MRI, decreased perfusion was noted in left parietal area and bilateral thalami. Conclusion: Tc-99m ECD SPECT imaging in patients with MELAS syndrome and mitochondrial myopathy showed hypoperfusion of parieto-occipital cortex, basal ganglia, thalamus and temporal cortex, which were not restricted to a specific vascular territory. There were no specific imaging features on SPECT. The significance of abnormal perfusion on SPECT without corresponding MR abnormalities needs to be evaluated further in larger number of patients.