1.Image Quality Evaluation of Digital X-Ray Detector Using Amorphous Selenium Layer and Amorphous Silicon TFT Array.
Chang Won KIM ; Jeong Key YOON ; Jong Hyo KIM
Korean Journal of Medical Physics 2008;19(4):219-226
In this study, we have conducted characterization of imaging performance for a flat panel digital X-ray detector using amorphous Selenium and a-Si TFT which was developed by the authors. The procedures for characterization were in concordance with internationally recommended standards such as IEC (international electrotechnical commission). The measures used for imaging performance characterization include response characteristic, modulation transfer function (MTF), detective quantum efficiency (DQE), noise power spectrum (NPS), and quantum limited performance. The measured DQEs at lowest and highest spatial frequencies were 40% and 25% respectively, which was superior to that of commercial products by overseas vendor. The MTF values were significantly superior to that of CR and indirect type DRs. The quantum limited performance showed the detector was limited by quantum noise at the entrance exposure level below 0.023 mR, which is sufficiently low for general X-ray examination.
Commerce
;
Noise
;
Selenium
;
Silicon
2.A Case of Herpes Zoster Ophthalmicus with Isolated Trochlear Nerve Involvement.
Key Chung PARK ; Sung Sang YOON ; Jeong Eun YOON ; Hak Young RHEE
Journal of Clinical Neurology 2011;7(1):47-49
BACKGROUND: Herpes zoster ophthalmicus (HZO) can involve the oculomotor nerve; however, isolated trochlear nerve palsy has rarely been reported. CASE REPORT: An 83-year-old man who suffered from HZO in the right frontal area and scalp subsequently developed vertical diplopia and severe pain. Cerebrospinal fluid examination and brain MRI revealed no abnormalities. Isolated right trochlear nerve palsy was diagnosed based on the findings of neuro-ophthalmological tests. CONCLUSIONS: Isolated trochlear nerve involvement associated with HZO is very rare and may be easily overlooked. Physicians should carefully examine oculomotor involvement in HZO.
Aged, 80 and over
;
Brain
;
Diplopia
;
Herpes Zoster
;
Herpes Zoster Ophthalmicus
;
Humans
;
Scalp
;
Trochlear Nerve
;
Trochlear Nerve Diseases
3.Usefulness of a FDG-PET Scan in Assessing Recurrent Gastric Cancer.
Hyeon Kook LEE ; Kyu Eun LEE ; Yoon Ho KIM ; Jae Min JEONG ; Han Kwang YANG ; June Key CHUNG ; Kuhn Uk LEE ; Kuk Jin CHOE
Journal of the Korean Gastric Cancer Association 2001;1(3):174-179
PURPOSE: For curative resection of recurrent gastric cancer, it is imperative that there be no unrecognized foci of tumoral disease outside the operation field. PET (positron emission tomography) with FDG (18 fluoro-2 deoxy-D-glucose) is a whole-body imaging technique that exploits the increased rate of glycolysis in tumor cells to detect disease. The authors evaluated the usefulness of FDG-PET in assessing resectability of recurrent gastric cancer. MATENRIALS AND METHODS: Seven patients with recurrent gastric cancer were studied with FDG-PET from December 1998 to October 2000. All FDG-PET images were interpreted in conjunction with conventional diagnostic methods. All imaging results were correlated with the pathological diagnosis and clinical outcome. Results: A final diagnosis of recurrence was obtained at 14 sites in all 7 patients by histology or clinical follow up. Locoregional recurrence, including distant metastasis, developed in 6 of 7 patients and distant recurrence in only one. FDG-PET detected all recurrent sites (5 locoregional and 5 distant) in 5 patients without peritoneal recurrence, but did not detect peritoneal seeding in 2 patients with peritoneal recurrence. The accuracy of FDG-PET in estimating resectability was 71.4% (5/7), and that of CT and PET together was 85.7% (6/7). A curative resection could be performed in three of the recurrent patients (2 locoregional and 1 distant recurrence). CONCLUSION: Our results suggest that FDG-PET may be useful for detecting locoregional and distant recurrence of gastric cancer and for selecting appropriate treatment. However, considering that FDG-PET was limited in detecting peritoneal seeding and determining the exact anatomical extension of tumor, it should be used in conjunction with other anatomical images.
Diagnosis
;
Follow-Up Studies
;
Glycolysis
;
Humans
;
Neoplasm Metastasis
;
Recurrence
;
Stomach Neoplasms*
4.HCV core protein promotes liver fibrogenesis via up-regulation of CTGF with TGF-beta1.
Ju Yeop SHIN ; Wonhee HUR ; Jin Sang WANG ; Jeong Won JANG ; Chang Wook KIM ; Si Hyun BAE ; Sung Key JANG ; Se Hwan YANG ; Young Chul SUNG ; Oh Joo KWON ; Seung Kew YOON
Experimental & Molecular Medicine 2005;37(2):138-145
Liver cirrhosis is one of the major complications of hepatitis C virus (HCV) infection, but the mechanisms underlying HCV-related fibrogenesis are still not clear. Although the roles of HCV core protein remain poorly understood, it is supposed to play an important role in the regulation of cellular growth and hepatocarcinogenesis. The aim of this study was to examine the role of HCV core protein on the hepatic fibrogenesis. We established an in vitro co-culture system with primary hepatic stellate cell (HSC) isolated from rats, and a stable HepG2-HCV core cell line which had been transfected with HCV core gene. The expressions of fibrosis-related molecules transforming growth factor beta1 (TGF-beta1), transforming growth factor b receptor II (TGF beta RII), alpha-smooth muscle actin (alpha-SMA) and connective tissue growth factor (CTGF) were analyzed via histological or molecular methods. In addition, the expression levels of matrix metaloprotinase-2 (MMP-2) and collagen type I (Col I) from the co-cultured media were measured by zymogram and ELISA, respectively. The expressions of alpha-SMA, TGF-beta1, Col I, TGF beta RII and MMP-2 were significantly increased in the co-culture of stable HepG2-HCV core with HSC. Moreover, the significant increases of CTGF and TGF-beta1 in the HCV core-expressing cells were observed by either Northern or Western blot analysis. These results suggest that HCV core protein may contribute to the hepatic fibrogenesis via up-regulation of CTGF and TGF-beta1.
Actins/metabolism
;
Animals
;
Cell Line, Tumor
;
Cells, Cultured
;
Coculture Techniques
;
Collagen Type I/metabolism
;
Gelatinase A/metabolism
;
Immediate-Early Proteins/*biosynthesis
;
Intercellular Signaling Peptides and Proteins/*biosynthesis
;
Liver/metabolism/*pathology
;
Liver Cirrhosis/*metabolism
;
Male
;
Rats
;
Rats, Sprague-Dawley
;
Receptors, Transforming Growth Factor beta/metabolism
;
Research Support, Non-U.S. Gov't
;
Transforming Growth Factor beta/*metabolism
;
Up-Regulation
;
Viral Core Proteins/genetics/*metabolism
5.Development and Assessment Individual Maximum Permissible Dose Method of I-131 Therapy in High Risk Patients with Differentiated Papillary Thyroid Cancer.
Jeong Chul KIM ; Jung Han YOON ; Hee Seung BOM ; Young Jong JAEGAL ; Ho Chun SONG ; Jung Joon MIN ; Hwan Jeong JEONG ; Seong Min KIM ; Young Jun HEO ; Ming Hao LI ; Young Kyu PARK ; June Key CHUNG
Korean Journal of Nuclear Medicine 2003;37(2):110-119
PURPOSE: Radioiodine (I-131) therapy is an effective modality to reduce both recurrence and mortality rates in differentiated thyroid cancer. Whether higher doses shows higher therapeutic responses was still debatable. The purpose of this study was to validate curve-fitting (CF) method measuring maximum permissible dose (MPD) by a biological dosimetry using metaphase analysis of peripheral blood lymphocytes. MATERIALS AND METHODS: Therapeutic effects of MPD was evaluated in 58 patients (49 females and 9 males, mean age 50+/-11 years) of papillary thyroid cancer. Among them 43 patients were treated with < or =7.4 GBq, while 15 patients with > or =9.25 GBq. The former was defined as low-dose group, and the latter high-dose group. Therapeutic response was defined as complete response when complete disappearance of lesions on follow-up I-131 scan and undetectable serum thyroglobulin levels were found. Statistical comparison between groups were done using chi-square test. P value less than 0.05 was regarded as statistically significant. RESULTS: MPD measured by CF method using tracer and therapeutic doses were 13.3+/-1.9 and 13.8+/-2.1 GBq, respectively (p=0.20). They showed a significant correlation (r=0.8, p< 0.0001). Exposed doses to blood measured by CF and biological methods were 1.54+/-0.03 and 1.78+/-0.03 Gy (p=0.01). They also showed a significant correlation (r=0.86, p=0.01). High-dose group showed a significantly higher rate of complete response (12/15, 80%) as compared to the low-dose group (22/43, 51.2%) (p=0.05). While occurrence of side effects was not different between two groups (40% vs. 30.2%, p=0.46). CONCLUSION: Measurement of MPD using CF method is reliable, and the high-dose I-131 therapy using MPD gains significantly higher therapeutic effects as compared with low-dose therapy.
Female
;
Follow-Up Studies
;
Humans
;
Lymphocytes
;
Male
;
Metaphase
;
Mortality
;
Recurrence
;
Thyroglobulin
;
Thyroid Gland*
;
Thyroid Neoplasms*
6.Factors Influencing Skin Tolerability to the Rivastigmine Patch in Patients with Alzheimer's Disease.
Hae Ri NA ; Moon Ho PARK ; Sangyun KIM ; Dong Won YANG ; Seong Hye CHOI ; Hyun Duk YANG ; Youngsoon YANG ; Hyun Jeong HAN ; Jung Seok LEE ; Young Chul YOON ; Seong Ho KOH ; Jung Eun KIM ; Bon D KU ; Hee Jin KIM ; Kyung Won PARK ; Eun Joo KIM ; Bora YOON ; Key Jung PARK
Dementia and Neurocognitive Disorders 2015;14(1):31-38
BACKGROUND AND PURPOSE: The one-day rivastigmine patch is reportedly well tolerated and has minimal side effects. However, Asian patients show more side effects than those in Western countries. We evaluated tolerability of the rivastigmine patch in South Korean patients with Alzheimer's disease (AD) and the specific factors affecting adverse events of the skin. METHODS: A 6-month, open labeled, multi-centered, observational study was carried out in 440 patients with probable AD from July 2009 to September 2010 (NCT01312363). RESULTS: A total of 25.9% of the patients experienced adverse skin events at the rivastigmine patch application site and 17.0% discontinued treatment due to adverse events at the skin application site. The most common adverse events were itching and erythema. Patients with an allergic history and users of electric heating appliances reported skin discomfort. Older age was associated with discontinuing treatment. CONCLUSION: These results suggest that the rivastigmine patch induced some adverse skin events and may contribute to understanding and improving skin tolerability to the rivastigmine patch.
Alzheimer Disease*
;
Asian Continental Ancestry Group
;
Erythema
;
Heating
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Hot Temperature
;
Humans
;
Observational Study
;
Pruritus
;
Skin*
;
Rivastigmine
7.A Comparison Study of Cilostazol and Aspirin on Changes in Volume of Cerebral Small Vessel Disease White Matter Changes: Protocol of a Multicenter, Randomized Controlled Trial
Hyun Jeong HAN ; Byeong C KIM ; Young Chul YOUN ; Jee Hyang JEONG ; Jong Hun KIM ; Jae Hong LEE ; Kee Hyung PARK ; Kyung Won PARK ; Eun Joo KIM ; Mi Sun OH ; Yong S SHIM ; Hyun Young PARK ; Bora YOON ; Soo Jin YOON ; Soo Jin CHO ; Key Chung PARK ; Duk L NA ; Sun Ah PARK ; Jong Min LEE ; Seong Hye CHOI
Dementia and Neurocognitive Disorders 2019;18(4):138-148
BACKGROUND AND PURPOSE: Cerebral small vessel disease (CSVD) is the most common cause of vascular dementia and a major contributor to mixed dementia. CSVD is characterized by progressive cerebral white matter changes (WMC) due to chronic low perfusion and loss of autoregulation. In addition to its antiplatelet effect, cilostazol exerts a vasodilating effect and improves endothelial function. This study aims to compare the effects of cilostazol and aspirin on changes in WMC volume in CSVD.METHODS: The comparison study of Cilostazol and aspirin on cHAnges in volume of cerebral smaLL vEssel disease white matter chaNGEs (CHALLENGE) is a double blind, randomized trial involving 19 hospitals across South Korea. Patients with moderate or severe WMC and ≥ 1 lacunar infarction detected on brain magnetic resonance imaging (MRI) are eligible; the projected sample size is 254. Participants are randomly assigned to a cilostazol or aspirin group at a 1:1 ratio. Cilostazol slow release 200 mg or aspirin 100 mg are taken once daily for 2 years. The primary outcome measure is the change in WMC volume on MRI from baseline to 104 weeks. Secondary imaging outcomes include changes in the number of lacunes and cerebral microbleeds, fractional anisotropy and mean diffusivity on diffusion tensor imaging, and brain atrophy. Secondary clinical outcomes include all ischemic strokes, all vascular events, and changes in cognition, motor function, mood, urinary symptoms, and disability.CONCLUSIONS: CHALLENGE will provide evidence to support the selection of long-term antiplatelet therapy in CSVD.TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01932203
Anisotropy
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Aspirin
;
Atrophy
;
Brain
;
Cerebral Small Vessel Diseases
;
Cognition
;
Dementia
;
Dementia, Vascular
;
Diffusion Tensor Imaging
;
Homeostasis
;
Humans
;
Korea
;
Magnetic Resonance Imaging
;
Outcome Assessment (Health Care)
;
Perfusion
;
Sample Size
;
Stroke
;
Stroke, Lacunar
;
White Matter
8.An Overview of Ophthalmologic Survey Methodology in the 2008-2015 Korean National Health and Nutrition Examination Surveys.
Kyung Chul YOON ; Won CHOI ; Hyo Seok LEE ; Sang Duck KIM ; Seung Hyun KIM ; Chan Yun KIM ; Ki Ho PARK ; Young Jeung PARK ; Seung Hee BAEK ; Su Jeong SONG ; Jae Pil SHIN ; Suk Woo YANG ; Seung Young YU ; Jong Soo LEE ; Key Hwan LIM ; Kyung Won OH ; Se Woong KANG
Korean Journal of Ophthalmology 2015;29(6):359-367
The Korea National Health and Nutrition Examination Survey (KNHANES) is a national program designed to assess the health and nutritional status of the noninstitutionalized population of South Korea. The KNHANES was initiated in 1998 and has been conducted annually since 2007. Starting in the latter half of 2008, ophthalmologic examinations were included in the survey in order to investigate the prevalence and risk factors of common eye diseases such as visual impairment, refractive errors, strabismus, blepharoptosis, cataract, pterygium, diabetic retinopathy, age-related macular degeneration, glaucoma, dry eye disease, and color vision deficiency. The measurements included in the ophthalmic questionnaire and examination methods were modified in the KNHANES IV, V, and VI. In this article, we provide detailed information about the methodology of the ophthalmic examinations in KNHANES in order to aid in further investigations related to major eye diseases in South Korea.
*Epidemiologic Methods
;
Eye Diseases/*epidemiology
;
Humans
;
Nutrition Surveys/*statistics & numerical data
;
Ophthalmology/*methods
;
Prevalence
;
Republic of Korea/epidemiology
;
Risk Factors
;
*Surveys and Questionnaires
9.Erratum to: Prognosis of Patients with Behavioral Variant Frontotemporal Dementia Who have Focal Versus Diffuse Frontal Atrophy.
Jin San LEE ; Na Yeon JUNG ; Young Kyoung JANG ; Hee Jin KIM ; Sang Won SEO ; Juyoun LEE ; Yeo Jin KIM ; Jae Hong LEE ; Byeong C KIM ; Kyung Won PARK ; Soo Jin YOON ; Jee H JEONG ; Sang Yun KIM ; Seung Hyun KIM ; Eun Joo KIM ; Key Chung PARK ; David S KNOPMAN ; Duk L NA
Journal of Clinical Neurology 2017;13(4):447-447
The original version of this article contained wrong information of an author which should be changed.
10.Prognosis of Patients with Behavioral Variant Frontotemporal Dementia Who have Focal Versus Diffuse Frontal Atrophy.
Jin San LEE ; Na Yeon JUNG ; Young Kyoung JANG ; Hee Jin KIM ; Sang Won SEO ; Juyoun LEE ; Yeo Jin KIM ; Jae Hong LEE ; Byeong C KIM ; Kyung Won PARK ; Soo Jin YOON ; Jee H JEONG ; Sang Yun KIM ; Seung Hyun KIM ; Eun Joo KIM ; Key Chung PARK ; David S KNOPMAN ; Duk L NA
Journal of Clinical Neurology 2017;13(3):234-242
BACKGROUND AND PURPOSE: Only a few studies have investigated the relationship between different subtypes and disease progression or prognosis in patients with behavioral variant frontotemporal dementia (bvFTD). Since a localized injury often produces more focal signs than a diffuse injury, we hypothesized that the clinical characteristics differ between patients with bvFTD who show diffuse frontal lobe atrophy (D-type) on axial magnetic resonance imaging (MRI) scans versus those with focal or circumscribed frontal lobe atrophy (F-type). METHODS: In total, 94 MRI scans (74 scans from bvFTD and 20 scans from age-matched normal controls) were classified into 35 D- and 39 F-type bvFTD cases based on an axial MRI visual rating scale. We compared baseline clinical characteristics, progression in motor and cognitive symptoms, and survival times between D- and F-types. Survival analyses were performed for 62 of the 74 patients. RESULTS: While D-type performed better on neuropsychological tests than F-type at baseline, D-type had higher baseline scores on the Unified Parkinson's Disease Rating Scale (UPDRS) Part III. Evaluations of motor progression showed that the disease duration with motor symptoms was shorter in D-type than F-type. Moreover, the survival time was shorter in D-type (6.9 years) than F-type (9.4 years). Cox regression analyses revealed that a high UPDRS Part III score at baseline contributed to an increased risk of mortality, regardless of the pattern of atrophy. CONCLUSIONS: The prognosis is worse for D-type than for those with F-type. Shorter survival in D-type may be associated with the earlier appearance of motor symptoms.
Atrophy*
;
Disease Progression
;
Frontal Lobe
;
Frontotemporal Dementia*
;
Frontotemporal Lobar Degeneration
;
Humans
;
Magnetic Resonance Imaging
;
Mortality
;
Neurobehavioral Manifestations
;
Neuropsychological Tests
;
Parkinson Disease
;
Prognosis*