1.Neuropathic Pruritus as Relapse Symptom in Neuromyelitis Optica.
Jun Yup KIM ; Jung Hwan SHIN ; Aryeon KIM ; Yoonho HONG
Journal of the Korean Neurological Association 2014;32(3):209-211
No abstract available.
Neuromyelitis Optica*
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Pruritus*
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Recurrence*
2.Convolutional Neural Network-Based Automatic Segmentation of Substantia Nigra on Nigrosome and Neuromelanin Sensitive MR Images
Junghwa KANG ; Hyeonha KIM ; Eunjin KIM ; Eunbi KIM ; Hyebin LEE ; Na-young SHIN ; Yoonho NAM
Investigative Magnetic Resonance Imaging 2021;25(3):156-163
Recently, neuromelanin and nigrosome imaging techniques have been developed to evaluate the substantia nigra in Parkinson’s disease. Previous studies have shown potential benefits of quantitative analysis of neuromelanin and nigrosome images in the substantia nigra, although visual assessments have been performed to evaluate structures in most studies. In this study, we investigate the potential of using deep learning based automatic region segmentation techniques for quantitative analysis of the substantia nigra. The deep convolutional neural network was trained to automatically segment substantia nigra regions on 3D nigrosome and neuromelanin sensitive MR images obtained from 30 subjects. With a 5-fold cross-validation, the mean calculated dice similarity coefficient between manual and deep learning was 0.70 ± 0.11. Although calculated dice similarity coefficients were relatively low due to empirically drawn margins, selected slices were overlapped for more than two slices of all subjects. Our results demonstrate that deep convolutional neural network-based method could provide reliable localization of substantia nigra regions on neuromelanin and nigrosome sensitive MR images.
3.Convolutional Neural Network-Based Automatic Segmentation of Substantia Nigra on Nigrosome and Neuromelanin Sensitive MR Images
Junghwa KANG ; Hyeonha KIM ; Eunjin KIM ; Eunbi KIM ; Hyebin LEE ; Na-young SHIN ; Yoonho NAM
Investigative Magnetic Resonance Imaging 2021;25(3):156-163
Recently, neuromelanin and nigrosome imaging techniques have been developed to evaluate the substantia nigra in Parkinson’s disease. Previous studies have shown potential benefits of quantitative analysis of neuromelanin and nigrosome images in the substantia nigra, although visual assessments have been performed to evaluate structures in most studies. In this study, we investigate the potential of using deep learning based automatic region segmentation techniques for quantitative analysis of the substantia nigra. The deep convolutional neural network was trained to automatically segment substantia nigra regions on 3D nigrosome and neuromelanin sensitive MR images obtained from 30 subjects. With a 5-fold cross-validation, the mean calculated dice similarity coefficient between manual and deep learning was 0.70 ± 0.11. Although calculated dice similarity coefficients were relatively low due to empirically drawn margins, selected slices were overlapped for more than two slices of all subjects. Our results demonstrate that deep convolutional neural network-based method could provide reliable localization of substantia nigra regions on neuromelanin and nigrosome sensitive MR images.
4.Salternamide E from a Saltern-derived Marine Actinomycete Streptomyces sp..
Seong Hwan KIM ; Yoonho SHIN ; Sang Kook LEE ; Jongheon SHIN ; Dong Chan OH
Natural Product Sciences 2015;21(4):273-277
Comprehensive chemical analysis of extracts and fractions of marine actinomycete strains led to the discovery of a new minor secondary metabolite, salternamide E (1), from a saltern-derived halophilic Streptomyces strain. The planar structure of salternamide E (1) was elucidated by a combinational analysis of spectroscopic data including NMR, MS, UV, and IR. The absolute configuration of salternamide E (1) was determined by circular dichroism spectroscopic analysis. Salternamide E displayed weak cytotoxicity against various human carcinoma cell lines.
Cell Line
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Circular Dichroism
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Humans
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Streptomyces*
5.General Public Knowledge Regarding Topical Corticosteroids: A Nationwide Survey in South Korea
Heenam SEO ; Seoung Yeon SONG ; Dahye KIM ; Ji Hwan PARK ; Yoonho SHIN ; Kang Hyuk LEE ; Soo An CHOI ; Ju-Yeun LEE ; Do Young KIM ; Wan Gyoon SHIN ; Eunyoung KIM
Korean Journal of Clinical Pharmacy 2022;32(2):84-92
Background:
Topical corticosteroids (TCs) are available both as over-the-counter drugs and prescription medicines at pharmacies.Although they are generally safe drugs, inappropriate and excessive use could result in potential side effects. Thus, it is important to have appropriate knowledge regarding the use of TCs. We performed a cross-sectional survey to assess public knowledge and the potential misuse or overuse of TCs.
Methods:
A cross-sectional and nationwide online survey was conducted among participants who were aware of TCs. The survey items included sources of information, indications, potential side effects, and methods of application of TCs. A comparative analysis was conducted between those with (TC users) and without (TC non-users) an experience of using TCs. Results: Among 3,000 participants, 74.4% were TC users. The mass media was the most common information source of TCs, and only one-third of the surveyed people relied on pharmacists or doctors for information. Regarding indications and application methods, incorrect answer rate was high in some items, but respondents showed adequate knowledge. However, awareness of the safety of TCs was low. Overall, the TC users showed a higher knowledge of TCs than TC non-users.
Conclusions
Public knowledge of the use of TCs appears to be appropriate. However, we found potential misuse or overuse of some items and a lack of awareness of the side effects concerning TCs. Thus, healthcare professionals’ significant role is required.
6.Relationship between Abnormal Hyperintensity on T2-Weighted Images Around Developmental Venous Anomalies and Magnetic Susceptibility of Their Collecting Veins: In-Vivo Quantitative Susceptibility Mapping Study
Yangsean CHOI ; Jinhee JANG ; Yoonho NAM ; Na Young SHIN ; Hyun Seok CHOI ; So Lyung JUNG ; Kook Jin AHN ; Bum soo KIM
Korean Journal of Radiology 2019;20(4):662-670
OBJECTIVE: A developmental venous anomaly (DVA) is a vascular malformation of ambiguous clinical significance. We aimed to quantify the susceptibility of draining veins (χvein) in DVA and determine its significance with respect to oxygen metabolism using quantitative susceptibility mapping (QSM). MATERIALS AND METHODS: Brain magnetic resonance imaging of 27 consecutive patients with incidentally detected DVAs were retrospectively reviewed. Based on the presence of abnormal hyperintensity on T2-weighted images (T2WI) in the brain parenchyma adjacent to DVA, the patients were grouped into edema (E+, n = 9) and non-edema (E−, n = 18) groups. A 3T MR scanner was used to obtain fully flow-compensated gradient echo images for susceptibility-weighted imaging with source images used for QSM processing. The χvein was measured semi-automatically using QSM. The normalized χvein was also estimated. Clinical and MR measurements were compared between the E+ and E− groups using Student's t-test or Mann-Whitney U test. Correlations between the χvein and area of hyperintensity on T2WI and between χvein and diameter of the collecting veins were assessed. The correlation coefficient was also calculated using normalized veins. RESULTS: The DVAs of the E+ group had significantly higher χvein (196.5 ± 27.9 vs. 167.7 ± 33.6, p = 0.036) and larger diameter of the draining veins (p = 0.006), and patients were older (p = 0.006) than those in the E− group. The χvein was also linearly correlated with the hyperintense area on T2WI (r = 0.633, 95% confidence interval 0.333–0.817, p < 0.001). CONCLUSION: DVAs with abnormal hyperintensity on T2WI have higher susceptibility values for draining veins, indicating an increased oxygen extraction fraction that might be associated with venous congestion.
Brain
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Edema
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Humans
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Hyperemia
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Magnetic Resonance Imaging
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Metabolism
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Oxygen
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Retrospective Studies
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Vascular Malformations
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Veins
7.Clinical Implications of Focal Mineral Deposition in the Globus Pallidus on CT and Quantitative Susceptibility Mapping of MRI
Hyojin KIM ; Jinhee JANG ; Junghwa KANG ; Seungun JANG ; Yoonho NAM ; Yangsean CHOI ; Na-young SHIN ; Kook-Jin AHN ; Bum-soo KIM
Korean Journal of Radiology 2022;23(7):742-751
Objective:
To assess focal mineral deposition in the globus pallidus (GP) by CT and quantitative susceptibility mapping (QSM) of MRI scans and evaluate its clinical significance, particularly cerebrovascular degeneration.
Materials and Methods:
This study included 105 patients (66.1 ± 13.7 years; 40 male and 65 female) who underwent both CT and MRI with available QSM data between January 2017 and December 2019. The presence of focal mineral deposition in the GP on QSM (GPQSM) and CT (GPCT) was assessed visually using a three-point scale. Cerebrovascular risk factors and small vessel disease (SVD) imaging markers were also assessed. The clinical and radiological findings were compared between the different grades of GPQSM and GPCT. The relationship between GP grades and cerebrovascular risk factors and SVD imaging markers was assessed using univariable and multivariable linear regression analyses.
Results:
GPCT and GPQSM were significantly associated (p < 0.001) but were not identical. Higher GPCT and GPQSM grades showed smaller gray matter (p = 0.030 and p = 0.025, respectively) and white matter (p = 0.013 and p = 0.019, respectively) volumes, as well as larger GP volumes (p < 0.001 for both). Among SVD markers, white matter hyperintensity was significantly associated with GPCT (p = 0.006) and brain atrophy was significantly associated with GPQSM (p = 0.032) in at univariable analysis. In multivariable analysis, the normalized volume of the GP was independently positively associated with GPCT (p < 0.001) and GPQSM (p = 0.002), while the normalized volume of the GM was independently negatively associated with GPCT (p = 0.040) and GPQSM (p = 0.035).
Conclusion
Focal mineral deposition in the GP on CT and QSM might be a potential imaging marker of cerebral vascular degeneration. Both were associated with increased GP volume.
8.Paramagnetic Rims in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorder: A Quantitative Susceptibility Mapping Study with 3-T MRI
Jinhee JANG ; Yoonho NAM ; Yangsean CHOI ; Na-Young SHIN ; Jae Young AN ; Kook-Jin AHN ; Bum-soo KIM ; Kwang-Soo LEE ; Woojun KIM
Journal of Clinical Neurology 2020;16(4):562-572
Background:
and Purpose: Iron retained by activated microglia and macrophages in multiple sclerosis (MS) lesions may serve as a marker of innate immune system activation. Among several magnetic resonance imaging (MRI) methods, there has been recent interest in using quantitative susceptibility mapping (QSM) as a potential tool for assessing iron levels in the human brain. This study examined QSM findings in MS and neuromyelitis optica spectrum disorder (NMOSD) lesions obtained with 3-T MRI to assess imaging characteristics related to paramagnetic rims around brain lesions in MS and NMOSD.
Methods:
This study included 32 MS and 21 seropositive NMOSD patients. MRI images were obtained using two 3-T MRI devices (Ingenia, Philips Healthcare; and Magnetom Verio, Siemens Healthineers) during routine diagnosis and treatment procedures. Multi and single echo gradient echo magnitude and phase images were obtained for QSM reconstruction.QSM images were used to characterize the detected lesions, and the findings were compared between MS and NMOSD.
Results:
Totals of 71 and 35 MRI scans were performed during the study period in MS and NMOSD patients, respectively. In QSM images, paramagnetic rims were found in 26 (81.2%) MS patients and 1 (4.8%) NMOSD patient. Eight of the 22 MS patients and only 1 of the 10 NMOSD patients who underwent follow-up MRI showed new paramagnetic rims. The paramagnetic rim lesions appeared after enhancement or in new T2-weighted lesions without enhancement.
Conclusions
Paramagnetic rims might be a characteristic MRI finding for MS, and therefore they have potential as an imaging marker for differentially diagnosing MS from NMOSD using 3-T MRI.