1.Analysis of fMRI Signal Using Independent Component Analysis.
Chan Hong MOON ; Dong Gyu NA ; Hyun Wook PARK ; Jae Wook RYOO ; Eun Jung RHEE ; Hong Sik BYUN
Journal of the Korean Society of Magnetic Resonance in Medicine 1999;3(2):188-196
The fMRI signals are composed of many various signals. It is very difficult to find the accurate parameter for the model of fMRI signal containing only neural activity, though we may estimating the signal patterns by the modeling of several signal components. Besides the nose by the physiologic motion, the motion of object and noise of MR instruments make it more difficult to analyze signals of fMRI. Therefore, it is not easy to select an accurate reference data that can accurately reflect neural activity, and the method of an analysis of various signal patterns containing the information of neural activity is an issue of the post-processing methods for fMRI. In the present study, fMRI data was analyzed with the Independent Component Analysis(ICA) method that doesn't need a priori-knowledge or reference data. ICA can be more effective over the analytic method using cross-correlation analysis and can separate the signal patterns of the signals with delayed response or motion related components. The Principal Component Analysis (PCA) threshold, wavelet spatial filtering and analysis of a part of whole images can be used for the reduction of the freedom of data before ICA analysis, and these preceding analyses may be useful for a more effective analysis. As a result, ICA method will be effective for the analysis of signal patterns in fMRI and the pre-filtering may be necessary for the reduction of the degree of freedom of the data.
Freedom
;
Magnetic Resonance Imaging*
;
Noise
;
Nose
;
Principal Component Analysis
2.A Case of Congenital Pericardial Defect Diagnosed by Computed Tomography.
Hong Youp CHOI ; Sang Wook LIM ; Joon Young KIM ; Byung Wook NA ; Kyung Wha WHANG ; Eun Mi JEONG ; Tae Yong KIM ; Dong Hoon CHA ; Jeung Sook KIM
Korean Circulation Journal 2000;30(10):1281-1284
Pericardial defect is a rare congenital cardiac disorder. Most patients were asymptomatic but some patients with partial pericardial defect occasionally complain acute symptoms such as angina, syncope, rarely sudden cardiac death. So, differential diagnosis with other ischemic or structural heart disease is crucial in the management of such patients. But there is no consistently successful diagnostic method. In the past, artificial diagnostic pneumothorax was used to document the absence of pericardium. However, it is not easily accepted due to excess morbidity and failure rate. Recently, echocardiography and more often, computed tomography, magnetic resonance imaging are used to confirm the diagnosis. We experienced a 52 years old male patient with atypical chest pain, who was diagnosed as complete left pericardial defect with computed tomography.
Chest Pain
;
Death, Sudden, Cardiac
;
Diagnosis
;
Diagnosis, Differential
;
Echocardiography
;
Heart Diseases
;
Humans
;
Magnetic Resonance Imaging
;
Male
;
Middle Aged
;
Pericardium
;
Pneumothorax
;
Syncope
3.Bilateral Congenital Coronary Arteriovenous Fistulas.
Byoung Wook NA ; Sang Wook LIM ; Jae Wan PARK ; Pil Won PARK ; Yoon Kyoung CHO ; Tae Yong KIM ; Dong Hoon CHA
Korean Circulation Journal 1998;28(9):1630-1632
Coronary arteriovenous fistulas (CAVF) are rare malformations of the coronary circulation. They are seen in approximately 0.1% to 0.2% of all patients undergoing selective coronary angiography. We experienced a 58-years old male patient with bilateral coronary AV fistulas whoes diagnosis was confirmed by selective coronary angiography.
Arteriovenous Fistula*
;
Coronary Angiography
;
Coronary Circulation
;
Diagnosis
;
Fistula
;
Humans
;
Male
;
Middle Aged
4.Behavioral Manifestation of Neuropathic Pain Following Sciatic Nerve Section in Rats.
Dong Jin YOO ; Heung Sik NA ; Young Wook YOON
Experimental Neurobiology 2008;17(2):79-86
The present study was performed to observe the time course of behavioral signs of painful sensations in sciatic neurectomy animal model and to test the effects of sympathectomy and saphenous nerve section on these behavioral signs. Sciatic nerve was ligated and cut at the mid-thigh level under gaseous anesthesia. The application of von Frey filaments to the medial plantar surface of foot revealed weak and long-lasting mechanical allodynia (until end of test period, 20 weeks PO). Acetone application to the plantar surface of foot was used ti measure the sensitivity to cold stimulation. Cold allodynia which is interpreted as increased response to acetone application developed fairly well and lasted the end of test period (20 weeks PO). The cumulative duration of foot lifts off neutral or cold plate was used to test spontaneous, ongoing pain and was increased until 16 weeks PO and 20 weeks PO respectively. These results suggest that sciatic neurectomy which has been widely used as chronic pain model shows behavioral signs suggsting painful sensations except autotomy, which has been used as index of pain in experimental animal. Surgical sympathectomy performed 1 week after sciatic neurectomy partially reduced the behavioral signs of mechanical allodynia and cold allodynia, suggesting behavioral changes developed following section of sciatic nerve was partially sympathetic dependent. Saphenous nerve section 1 week after sciatic neurectomy almost completely reduced mechanical allodynia and cold allodynia, but did not change spontaneous, ongoing pain. These results suggest that evoked responses such as mechanical and cold allodynia are mediated by saphenous nerve activity and activating and/or maintaining mechanisms of spontanous, ongoing pain and evoked pain may be different.
Acetone
;
Anesthesia
;
Animals
;
Chronic Pain
;
Cold Temperature
;
Foot
;
Hyperalgesia
;
Models, Animal
;
Neuralgia
;
Rats
;
Sciatic Nerve
;
Sensation
;
Sympathectomy
5.Association of Depression with Atypical Features and Metabolic Syndrome in Korean Adults
Chung Yeol LEE ; Do Un JUNG ; Sung Jin KIM ; Je Wook KANG ; Jung Joon MOON ; Dong Wook JEON ; You Na KIM ; Dong Jin SHIN ; Sang Hun NAM
Korean Journal of Psychosomatic Medicine 2019;27(2):90-100
OBJECTIVES:
This study aimed to investigate the association between depression with atypical features and metabolic syndromes in Korean adults using the 2016 Korean National Health and Nutrition Examination Survey (KNHANES) data.
METHODS:
We used the 2016 KNHANES data to enroll 277 participants with a score of 10 or higher on Patient Health Questionnaire-9. Depression with atypical features was diagnosed when at least two of the following criteria were met : 1) sleeping more than 10 hours a day ; 2) weight gain of more than 3 kg in a year ; and 3) fatigue/anergia. Depression was divided into two groups based on the presence/absence of atypical features. Physical and mental health, and risk of metabolic syndrome were compared between the groups.
RESULTS:
Among the 277 participants, 91 had depression with atypical features. We identified significant differences in age, sex, income, and education between the two groups. After adjusting for these variables, depression with atypical features had lower EuroQol-5D index scores (p<0.001) and higher prevalence of metabolic syndromes (p=0.035) compared to the depression without atypical features. Depression with atypical features had higher odds ratio (OR) in association with metabolic syndromes after adjusting for confounding variables (OR=1.923 ; 95% confidence interval : 1.069–3.460).
CONCLUSIONS
Depression with atypical features increases the risk of metabolic syndromes and lowers the quality of life.
6.Korean Thyroid Association Guidelines on the Management of Differentiated Thyroid Cancers; Part I. Initial Management of Differentiated Thyroid Cancers - Chapter 4. Pathological Diagnosis and Staging after Thyroidectomy 2024
Su-Jin SHIN ; Hee Young NA ; Ho-Cheol KANG ; Sun Wook KIM ; Dong Gyu NA ; Young Joo PARK ; Young Shin SONG ; Eun Kyung LEE ; Dong-Jun LIM ; Yun Jae CHUNG ; Chan Kwon JUNG ;
International Journal of Thyroidology 2024;17(1):61-67
Postoperative pathological diagnosis of differentiated thyroid cancer (DTC) is important to confirm the diagnosis and predict the risk of recurrence and death. Further treatment plans, such as completion thyroidectomy, radioiodine remnant ablation, or external beam radiation therapy, are then opted for to reduce the predicted risk of recurrence or death. The World Health Organization has classified thyroid cancers into seven distinct categories based on the molecular profile and tumor cell origin. Our recommendation is applicable to differentiated follicular cell-derived carcinoma, the most common form of thyroid cancer, and cribriform morular thyroid carcinoma. Postoperative clinical and pathological staging is recommended for all patients with DTC to determine their prognosis and subsequent treatment decisions. In particular, the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) staging system is recommended for staging DTCs for disease mortality prediction and national cancer registries. The information in the pathology report, including histologic features of the tumor that are necessary for AJCC/UICC staging and recurrence prediction, can help assess the patient’s risk.
7.Early Detection of Hyperacute Cerebral Infarction in Dogs: Comparison of Unenhanced CT, Diffusion-weighted,Spin-echo T2 - weighted, and Fast FLAIR MR Imaging.
Jung Hwan YOON ; Dong Gyu NA ; Hong Sik BYUN ; Seung Kwon KIM ; Sung Ki CHO ; Jae Wook RYU ; Jae Min CHO ; Byung Tae AHN ; Hae Kyung LEE
Journal of the Korean Radiological Society 1999;41(1):17-25
PURPOSE: This study was performed in order to compare unenhanced CT with diffusion-weighted, T2-weight-ed,and fast FLAIR MR imaging in the detection of hyperacute cerebral ischema induced in a dog and to deter-mine whichmodality first detected cerebral ischemia. MATERIALS AND METHODS: Experimental cerebral infarction was induced bythe occlusion of intracerebral arter-ies using embolic materials (polyvinyl-alcohol, 300 -6 00 micro) introducedthrough a microcatheter into the internal carotid artery of five dogs weighing 12 -20 kg. Serial CT and MR imageswere obtained at one hour intervals from one to five hours after occlusion, and were analyzed independently by tworadiologists. We assessed changes in attenuation, as seen on unenhanced CT and the signal intensity of the lesionon each MR image, and measured the contrast-to-noise ratio (CNR) of the lesions. RESULTS: Ischemic lesions weredetected on unenhanced CT 1 -3 hours after occlusion of cerebral arteries. In all dogs, the lesions were detectedearliest on diffusion-weighted images obtained at 1 hour. They were detect-ed on T2-weighted images at 3 -5 hoursand on fast FLAIR images of 2 -5 hours. The CNR of ischemic lesions increased gradually during the 5-hour period.It was highest on diffusion-weighted images, while on unen-hanced CT, T2-weighted, and fast FLAIR images it wassimilar. CONCLUSION: Hyperacute ischemic lesions were detected earliest on diffusion-weighted images, and earlieron unenhanced CT than on fast FLAIR or T2-weighted MR image.
Animals
;
Brain Ischemia
;
Carotid Artery, Internal
;
Cerebral Arteries
;
Cerebral Infarction*
;
Dogs*
;
Magnetic Resonance Imaging*
8.A Case of Lichen Spinulosus.
Gi Na KIM ; Dong Soo YU ; Sang Wook SON ; Ae Ree KIM ; Il Whan KIM
Korean Journal of Dermatology 2001;39(9):1046-1048
Lichen spinulosus is a benign follicular eruption seen primarily in younger persons and is frequently classified a disorder of keratinization. The lesion is characterized by the development of patches of small perifollicular papules that have a central horny spine. We report a case of lichen spinulosus developed in an 8-year-old male patient who had atopic dermatitis.
Child
;
Dermatitis, Atopic
;
Humans
;
Lichens*
;
Male
;
Spine
9.Helical CT Finding of Carotid-Cavernous Fistula: A Sign of Early Enhancing Superior Ophthalmic Vein.
Jae Hyung KIM ; Dong Gyu NA ; Hong Sik BYUN ; Jae Wook RYOO
Journal of the Korean Radiological Society 2000;43(2):131-137
PURPOSE: The purpose of this study was to determine the diagnostic value of a sign of early enhancing superior ophthalmic vein (SOV), as seen on helical CT images in patients with carotid-cavernous fistula (CCF). MATERIALS AND METHODS: This study involved 16 patients with CCF and 28 control patients. Axial CT images with scanning delays of 30 seconds following bolus injection of contrast material (90 mL, 3 mL/sec) were obtained, and this procedure was followed by coronal CT imaging. To determine the presence or absence of early enhancement or, dilatation of the SOV, bulging of the cavernous sinus, and enlargement of extraocular muscle, CT images were analysed by three observers in a blinded, random manner. Early enhancement of SOV was determined to be present where enhancement of the SOV was similar to or stronger than that of the ipsi-lateral posterior cerebral artery. RESULTS: A sign of early enhancing SOV was seen in 14 of the 16 patients with CCF but in no control patients (88% sensitivity and 100% specificity). The respective sensitivity and specificity of other CT features were 71% and 100% (dilatation of the SOV, as seen on axial images), 60% and 83% (dilatation of the SOV, as seen on coronal images), 71% and 89% (dilatation of the cavernous sinus), and 65% and 98% (enlargement of extraocular muscle). CONCLUSION: A sign of early enhancing SOV is a characteristic and specific CT finding of CCF, and is useful for the diagnosis of CCF.
Cavernous Sinus
;
Diagnosis
;
Dilatation
;
Fistula*
;
Humans
;
Posterior Cerebral Artery
;
Sensitivity and Specificity
;
Tomography, Spiral Computed*
;
Veins*
10.Mucoepidermoid Carcinoma with Distant Metastases to the Kidney, Adrenal Gland, Skull and Gluteus Maximus Muscle: a Case Report.
Sang Wook SON ; Kye Ho LEE ; Jai Hyuen LEE ; Na Hye MYONG ; Dong Soo YOO
Investigative Magnetic Resonance Imaging 2016;20(1):66-70
INTRODUCTION: Distant metastases of mucoepidermoid carcinoma (MEC) are reported with the most common sites being the soft tissue of skin, lung, liver, and bone. We report here a very rare case of MEC with multiple metastases to the kidney, adrenal gland, skull and gluteus maximus muscle. CASE REPORT: A 63-year-old male patient presented with left-sided headache. Radiologic evaluations including CT and MRI showed ill-defined soft tissue lesion involving the left infratemporal fossa and left sphenoid sinus, and multiple enlarged lymph nodes in neck and mediastinum. PET-CT demonstrated multiple hypermetabolic lesions in and around the left kidney, left adrenal gland, right ischium, right gluteus maximus and skull base. These lesions were confirmed as MEC with multiple metastases through biopsy. DISCUSSION: Only one case of metastasis to the skull has been previously reported, and moreover, there has not been a case of metastatic MEC to the kidney, adrenal gland and gluteus maximus muscle so far in the medical literature. It is important to acknowledge the possibility of every unusual MEC metastases, since the presence of metastasis has statistically significant influence on the survival of MEC.
Adrenal Glands*
;
Biopsy
;
Carcinoma, Mucoepidermoid*
;
Headache
;
Humans
;
Ischium
;
Kidney*
;
Liver
;
Lung
;
Lymph Nodes
;
Magnetic Resonance Imaging
;
Male
;
Mediastinum
;
Middle Aged
;
Neck
;
Neoplasm Metastasis*
;
Positron-Emission Tomography
;
Skin
;
Skull Base
;
Skull*
;
Sphenoid Sinus