• Investigative Magnetic Resonance Imaging
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• v.3 no.2
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• pp.173-178
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• 1999

Purpose : To evaluate the usefulness of functional MRI (fMRI) of visual cortex in patients with ischemic infarction in the occipital lobe. Materials and Methods : Four patients with the symptoms and signs of visual cortical ischemia were included. Functional MRI was performed by 2D-FLASH technique with the parameter of 90/56msec TR/TE, $40^{\circ}$ flip angle, $240{\times}240{\;}FOV,{\;}64{\times}128$ matrix number, 8.32 seconds acquisition time, 8mm slice thickness. An axial slice including both visual cortices was selected and alternative activation and resting of the visual cortex was performed using red color photostimulator. all patients undertook visual field test, and vascular abnormality was examined by MRA (n=4) and DSA (n=2). fMRI results were compared with the results of a visual field test, conventional MRI and cerebral angiography. Results : On fMRI, decreased activity of the visual cortex was found in the occipital lobe corresponding to stenosis of the posterior cerebral artery or its branch noted on angiogram. However, 2 of 4 patients showed no abnormal findings on conventional MRI. Visual field defect was noted in 3 patients, one and of whom showed no abnormality on conventional MRI and diffusion-weighted image, but revealed decreased activity in the corresponding visual cortex on fMRI. Conclusion : fMRI may be a sensitive method for detection of the status of decreased blood flow or vascular reserve which other methods can not.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.3 no.2
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• pp.169-174
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• 2000

Purpose: Previously reported ocular complications of interferon alfa administration are extremely rare. We experienced a 15-year-old boy with chronic hepatitis B who developed glaucoma after interferon alfa therapy. The purpose of this prospective study was to evaluate the possible development of glaucoma after interferon alfa therapy for chronic hepatitis B. Methods: Nine patients with chronic hepatitis B who visited Inha university hospital between February 1998 and July 1999 received interferon alfa therapy. We measured visual acuity, intraocular pressure, C/D ratio, and visual field examination at pre-interferon therapy, three and six months after therapy, respectively. Results: The total number of patients was 9 (4 boys and 5 girls). Mean age was $11.7{\pm}4.1$ years. The duration of therapy was 6 months and mean dosage of interferon was 5 million units. Compared with visual acuity, intraocular pressure, and C/D ratio at pre-therapy, those parameters at 3 months and 6 months after therapy showed no significant differences and none showed visual field defect after therapy. Conclusion: Our prospective study showed no evidence of development of glaucoma after interferon therapy. However, it is necessary to be concerned about the possibility of developing glaucoma or other ophthalmologic diseases after interferon therapy in chronic hepatitis B.

• Journal of Digital Contents Society
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• v.4 no.1
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• pp.11-21
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• 2003

In computer vision, the goal of stereopsis is to determine the surface structure of real world form two or more perspective views of scene. It is similar to human visual system. We can avoid obstacles, recognize objects, and manipulate machine using three-dimensional information. Until recently, only gray-level images have been used as input to computation for depth determination, but the availability of color can further enhance the performance of computational stereopsis. There are many models to provide efficient color system. The simplest model, RGB model treats color as if it were composed of separate entities. Each color channel is processed individually by the same stereopsis module as used in the gray-level model. His Model decouples intensity component from color information. So it can deal with color properties without defect intensity information. Opponent color model is based on human visual system. In this model, the red-green-blue colors are combined into three opponent channels before further processing.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.30 no.1
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• pp.42-44
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• 2019

Hashimoto's encephalopathy (HE) is a rare and underdiagnosed neuropsychiatric illness. We present the case of a 17-year-old girl who was admitted to a tertiary-care psychiatric center with acute onset psychosis and fever. Her psychotic symptoms were characterized by persecutory and referential delusions, as well as tactile and visual hallucinations. Her acute behavioral disturbance warranted admission and treatment in a psychiatric setting (risperidone tablets, 3 mg/day). She had experienced an episode of fever with a unilateral visual acuity defect approximately 3 years before admission, which was resolved with treatment. Focused clinical examination revealed an enlarged thyroid, and baseline blood investigations, including thyroid function test results were normal. Abnormal laboratory investigations revealed elevated anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-TG) levels (anti-TPO of 480 IU/mL; anti-TG of 287 IU/mL). Results of other investigations for infection, including cerebrospinal fluid examination, electroencephalography, and brain magnetic resonance imaging were normal. She was diagnosed with HE and was treated with intravenous corticosteroids (methylprednisolone up to 1 g/day; tapered and discontinued after a month). The patient achieved complete remission of psychotic symptoms and normalization of the anti-thyroid antibody titers. Currently, at the seventh month of follow-up, the patient is doing well. This case highlights the fact that in the absence of well-defined clinical diagnostic criteria, a high index of suspicion is required for early diagnosis of HE. Psychiatrists need to explore for organic etiologies when dealing with acute psychiatric symptoms in a younger age group.

• Journal of Korea Entertainment Industry Association
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• v.14 no.8
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• pp.213-219
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• 2020

The purpose of this study was to investigate the characteristics of error types in naming task for 8 questionable demeatia groups, 9 definite dementia groups, and 10 normal groups. The items of naming error analysis were classified into visual perception errors, semantic association errors, semantic non-correlation errors, phoneme errors, Don't Know, and No Response. For the analysis, descriptive statistics analysis, analysis of variance, and multivariate analysis of variance were conducted using SPSS 21.0. As a result, there was a significant difference in the error rate between groups according to the error type. The errors that showed significant differences between the normal group and the other two groups were visual perception errors and semantic non-related errors. The error of non-response was different from the dementia confirmation group, but there was no significant difference from the dementia suspicion group. These results showed that Alzheimer's patients had a defect in confrontation naming ability. Also, it was found that it is appropriate to provid other clues when the defects caused by the degeneration of a specific step during the information processing process become severe.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.2
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• pp.68-73
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• 2015

Purpose The purpose of this study was to evaluate image quality change by truncated region in field of view (FOV) of attenuation correction computed tomography (AC-CT) in brain PET/CT. Materials and Methods Biograph Truepoint 40 with TrueV (Siemens) was used as a scanner. $^{68}Ge$ phantom scan was performed with and without applying brain holder using brain PET/CT protocol. PET attenuation correction factor (ACF) was evaluated according to existence of pallet in FOV of AC-CT. FBP, OSEM-3D and PSF methods were applied for PET reconstruction. Parameters of iteration 4, subsets 21 and gaussian 2 mm filter were applied for iterative reconstruction methods. Window level 2900, width 6000 and level 4, 200, width 1000 were set for visual evaluation of PET AC images. Vertical profiles of 5 slices and 20 slices summation images applied gaussian 5 mm filter were produced for evaluating integral uniformity. Results Patient pallet was not covered in FOV of AC-CT when without applying brain holder because of small size of FOV. It resulted in defect of ACF sinogram by truncated region in ACF evaluation. When without applying brain holder, defect was appeared in lower part of transverse image on condition of window level 4200, width 1000 in PET AC image evaluation. With and without applying brain holder, integral uniformities of 5 slices and 20 slices summation images were 7.2%, 6.7% and 11.7%, 6.7%. Conclusion Truncated region by small FOV results in count defect in occipital lobe of brain in clinical or research studies. It is necessary to understand effect of truncated region and apply appropriate accessory for brain PET/CT.

• Journal of The Korean Ophthalmological Society
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• v.54 no.9
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• pp.1445-1451
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• 2013

Purpose: To report long-term changes in the average retinal nerve fiber layer (RNFL) thickness in 2 patients who had intravitreal bevacizumab (IVB) injection for diabetic papillopathy. Case summary: A 36-year-old patient with diabetes complained of decreased visual acuity (20/200) in the right eye. The fundus examination showed optic disc swelling in both eyes. The average RNFL thickness based on optical coherence tomography (OCT) increased to $278{\mu}m$ and Goldmann perimetry showed nasal visual field defect in the right eye. The IVB was injected into the right eye. Three weeks after the IVB injection, RNFL thickness decreased to $135{\mu}m$ and visual acuity improved to 20/25 in the right eye. However, RNFL thickness increased from 126 to $207{\mu}m$ and visual acuity decreased to 20/32 in the left eye. Thus, IVB was injected into the left eye. In week 3, RNFL thickness decreased to $147{\mu}m$ and visual acuity improved to 20/20 in the left eye. At 12 months after IVB injection, RNFL thickness was $87{\mu}m$ in the right eye and $109{\mu}m$ in the left eye. A 57-year-old patient with diabetes complained of decreased visual acuity (20/200) and showed optic disc swelling in the right eye. The average RNFL thickness increased to $252{\mu}m$ and Goldmann perimetry showed an enlarged blind spot in the right eye. IVB was injected into the right eye. After 3 weeks, RNFL thickness decreased to $136{\mu}m$ and visual acuity improved to 20/70 in the right eye. Six months after IVB injection, RNFL thickness was $83{\mu}m$ in the right eye. Conclusions: Visual acuity progressively improved within 3 weeks and RNFL thickness measured by spectral domain OCT showed progressive thickness reduction in 2 cases of diabetic papillopathy patients who had IVB injections.

• The Journal of Korean Medicine
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• v.23 no.3
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• pp.119-133
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• 2002

Objectives : This study was designed to investigate significant differences between the first attack and reattack groups to form fundamental data for decreasing recurrence and secondary prevention of stroke. Methods : I studied 204 patients admitted within 7 days of onset, after the diagnosis of stroke, in the Oriental Medical Hospital of Dongeui University from February to July in 2001.compared the reattack group with the first attack group for risk factors, clinical symptoms and progress, average mark and degree of improvement in Activity Index. Results : 1. Meaningful risk factors associated with the reattack group were male sex, a past history of hypertension and transient ischemic attack, and a family history of stroke. 2. The reattack group had conscious or cognitive disorder in early stage of onset, dysphagia, constipation, urinary incontinence, visual field defect in acute stage, high blood pressure and tachycardia in abnormalvital sign in acute stage, neuropsychosis, shoulder pain and rigidity, and pneumonia in complications more than the first attack group. 3. In Activity Index, the average mark of reattack group was lower than that of the first stroke group and improvement of the reattack group was delayed compared with the first attack group. Conclusions : The reattack group had more severe symptoms and clinical progress than the first attack group.

• Computers and Concrete
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• v.14 no.6
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• pp.727-743
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• 2014

The management of existing concrete bridges has become a major social concern in many developed countries due to the large number of bridges exhibiting signs of significant deterioration. This problem has increased the demand for effective maintenance and renewal planning. In order to implement an appropriate management procedure for a structure, a wide array of corrective strategies must be evaluated with respect to not only the condition state of each defect but also safety, economy and sustainability. This paper describes a new performance evaluation system for existing concrete bridges. The system evaluates performance based on load carrying capability and durability from the results of a visual inspection and specification data, and describes the necessity of maintenance. It categorizes all girders and slabs as either unsafe, severe deterioration, moderate deterioration, mild deterioration, or safe. The technique employs an expert system with an appropriate knowledge base in the evaluation. A characteristic feature of the system is the use of neural networks to evaluate the performance and facilitate refinement of the knowledge base. The neural network proposed in the present study has the capability to prevent an inference process and knowledge base from becoming a black box. It is very important that the system is capable of detailing how the performance is calculated since the road network represents a huge investment. The effectiveness of the neural network and machine learning method is verified by comparing diagnostic results by bridge experts.

• Archives of Reconstructive Microsurgery
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• v.22 no.2
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• pp.63-68
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• 2013

Purpose: In case of the failed replantation, if the patients want to preserve the length of amputated stump, toe transfer is the ideal choice. However, reconstruction of these amputated stump with a free flap can be a useful method when the patients refuse sacrificing their toe. Our purpose of this study is to evaluate availability of functional results and patient satisfaction after this procedure. Materials and Methods: From March 2008 to February 2012, we reconstructed the amputated stump with free flap by patients demand. Eleven patients were included, medial plantar artery perforator flap in seven cases and great toe pulp flap in five cases. Follow-up range 12 to 24 months and we evaluate patient satisfaction by using a visual analogue scale (VAS; 1=unsatisfied, 5=excellent) and functional recovery by measuring the range of motion of remaining joint at 12 months after operation. Results: During follow-up period, all transferred free flaps survived and no major complications were noted. Range of motion of remaining joint appeared satisfactory result ($15^{\circ}$ to $100^{\circ}$). The VAS patient satisfaction score for aesthetic were five in six patients, four in four patients, and three in one patient. Conclusion: In case of the failed digital replantation, if patient refuse toe transfer, it could be useful method to reconstruction with the free flap to preserving maximal length of amputated stump.