• Sleep Medicine and Psychophysiology
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• v.3 no.2
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• pp.1-17
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• 1996

To demonstrate the clinical usefulness of electroencephalography (EEG) and factors increasing the usefulness of EEG, the authors evaluated each relationship between EEG related factors and clinical variables, and neuroimaging studies (CT and MRI)-related factors, and factors which are related with routine neurological examination for 207 patients who had been evaluated with both of EEG and neuroimaging study(CT or/and MRI). The results were as follows: 1) Abnormality of EEG findings had significant relationships with chief complaints, diagnosis, medication use, seizure attack, pathological reflex, and level of consciousness. However there were no significant correlations between abnormality of EEG findings and neuroimaging studies (CT and MRI)- related factors. 2) Laterality of EEG findings had significant relationships with abnormality, laterality, and focality of CT findings, and also with abnormality of MRI findings. But there were no significant correlations between laterality of EEG findings and clinical variables, and neurological examination-related factors. 3) Anterior-posterior distribution of EEG findings was significantly related with medication use. 4) Focality of EEG findings had significant relationships with sex, sensory dysfunction sign, and cerebellar dysfunction sign. But there were no significant correlations between focality of EEG findings and neuroimaging studies(CT and MRI) related factors. 5) Abnormal EEG pattern had significant correlations with various factors, such as age, chief complaints, duration from onset of symptom to taking MRI, seizure attack, abnormality and nature of lesion in CT findings, cortical atrophy in MRI findings, motor dysfunction sign, sensory dysfunction sign, and pathological reflex. 6) With abnormality on sleep activation, age, age of onset, seizure attack, ventricular enlargement in CT findings, and abnormality of MRI findings were significantly correlated. 7) With abnormality on hyperventilation activation, duration of illness and laterality of MRI findings were significantly correlated. Above results may suggest that abnormality of EEG findings is more closely related with functional change of the brain than structural changes of the brain and laterality of EEG findings is vice versa. And also that medication use has an influence on anterior versus posterior distribution of EEG findings and focality of EEG findings is not related with structural changes of the brain. Activation with sleep may be effective to show age differences and provocation of seizure activity and hyperventilation may be effective to detect the abnormal EEG findings by cerebrovascular insufficiency.

• Progress in Medical Physics
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• v.15 no.1
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• pp.54-58
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• 2004

The aim of this study was to develop special birdcage resonators for small objects including the human wrist, hand and small animals, using 3T MRI/MRS. Before substantial development, different types of parameters were arranged, based on theoretical analysis, through lumped element transmission line theory. The primary analysis was peformed with a network analyzer (HP 4195A) and the final experimental analysis was carried out with 3T MRI (Medinus, Korea). The manufactured birdcage resonator is typically composed of 12-element structures to which a low-pass filter is fundamentally applied. The diameter and length of each element of the birdcage resonator were as follows: (1) diameter 12 cm, length of element 22 cm, (2) diameter 15 cm, length of element 22 cm, and (2) diameter 17 cm, length of element 25 cm. Copper tape with a width of 1 cm was used for the coils. MRI acquisition parameters were TR=500 ms, TE=17 ms, and Ave=2 for T1-WT images, and TR=4,000 ms, TE=96 ms, and Ave=2 for T2-WT images. The ratio of the samples diameter to the birdcage resonators diameter was approximately 55%, 63% and 70%, respectively, for the three elements. This study determined that the best image quality and S/N ratio were obtained when the ratio of the object's diameter was approximately 50∼80%. A general theoretical analysis of the birdcage coil differs in many respects from the experimental results which were influenced by many factors that were not considering when the general theoretical analysis of the birdcage coil was peformed. The induced resistance may be considered as part of the resistive loss if the quantitative value can be determined using a radiation resistance approach.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.4 no.1
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• pp.1-6
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• 2011

Purpose: To evaluate the usefulness of ultrasonography in diagnosis of the medial meniscus tear as a screening tool before performing magnetic resonance imaging. Materials and Methods: From April 2009 to September 2010, magnetic resonance imaging (MRI) was taken in 147 knees out of 341 knees examined with ultrasonography (US) under the suspicion of medial meniscus tear. The sonographic findings were 16 without abnormality, 12 inhomogeneity, 4 cluster, 60 cleavage and 55 more than 5mm medial extrusion of medial meniscus. In Statistical analysis, sensitivity and specificity, positive predictive value and negative predictive values were calculated. Results: The MRI showed abnormality in 104 knees. Sensitivity and specificity of ultrasonography for MRI was 94.2% and 23.3%, respectively. Positive predictive value was 74.8%, negative predictive value was 62.5%. The positive predictive value of ultrasonography were 58.3% in heterogeneity, 100% in showing cluster, 75% in visible cleft and 80% in medial extrusion. Conclusion: The US is a useful tool in prediction of medial meniscus tear before confirming it in high-cost MRI.

• Journal of Veterinary Clinics
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• v.27 no.5
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• pp.588-592
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• 2010

A 15-year-old neutered male Yorkshire terrier was presented with a gait disorder of the pelvic limbs. For differential diagnosis of neural disease, magnetic resonance imaging (MRI) and computed tomography (CT) scan were performed. CT showed bone defect in the 4th lumbar vertebra and adjacent soft tissue mass. MRI revealed a mass in left side of the 4th lumbar vertebra. The mass was uniformly enhanced on contrast-enhanced T1-weighted imaging (T1W1). Excision of the mass alleviated back pain. Vertebral osteosarcoma was identified by the histopathological examination. Therefore, CT and MRI were helpful to diagnose vertebral osteosarcoma in the dog and to plan surgical excision of the mass.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5005-5011
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• 2011

The purpose of this work is to know the validity of a new stimulation method in cognitive functional imaging using custom-designed images correspond to words or syllables improving the shortcomings of existing method using text. From March 2011 to May five Subjects in need of language related functional MRI scanning were selected and both of text stimulating method and image stimulating method sacanning were carried out three times each. Using 3.0T Philps MRI machine and Invivo Co's Eloquence system, data acquisition was performed with EPI-BOLD technique. Post processing was performed with SPM 99 while the activated signals were determined within 95 percent confidence level.The number of activation clusters and the activation ratio inside ROI were compared. As as result, all of the subject showed activation inside Broca area but it did not have statistical significance. In conclusion, the image sitimulation method has potential because image itself is a common means of recognition and it can be recognised easily even if there language barrier. This stimulation method can be applied to replacing the exising scanning method especially in the elderly, infants, foerigners who may not fully understand about the examination.

• Journal of the Korean Orthopaedic Association
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• v.53 no.6
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• pp.530-539
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• 2018

Purpose: We aimed to evaluate the magnetic resonance imaging (MRI) findings of congenital postaxial polydactyly of the foot. Materials and Methods: Three-hundred and forty-seven feet of 288 patients who underwent congenital postaxial polydactyly or polysyndactyly correction were divided into five subtypes according to the radiographic shapes of deformity origins (widened metatarsal head, bifid, fused duplicated, incompletely duplicated, or completely duplicated). MRIs were assessed to determine whether they unrevealed areas were fused or separated. MRI was also used to assess cases with radiographic phalangeal aplasia. Results: Huge variations were noted in MRIs. Fusion or separation at the base or head between original and extra digits were observed, and MRI effectively depicted phalangeal aplastic areas. Conclusion: MRI evaluations of congenital postaxial polydactyly of the foot are useful for determining the anatomical statuses which were not visualized by plain radiography (level of evidence: 3).

• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.99-106
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• 2023

This study measured the signal intensity (SI) of the hippocampus in relation to memory via fMRI analysis of 3 types of radiology symbols, 3 types of nuclear medicine symbols, and 3 types of oncology symbols among the most commonly employed medical symbols in hospitals. The following are the conclusions of the study. result of analyzing the SI values for symbol 1, symbol 2, and symbol 3 of the radiology, nuclear medicine, and oncology departments, symbol 3 had the highest SI value (1.72 ± 0.56) in radiology, symbol 2 had the highest SI value (1.69 ± 0.64) in nuclear medicine, and symbol 2 had the highest SI value (1.64 ± 0.63) in oncology. The overall mean of radiology, nuclear medicine, and oncology symbols was 1.62 ± 0.60 for nuclear medicine, 1.61 ± 0.59 for oncology, and 1.49 ± 0.49 for radiology. According to the overall SI measurement results, symbol 3 in radiology, symbol 2 in nuclear medicine, and symbol 2 in oncology were confirmed to have high SI values. If symbols with high SI values are used in a hospital, it is believed to be beneficial for navigating in any hospital.

• Journal of the Korean Arthroscopy Society
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• v.2 no.2
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• pp.151-154
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• 1998

In the diagnosis of the meniscal tear of the knee, the high accuracy of the MRI diagnosis is well-known, but the accuracy of the MRI in the diagnosis of the very pattern of the tear of menisci is not well-established. The purpose of this study is to give some informations to consider in the diagnosis and therapeutic planning of torn menisci. The authors performed a retrospective study comparing the MRI and arthroscopic findings of 141 knees which had undergone arthroscopic surgery from Mar. 1997 to Mar. 1998. The results are as follows. In the diagnosis of tear of the menisci, MRI had sensitivity of 91%, specificity of 96%, accuracy of 95%. The mismatch of the tear patterns of the menisci between MRI and arthroscopic findings was identified in 59%, especially high in flap tear(100%), complex tear(84%), peripheral tear(55%). In conclusion, MRI is very accurate in the diagnosis of the tear of menisci, but the tear patterns of the menisci cannot be accurately determined by MRI. In the cases of flap tears, complex tears and peripheral tears, it is more difficult to determine the tear patterns of the menisci by MRI. False-negative rate of MRI was especially high(44%) in the peripheral tear type. So, other clinical correlations should be made in determination of the presence of the tear in the diagnosis of peripheral tear of the menisci.

• The Korean Society of Law and Medicine
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• v.25 no.1
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• pp.61-86
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• 2024

The purpose of this study was to investigate the importance of continuous and detailed follow-up of patients after spinal surgery by reviewing the literature on epidural hematoma and the lower court ruling on lumbar MRI during the judgment on the negligence of postoperative follow-up. In the case of neglecting MRI examination or cooperation after surgery, delaying MRI examination after pain and symptom appeal after surgery, and returning home immediately after neurological symptom development after surgery, negligence in progress observation was recognized. In the case of the case where the negligence was not recognized even after the occurrence of the aftereffects by taking measures against the symptoms, and the case where the scope of the doctor's discretion for the execution of the test was recognized, It is hoped that this study will help prevent medical accidents and disputes related to follow-up after spinal surgery by increasing awareness of the importance of prompt MRI examination, diagnosis, surgical treatment, and power, especially in the case of new neurological symptoms.

• Journal of Veterinary Clinics
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• v.25 no.2
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• pp.126-130
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• 2008

A six year-old male Maltese dog was presented to the Konkuk University Veterinary Teaching Hospital (KUVTH) with mass in right scapula region. Physical examination, radiography, magnetic resonance imaging (MRI), complete blood count (CBC), serum biochemistry, cytological analysis of fine needle aspiration and histopathological examination were performed. There was no remarkable finding in CBC. Alkaline phosphatase (ALP) was found to be increased in serum chemistry profile. Osteolysis was seen on radiographs of the scapula. MRI revealed mixed signal intensity in scapula. Cytological examination of fine-needle aspirate (FNA) was suggestive of sarcoma. We confirmed that the neoplastic cells were fibrosarcoma by immunohistochemical and Masson's trichrome staining.