• Investigative Magnetic Resonance Imaging
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• v.18 no.4
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• pp.279-289
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• 2014

Objective: The aims of this article are to differentiate soft tissue masses showing low signal intensity on T2-weighted images (T2WIs) according to the histopathologic findings. Conclusion: To know relatively small numbered soft tissue masses with low signal intensities on T2WIs adding characteristic location, morphology, signal intensities on other sequences might be helpful for differential diagnosis of mostly non-specific soft tissue tumors on MRI.

• Journal of Biomedical Engineering Research
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• v.20 no.3
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• pp.283-290
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• 1999

Because MR(Magnetic Resonance) slice images have much information of functions about body organs, it is very effeclive for diagnoses lo analyze and visualize MR slice images. A visuahzation process is composed of medical image acquisition, preprocessmg, segmentation, inlerpolation, rendering. Segmentation and interpolation among thenl ,1re currenl hot topics because of MR slice image imperfections. This paper proposes a method for segmentalion, mlerpolation respectively and addresses 3 D-visualizmg of a head. We segmented head tissues uomg otructural knowledge of head studied by clinical experiments sequentially. We improved the dynamic elastic inlerpolation to Utilize in concave conlour. We compared the proposed segmentation method and the interpolation method with other methods.

• Imaging Science in Dentistry
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• v.33 no.1
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• pp.1-4
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• 2003

Purpose : The purpose of this study was to investigate the distribution and frequency of temporomandibular joint (TMJ) effusion in magnetic resonance (MR) images of patients with disc displacements. Materials and Methods: On T2 weighted MR images of 148 TMJs taken from 74 patients presenting with TMJ pain and dysfunction, we assessed the cases showing TMJ effusion, defined as an amount of fluid that exceeded the maximum amount seen in a control group of asymptomatic volunteers. The amount of TMJ fluid was graded as: I (none or minimal), II (moderate), III (marked), and IV (extensive), according to a standard set by a reference. Disc displacement categories were also recorded. Results: Of the 148 TMJs examined in this study, 52 joints (35.1%) presented with joint effusion, 24 (16.2%) showing bilateral joint effusion. 38 joints showed upper joint space effusion, 3 showed lower joint space effusion, and 11 showed both upper and lower joint space effusion. 96 joints (64.9%) had grade I joint fluid, 27 (18.2%) grade II, 15 (10.1 %) grade III, and 10 (6.8%) grade IV. 80.0% of the joints presenting with grade IV effusion showed disc displacement without reduction. Conclusion: Joint effusion was found not only in upper, but also in lower joint spaces. The higher the effusion grade, the greater the frequency of disc displacement without reduction.

• Journal of Veterinary Clinics
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• v.24 no.2
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• pp.247-250
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• 2007

A 3-year-old, intact female English cocker spaniel dog was evaluated for an acute onset of tetraplegia. Utilizing magnetic resonance (MR) imaging, the cause of the neurologic deficits was determined to be an peracute hemorrhage of spinal cord. The MR study additionally demonstrated parenchymal hyperintensity on T2weighted images and similarly located hypointensity on T1weighted images. Hemorrhagic myelomalcia was suspected based on these MR characteristics, which was subsequently confirmed histopathologically.

• Journal of Korean Neurosurgical Society
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• v.38 no.1
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• pp.23-27
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• 2005

Objective : The aim of this study is to assess the significance of an apparent diffusion coefficient[ADC] study for diagnosis of ventriculitis. Methods : Seven patients with ventriculitis were enrolled in this study. Diffusion-weighted[DW] magnetic resonance images[MRI] and ADC maps in the dependent intraventricular collection, periventricular white matter and non-dependent cerebrospinal fluid[CSF] were obtained. The images and ADC data from the different lesions were compared. Results : The DW MRI showed marked hyperintensity in the purulent pus lesion, and the corresponding ADC maps revealed prominent hypointensity and restricted ADC values compared with the non-dependent CSF and normal white matter. Conclusion : The decreased ADC value and increased signal intensity of the dependent intraventricular fluid on the DW MRI show restricted water diffusion in the purulent fluid, which is indicative of a pyogenic ventriculitis diagnosis.

• Journal of Acupuncture Research
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• v.36 no.2
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• pp.107-112
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• 2019

The aim of this study was to report on the resorption of herniated nucleus pulposus following acupotomy treatment. Two patients were treated with acupotomy which included integrative Korean Medicine treatment, for either cervical, or lumbar herniated nucleus pulposus. Magnetic Resonance Imaging was used to produce images before and after (several months) treatment. The Numerical Rating Scale scores and Range of Motion were used to assess the patients at admission and discharge. In both cases, substantial resorption of the respective herniated disc was observed in the magnetic resonance images, with a decrease in the Numerical Rating Scale score. Range of Motion improved in 1 case. This study shows that acupotomy treatment may be a clinically effective treatment for herniated nucleus pulposus resorption and pain relief.

• Investigative Magnetic Resonance Imaging
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• v.26 no.2
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• pp.96-103
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• 2022

Purpose: The survival of organisms critically depends on avoidance responses to life-threatening stimuli. Information about dangerous situations needs to be remembered to produce defensive behavior. To investigate underlying brain regions to process information of danger, manganese-enhanced MRI (MEMRI) was used in olfactory fear-conditioned rats. Materials and Methods: Fear conditioning was conducted in male Sprague-Dawley rats. The animals received nasal injections of manganese chloride solution to monitor brain activation for olfactory information processing. Twenty-four hours after manganese injection, rats were exposed to electric foot shocks with odor cue for one hour. Control rats were exposed to the same odor cue without foot shocks. Forty-eight hours after the conditioning, rats were anesthetized and their brains were scanned with 9.4T MRI. Acquired images were processed and statistical analyses were performed using AFNI. Results: Manganese injection enhanced brain areas involved in olfactory information pathways in T1 weighted images. Rats that received foot shocks showed higher brain activation in the central nucleus of the amygdala, septum, primary motor cortex, and preoptic area. In contrast, control rats displayed greater signals in the orbital cortex and nucleus accumbens. Conclusion: Nasal delivery of manganese solution enhanced olfactory signal pathways in rats. Odor cue paired with foot shocks activated amygdala, the central brain region in fear, and related brain circuits. Use of MEMRI in fear conditioning provides a reliable monitoring technique of brain activation for fear learning.

• Journal of Yeungnam Medical Science
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• v.40 no.2
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• pp.212-217
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• 2023

We report a case of transient osteoporosis of the hip with a femoral neck fracture found during follow-up. A 53-year-old man presented with left hip pain without trauma. The pain did not improve after 2 weeks and he was brought to our hospital by ambulance. Magnetic resonance imaging (MRI) of the left hip joint showed diffuse edema in the bone marrow, which was identified by low signal intensity on T1-weighted images, high signal intensity on T2-weighted images, and increased signal intensity on short tau inversion recovery. This edema extended from the femoral head and neck to the intertrochanteric area. He was diagnosed with transient osteoporosis of the left hip. Rest gradually improved his pain; however, 3 weeks later, his left hip pain worsened without trauma. X-ray, computed tomography, and MRI results of the hip joint demonstrated a left femoral neck fracture, and osteosynthesis was performed. Differential diagnoses included avascular necrosis of the femoral head, infection, complex regional pain syndrome, rheumatoid arthritis, leukemia, and other cancers. Transient osteoporosis of the hip generally has a good prognosis with spontaneous remission within a few months to 1 year. However, a sufficient length of follow-up from condition onset to full recovery is necessary to avoid all probable complications such as fractures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4891-4895
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• 2010

RF coil is an important component of the Magnetic Resonance Imaging (MRI) system and the performance of RF coil is one of major factors for high SNR images. Sensitivity and RF field uniformity are parameters for evaluating RF coil performance. Since the B1 field is induced by RF coil, MR signal is strongly affected by RF coil structure and arrangement. In receiving MR signal, the RF coil sensitivity to MR Signal is also determined by the induced B1 field of RF coil. Therefore, the spatial distribution of B1 field must be verified. In this work, we performed computer simulation of the basic RF coil structures using Matlab and verified their sensitivity and uniformity through their B1 field distribution. This work will be useful for the advanced multi-channel RF coil design.

• Investigative Magnetic Resonance Imaging
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• v.8 no.2
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• pp.86-93
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• 2004

Purpose: We evaluated $^1H$ MR spectroscopy improves the preoperative diagnosis of diffuse infiltrative type of primary central nervous system lymphomas. Materials and methods: After review of conventional MR images and medical records, we retrospectively reviewed proton MR spectra in seven patients with primary central nervous system lymphoma diagnosed by means of biopsy. Relative ratio of choline (Cho), N-acetylaspartate (NAA), and lipid-lactate (Lip-Lac) to creatine (Cr) were measured for quantitative analysis. Results: The average ratio of Cho/Cr was $1.80{\pm}0.95$, NAA/Cr was $1.34{\pm}0.41$, and Lip-Lac/Cr was $1.12{\pm}0.16$. All cases of lymphomas showed increased Lip-Lac peak. Two case of mass forming lymphoma showed decreased NAA/Cr significantly, whereas five cases of lymphoma without mass formation showed preserved NAA/Cr. Conclusion : We thought the presence of Lip-Lac peak without significant reduction of NAA on the MR spectroscopy was helpful for diagnosis of diffuse infiltrative type of central nervous system lymphoma.