• Smart Media Journal
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• v.5 no.1
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• pp.44-48
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• 2016

In a longitudinal neuroimaging study, the upgrades of a magnetic resonance imaging (MRI) scanner due to outdated hardwares and softwares make it difficult to maintain the same MRI conditions in the long-term research period. Particularly, high field MRI systems such 3T scanners become popular in recent years. However, it is still unclear whether an integrated analysis of 3T and 1.5T images is possible without consideration of the field strength. In this study, we evaluated the reproducibility of hippocampal volumes between brain images with different field strengths and slice orientations. 296 participants underwent both 3T and 1.5T MRI and both sagittal and axial scans for high resolution brain images, and their hippocampal volumes were measured using Freesurfer, a well-known software for neuroimaging analysis. Paired t-tests showed that the hippocampal volumes were significantly different between the image types. These results suggest that it is necessary to develop data analysis techniques for integrating diverse types of MRI images.

• Journal of Veterinary Clinics
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• v.41 no.2
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• pp.79-87
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• 2024

The tarsus in dogs has a complex structure that makes its evaluation relatively challenging. Because an accurate diagnosis of the tarsus is difficult through basic examinations alone, imaging tests are essential. Previous studies have explored the anatomical and radiological features of the canine tarsus using several imaging modalities. However, the imaging utility of the tarsus across different modalities has not been thoroughly evaluated. This study aimed to visualize the tarsal structures using magnetic resonance imaging (MRI) and ultrasonography, compare their utility, and propose suitable imaging modalities and conditions for evaluating specific tarsal structures. Magnetic resonance imaging and ultrasound scans of the tarsus of four healthy dogs were performed, and two observers rated the utility of each image on a five-point scale. Although MRI is more beneficial for assessing the tarsal structures than ultrasound, ultrasound also appears clinically useful for evaluating the cranial tibialis muscle, deep digital flexor tendon, subcutaneous fat, joint space, and superficial digital flexor tendon. In addition, each structure of interest can be evaluated for optimal visibility using specific ultrasound sections, MRI sequences, and planes. In veterinary clinical practice, an initial assessment using ultrasound imaging with optimal visibility is required and if further evaluation is necessary, MRI examinations with optimal MRI sequences and planes can be performed.

• Journal of the Korean Society of Radiology
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• v.5 no.4
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• pp.161-169
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• 2011

This research experimented on the change of the multiple colleague scan angle facing one scan object facet to many directions of the form of 3D about the visual angle nervous system forming the cubic distribution with the gradient magnetic field of the mri system and considered the existing basic angle oblique direction test coverage and comparison. MR system can freely select various pulse sequence and image slice. To oblique imaging for optic nerve viewing, we have studied the variation of scan angle between typical oblique scan method (sagittal-coronal plane) and multi directional angles oblique scan method (sagittal-coronal-axial plane) using gradient of MR system. In this study, the subjects of the experiment were normal adults in our country. As a result, we confirmed that multi directional angles oblique scan method can display anatomical information of more wider area than typical oblique scan method. In addition, to clearly display optic nerve, we also confirmed that image slice thickness and pulse sequence have effect on it.

• Clinical and Experimental Pediatrics
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• v.45 no.2
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• pp.256-260
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• 2002

Bone marrow necrosis is a rare complication of a variety of diseases affecting the marrow. The cause and incidence are unknown, and reports of treatment response are rare. We describe a case of relapsed acute mixed type leukemia with bone marrow necrosis. The patient was a 10 year old female diagnosed with acute mixed type leukemia four years ago. She had been on second remission state for 1 year, presented with severe back pain, tenderness in lower extremities, low-grade fever and general weakness. Her level of serum lactic dehydrogenase on admission was increased. Bone marrow aspiration from both posterior iliac crest showed marrow necrosis. Subsequent examination showed the same feature. Hip MRI showed heterogenous low signal intensity in both iliac bone on T-1 weighted image and heterogenous high signal intensity on T-2 wieghted image. Remission induction therapy was started but she expired on 59th hospital day due to the complication of sepsis.

• Journal of the Korea Society of Computer and Information
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• v.19 no.1
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• pp.131-140
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• 2014

TMost of the medical images that are being used today are to confirm the existence of lesions. These kind of medical images can not only be used to confirm lesions but if we could use it for academic studies or for analysis and reference materials for surgical operations, it could offer great help in medical studies. Furthermore, we could reduce the number of errors in treatment through simulations in the surgical operations and treatments. In this paper, the necessary parts regarding the medical image visuals were extracted through the point cloud and by using the information obtained through it, it manufactures the necessary information for academic studies, diagnoses or operations. By designing and realizing the system which makes simulation possible with the manufactured information, the paper attempts to provide a more effective way to approach academic studies or giving appropriate diagnoses in the treatment of patients.

• Journal of Biosystems Engineering
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• v.39 no.3
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• pp.205-214
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• 2014

Purpose: Phytosanitary irradiation treatment can effectively control regulated pests while maintaining produce quality. The objective of this study was to establish the best irradiation treatment for mangosteen, a popular tropical fruit, using a Monte Carlo simulation. Methods: Magnetic resonance image (MRI) data were used to generate a 3-D geometry to simulate dose distributions in a mangosteen using a radiation transport code (MCNP5). Microsoft Excel with visual basic application (VBA) was used to divide the image data into seed, flesh, and rind. Radiation energies used for the simulation were 10 MeV (high-energy) and 1.35 MeV (low-energy) for the electron beam, 5 MeV for X-rays, and 1.25 MeV for gamma rays from Co-60. Results: At 5 MeV X-rays and 1.25 MeV gamma rays, all areas (seeds, flesh, and rind) were irradiated ranging from 0.3 ~ 0.7 kGy. The average doses decreased as the number of fruit increased. For a 10 MeV electron beam, the dose distribution was biased: the dose for the rind where the electrons entered was $0.45{\pm}0.03$ kGy and the other side was $0.24 {\pm}0.10$ kGy. Use of an electron kinetic energy absorber improved the dose distribution in mangosteens. For the 1.35 MeV electron beam, the dose was shown only in the rind on the irradiated side; no significant dose was found in the flesh or seeds. One rotation of the fruit while in front of the beam improved the dose distribution around the entire rind. Conclusion: These results are invaluable for determining the ideal irradiation conditions for phytosanitary irradiation treatment of tropical fruit.

• Journal of Korean Medicine Rehabilitation
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• v.19 no.4
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• pp.151-163
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• 2009

Objectives : In the assessment of the lumbar spine by magnetic resonance imaging (hereinafter, "MRI"), changes in the paraspinal muscles are overlooked. The purpose of our study is to examine the correlation between the multifidus muscle atrophy on MRI findings and the clinical findings in low back pain (hereinafter, "LBP") patients. Methods : The retrospective study on 38 LBP patients, presenting either with or without associated leg pains, was undertaken. The MRI findings on the patients were visually analysed to find out a lumbar multifidus muscle atrophy, disc herniation, disc degeneration, spinal stenosis and nerve root compressions. The clinical history in each case was obtained from their case notes and pain drawing charts. Results : The lumbar multifidus muscle atrophy has occurred from more than 80% of the patients with LBP. Most of lumbar multifidus muscle atrophies have increased from lower level of lumbar spine. It was bilateral in the majority of the cases. In addition, multifidus muscle atrophy was correlated to the patient's age, disc degenerations and spinal stenosis. On the contrary, gender, the duration of LBP, referred leg pain, disc herniation and nerve root compressions had no relevance to multifidus muscle atrophies. Therefore, when assessing the MRIs of the lumbar spine, we should have more attetion on multifidus muscle, because it has lot's of information about spinal neuropathy problems. Conclusions : Therefore, the examination of multifidus muscle atrophies should be considered when assessing the MRIs of the lumbar spine. In addition, it helps to evaluate and plan the treatment modalities of LBP. Moreover, it prevents from LBP by discovering the importance between the multifidus muscle and the spine stabilization exercise.

• Journal of the Optical Society of Korea
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• v.14 no.3
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• pp.235-239
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• 2010

In this study, we have fabricated two types of non-invasive fiber-optic respiration sensors that can measure respiratory signals during magnetic resonance (MR) image acquisition. One is a nasal-cavity attached sensor that can measure the temperature variation of air-flow using a thermochromic pigment. The other is an abdomen attached sensor that can measure the abdominal circumference change using a sensing part composed of polymethyl-methacrylate (PMMA) tubes, a mirror and a spring. We have measured modulated light guided to detectors in the MRI control room via optical fibers due to the respiratory movements of the patient in the MR room, and the respiratory signals of the fiber-optic respiration sensors are compared with those of the BIOPAC$^{(R)}$ system. We have verified that respiratory signals can be obtained without deteriorating the MR image. It is anticipated that the proposed fiber-optic respiration sensors would be highly suitable for respiratory monitoring during surgical procedures performed inside an MRI system.

• Imaging Science in Dentistry
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• v.52 no.4
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• pp.393-398
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• 2022

Purpose: This study proposed a generative adversarial network (GAN) model for T2-weighted image (WI) synthesis from proton density (PD)-WI in a temporomandibular joint(TMJ) magnetic resonance imaging (MRI) protocol. Materials and Methods: From January to November 2019, MRI scans for TMJ were reviewed and 308 imaging sets were collected. For training, 277 pairs of PD- and T2-WI sagittal TMJ images were used. Transfer learning of the pix2pix GAN model was utilized to generate T2-WI from PD-WI. Model performance was evaluated with the structural similarity index map (SSIM) and peak signal-to-noise ratio (PSNR) indices for 31 predicted T2-WI (pT2). The disc position was clinically diagnosed as anterior disc displacement with or without reduction, and joint effusion as present or absent. The true T2-WI-based diagnosis was regarded as the gold standard, to which pT2-based diagnoses were compared using Cohen's ĸ coefficient. Results: The mean SSIM and PSNR values were 0.4781(±0.0522) and 21.30(±1.51) dB, respectively. The pT2 protocol showed almost perfect agreement(ĸ=0.81) with the gold standard for disc position. The number of discordant cases was higher for normal disc position (17%) than for anterior displacement with reduction (2%) or without reduction (10%). The effusion diagnosis also showed almost perfect agreement(ĸ=0.88), with higher concordance for the presence (85%) than for the absence (77%) of effusion. Conclusion: The application of pT2 images for a TMJ MRI protocol useful for diagnosis, although the image quality of pT2 was not fully satisfactory. Further research is expected to enhance pT2 quality.

• Journal of Digital Contents Society
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• v.17 no.6
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• pp.603-611
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• 2016

Generally, the doctors manually delineated the prostate boundary seeing the image by their eyes, but the manual method not only needed quite much time but also had different boundaries depending on doctors. To reduce the effort like them the automatic delineating methods are needed, but detecting the boundary is hard to do since there are lots of uncertain textures or speckle noises. There have been studied in SVM, SIFT, Gabor texture filter, snake-like contour, and average-shape model methods. Besides, there were lots of studies about 2 and 3 dimension images and CT and MRI. But no studies have been developed superior to human experts and they need additional studies. For this, this paper proposes a method that delineates the boundary predicting its texture features and its average distribution on the prostate image. As result, we got the similar boundary as the method of human experts.