• Journal of Korean Neurosurgical Society
• /
• v.54 no.5
• /
• pp.384-389
• /
• 2013

Objective : Use of quantitative computed tomography (CT) to evaluate bone mineral density was suggested in the 1970s. Despite its reliability and accuracy, technical shortcomings restricted its usage, and dual-energy X-ray absorptiometry (DXA) became the gold standard evaluation method. Advances in CT technology have reduced its previous limitations, and CT evaluation of bone quality may now be applicable in clinical practice. The aim of this study was to determine if the Hounsfield unit (HU) values obtained from CT correlate with patient age and bone mineral density. Methods : A total of 128 female patients who underwent lumbar CT for back pain were enrolled in the study. Their mean age was 66.4 years. Among them, 70 patients also underwent DXA. The patients were stratified by decade of life, forming five age groups. Lumbar vertebrae L1-4 were analyzed. The HU value of each vertebra was determined by averaging three measurements of the vertebra's trabecular portion, as shown in consecutive axial CT images. The HU values were compared between age groups, and correlations of HU value with bone mineral density and T-scores were determined. Results : The HU values consistently decreased with increasing age with significant differences between age groups (p<0.001). There were significant positive correlations (p<0.001) of HU value with bone mineral density and T-score. Conclusion : The trabecular area HU value consistently decreases with age. Based on the strong positive correlation between HU value and bone mineral density, CT-based HU values might be useful in detecting bone mineral diseases, such as osteoporosis.

• Journal of radiological science and technology
• /
• v.23 no.2
• /
• pp.13-19
• /
• 2000

There were some controversies about direct cause of hip fracture. We attempted to look at 40 osteoporotic proximal femur fractures in women over 50 years between March in 1999 and Febuary in 2000. The bone density of the fracture group and the healthy 85 control group was measured by Dual Energy X-ray absorptiometry(DEXA). The result was compared using age matched paired T test. The results were as follows ; 1. The femoral neck fractures were 14 cases and the trochanteric fractures were 26 cases. Mean age at a fracture was 67.1 years in neck fracture group and 76.5 years in trochanteric fracture. 2. In the control group, the bone density of both side of the proximal femur was measured and it showed statistically no difference between both sides in same person. 3. The bone density of neck, Ward's triangle, trochanter(P<0.05) and lumbar spine(P<0.001) was significantly reduced in the proximal femoral fracture group comparing with the control group. 4. The bone density of neck, Ward's triangle, trochanter(P<0.05) was significantly reduced in the proximal femoral neck fracture group comparing with the control group, but there was no statistical difference in lumbar spine comparing with the control group. 5. The bone density of neck, Ward's triangle, trochanter and lumbar spine(P<0.001) was significantly reduced in the proximal femoral neck fracture group comparing with the control group. We concluded that the bone mineral densities(BMD) of proximal femur and lumbar spine had decreased in hip fractures but that the bone mineral density and T-score % of the proximal femur were statistically lower than that of the lumbar spine. We suggest that measuring the bone mineral density of the proximal femur may reflect the weakness of the proximal femur more precisely than measuring the bone mineral density of the lumbar spine.

• Imaging Science in Dentistry
• /
• v.37 no.2
• /
• pp.69-77
• /
• 2007

Purpose: To evaluate the accuracy of the imaging reformation of cone beam computed tomography for the assessment of bone defect healing in rat model. Materials and Methods: Sprague-Dawley strain rats weighing about 350 gms were selected. Then critical size bone defects were done at parietal bone with implantation of collagen sponge. The rats were divided into seven groups of 3 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 6 weeks, and 8 weeks. The healing of surgical defect was assessed by multi planar reconstruction (MPR) images and three-dimensional (3-D) images of cone beam computed tomography, compared with soft X-ray radiograph and histopathologic examination. Results: MPR images and 3-D images showed similar reformation of the healing amount at 3 days, 1 week, 2 weeks, and 8 weeks, however, lower reformation at 3 weeks, 4 weeks, and 6 weeks. According to imaging-based methodologies, MPR image revealed similar reformation of the healing amount than 3-D images compare with soft X-ray image. Among the four threshold values for 3-D images, 400-500 HU revealed similar reformation of the healing amount. Histopathologic examination confirmed the newly formed trabeculation correspond with imaging-based methologies. Conclusion: MPR images revealed higher accuracy of the imaging reformation of cone beam computed tomography and cone beam computed tomography is a clinically useful diagnostic tool for the assessment of bone defect healing.

• Tuberculosis and Respiratory Diseases
• /
• v.38 no.2
• /
• pp.119-127
• /
• 1991

This study was designed to observe the problems in performing the screening for early detection of lung cancer, and the degree to which regular radiographic and cytologic screening contributes to the early detection of lung cancer in asymptomatic volunteers. Through mass media campaign, 346 male volunteers had registered to receive radiographic and sputum cytologic screening every four months. Initial chest x-ray examination showed 83 cases of lesions suggesting tuberculosis. Among them, two cases were proved to be active tuberculosis. The rate of long-term follw-up over two years was about 15%. The screening tests detected two cases of lung cancer, one prevalent lung cancer by sputum cytologic examination, and the other by sputum cytologic examination during follow-up. So the prevalence rate of lung cancer was 0.28% and the incidence rate was 3.1/1,000 person·years. Both were localized lesions; ie, American Joint Committee on Cancer (AJCC) stage I and occult lung cancer, respectively. With these results, we suggest that the maintenance of long-term follow-up seems to be the most important problem to evaluate the effect of early detection of lung cancer. It would require thorough explanation of the risk of smoking in lung cancer and the wide public education on the government's base. It should be done at several hospitals simultaneously to include a large population in the study. Although we couldn't determine the effect of screening for the early detection of lung cancer in this report, new diagnostic procedure other than chest x-ray and sputum cytologic examination would be required, according to the literature, to reduce the mortality of lung cancer by the screening program for the early detection of lung cancer.

• Journal of Life Science
• /
• v.15 no.4 s.71
• /
• pp.668-672
• /
• 2005

Nasal tumors have been reported frequently in dogs and nasal discharge has been the primary presenting complaint in nasal tumor patients. A 10-year-old 7 kg male mixed breed dog was presented to the animal hospital for evaluation of severe bloody nasal discharge. After physical examination, blood examination and X-ray examination, magnetic resonance imaging (MRI) examination was also conducted. Based on MRI nasal tumor which does not extend cranial vault was diagnosed. The nasal tumor was confirmed as adenosquamous cell carcinoma by histopathological examination after necropsy. The invasive characteristics of the neoplasm were documented by MRI. MRI was very valuable diagnostic tool for identifying extracranial and intracranial tumor invasion in a small animal.

• Archives of design research
• /
• v.17 no.4
• /
• pp.51-60
• /
• 2004

The medical instrument industry which is one of the high value added industry has been neglected on the various system and political support because it has been recognized as an unknown field to the public although it is the very easy-approaching field for the export market that minimize a technological gap between advanced country and Korea. Especially, the product design that is very important element for the efficient medical treatment and the psychological stabilization of patient is a typical field of lack of investment and support by the unconcern and lack of understanding of design. Therefore this research suggests the current problem of design with the general inquiry of internal and external market situation and domestic medical instrument industry and also it has the conclusion of an alternative proposal for the solution with the design development processing of a moving type-image diagnostic equipment. We will emboss the importance of design competitiveness, suggest the model and basic data to the medical instrument company that starts later, and be a role of inspiration for the lasting investible desire with this research.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.390-392
• /
• 2005

The digital radiation detectors are used clinically by diagnostic apparatus. However the digital radiation detector are some problem like high operating voltage, light blurring, low conversion efficiency, low fill factor, etc. Thus we propose a new radiation detector that the photoconductor layer and liquid crystal layer are coupled in sandwich structure. X-ray absorption in the photoconductor layer controls the state of the liquid crystal via creation of charge carrier and the light modulation of liquid crystal make image formation. The advantage of the new radiation detector is that high resolution image is acquired and the signal amplification is possible by external visible light source. In this study, we study the optical properties and electrical properties of the new radiation detector to irradiate X-ray. The Mercury Iodide($HgI_2$) was used by photoconductor material, and the aluminum is used by reflective layer. The thickness of Mercury Iodide is about $200{\mu}m$, the operating voltage of the liquid crystal is 1.5~5V. The electrical properties of Mercury Iodide was measured, and the transmission efficiency of liquid crystal was measured by modulation potential.

• Advances in nano research
• /
• v.4 no.1
• /
• pp.1-14
• /
• 2016

Superparamagnetic iron oxide nanoparticles (Nps), composed of magnetite, $Fe_3O_4$, or maghemite, ${\gamma}-Fe_2O_3$, core and biocompatible polymer shell, such as dextran or chitozan, have recently found wide applications in magnetic resonance imaging, contrast enhancement and hyperthermia therapy. For different diagnostic and therapeutic applications, current attempt is focusing on the synthesis and biomedical applications of various ferrite Nps, such as $CoFe_2O_4$ and $MnFe_2O_4$, differing from iron oxide Nps in charge, surface chemistry and magnetic properties. This study is focused on the synthesis of manganese ferrite, $MnFe_2O_4$, Nps by most commonly used chemical way pursuing better control of their size, purity and magnetic properties. Co-precipitation syntheses were performed using aqueous alkaline solutions of Mn(II) and Fe(III) salts and NaOH within a wide pH range using various hydrothermal treatment regimes. Different additives, such as citric acid, cysteine, glicine, polyetylene glycol, triethanolamine, chitosan, etc., were tested on purpose to obtain good yield of pure phase and monodispersed Nps with average size of ${\leq}20nm$. Transmission electron microscopy (TEM), X-ray diffraction, energy dispersive X-ray spectroscopy (EDX), $M\ddot{o}ssbauer$ spectroscopy down to cryogenic temperatures, magnetic measurements and inductively coupled plasma mass spectrometry were employed in this study.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2019.05a
• /
• pp.104-107
• /
• 2019

Modern people have abundant food and various forms of life compared to the past, but they have come to form an unhealthy diet, such as skipping breakfast and not eating in time in a busy life. When these eating habits are maintained for a long time, it leads to digestive trouble. The most easily occurring symptoms are called reflux esophagitis and dysphagia. Among them, dysphagia requires quick and accurate diagnosis as they develop into various forms of complications or are also identified as presymptoms of gastric and laryngeal cancers. The result of the diagnosis is still passively judged by the doctor and each of results are different depending on the doctor. The result of the diagnosis here means the severity. When they identify treatment or complications following the results of the diagnosis, the wrong diagnosis may lead to excessive or insufficient treatment. In this paper, to figure out the severity of dysphagia in the diagnosis of dysphagia, we studied the development of a program using the K-means algorithm in the processing of X-ray images for identifying residual food in epiglottic vallecula and pyriform sinus in the section leading to esophagus.

• Journal of the Korean Society of Radiology
• /
• v.16 no.7
• /
• pp.825-833
• /
• 2022

In 3D printing technology, materials that can be printed are increasing along with the development of material engineering, and materials that can be used in the field of radiation are also increasing. Therefore, depending on the composition and density of the materials used, the applied field can be different and applied, so the composition and characteristics of the materials must also be considered. In this study, 10 filaments with different properties were selected using a 3D printer of the FDM (Fused Deposition Modeling) method, and the brightness change of each filament was checked using a diagnostic X-ray generator, and the CT number was measured through CT. I wanted to find a material similar to bone. As a result, a material called silicon carbide was found, which has a similar brightness and CT number to bone. It is thought that further research will be presented as basic data for various studies with a density similar to that of human bones.