• 대한방사선치료학회:학술대회논문집
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• 2005.06a
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• pp.23-26
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• 2005

Introduction: To evaluate whether modified MUPIT applicator can effectively eradicate recurrent tumor in uterine cervix cancer and reduce rectal complication after complete radiation treatment. Methods and Materials: Modified MUPIT applicator basically consists of an acrylic cylinder with flexible brain applicator , an acrylic template with a predrilled array of holes that serve as guides for interstitial needles and interstitial needles. CT scan was performed to determine tumor volume and the position of interstitial needles. Modified MUPIT applicator was applied to patient in operation room and the accuracy for position of interstitial needles in tumor volume was confirmed by CTscan. Brachytherapy was delivered using modified MUPIT applicator and RALS (192-Ir HDR) after calculated computer planning by orthogonal film. The daily dose was 600cGy and the total dose was delivered 3000cGy in tumor volume by BID. Rectal dose was measured by TLD at 5 points so that evaluated the risk of rectal complication. Result: The application of modified MUPIT applicator improved dramatically dose distributions in tumor volume and follow-up of 3 month for this patient was clinically partial response without normal tissue complication, Rectal dose was measured 34.1cGy, 57.1cGy, 103.8cGy, 162.7cGy, 165.7cGy at each points, especially the rectal dose including previous EBRT and ICR was 34.1cGy, 57.1cGy Conclusion: Patients with locally recurrent tumor in uterine cervix cancer treated with modified MIUPIT applicator can expect reasonable rates of local control. The advantages of the system are the fixed geometry Provided by the template and cylinders, and improved dose distributions in irregular tumor volume without rectal complication

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.3-7
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• 2010

Purpose: The usefulness of Positron Emission Tomography (PET) images in diagnosis, staging, recurrent and treatment response evaluation has already been known. However, tumors which are small size, located in lower lobe of lung or upper lobe of liver are shown misalignment, distortion and different Standard Uptake Value (SUV) by respiration in PET images. Therefore, if radiotherapy based on normal respiration, it may cause low treatment response or more side effects because targets which had to treat, out of treat range or over dose to normal tissue. The purpose of this study is to evaluate attenuation-correction with Average CT (ACT) for more accuracy SUV measurement and minimize artifact by respiration. Materials and Methods: 13 patients, who had tumors which are around the diaphragm, underwent ACT scan after Helical CT (HCT) scan with PET/CT (Discovery DSTE 8; GE Healthcare). We quantified the differences between attenuation corrected image with HCT and attenuation corrected image with ACT in artifact size and maximum SUV ($SUV_{max}$). Artifacts were evaluated by measurement of the curved photogenic area in the lower thorax of the PET images for all patients. $SUV_{max}$ was measured separately at the primary tumors. Analysis program was Advantage Workstation v4.3 (GE Healthcare). Patients were injected with 7.4 MBq (0.2 $mC_i$) per kg of $^{18}F$-FDG and scanned 1 hour after injection. The PET acquisition was 3 minute per bed. Results: Significantly lower artifact were observed in PET/ACT images than in PET/HCT images (below-thoracic artifacts caused by under corrected $1.5{\pm}3.5$ cm vs. $13.4{\pm}4.2$ cm). Significantly higher $SUV_{max}$ were noted in PET/ACT images than in PET/HCT images in the primary tumor. Compared with PET/HCT images, $SUV_{max}$ in PET/ACT images were higher by $5.3{\pm}3.9%$ (mean value) tumor. The highest difference was observed in Lower lobe of lung (7.7 to 8.7; 13%). Conclusion: Due to its significantly reduced artifacts in lower thoracic, attenuation corrected image with ACT images provided more reliable $SUV_{max}$ and may be helpful in monitoring treatment response. Moreover, ACT can separate upper lobe of liver and lower lobe of lung, it may be helpful in interpretation. ACT will be clinically useful, considering increased dose caused by ACT scan and adapt.

• Journal of the Korean Society of Radiology
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• v.14 no.7
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• pp.975-980
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• 2020

Cervical neural foraminal stenosis is a very common spinal disease that affects a relatively large number of people of all ages. However, since imaging methods that quantitatively provide neural foraminal stenosis are lacking, this study attempts to present quantitative measurement results by reconstructing 3D computed tomography images. Using a 3D reconstruction software, the surrounding bones were removed, including the spinous process, transverse process, and lamina of the cervical spine so that the neural foramen were well observed. Using Image J, a region of interest including the neural foramen area of the 3D image was set, and the number of pixels of the neural foramen area was measured. The neural foramen area was calculated by multiplying the number of measured pixels by the pixel size. In order to measure the widest area of the neural foramen, it was measured between 40-50 degrees in the opposite direction and 15-20 degrees toward the head. The measured cervical neural foramen area showed consistent measurement values. The largest measured area of the right neural foramen C5-6 was 12.21 ㎟, and after 2 years, the area was measured to be 9.95 ㎟, indicating that 18% stenosis had progressed. Since 3D reconstruction using axial CT scan images, no additional radiation exposure is required, and the area of stenosis can be objectively presented. In addition, it is good to explain to patients with neural stenosis while viewing 3D images, and it is considered a good method to be used in the evaluation of the progression of stenosis and post-operative evaluation.

• Composites Research
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• v.26 no.3
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• pp.175-181
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• 2013

The evaluation and prediction for the absorbed energy, residual velocity, and impact damage are the key things to characterize the impact behavior of composite laminated panel subjected to high-velocity impact. In this paper, the method to predict the residual velocity and the absorbed energy of Carbon/Epoxy laminated panel subjected to high velocity impact are proposed and examined by using quasi-static perforation test and high-velocity impact test. Total absorbed energy of specimen due to the high-velocity impact can be grouped with static energy and kinetic energy. The static energy are consisted of energy due to the failure of the fiber and matrix and static elastic energy, which are related to the quasi-static perforation energy. The kinetic energy are consisted of kinetic energy of moving part of specimen, which are modelled by three modified kinetic model. The high-velocity impact test were conducted by using air gun impact facility and compared with the predicted values. The damage area of specimen were examined by C-scan image. In the high initial impact velocity above the ballistic limit, both the static energy and the kinetic energy are known to be the major contribution of the total absorbed energy.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.123-126
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• 1997

We present a method for the estimation of 3D solid angle assessment of the acetabular coverage of the femoral head in 3D space. At first, femoral head and acetabulum is segmented from the original CT scan images. The slice thickness is 1.5mm and the number of slices is usually 30-40 to cover the entire acetabulum. The superior half of the femoral head is modeled as part of a sphere. Thus, the axial cross sections of the upper half of the femoral head are also modeled as circles. A set of points from each outline image of femoral head is fitted recursively into a circle by minimizing root-mean-square (RMS) error. With these fitted circles, a center point of the femoral head model is evaluated. This is a reference point for calculating the solid angle of the acetabular inner surface. Next, the tangent lines connecting from a set of points of the acetabular edge to the center of the fitted sphere are obtained. The lines pass through the unit sphere whose center is the same as that of the femoral head. With the points on the unit sphere, we calculate area and estimate the solid angle. Based on this solid angle, the deformity of the acetabulum is analyzed. In case of normal subject, the solid angle is about 4.3 (rad) and acetabular coverage is 68%.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.1
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• pp.46-53
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• 2008

Ultrasonic C-scan technique is one of very popular techniques being used for detection of flaws in polymer matrix composite(PMC). However, the application of this technique is very limited for evaluation of defects in PMC fabricated by the automated fiber placement process. The purpose of this study is to develop a novel ultrasonic hybrid system based on nondestructive and non-contact ultrasonic techniques for evaluation of delamination in carbon/epoxy and carbon/PPS composite laminates. It was shown that the newly developed ultrasonic hybrid system based on dual air-coupled pitch-catch technique with ultrasonic scattering reflection concept could provide excellent image with higher resolution of delamination in PMC compared with the conventional pitch-catch method. It is expected that this ultrasonic hybrid technique can be applied for on-line inspection of flaws in PMC during the fabrication process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.183-184
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• 2006

Some researchers proposed positive effects of whole body vibration (WBV) on osteoporotic trabecular bones of animals. In the present study, the correlation between the improvement of morphological characteristics and the effect of WBV was investigated and analyzed in OVX rats. The rats were randomly assigned to 5 groups: control, sham, WBV 17Hz, WBV 30Hz and WBV 45Hz. The WBV groups were exercised on a vibration platform (magnitude : $1mm_{peak-peak}$, frequency : 17Hz, 30Hz and 45Hz, 30 minutes/day for 5 days/week). The 4th lumbar on rats was scanned by In-vivo Micro-CT at the week 0(just before WBV) and the week 8(after WBV). Structural parameters of the 4th lumbar, based on two dimensional (2D) scan image data, were investigated and analyzed. The quantitative decrement rate of trabecular bone on WBV groups with 30Hz and 45Hz were lower than control and sham groups. The results showed the positive effect of WBV on osteoporotic bones of OVX rats.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.649-650
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• 2006

Some researchers proposed positive effects of whole body vibration (WBV) on osteoporotic trabecular bones of animals. In the present study, the correlation between the improvement of morphological characteristics and the effect of WBV was investigated and analyzed in OVX rats. The rats were randomly assigned to 5 groups: control, sham, WBV 17Hz, WBV 30Hz and WBV 45Hz. The WBV groups were exercised on a vibration platform (magnitude $1mm_{peak-peak}$, frequency : 17Hz, 30Hz and 45Hz, 30 minutes/day for 5 days/week). The 4th lumbar on rats was scanned by In-vivo Micro-CT at the week 0(iust before WBV) and the week 8(after WBV). Structural parameters of the 4th lumbar, based on two dimensional (2D) scan image data, were investigated and analyzed. The quantitative decrement rate of trabecular bone on WBV groups with 30Hz and 45Hz were lower than control and sham groups. The results showed the positive effect of WBV on osteoporotic bones of OVX rats.

• Journal of the Optical Society of Korea
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• v.17 no.1
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• pp.91-96
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• 2013

We report a method for optical monitoring of tumors in an animal model using optical coherence tomography (OCT). In a spectral domain OCT system, a superluminescent diode light source with a full width of 66 nm at half maximum and peak wavelength of 950 nm was used to take images having an axial resolution of 6.8 ${\mu}m$. Cancer cells of PC-3 were cultured and inoculated into the hypodermis of auricle tissues in BALB/c nude mice. We observed tumor formation and growth at the injection region of cancer cells in vivo and obtained the images of tumor mass center and sparse circumferences. On the $5^{th}$ day from an inoculation of cancer cells, histological images of the tumor region using cross-sectional slicing and dye staining of specimens were taken in order to confirm the correlation with the high resolution OCT images. The OCT image of tumor mass compared with normal tissues was analyzed using its A-scan data so as to obtain a tissue attenuation rate which increases according to tumor growth.

• Journal of the Korean Society of Radiology
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• v.6 no.5
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• pp.357-363
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• 2012

The purpose of this study on head computed tomography scan corporate reorganization adaptive iteration algorithm using the statistical noise, and quality assessment, reduction of dose was evaluated. Head CT examinations do not apply ASIR group [A group], ASIR 50 applies a group [B group] were divided into examinations. B group of each 46.9 %, 48.2 %, 43.2 %, and 47.9 % the measured in the phantom research result of measurement of CT noise average were reduced more than A group in the central part (A) and peripheral unit (B, C, D). CT number was measured with the quantitive analytical method in the display-image quality evaluation and about noise was analyze. There was A group and difference which the image noise notes statistically between B. And A group was high so that the image noise could note than B group (31.87 HUs, 31.78 HUs, 26.6 HUs, 30.42 HU P<0.05). The score of the observer 1 of A group evaluated 73.17 on 74.2 at the result 80 half tone dot of evaluating by the qualitative evaluation method of the image by the bean curd clinical image evaluation table. And the score of the observer 1 of B group evaluated 71.77 on 72.47. There was no difference (P>0.05) noted statistically. And the inappropriate image was shown to the diagnosis. As to the exposure dose, by examination by applying ASIR 50 % there was no decline in quality of the image, 47.6 % could reduce the radiation dose. In conclusion, if ASIR is applied to the clinical part, it is considered with the dose written much more that examination is possible. And when examination, it is considered that it becomes the positive factor when the examiner determines.