• Journal of Digital Contents Society
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• v.11 no.4
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• pp.553-559
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• 2010

By applying the various reformation techniques by using a circle raw data of after computed tomography image in the patient enforcing the spine screw fixation, this research tried to look into the various information including the exact location of the position of the screw spike and accuracy of an operation. In a clinical, by applying the or multi planar reformatting(MPR), that is the re-composition technique used mainly, maximum intensity projection (MIP), and volume rendering technique(VRT) and transformation removal from a register modifying VRT, video data were compared and were analyzed by the quantitative method and qualitative method. It is judged as the transformation volume rendering technique of the re-composition technique which is most useful in minimizing the artifact shadow by the exact location of the position of a screw and metal among the analysis and evaluation result computed tomography image reformation technique of the reformation image after the spine screw fixation.

• Journal of KIISE:Software and Applications
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• v.33 no.3
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• pp.335-343
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• 2006

This paper proposes a novel technique of marker-based 2D-3D registration to combine 3D information obtained from preoperative CT images into 2D image obtained from intraoperative x-ray fluoroscopy image. Our method is divided into preoperative and intraoperative procedures. In preoperative procedure, we generate CT-derived DRRs using graphics hardware and detect markers automatically. In intraoperative procedure, we propose a hierarchical two- step registration to reduce a degree of freedom from 6-DOP to 2-DOF which is composed of in-plane registration using principal axis method and out-plane registration using minimal error searching method in spherical coordinate. For experimentation, we use cardiac phantom datasets with confirmation markers and evaluate our method in the aspects of visual inspection, accuracy and processing time. As experimental results, our method keeps accuracy and aligns very fast by reducing real-time computations.

• Journal of the Korean Society of Radiology
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• v.81 no.4
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• pp.770-793
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• 2020

Newborn gastrointestinal tract emergency diseases include various disorders that occur anywhere along the digestive tract. Most of them are congenital malformations, not acquired diseases. Many of them cannot be confirmed on prenatal examination, and consequently, postnatal evaluation is required. Unlike adults, in newborn babies, detailed evaluations with computed tomography (CT) and magnetic resonance imaging (MRI) are often limited, so making the diagnosis based on early abdominal radiography is most important. Therefore, it is necessary to be familiar with the radiologic findings that may be seen on imaging studies. In addition, it is important to understand abdominal ultrasound and fluoroscopy findings, which can be used in addition to simple radiography and indications that can be used for further diagnosis and appropriate treatment. Therefore, this study describes and organizes the various imaging findings that may occur in neonatal gastrointestinal emergencies.

• Journal of the Korean Society of Radiology
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• v.14 no.4
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• pp.353-360
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• 2020

This research aims at suggesting exposure condition that shows maintaining the value of the physical image quality factor by decreasing tube voltage and tube current from the standard exposure condition(80 kV, 7 mA) of a CBCT apparatus. To measure the value of the physical image quality factor, modular transfer function(MTF) was analyzed and dose-area product(DAP) was used for the measurement of exposure dose. CBCT images of a Sedentex IQ phantom were obtained under 15 exposure conditions of different combination of tube voltage(80, 78, 76 kV) and tube current(7, 6, 5, 4, 3 mA) and MTF 10 was calculated under each exposure conditions. There were no significant differences in MTF 10 under 80 kV-6 mA, 80 kV-5 mA exposure conditions in comparison with standard exposure condition. Based on the results of this research, 80 kV-5 mA condition are expected to be able to reduce exposure dose with maintaining the value of the physical image quality factor of the standard exposure condition.

• Investigative Magnetic Resonance Imaging
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• v.13 no.1
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• pp.101-105
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• 2009

We report radiological findings of ultrasonography (US), 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) computed tomography (CT), and magnetic resonance (MR) imaging for a rare case of skeletal muscle metastasis from an underlying known malignant phyllodes tumor. To our knowledge, there has been no previous published report of imaging findings of skeletal muscle metastasis from a sarcoma such as malignant phyllodes tumor.

• Journal of the Korean Society of Radiology
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• v.7 no.1
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• pp.45-50
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• 2013

Non-invasive technique CT, called automated computed tomography, is used to detect lesion of a patient when diagnosing human body. Information obtained from CT plays an important role in assembling 3 dimensional images. Recently, new equipment, operated by CT, is required which can be appliable to physical and biological research. In accordance to this quest, micro-CT is invented that produce more detail and concrete information. Images supplied by CT are even more detailed and concrete, so it contributes much to the development of biology and polymer material engineering field. However, there has been little reliable reports regarding measuring information of space dose distribution about exposure dose limit of users operating micro-CT. In addition, little reports regarding space dose distribution of exposure has been known about unwanted diffraction light produced by usage of micro-CT. The exterior of micro-CT is covered by lead, which is for removing exposure of diffraction light. Thus, even if it is good enough to prevent exposure of diffraction light, consistent management of equipment will be required as time goes by and equipment are getting old as well. We measured space dose distribution regarding exposure of diffraction light of users operating micro-CT directly. Therefore, we suggest that proper management should be necessary for users operating micro-CT not to be exposed by unwanted diffraction light.

• Journal of radiological science and technology
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• v.38 no.2
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• pp.121-126
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• 2015

To image diagnosis in neurovascular diseases using Multi-Detector Computed Tomography(MDCT), injected the same contrast material when inspecting Brain Computed Tomography Angiography(BCTA) to examine radiation dose and Image quality on changing Cerebral Artery CT number by tube voltage. Executed an examination with same condition[Beam Collimation $128{\times}0.6mm$, Pitch 0.6, Rotation Time 0.5s, Slice Thickness 5.0mm, Increment 5.0mm, Delay Time 3.0sec, Care Dose 4D(Demension ; D)] except for tube voltage on 50 call patients for BCTA and divided them into two groups (25 people for a group, group A: 80, group B: 120kVp). From all the acquired images, set a ROI(Region of Interest) on four spots such as left cerebral artery, right cerebral artery, posterior cerebral artery and cerebral parenchyma to compare quantitative evaluation, qualitative evaluation and effective dose after measuring CT number value from Picture Archiving Communications System(PACS). Evaluating images with CT number acquired from BCTA examination, images with 80 kVp was 18% higher in Signal to Noise Ratio and 19% in Contrast to Noise Ratio than those with 120 kVp. It was seen that expose dose was decreased by over 50% with tube voltage 80 kVp than with 120 kVp. Group A (25 patients) was examination with tube voltage 80kVp while group B with 120 kVp to examine radiation dose and Image quality. It is considered effective to inspect with lower tube voltage than with conventional high kVp, which can reduce radiation dose without any affect on diagnosis.

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.619-625
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• 2022

In the field of imaging medicine, computed tomography is one of the most common test methods and one of the most frequently used test methods in hospitals. However, it is accompanied by a very high radiation exposure compared to other test methods. In order to reduce exposure, CT scans should be performed only when absolutely necessary, and even if the tests are performed because they are absolutely necessary, a protocol that serves the purpose of the test and allows the test to be performed in a small dose should be used. In this study, we wanted to learn about the most up-to-date radiation dose usage information used by the region's leading general hospitals and develop a diagnostic reference level (DRL). In the experimental results, the Head CT and Abdomen CT tests showed that DLP was higher than the NRPB (U.K) and Korean DRL. The DLP values used by Chest CT were low for all 3 types of CT devices. The hospital found that efforts to reduce exposure should be made during CT examinations, and in particular, Head CT and Abdomen CT determined that efforts to reduce exposure were necessary.

• Journal of the Korean Magnetics Society
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• v.25 no.6
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• pp.208-218
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• 2015

Recently, radiation therapy is used in the CT existing conventional two-dimensional radiation image, and set the size and location of the tumor in a manner that the image is going to change the treatment plan. After using the simulation using CT, radiation therapy it is four-dimensional or three-dimensional treatment made possible. and radiation therapy became the more effective ever before. High technology radiation therapy such as the treatment of SRS,IMRT, IGRT, SBRT, is a need to try contemplating the possibility to apply appropriate analysis and situation, so it has its own characteristics. and then it is believed that it is necessary to analyze and try it worries the proper applicability of the situation. The configuration of the various treatment that is applicable in many hospitals is necessary to try to determine how to practically apply the patients. Critical organs surrounding tumor give a small dose to avoid side effects and then the tumor has the therapeutic effect by providing a larger dose than before the radiation treatment.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.4
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• pp.349-357
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• 2012

The purpose of this study was to measure the thickness of the sinus lateral wall using cone-beam computed tomography (CBCT), and to find the most suitable vertical position for lateral window opening prior to sinus elevation. Fifty three patients requiring sinus elevation had CBCT scans acquired by CB MercuRay (Hitachi, Medico, Tokyo, Japan) from July, 2010 to June, 2012. The thickness of the sinus lateral wall was measured according to its vertical position against the sinus inferior border (SIB), and its mean was calculated through two repeated measurements. The thickness of the sinus lateral wall was more than 2 mm at 2 mm above the sinus inferior border (SIB+2), however, it was less than 2 mm at 3 mm above the sinus inferior border (SIB+3). In conclusion, it is recommended that the inferior border of lateral wall window be made 3 mm above the sinus inferior border during sinus elevation using the lateral approach considering the thickness of the sinus lateral wall.