• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.605-610
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• 2017

Unlike adults, cognitive ability and communication are not accurate in pediatric patients. Therefore movement due to psychological anxiety in X-ray photography is one of the factors that increase repeated irradiation. In order to minimize the rejection of X-ray and to improve the satisfaction of medical service, it is necessary to improve the environment of the radiological room to help psychological stability and to find a positive measure for reduction of radiation dose, including unnecessary. The subjects of this study were 186 pediatric patients from May to July, 2017, who were from 6 months to 36 months, The study group was set up a radiological room without auditory and visual environment changes is A group, except for changes in visual environment, the room where only auditory environmental changes were applied was group B, the auditory environment changes were excluded, and the room where only the visual environment change was applied was divided into group C, the auditory and visual environment changes were applied to the D. In group A, 10 retrospectives were obtained, 7 in group B, 5 in group C, and 2 in group D. Especially in group A and group D, statistically significant at p <0.053 In conclusion, hearing and visual environment changes affected the psychological stability of pediatric patient, and the repeated irradiation was reduced, thus improving the quality of medical services.

• Journal of radiological science and technology
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• v.42 no.6
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• pp.423-428
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• 2019

The Precise measurement of the knee's Congruence angle is required for diagnosis of patella dislocation. The purpose of this study is to consider the distortion diagram and usefulness about the test of the bilateral side and one side through the evaluating congruence angle from Merchant view of patellofemoral joint to central X-ray. We've evaluated the sulcus angle and Congruence angle following central X-ray's changes when we took Merchant view of patellofemoral joint aimed to right lower limb from human whole body phantom. The subject of the evaluation was classified as normal group and varus group, and the varus group has experimented with External rotation of legs as 15° and 30°. When normal groups result as 0, 7.5, 15 cm, it was measured as 17.25 ± 1.34°, 19.60 ± 1.41°, 20.55 ± 1.77° each. The gap between minimal and maximum angle was 3.3°, and the value was shown as getting bigger when it further away from the centeral X-ray. When Congruence angle in 15° varus group was 0, 7.5, 15 cm, it was each 16.45 ± 1.34°, 17.10 ± 0.99°, 17.80 ± 1.13°. And when Congruence angle in 30° varus group was 0, 7.5, 15 cm, it was measured each 18.35 ± 1.63°, 18.95 ± 1.06°, 19.60 ± 1.41°. The difference between minimum and maximum of angle in 15° varus group and 30° varus group was each 1.35° and 1.25°, the angles have shown as increasing the further away from the center. The patellofemoral joint showed that the congruence angle increases as the further away from Central X-ray, and also it is judged that is possible to change the congruence angle by a degree of varus knee. Thus, accurate measurement of the congruence angle is shown to advantage that methods for examining by split each side at two times than methods for examining both sides at a time. Therefore, it is expected to helpful on the diagnostic side of patella dislocation and subluxation.

• Journal of radiological science and technology
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• v.40 no.1
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• pp.19-25
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• 2017

The aim of this study was to evaluate Magnetic Resonance Imaging safety by measuring the translational attraction, torque and susceptibility artifact for Bone-Anchored Hearing Aid (BAHA) implant at 1.5 T and 3.0 T MRI by standard criteria. In vitro assessment tools were made of acrylic-resin by American Society for Testing and Materials (ASTM) F2052-06 and F2119-07 standard. Translational attraction of BAHA implant was measured by the maximum deflection angle at 96 cm position, where the magnetically induced deflection was the greatest. The torque was assessed by the qualitative criteria of evaluating the alignment and rotation pattern, when the BAHA implant was positioned on a line with $45^{\circ}$ intervals inside the circular container in the center of the bore. The susceptibility artifact images were obtained using the hanged test tool, which was filled with $CuSO_4$ solution. And then the artifact size was measured using Susceptibility A rtifact Measurement (SA M) software. In results, the translational attraction was 0 mm at both 1.5 T and 3.0 T and the torque was 0(no torque) at 1.5 T, and +1(mild torque) at 3.0 T. The size of susceptibility artifacts was between 13.20 mm and 38.91 mm. Therefore, The BAHA implant was safe for the patient in clinical MR environment.

• Journal of the Korean Society of Radiology
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• v.17 no.7
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• pp.1115-1122
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• 2023

This study aimed to present reasonable reception bandwidth application standards for the purpose of suppressing metal objects during MRI examinations. For this purpose, T2 contrast images were acquired using high-speed spin echo technology on a phantom made of screws for spinal surgery, and metal objects were detected. In addition, images were obtained by increasing the reception bandwidth from 100 Hz/PX to 800 Hz/PX by 100 Hz/PX. The metal artifacts were determined as the sum of the areas of the signal attenuation area and the signal accumulation area. In addition, Pearson correlation analysis was performed to analyze the pattern of metal artifacts according to imaging variables. As a result, the signal accumulation area did not change significantly as the reception bandwidth increased (p>0.05), but the signal loss area and the area of metal artifacts decreased as the reception bandwidth increased (p<0.05). Interestingly, the area of metal objects decreased to a maximum in the section where the reception bandwidth was increased from 100 Hz/PX to 200 Hz/PX, consistent with the section where the echo spacing was reduced to a maximum due to the increase in reception bandwidth. In addition, the correlation analysis results also showed that the eco spacing was more related to the signal attenuation area and the area of metal objects than to the reception bandwidth. Therefore, if the reception bandwidth is increased for the purpose of reducing metal objects, it is reasonable to set it based on a value that minimizes the echo spacing in consideration of image quality factors.

• Annual Conference of KIPS
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• 2019.10a
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• pp.40-43
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• 2019

본 논문은 국제표준화인 OHDSI OMOP-CDM 의 확장으로 의료영상 표준기반으로 한 관리시스템에 대해 기술한다. 이를 위해 기존 공통데이터모델과 연계에 중점을 두어 DICOM 메타태그정보 기반의 의료영상 표준 모델의 스키마를 제시한다. 이를 기반으로 머신러닝 기술개발을 위한 데이터 셋 생성과 관리를 위한 웹 기반 시스템 구조와 기능에 대해서 기술한다. 끝으로 구현된 시스템에서 제공하는 웹 서비스 수행 결과를 보인다.

• Imaging Science in Dentistry
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• v.49 no.1
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• pp.71-77
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• 2019

Primary intraosseous squamous cell carcinoma is a rare malignant central jaw tumor derived from odontogenic epithelial remnants. Predominantly, it affects mandible, although both jaw bones may be involved. This report describes a 60-year-old man who was initially misdiagnosed with a periapical infection related to the right lower wisdom tooth. After four months, the patient presented to a private dental clinic with a massive swelling at the right side of the mandible. Panoramic radiographs and advanced imaging revealed a lesion with complete erosion of the right ramus, which extended to the orbital floor. A biopsy from the mandibular angle revealed large pleomorphic atypical squamous cells, which is the primary microscopic feature of a poorly differentiated squamous cell carcinoma.

• Nuclear Engineering and Technology
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• v.56 no.7
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• pp.2781-2789
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• 2024

We developed lead gloves that minimize radiation dose to the operator's hands during interventional radiological procedures and that do not impede the operator's surgical capabilities. Existing lead gloves can protect the operator's hands by shielding radiation, but use of such gloves may impair preception sensitivity, resulting in a reduction in the operator's surgical ability. Accordingly, in this study, we developed modified lead gloves that can reduce radiation dose while maintaining operator sensitivity during procedures by modifying the operator's main surgical finger area in existing lead gloves. To evaluate the performance of developed modified lead gloves, radiation was applied in surgical conditions without gloves and with surgical gloves, lead gloves, and modified lead gloves. The radiation dose was evaluated for each condition. When the modified lead gloves were worn, the degree of shielding was similar to when conventional lead gloves were worn. Based on these results, if the operator wears modified lead gloves during interventional radiological procedures, they will protect the hands from radiation while maintaining physical sensitivity in the hands.

• Journal of the Korean Society of Radiology
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• v.3 no.4
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• pp.35-38
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• 2009

Flat-panel x-ray detectors using a phosphor and photoconductor material have been used for application in various medical modalities. In this study, the monte carlo simulation, optical and x-ray response characteristics were investigated in the conversion structure obtained by a columnar CsI:Na scintillation layer with a photosensitive amorphous selenium layer. Firstly, from the measurement of luminescent spectrum of CsI:Na and absorption spectrum of a-Se layer, the signal conversion characteristics are analysed. And also, the x-ray sensitivity is measured and compared with conventional a-Se($500{\mu}m$) as a function of electrical field. From the experimental result, the x-ray sensitivities of the CsI:Na($180{\mu}m$)/a-Se($30{\mu}m$) detector and the a-Se($500{\mu}m$) detector were $7.31nC/mR-cm^{2}$ and $3.95nC/mR-cm^{2}$at an electric field of $10V/{\mu}m$, respectively.

• Journal of the Korean Society of Radiology
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• v.9 no.5
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• pp.323-329
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• 2015

This study is aimed at assessing whether dynamic wedge filters are appropriate to be used instead of physical wedge filters. The X-ray energy generated from linear accelerator is commercialize 6 MV and 10 MV. $15^{\circ}$, $30^{\circ}$, $45^{\circ}$, and $60^{\circ}$ of physical wedge filter was irradiated by dose rate 100, 200, 300, 400, 500, and 600 MU/min for each angle and for comparison with a dynamic wedge filter, irradiate 96 times under the same conditions. The measurement conditions are as 100 cm source-film distance and $10{\times}10cm$ irradiated surface. A developed film was scanned and analyzed after a calibration through a dose analysis program and the dose rate was compared after calculating the standard deviation. Dynamic wedge filters make dose, scattered rays and treatment time reduced and very useful due to less irradiated doses to patients. The errors at each dose rate under the same conditions were irrelevant. Thus, treatment based on a high dose rate depending on the patient is expected to be feasible.

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.409-413
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• 2011

An X-ray tube used an X-ray fluorescence analysis system has a low X-ray photon intensity which results in reducing measurement accuracy and increasing exposure time. These shortages can be overcame by using a monocapillary optics. A monocapillary optics was optimally designed for focusing the characteristic X-ray of tungsten (8.4 keV). The monocapillary optics can achieve a gain of 10 at the least. The monocapillary optics was fabricated by using puller and pyrex glass, raw material. In fabrication, a weigh of 45g and a temperature of $650^{\circ}$ was loaded. The total fabrication time was 460 minutes. The fabricated capillary had 87 mm in length and maximum diameter of 300 ${\mu}m$ and minimum diameter of 192 ${\mu}m$. When the fabricated monocapillary optics is applied to an X-ray fluorescence analysis system, the detection accuracy for soft elements, for example sulfur (S), will be improved.