• International Journal of Contents
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• 제17권1호
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• pp.18-26
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• 2021

The obesity leads to be the result of the weakening of anatomical structure as well as the gravity effect. And, the obesity interferes with normal sagittal balance and fails to maintain a straight posture with minimal energy. Therefore, the obesity can be an important factor in causing back pain by changing the lumbar lordosis. In this study, we will present an appropriate angle of incidence for obese people to reduce the image distortion of L4, L5 during a general anteroposterior radiography examination. To reduce image distortion according to the change of lordosis, the angle of incidence was applied 9 ° and 21 ° to L4 and L5 vertebra body when obesity and low back pain (LBP) perform the general anteroposterior radiography examination.

• 치과방사선
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• 제20권2호
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• pp.219-225
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• 1990

Panoramic radiography is convenient in clinic and visualizes those areas which other technique do not give. But the technique has limitation of image distortion which results from the relationship of the ramus to the focal trough and from the direction of the central ray. This study is, using 7 dry skulls, to determine the effect of rotation of patient's head on reducing those distortion and determine the magnification ratio of images of mandibular condyle in rotated patient head position. The obtained results were as follows: 1. Generally, in panoramic radiography the anterolateral portion of the mandibular condyle was best to be visualized. 2. There are no significant difference between the image readability of anteromedial portion and that of anterocentral portion of the mandibular condyle. 3. Anterolateral portion of the mandibular condyle was better visualized in rotated head position by 20 degree or horizontal condylar inclination than in conventional position or in rotated head position by 10 degree. 4. The magnification ratio of the anteroposterior diameter in the image of mandibular condyle was least in the rotated head position by horizontal inclination of the mandibular condyle and was largest by 20 degree.

• 대한방사선기술학회지:방사선기술과학
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• 제44권4호
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• pp.295-300
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• 2021

This study aims to present new chest AP examination exposure conditions through a study on the effect on image quality and patient dose by applying high tube voltage and scatter ray post-processing software during chest AP examination in digital radiography equipment. This study was used a human body phantom and in the chest AP position, the dosimeter was placed horizontally at the thoracic spine 6. The experiment was conducted by dividing into a low tube voltage (70 kVp, 400 mA, 3.2 mAs) group and a high tube voltage (100 kVp, 400 mA, 1.2 mAs) group. The collimation size (14″× 17″) and the source to image receptor distance(110 cm) were same applied to both groups. Radiation dose was presented to dose area product and entrance surface dose. Image quality was compared and analyzed by comparing the difference between the signal-to-noise ratio and the contrast-to-noise ratio of the image according to the application of the scatter ray post-processing software under each condition. The average value of the entrance surface dose in the low and high tube voltage conditions was 93.04±0.45 µGy and 94.25±1.51 µGy, which was slightly higher in the high tube voltage condition, but the dose area product was 0.97±0.04 µGy and 0.93±0.01 µGy. There was a statistically significant difference in the group mean value(p<0.01). In terms of image quality, the values of the signal-to-noise ratio and the contrast noise ratio were higher in the high tube voltage than in the low tube voltage, and decreased when the scattering line post-processing function was used, but the contrast resolution was improved. If there is a scatter ray post-processing function during chest AP examination, it is helpful to actively utilize it to improve the image quality. However, when this function is not available, I thought that applying a higher tube voltage state than a low tube voltage state will help to realize images with a large amount of information without changing the dose.

• 대한족부족관절학회지
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• 제16권1호
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• pp.53-57
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• 2012

Purpose: To study computerized measurements of angular parameters on 100% and 150% resized digital radiography of hallux valgus deformity Materials and Methods: 30 digital radiography of standing foot anteroposterior view of hallux valgus patients were included. Two observers(A, B) independently measured hallux valgus angle (HVA), 1-2 intermetatarsal angle (IMA), and distal metatarsal articular angle (DMAA) in two times on both 100%-size and 150% magnified images respectively, using computerized measurement software tools. The results were interpreted with the statistical software program, Statistical Analysis System, version 9.2. Results: In repeated measurements of each observer, measurements on 150% magnified image showed no differences of all three parameters and with 100%-size image, there were differences of HVA (observer A) and 1-2 IMA (observer B) (p>0.05). When testing interobserver reliability, both observers showed differences in measurement of HVA and DMAA (p<0.05), but no differences in measurement of 1-2 IMA in both images. Within the 95% confidence interval, limits of error of measurements between two observers on HVA, IMA and DMAA were $2.7^{\circ}$ $1.4^{\circ}$ and $5.0^{\circ}$ respectively in 100%-size images, and $2.6^{\circ}$, $1.6^{\circ}$ and $4.7^{\circ}$ respectively in 150% magnified images. Conclusion: In computerized measurements for angular parameters of hallux valgus with digital radiography, 150% magnified images showed intraobserver reliability. Both 100% and 150% magnified images failed to show interobserver reliability. Measurement of 1-2 IMA in both 100% and 150% images showed less interobserver error.

• Journal of Radiation Protection and Research
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• 제48권1호
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• pp.9-14
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• 2023

Background: The detectors of both computed radiography (CR) and direct digital radiography (DR) have a wide dynamic range that could tolerate high values of exposure factors without an adverse effect on image quality. Therefore, this study aims to assess patient radiation dose and proposes institutional diagnostic reference levels (DRLs) for two teaching hospitals in Ghana. Materials and Methods: CR and DR systems were utilized in this study from two teaching hospitals. The CR system was manufactured by Philips Medical Systems DMC GmbH, while the DR system was manufactured by General Electric. The entrance skin doses (ESDs) were calculated using the standard equation and the tube output measurements. Free-in-air kerma (µGy) was measured using a calibrated radiation dosimeter. The proposed institutional DRLs were estimated using 75^th percentiles values of the estimated ESDs for nine radiographic projections. Results and Discussion: The calculated DRLs were 0.4, 1.6, 3.4, 0.5, 0.4, 1.1, 1.0, 1.2, and 1.7 mGy for chest posteroanterior (PA), lumbar spine anteroposterior (AP), lumbar spine lateral (LAT), cervical spine AP, cervical spine LAT, skull PA, pelvis AP, and abdomen AP, respectively in CR system. In the DR system, the values were 0.3, 1.6, 3.1, 0.4, 0.3, 0.7, 0.6, 0.9, and 1.3 for chest PA, lumbar spine AP, lumbar spine LAT, cervical spine AP, cervical spine LAT, skull PA, pelvis AP, and abdomen AP, respectively. Conclusion: Institutional DRLs in nine radiographic projections have been proposed for two teaching hospitals in Ghana for the first time. The proposed DRLs will serve as baseline data for establishing local DRLs in the hospitals and will be a valuable tool in optimizing patient doses.

• 대한방사선기술학회지:방사선기술과학
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• 제45권4호
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• pp.299-304
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• 2022

This study uses the 'S-align' function to present a reference value of the X-ray tube angle for the realization of an image similar to that of the chest PA image during chest AP radiography. This study targeted dummy phantom and used a 17"×17" DR image receptor. The irradiation conditions were 110 kVp, 160 mA, 50 ms, and the distance between the central X-ray and the image receptor was set to 180 cm and 110 cm, respectively. The end of the catheter was placed at the 11th thoracic height to indicate the nasogastric tube. In the case of lung apex length measurement, the mean value of measurement was 30.53±0.47 in PA. T 0°, TCA 5~25°, TCE 5~15° were 21.07±0.29, 27.60±0.21, 34.13±0.44, 39.86±0.31, 45.96±0.61 mm, 54.13±0.37 mm, 16.16±0.46 mm, 9.81±0.35 mm, 2.75±0.30 mm, respectively. For the depth of the catheter end, the average value measured at PA was 6.70±0.31 mm. T 0°, TCA 5~25°, TCE 5~15° were 15.72±0.38 mm, 24.10±0.50 mm, 29.24±0.86 mm, 34.35±0.35 mm, 41.06±1.08 mm, 48.07±0.38 mm, 12.85±0.25 mm, 7.92±0.36 mm, 3.01±0.39 mm, respectively. The length of the lung apex was similar to that of chest PA when the angle of incidence was adjusted from 5° to 10° in the leg direction, and the depth of the catheter tip was most similar when the X-ray tube angle was incident at 10° in the head direction. Therefore, To change the X-ray tube angle according to the purpose of the examination during the chest AP radiography using 'S-align' function is considered necessary.

• 한국콘텐츠학회논문지
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• 제19권6호
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• pp.471-480
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• 2019

정상인을 대상으로 체질량지수, 전만각도에 따른 L-spine 3~4, L-spine 4~5, L-spine 5~Sacrum 1의 각각의 추간판각도를 비교 분석하여 입사각을 제시하였다. 체질량지수의 L-spine 3~4, L-spine 4~5, L-spine 5~Sacrum 1의 정면 입사각도는 머리 쪽 방향으로 5.66도, 13.23도, 29.13도였으며, 전만각도의 L-spine 3~4, L-spine 4~5, L-spine 5~Sacrum 1의 정면 입사각도는 머리 쪽 방향으로 6.32도, 16.09도, 35.36도였다. 체질량지수, 전만각도에 따른 정면 입사각도에 따라 적용한 팬텀의 일반 전후방향 영상의 왜곡정도를 면적비율로 비교한 결과 L-spine 4~5, L-spine 5~Sacrum 1의 추간판각도에서 유의미한 차이가 있었고(p<0.05), 전만각도와 추간판각도는 양의 상관관계를 보였다(p<0.05). 팬텀의 전만각도에 따른 추간판각도 계측 값을 머리 쪽 방향으로 입사각을 L4는 11도, L5는 26도로 적용하여 영상의 유용성을 평가한 결과, 왜곡비율면적은 L4에서 14.90%에서 12.11%로 줄어들었고, L5에서는 15.25%에서 13.72%로 줄어들었다. 계측된 추간판 각도에 따른 입사각을 적용한 허리뼈 일반 전후방향 영상에서 허리뼈 4번, 5번을 목적으로 하는 허리뼈 정면 영상에서 왜곡을 줄여, 정확한 구조의 정면 추체상과 인접하는 관절 간 영상을 얻을 수 있었고, 목적하는 부위의 영상의 질과 진단적 정보를 향상시킬 수 있었다.

• 대한방사선기술학회지:방사선기술과학
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• 제43권3호
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• pp.155-159
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• 2020

The purpose of this study is to investigate the effect of posture changes(Anteroposterior projection, Posteroanterior projection) in the plain abdominal examination on breast dose and to examine its clinical usefulness. This study was used a human body phantom and a glass dosimeter. Glass dosimeters were directly inserted from the center and outside of medial and lateral. In this study, the deep dose was measured in the right breast and the surface dose in the left breast. During the abdominal examination, the central X-ray incident point was perpendicularly incident to the image receptor 5 cm above the iliac crest. The exposure parameters were 82 kVp, 320 mA, 50 ms, x-ray field size 14×17 inch The distance between the center X-ray and the detector was fixed at 110 cm, and only the top two AEC chambers were used. As a result of this study, the medial and lateral side doses of the right breast were 535.73±30.68 μGy and 414.46±33.52 μGy for erect AP, and 145.80±18.52 μGy and 148.76±12.92 μGy in erect PA. The superficial breast dose was 754.00±68.36 μGy on the medial side and 674.06±45.58 μGy on the lateral side in the erect AP, 70.66±7.98 μGy on the medial side, and 86.46±15.35 μGy on the lateral side in the erect PA. There was a statistically significant difference in the difference between the mean values of the medial and lateral side doses in the deep and superficial areas of the breast according to the postural change (p <0.01). As a result of this study, If the abdominal radiography was examined in the PA position, the dose reduction effect was 72.78% on the medial side, 64.10% on the lateral side of the deep breast, 90.62% on the medial side, and 87.17% on the lateral side of the superficial breast compared to the AP position.

• 한국방사선학회논문지
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• 제16권7호
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• pp.897-904
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• 2022

본 연구의 목적은 디지털 방사선 환경에서 두부 방사선검사 시 진단참고수준(DRL)에서 제시하는 검사 조건과 현재 임상에서 적용하고 있는 검사 조건 적용 시 선량과 화질의 차이 비교를 통해, 디지털 방사선환경에 적절한 두부 방사선검사의 조건에 대해 고찰하고자 한다. 본 연구는 두부모형팬텀을 대상으로 하였으며, 조사 조건은 임상에서 사용하는 조건(Clinic)과 DRL값(DRL₇₅), DRL 평균값(DRL_mean)으로 구분하여 실험하였다. 선량은 입사표면선량(ESD)을 측정하였고, 화질은 신호 대 잡음비와 대조도 대 잡음비를 측정하여 비교 분석하였다. 검사 조건 변화에 따른 skull AP ESD의 평균값은 Clinic 1214.03±4.21 µGy, DRL₇₅ 301 7.83±8.14 µGy, DRL_mean 2283.50±7.09 µGy이었으며, skull Lat. ESD의 평균값은 Clinic 762.79±3.54 µGy, DRL₇₅ 2168.57±10.83 µGy, DRL_mean 1654.43±6.48 µGy로 통계적으로 유의한 것으로 나타났다(p<0.01). 안와, 상악동, 전두동, 터키안장에서 측정한 SNR과 CNR의 평균값은 통계적으로 유의하였다(p<0.01). 본 연구 결과 임상에서 사용하는 조건이 DRL에 비해 AP는 약 58%, Lat.은 약 70% 정도의 낮은 선량 수치를 나타내었으며, 화질 측면에서 정성적인 차이가 없었다. 본 연구를 통해 디지털 방사선 환경에 적합한 새로운 진단참고수준에 대해 고려해 볼 필요가 있으며, 그에 따른 선량의 저감화가 이루어져야 할 것으로 사료된다.

• Journal of Chest Surgery
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• 제34권7호
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• pp.534-538
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• 2001

배경: 기관의 크기와 기관주위의 정상형태에 대한 지식은 임상에서 기도나 호흡관리, 그리고 기관재건술을 시행하는데 중요한 정보가 된다. 흉부 단순촬영은 기관의 직경을 재는 간단한 방법이지만 그 상이 확대되는 경향과 측면촬영에서 어깨와 상이 겹쳐서 나타나는 단점이 있다. 이에 저자들은 한국인 정상 성인의 기관의 정상치를 알기 위해 흥부 전산화 단층촬영을 이용하여 기관의 내경과 단면적을 측정하였다. 대상 및 방법: 남자 43명과 여자34명을 대상으로 하여 각각 나이에 따라 20~39세는 제 1군, 40~59세는 제2군, 60세 이상은 제 3군으로 구분하였다. 흉부 유입구와(Level 1) 대동맥궁에서(Level 2) 흉부 전산화 단층촬영을 이용하여 각각 전후경과 횡경을 재고 그 단면적을 구하였다. 결과: level 1에서 한국인 성인 남자의 기관의 전후경은 15.95$\pm$2.99 m, 횡경은 17.72$\pm$2.13 m이었고, 여자의 경우 전후경은 15.56$\pm$2.12 m, 횡경은 14.18$\pm$2.07mm로 남녀간에 유의한 차이가 있었다(p 0.05). Level 2에서 남자의 전후경은 19.77$\pm$2.57 m, 횡경은 18.02$\pm$2.19 mm이었고 여자의 전후경은 15.35$\pm$1.82 m, 횡경은 15.00$\pm$1.60 mm로 남녀간에 유의한 차이가 있었다 (p 0.05). 기관단면적은 남자가 각 Level에서 279.14$\pm$61.37 $\textrm{mm}^2$(Level 1), 281.93$\pm$63.97 $\textrm{mm}^2$(level 2)였고, 여자가 173.29$\pm$35.81 $\textrm{mm}^2$(Level 1), 181.88$\pm$34.74 $\textrm{mm}^2$(Level 2)로 두 위치에서 단면적은 남녀간에 유의한 차이가 있었다(p 0.05). 기관의 각각의 위치에서 내경과 단면적은 연령군에 따라 고연령층에서 증가하는 추세를 나타내었으나 통계적인 의미는 없었다. 결론: 한국 정상 성인의 기관내경과 단면적의 크기는 성별에 따라 통계적으로 유의한 차이가 있었으나 연령에 따른 차이는 없었고, 전산화 단층촬영은 기관의 내경과 단면적의 크기를 얻는데 비교적 정확하고 안전한 방법이라 생각된다.