• 치과방사선
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• 제9권1호
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• pp.19-23
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• 1979

A study was made primarily to investigate vertical and horizontal distortion of the image at the apical region of the dental roots in orthopantomographs. The subjects consisted of two dry skulls with radiopaque materials attached to root surface. Measuring of the width and length of each predetermined point at 23 teeth was performed in dry skulls and radiographic films. The results obtained were as follows; 1. There was overall magnification of image in the vertical dimension. And anterior portion had greater magnification rate than posterior portion, while lower anterior portion had less magnification rate than upper anterior portion. 2. There was reduction of the image in the horizontal dimension of the teeth, because of the position relation between dry skull and image layer of the orthopantomograph. 3. There was a significant difference in distortion rate between the oposite teeth. 4. Cervical portion of the tooth had more decreased rate of horizontal distortion than apical portion.

• 치과방사선
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• 제16권1호
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• pp.59-68
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• 1986

The purpose of this investigation was to locate the central plane of the image layer on the panoramic machine relative to a specific point on the machine. In the study of the central plane of the image layer of panoramic radiograph, using the Morrita Company PANEX-EC a series of 33 exposures were taken with the 4-5 experimental pins placed in the holes of the plastic model plate, then evaluated by human eye. The author analyzed the central plane of the image layer by Mitutoyo-A-221 and calculated horizontal and vertical magnification ratio in the central plane of the image layer determined experimentally. The results were as follows: 1. The location of the central plane of the image layer determined experimentally was to lateral, compared with manufactural central plane. 2. Horizontal magnification ratio in the central plane of the image layer determined experimentally was 9.25%. 3. Vertical magnification ratio in the central plane of the image layer determined experimentally was 9.17%.

• 치과방사선
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• 제16권1호
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• pp.25-30
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• 1986

The author studied the magnification ratio of teeth length in orthopantomogram through intraoral film taken by standardized paral1eing technique. In this study, intraoral radiograph and orthopantomogram were taken in 2 cases of dry skull and 36 adults (504 teeth). 1. The obtained results were as follows: In case of dry skull, the magnification ratio of standard films was 4.6% to 5.9% and that of Orthopantomograph 5 was 15.1% to 33.1%. The magnification ratio of to the standard film was 9.2% to 26.5% 2. In case of adults, the magnification ratio of Orthopantomograph 5 to the standard films was 9.5% to 24.6%. 3. There were no significant difference in magnification between left and right. 4. Anterior teeth had lesser magnification than posterior teeth. 5. It was considered that teeth length showed in Orthopontomograph 5 was magnified 15.4% to 31.3% than actual teeth length.

• 치과방사선
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• 제21권2호
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• pp.287-296
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• 1991

The purpose of this experiments is to compare the vertical and horizontal magnification, and the distortion of the radiographic image according to the types of panoramic machines. Total 70 radiographs, 10 radiographs out of 7 panoramic machines respectively, were taken from the dry skull with metal balls in the periapical areas of the central incisor, the canine, the second premolar, and the second molar in the maxilla and the mandible. And the author evaluated the vertical and horizontal magnification degrees, and the distortion degrees of radiographic images obtained from each panoramic machine. The results were as follows: There were no significant differences in the vertical and horizontal magnification degrees on the various portions of the jaws (p> 0.05). But there were higher magnification degrees in the Panoura 10C, Panograph Ⅱ, and Veraview than those in other panoramic machines. The lowest average magnification degree was 20.27% vertically, 20.94% horizontally using the Panoradix. The highest average magnification degree was 27.64% vertically, 28.48% horizontally using the Panograph Ⅱ. The lowest distortion was shown using the Panoura 10C in the maxilla, but there was not statistically significant difference between the panoramic machines in the mandible (p>0.05). There were no differences in the vertical and horizontal magnification degrees according to the types of the rotation centers.

• 디지털산업정보학회논문지
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• 제6권4호
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• pp.217-223
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• 2010

In the case of image magnification by using interpolation methods, interpolated pixels are estimated from the known pixels in source image. The magnified image is composed of the known pixels in source image and the interpolated pixels which is estimated. If the interpolated pixels are estimated to have the locality which is exists in real images, the magnified image is much closer to the real image. In this paper, an improved interpolation scheme is proposed to estimate pixels from the known pixels in source image using the locality which is exists in real images. The magnified image by using the proposed interpolation scheme is much closer to the real image. The performance of the proposed interpolation scheme is evaluated by using PSNR(Peak Signal to Noise Ratio) in experiment. The PSNR of the magnified image by using the proposed scheme is improved than that of the magnified images by using existing interpolation methods. So, the proposed interpolation scheme is an efficient interpolation method for the quality improvement of magnified image.

• 한국방사선학회논문지
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• 제17권1호
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• pp.167-173
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• 2023

일반 X-선 검사는 간단하고 많은 정보를 얻을 수 있어 가장 기본이 되는 검사방법이며 획득된 영상에서는 인체 해부학적 구조와 시간 경과에 따른 질병의 변화 정보를 쉽게 획득할 수 있다. 그럼에도 불구하고 영상이 확대되는 단점으로 인하여 병변의 크기와 형태가 왜곡되어 나타나기 때문에 현재 X-선 영상의 깊이 있는 관찰은 이루어지지 않고 있다. 본 연구에서는 후전촬영(PA)과 측방향촬영(LAT) 영상을 획득하고 각각의 영상에서 암 시료가 위치하는 거리를 측정하여 암 시료의 확대율을 계산하고 측정한 암 시료 길이에 보정한다. 암 시료의 길이와 두께에 따른 확대율 보정 값을 전산화단층촬영장치(Computed Tomography, CT)로 획득된 영상 및 실제 제작한 암 시료 크기와 각각 비교하였다. 기존의 확대율은 검출기에서 암의 거리를 측정하여 계산할 수 있었으나 본 연구에서는 획득된 PA와 LAT 영상을 이용하여 확대율을 계산하였다. 6 mm 암 시료를 PA와 LAT 영상을 획득하여 확대율을 구한 후 보정한 결과 길이는 5.9 mm, 두께는 6.1mm로 실제와 비슷한 값이 측정되었으며 영상을 이용한 확대율 계산이 가능하다는 것을 알 수 있었다. X-선 영상만으로도 병변의 확대율을 손쉽게 보정하여 정확한 길이 측정이 가능하고 이는 영상 판독 및 정확한 진단에 유용한 정보를 제공할 것이다.

• 대한디지털의료영상학회논문지
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• 제15권2호
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• pp.39-44
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• 2013

Purpose : The purpose of this study is the magnification rates depending on the area of patient dose (DAP) and glass dosimeter see the change of the dose according to the dose characteristics of low-magnification aims to raise standards. Materials and Method : Direct DR equipment Sonialvision DAR-8000f, Shimadzu was used, the patient entrance dose measurements to the surface of the Rando Phantom of the neck and the abdomen was placed on the Xi unfors. glass dosimeter for measuring organ doses at the same time the Rando Phantom of the major organs in place by inserting a 9 ", 12", 15 ", 17" and 30 seconds for each magnification were measured according in fluoroscopy. DAP meter area of the patient dose was measured. Result : Esophagography at 17" 143% than 9"magnification the average area dose was increased. Organ dose of Esophagography at 17" was decreased 25.32% than 9" magnification. UGI at 17" was increased 129.73% DAP than 9" magnification. Organ dose of UGI at 17" was decreased 23.32% than 9" magnification. Where the major organs of magnification at 17" were decreased(lung -25.96%, stomach -33.09%, spleen -27.81%, liver -4.92%) than 9" magnification. Conclusion : Expected to get better quality image While using the proper magnification, and have recognition that difference Organ doses and DAP meter in fluoroscopy.

• 치과방사선
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• 제12권1호
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• pp.115-121
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• 1982

In the study of the focal trough of panoramic radiograph, using the Moritta compony Panex-EC a series of 48 exposures were: taken with the 6-18 brass pins placed in the holes of the plastic model plate, then eveluated by 4 observers. The author analyzed the focal trough defined by the sharpness criteria and calcuated the vertical and horizontal magnification range in the corrected focal trough. The results were as follows; 1. Continuous focal trough was not defined in the anterior region using a very high degree of sharpness. 2. As degree of sharpness used in the analysis became less, focal trough was continuous in the anterior and posterior regions, symmetrized bilaterally, and the widths of the focal trough increased more in the posterior region. e. As sharpness criteria were reduced, the percentage range of image magnification increased on both vertical and horizontal magnification, and especially the percentage range of horizontal magnification was greater than that of vertical magnification.

• 한국정보통신학회논문지
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• 제13권11호
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• pp.2283-2288
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• 2009

인간의 시각정보처리는 망막에서 입력된 영상을 시각피질에 전달될 때 많은 특성을 가지고 있다. 그 중에서 확대성질과 방향성에 대한 민감도를 분석하여 영상인식에 미치는 영향을 분석하고자 한다. 확대성질은 중심와의 영역이 시각피질에서 확대영역으로 할당되는 사실을 확대배율이라고 부른다. 방향수직반응의 가중치와 수평 및 대각선반응의 가중치를 여러 가지로 변동하여 영상의 인식률을 비교함으로써 수직반응 정도에 매우 민감함을 보이며 차후 인간시각모델 구성에 적용하고자 한다.

• 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.