• Title/Summary/Keyword: 공제영상

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GEOMETRIC CORRECTION OF RADIOGRAPHIC IMAGES USING GENERAL PURPOSE IMAGE PROCESSING PROGRAM (일반 영상처리 프로그램을 이용한 방사선사진의 기하학적 보정에 관한 연구)

  • Cheong Ji-Seong;Kim Eun-Kyung;Lee Sang-Hoon
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.24 no.2
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    • pp.371-379
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    • 1994
  • 본 연구는 비규격화시켜 촬영한 두장의 방사선 사진을 일반 영상처리 프로그램으로 기하학적 보정을 하여 디지탈 공제 촬영술을 시행한 결과를 개인별로 제작된 필름유지장치를 이용하여 규격화 시켜 촬영한 두장의 방사선사진을 디지탈 공제 촬영술을 시행한 결과와 비교하여 일반 영상처리 프로그램의 임상적 유용성을 평가해보고자 시행하였다. 19명의 자원자를 대상으로 하여, 각 환자에서 4매의 하악구치부 치근단 사진을 촬영하였다. 그중 2매는 XCP 필름 유지장치만으로 평행촬영법으로 촬영하였고, 나머지 2매는 교합제에 인상재를 부가하여 개인별로 제작된 XCP필름 유지장치를 이용하여 표준화시켜 역시 평행촬영법으로 촬영하였다. 기하학적 보정은 "Adobe Photoshop"과 "NIH Image" 프로그램으로 시행하였다. 특히 "Adobe Photoshop"의 임의영상회전 기능과 "IH Image"의 공제시술시 중첩된 사진을 투명하게 보여주는 기능, 병진기능을 활용하였다. 두 사진의 유사성을 측정하기 위해 공제된 사진의 계조도의 표준편차를 구하였다. 표준화군의 평균 표준편차가 기하학적 보정군의 평균 표준편차보다 약간 낮았으나, 통계적으로 유의성이 있는 차이를 보이지는 않았다. 위의 결과로 미루어보아, 하악구치부 에서 XCP필름 유지장치로 평행촬영한 비표준화방사선사진을 "Adobe Photoshop"과 "NIH Image" 프로그램을 이용하여 기하학적 보정을 할 수 있으리라 사료된다.

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The Effect of Splinting with Concomitant Root Planing;Clinical and Digital Subtraction Radiographic Study (치근활택술과 스프린트 병행처치의 효과에 관한 연구;디지털 공제 촬영술을 이용한 임상적 연구)

  • Lee, Ji-Young;Kye, Seung-Bum;Kim, Won-Kyoung;Lee, Yong-Moo;Ku, Young;Ryu, In-Chul;Chung, Chong-Pyoung;Choi, Sang-Mook;Han, Soo-Boo
    • Journal of Periodontal and Implant Science
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    • v.31 no.1
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    • pp.207-227
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    • 2001
  • 스프린트는 치주처지료에서 부가적 처치법으로 널리 사용되고 있으며, 한편, 디지털 공제 활영술은 기존방사선촬영술의 한계점을 극복하기 위해 기발된 새로운 방법이다. 이번 연구에서는 치근활택술 단독시행시와 스피린트 병행 처치시의 효과를 임상적, 방사선학적으로 비교하였다. 중정도의 성인성 치주염을 가진 20명의 환자를 대상으로 하되 10명은 치근활택술 단독으로, 나머지 10명은 스프린트 병행처치로 처치하였다. 임상적, 방사선학적인 평가는 처치전, 처치후 6개월에 행하고, 임상적 평가의 경우 3개월에 추가로 실시하였다. 이번 연구에서 사용된 임상 지수로는 치태지수, 치은지수, 치은퇴축, 치주낭깊이, 임상부착수준, 임상부착증가, 탐침시출혈, 치아동요도 등이며, 방사선학적 평가는 기존 방사선촬영술에 의한 방법과 디지털 공제촬영수렝 의한 방법으로 행하였다. 디지털 공제 촬영술에 의한 평가시, 영상은 Digora 프로그램에 의해 획득하고 Emago 프로그램으로 처리 하여 다음과 같은 결론을 얻었다. 1. 처치후 3개월에 치태지수, 치은지수, 치은퇴축, 치주낭깊이, 임상적부착수준, 탐침시 출혈 등의 임상지수들이 변했으며, 특히 이러한 변화는 치주낭깊이, 치은퇴축, 탐침시출혈에서 유의성이 있었다. ( p<0.05 ) 그러나 두군간 차이는 인정되지 않았다. ( p>0.05 ) 2. 처치후 6개월에도 치태지수, 치은지수, 치은퇴축, 치주낭깊이, 임상적부착수준, 탐침시출혈, 치아동요도 등의 임상지수들이 변했으며, 특히 이러한 변화는 치주낭깊이, 치은퇴축, 탐침시출혈, 치태지수, 치아동요도에서 유의성이 있었다. ( p<0.05 ) 그러나 두 군간 차이는 인정되지 않았다. ( p>0.05 ) 3. 켄달 상관분석시, 임상적 평가와 기존 방사선 촬영술에 의한 평가사이의 관련성을 낮았으며 거의 0에 가까운 수치를 보였으며 (r=0.110, p=0.639 ) 임상적 평가와 디지털 공제 방사선 촬영술에 의한 평가사이에서 약간 높은 관련성을 보였다. ( r=0.257, p=0.315 ) 즉 치주치료후의 골변화는 디지털 공제 방사선 촬영술에 의한 평가시 기존 방사선 사진보다 임상적 부착증가와 더욱 긴밀한 관련성을 보여준다. 이상의 결과로 볼 때, 스프린팅 처치는 치주 치료에 있어 치근활택술에 부가적 표과를 제공하지 못한다.

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A comparison of subtracted images from dental subtraction programs (디지털공제프로그램간의 디지털공제영상 비교)

  • Han Won-Jeong
    • Imaging Science in Dentistry
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    • v.32 no.3
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    • pp.147-151
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    • 2002
  • Purpose: To compare the standard deviation of gray levels on digital subtracted images obtained by different dental subtraction programs. Materials and Methods: Paired periapical films were taken at the lower premolar and molar areas of the phantoms involving human mandible. The bite registration group used Rinn XCP equipment and bite registration material, based on polyvinyl siloxane, for standardization. The no bite registration group used only Rinn XCP equipment. The periapical film images were digitized at 1200 dpi resolution and 256 gray levels by a flat bed scanner with transparency unit. Dental digital subtraction programs used for this study were Subtractor (Biomedisys Co., Korea) and Emago (Oral Diagnostic Systems, The Netherlands). To measure the similarities between the subtracted images, the standard deviations of the gray levels were obtained using a histogram of subtracted images, which were then analyzed statistically. Results: Subtracted images obtained by using the Emago program without manual selection of corresponding points showed the lowest standard deviation of gray levels (p<0.01). And the standard deviation of gray levels was lower in subtracted images in the group of a bite registration than in the group of no use of bite registration (p < 0.01). Conclusion: Digital radiographic subtraction without manual selection of reference points was found to be a convenient and superior method.

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The Study of Standard Deviation of Gray Scale Histogram in Digital Subtraction Radiography as a Test Parameter for SuperimpoSition Error (중첩 불일치 평가기준으로서의 계수공제영상의 계조도 표준편차 연구)

  • Cho Bong-Hae
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.29 no.2
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    • pp.417-422
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    • 1999
  • Purpose : The aim of this study was to assess the validity of standard deviation of gray scale histogram in digital subtraction radiography as a test parameter for superimposition error. Materials and Methods : Twenty periapical radiographs were used as baseline images and they were copied to exclude the influence of exposure geomety and contrast differences. These subsequent images were linearly displaced by 0.1-0.5 mm in the x-. y- and xy-directions, rotated by 0.5-3° and distorted by angular contraction of 1-5° in x- and y-axis before subtraction. The standard deviations of gray levels in the subtraction images were obtained and paired t-tests were performed. Pearson correlation coefficients(r) were calculated between the standard deviations and the superimposition errors. Results : Linear displacement showed high correlation coefficients of 0.997, 0.997 and 0.995 in x-. y- and xy-axis respectively. Statistically significant different standard deviation existed among all linearly displaced groups(p<0.05). Distortion showed relatively low correlation coefficients of 0.982 and 0.959 in x- and y-axis. The standard deviations between the two distortion groups were statistically significant different(p<0.05). Conclusion : Standard deviation of gray level distribution in digital subtraction images is satisfactory but not perfect similarity measure to assess the superimposition errors.

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A study on the geometric correction for the digital subtraction radiograph (디지털 공제방사선영상의 기하학적 보정에 관한 연구)

  • Lim Suk-Young;Koh Kwang-Joon
    • Imaging Science in Dentistry
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    • v.31 no.1
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    • pp.23-34
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    • 2001
  • Purpose : To develop a new subtraction program for registering digital periapical images based on the correspondence of anatomic structures. Materials and Methods: The digital periapical images were obtained by Digora system with Rinn XCP equipment after translation of 1-16 mm, and rotation of 2-20° at the premolar and molar areas of the human dried mandible. The new subtraction program, NIH Image program and Emago/Advanced program were compared by the peak-signal-to noise ratio (PSNR). Results : The new subtraction program was superior to NIH Images program and Emagol Advanced program up to 16 mm translation and horizontal angulation up to 4°. Conclusion: The new subtraction program can be used for subtracting digital periapical images.

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A STUDY ON THE CHANCES OF THE SOFT TISSUE PROFILE FOLLOWING ORTHODONTIC TREATMENT BY DIGITAL SUBTRACTION METHOD (교정치료에 따른 측모 연조직의 변화에 관한 계수공제 영상측정법적 연구)

  • Cho, Won-Tak;Yu, Dong-Hwan
    • The korean journal of orthodontics
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    • v.27 no.3 s.62
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    • pp.411-420
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    • 1997
  • The propose of this study was to quantify the changes of soft tissue profile following orthodontic treatment and to evaluate the relationship of those to the skeletal elements. Pre-and post-treatment lateral cephalometric head films of 40 cases(20 extraction cases, 20 non-extraction cases) were traced, and the changes following treatment were measured and quantified by digital subtraction method, and statisticall analyzed. The obtained results were as follows; 1. in extraction group, the change of upper lip area(UL) was $558.60\pm355.17$ pixels, that of lower lip area(LL) was $941.15\pm364.07$ pixels. But, in non-extraction group the change of uper lip area(UL) was $125.65\pm404.16$ pixels, that of lower lip area(LL) was $104.05\pm440.93$ pixels, which was significantly lesser than those in extraction group. 2. In extraction group, there was significant correlationship between upper lip area change(UL) and difference of upper incisor point(${\Delta}UIP$). Lower lip area change(LL) was significantly correlated with difference of upper incisor(${\Delta}UIP$), difference of Franlrfort upper incisor angle(${\Delta}FUIA$) or difference of interincisal angle(${\Delta}IIA$). 3. In extraction group, the ratio of difference of upper incisor point(${\Delta}UIP$) to difference of labrale superius(${\Delta}LSP$) was 1.68; difference of lower incisor point(${\Delta}LIP$) to difference of labrale inferius(${\Delta}LI$) was 1.19; difference of upper incisor point(${\Delta}UIP$) to increment in upper lip thickness(${\Delta}TUL$) was 1.95. 4. In non-extraction group, there was a significant correlationship between upper lip area change(UL) and difference of upper incisor point(${\Delta}UIP$).

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Digital contrast subtraction radiography for proximal caries diagnosis (인접면 치아우식 진단을 위한 디지털 방사선 조영 공제술)

  • Kang Byung-Cheol;Yoon Suk-Ja
    • Imaging Science in Dentistry
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    • v.32 no.3
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    • pp.123-127
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    • 2002
  • Purpose : To determine whether subtraction images utilizing contrast media can improve the diagnostic performance of proximal caries diagnosis compared to conventional periapical radiographic images. Materials and Methods: Thirty-six teeth with 57 proximal surfaces were radiographied using a size #2 RVG-ui sensor (Trophy Radiology, Marne-la-Vallee, France). The teeth immersed in water-soluble contrast media and subtraction images were taken. Each tooth was then sectioned for histologic examination. The digital radiographic images and subtraction images were examined and interpreted by three dentists for proximal caries. The results of the proximal caries diagnosis were then verified with the results of the histologic examination. Results: The proximal caries sensitivity using digital subtraction radiography was significantly higher than simply examining a single digital radiograph. The sensitivity of the proximal dentinal carious lesion when analyzed with the subtraction radiograph and the radiograph together was higher than with the subtraction radiograph or the radiograph alone. Conclusion: The use of subtraction radiography with contrast media may be useful for detecting proximal dentinal carious lesions.

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