Virtual Digital Test Pattern을 이용한 Computed Radiography의 특성 평가
Characteristic evaluation by virtual digital test pattern in computed radiography
- 주제(키워드) Computed Radiography , virtual digital test pattern , 영상처리 , 영상평가
- 발행기관 고려대학교 대학원
- 지도교수 김정민
- 발행년도 2010
- 학위수여년월 2010. 2
- 학위구분 석사
- 학과 일반대학원 보건과학과
- 세부전공 방사선과학 전공
- 원문페이지 90 p
- 실제URI http://www.dcollection.net/handler/korea/000000021745
- 본문언어 한국어
- 제출원본 000045579328
초록/요약
The objectives of this study is to evaluate characteristic in the whole CR system. I have implemented the processing curve of each Look up table (LUT) in REGIUS 150 CR system by using virtual digital test pattern method. The characteristic of Dry Imager was measured also. And then I have acquired the evaluation of the image quality by MTF, WS, and DQE in physical. In addition, I have evaluated the image quality with Hawlet chart and Kim's chart in visual. First of all, I have generated the virtual digital test pattern file with binary file editing method. This file was used as an input data of CR system (REGIUS 150 CR system, KONICA MINOLTA). The DICOM files which were automatically generated output files by the CR system, were used to figure out the processing curves of each LUT modes (THX, ST, STM, LUM, BONE, LIN). The gradation curves of Dry Imager were also measured to figure out the characteristics of hardcopy image. According to the results of each parameters, I identified parameter's characteristic of image processing in CR system. And then I had the experiments in the evaluation of the image quality in CR system. First, I measured MTF (with Edge method), WS, DQE in compliance with the method of IEC 62202-1. And for the visual evaluation of image quality I used Hawlet chart and Kim's chart. The processing curves which were measured by this proposed method showed the characteristics of CR system. And I found the linearity of Dry Imager in the middle area of processing curves. With these results I found that the relationship between the curves and each parameters. The G value is related to the slope and the S value is related to the shift in X-axis of processing curves. And I found a little difference between normal resolution mode and high resolution mode offered in REGIUS 150 system by the evaluation of image quality in physical and visual. In conclusion, this study evaluated characteristic in the whole CR system by virtual digital test pattern method, characteristic of image processing, the evaluation of image quality. And the proposed method which uses virtual digital test pattern, can measure the characteristics and parameters of the image processing patterns of the CR system. I expect that the proposed method is useful to analogize the image processing not only for this CR system, but also for the other commercial digital systems.
more목차
제1장 서 론 1
1.1 논문 구성 1
1.2 Digital Radiography 3
1.3 연구 목적 4
제2장 연구 배경 5
2.1 CR system의 Image Processing 5
2.2 Resolution Property 11
2.3 Noise Property 20
2.4 DQE (Detective Quantum Efficiency) 25
2.5 시각적 화질 평가 28
제3장 실험 재료 및 방법 32
3.1 실험 재료 32
3.2 실험 방법 33
제4장 실험 결과 46
4.1 선질 (Radiation Quality) 46
4.2 선량 (Radiation Quantity) 48
4.3 Virtual Digital Test Pattern method 49
4.4 Image Processing의 Parameter 56
4.5 물리적 화질평가 63
4.6 시각적 화질평가 67
제5장 고 찰 70
제6장 결 론 75
참고 문헌 77
