Baseline Correction in Computed Radiography Images with 1D Morphological Filter

• 영문명: Baseline Correction in Computed Radiography Images with 1D Morphological Filter
• 발행기관: 대한방사선과학회(구 대한방사선기술학회)
• 저자명: 김용권(Yong-Gwon Kim) 류연철(Yeunchul Ryu)
• 간행물 정보: 『방사선기술과학』제45권 제5호, 397~405쪽, 전체 9쪽
• 주제분류: 의약학 > 방사선과학
• 파일형태: PDF
• 발행일자: 2022.10.31

영문 초록

Computed radiography (CR) systems, which convert an analog signal recorded on a cassette into a digital image, combine the characteristics of analog and digital imaging systems. Compared to digital radiography (DR) systems, CR systems have presented difficulties in evaluating system performance because of their lower detective quantum efficiency, their lower signal-to-noise ratio (SNR), and lower modulation transfer function (MTF). During the step of energy-storing and reading out, a baseline offset occurs in the edge area and makes low-frequency overestimation. The low-frequency offset component in the line spread function (LSF) critically affects the MTF and other image-analysis or qualification processes. In this study, we developed the method of baseline correction using mathematical morphology to determine the LSF and MTF of CR systems accurately. We presented a baseline correction that used a morphological filter to effectively remove the low-frequency offset from the LSF. We also tried an MTF evaluation of the CR system to demonstrate the effectiveness of the baseline correction. The MTF with a 3-pixel structuring element (SE) fluctuated since it overestimated the low-frequency component. This overestimation led the algorithm to over-compensate in the low-frequency region so that high-frequency components appeared relatively strong. The MTFs with between 11- and 15-pixel SEs showed little variation. Compared to spatial or frequency filtering that eliminated baseline effects in the edge spread function, our algorithm performed better at precisely locating the edge position and the averaged LSF was narrower.

목차

Ⅰ. Introduction

Ⅱ. Materials and Methods

Ⅲ. Results

Ⅳ. Discussion

Ⅴ. Conclusions

REFERENCES

키워드

모폴로지컬 필터 변조전달 함수 기저선 보정 저주파수 옵셋 컴퓨터 방사선촬영 Morphological filter Modulation transfer function Baseline correction Low frequency offset Computed radiography