간 초음파 영상에서의 스페클 노이즈 제거를 위한 필터들의 비교 평가

• Published in: 방사선기술과학 Vol. 46; no. 6; pp. 475 - 484
• Main Authors: 김하진(Hajin Kim), 이영진(Youngjin Lee)
• Format: Journal Article
• Language: Korean
• Published: 대한방사선과학회(구 대한방사선기술학회) 31.12.2023; KOREAN SOCIETY OF RADIOLOGICAL TECHNOLOGY
• Subjects: Liver Ultrasound Image; Lee Filter; Window Size; Speckle Noise Reduction; 간 혈관; Lee 필터; 간 초음파 영상; Liver Blood Vessel; 스페클 노이즈 제거; Quantitative Evaluation; 윈도우 크기; 정량적 평가; Lee
• ISSN: 2288-3509

This study aimed to compare filters for reducing speckle noise in ultrasound images using clinical liver images. We acquired the clinical liver ultrasound images, and noisy images were obtained by adding 0.01, 0.05, 0.10, and 0.50 intensity levels of speckle noise to the liver images. The Wiener filter, median modified Wiener filter, gamma filter, and Lee filter were designed for the noisy images by setting window sizes at 3×3, 5×5, and 7×7. The coefficient of variation (COV) and contrast to noise ratio (CNR) were calculated to evaluate noise reduction and various filters. Moreover, the filter with the highest image quality was selected and quantitatively compared to a noisy image. As a result, COV and CNR showed the noise improved result when the Lee filter was applied. Furthermore, the Lee filter image with a window size of 7×7 was noted to possess approximately a minimum of 1.28 to a maximum of 3.38 times better COV and a minimum of 2.18 to a maximum of 5.50 times better CNR than the noisy image. In conclusion, we confirmed that the Lee filter was effective in reducing speckle noise and proved that an appropriate window size needs to be set considering blurring.