Denoising Projection Data with a Robust Adaptive Bilateral Filter in Low-Count SPECT

• 作者: Jun’ichi Kotoku Kenshiro Shiraishi Norikazu Arai Shinobu Kumagai Susumu Nakabayashi Takahide Okamoto Takao Okamoto Takashi Chikamatsu Takenori Kobayashi Tatsuro Kaminaga
• 来源期刊: 医学物理学、临床工程、放射肿瘤学(英文)
• 学科: 医学
• 关键词: BILATERAL Filter DENOISING SPECT NUCLEAR MEDICINE
• 年，卷（期）: 2018,（3）
• 页码范围: 363-375
• 页数: 13页
• 分类号: R73

摘要

Low-count SPECT images are well known to be smoothed strongly by a Butterworth filter for statistical noise reduction. Reconstructed images have a low signal-to-noise ratio (SNR) and spatial resolution because of the removal of high-frequency signal components. Using the developed robust adaptive bilateral filter (RABF), which was designed as a pre-stage filter of the Butterworth filter, this study was conducted to improve SNR without degrading the spatial resolution for low-count SPECT imaging. The filter can remove noise while preserving spatial resolution. To evaluate the proposed method, we extracted SNR and spatial resolution in a phantom study. We also conducted paired comparison for visual image quality evaluation in a clinical study. Results show that SNR was increased 1.4 times without degrading the spatial resolution. Visual image quality was improved significantly (p < 0.01) for clinical low-count data. Moreover, the accumulation structure became sharper. A structure embedded in noise emerged. Our method, which denoises without degrading the spatial resolution for low-count SPECT images, is expected to increase the effectiveness of diagnosis for low-dose scanning and short acquisition time scanning.