Eldevik K, Nordhøy W, Skretting A
The Interventional Centre, Oslo University Hospital, Oslo, Norway.
Radiat Prot Dosimetry. 2010 Apr-May;139(1-3):430-3. doi: 10.1093/rpd/ncq063. Epub 2010 Feb 24.
The sharpness expressed as the full-width at half-maximum of the line spread function (LSF) was derived for different CT scanners and reconstruction kernels. The LSFs were calculated from images of a 0.28 mm tungsten bead and successfully fitted to cumulative Gaussians by means of probit plots. The corresponding image noise was measured in a homogeneous material. The investigation showed that the noise increases strongly for small improvements in sharpness. The method was reproducible and insensitive to small positional shifts of the phantom.
针对不同的CT扫描仪和重建内核，得出了以线扩展函数（LSF）半高全宽表示的清晰度。LSF是根据0.28毫米钨珠的图像计算得出的，并通过概率图成功拟合为累积高斯分布。在均匀材料中测量了相应的图像噪声。研究表明，清晰度稍有提高，噪声就会大幅增加。该方法具有可重复性，并且对体模的小位置偏移不敏感。
