Sorzano C O S, Marabini R, Herman G T, Censor Y, Carazo J M
Escuela Politécnica Superior, Universidad San Pablo-CEU, Campus Urb Montepríncipe, s/n, 28668 Boadilla del Monte, Madrid, Spain.
Phys Med Biol. 2004 Feb 21;49(4):509-22. doi: 10.1088/0031-9155/49/4/003.
Three-dimensional electron microscopy (3D-EM) is a powerful tool for visualizing complex biological systems. As with any other imaging device, the electron microscope introduces a transfer function (called in this field the contrast transfer function, CTF) into the image acquisition process that modulates the various frequencies of the signal. Thus, the 3D reconstructions performed with these CTF-affected projections are also affected by an implicit 3D transfer function. For high-resolution electron microscopy, the effect of the CTF is quite dramatic and limits severely the achievable resolution. In this work we make use of the iterative data refinement (IDR) technique to ameliorate the effect of the CTF. It is demonstrated that the approach can be successfully applied to noisy data.
三维电子显微镜（3D-EM）是用于可视化复杂生物系统的强大工具。与任何其他成像设备一样，电子显微镜在图像采集过程中引入了一个传递函数（在该领域称为对比度传递函数，CTF），该函数调制信号的各种频率。因此，用这些受CTF影响的投影进行的三维重建也受到隐式三维传递函数的影响。对于高分辨率电子显微镜，CTF的影响相当显著，并严重限制了可实现的分辨率。在这项工作中，我们利用迭代数据细化（IDR）技术来改善CTF的影响。结果表明，该方法可以成功应用于噪声数据。
