Determination of the presampled MTF in computed tomography
Determination of the presampled MTF in computed tomography
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DOI：
10.1118/1.1350438
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发表时间：
2001-03-01
期刊：
影响因子：
3.8
通讯作者：
Boone, JM
中科院分区：
文献类型：
--
作者：
Boone, JM
描述了一种在 CT 扫描仪中测量预采样 MTF 的技术。该技术使用一个简单的模型，该模型由类似 0.050 毫米的铝箔组成，中间夹有扁平塑料或组织等效板。铝箔相对于重建矩阵稍微倾斜，并采集 CT 图像。采集的 CT 图像产生有角度的狭缝图像，可用于合成预采样线扩散函数 (LSF)。预采样 MTF 是根据预采样 LSF 计算得出的。该技术是 Fujita 等人提出的技术的直接扩展。 [IEEE 传输。医学。 Imaging 11, 34-39 (1993)] 用于数字射线照相图像的 MTF 计算。虽然临床 CT 扫描仪中的 MTF 通常在奈奎斯特频率以下达到可忽略不计的幅度，但该技术易于实现，需要廉价的材料，对混叠具有鲁棒性，并且由于比传统的 PSF 积分技术具有更大的数据平均，因此对噪声具有更强的弹性。所提出的技术的使用在临床多探测器阵列扫描仪上进行了说明，并且显示了几种常见重建内核的 MTF。所提出的技术很可能适用于所有断层扫描成像系统，包括单光子发射计算机断层扫描、正电子发射断层扫描、磁共振成像和超声扫描仪。 (C) 2001 年美国医学物理学家协会。 [DOI：10.1118/1.1350438]。
A technique for measuring the presampled MTF in CT scanners is described. The technique uses a simple phantom consisting of similar to0.050 mm aluminum foil sandwiched by flat plastic or tissue equivalent slabs. The aluminum foil is slightly angled with respect to the reconstruction matrix, and CT images are acquired. The acquired CT image yields an angled slit image that can be used to synthesize the presampled line spread function (LSF). The presampled MTF is calculated from the presampled LSF. The technique is a direct extension of that proposed by Fujita et al. [IEEE Trans. Med. Imaging 11, 34-39 (1993)] for MTF calculation on digital radiography images. While the MTF in clinical CT scanners often reaches negligible amplitude below the Nyquist frequency, the technique is easy to implement, requires inexpensive materials, is robust to aliasing, and is more resilient to noise due to greater data averaging than conventional PSF-integration techniques. Use of the proposed technique is illustrated on a clinical multiple detector array scanner, and MTFs are shown for several common reconstruction kernels. It is likely that the proposed technique would be useful for all tomographic imaging systems, including single photon emission computed tomography, positron emission tomography, magnetic resonance imaging and ultrasound scanners. (C) 2001 American Association of Physicists in Medicine. [DOI: 10.1118/1.1350438].