Spiral interpolation algorithms for multislice spiral CT. II. Measurement and evaluation of slice sensitivity profiles and noise at a clinical multislice system
Spiral interpolation algorithms for multislice spiral CT. II. Measurement and evaluation of slice sensitivity profiles and noise at a clinical multislice system
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多层螺旋CT的螺旋插值算法。
DOI：
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发表时间：
2000
影响因子：
10.6
通讯作者：
W. Kalender
中科院分区：
文献类型：
--
作者：
T. Fuchs;J. Krause;S. Schaller;T. Flohr;W. Kalender
对于点。我见同上，第19卷，第9号，第822-34页(2000)。最近推出的用于计算机断层扫描(CT)的多层数据采集基于多行探测器设计、更高的旋转速度以及先进的z-内插和z-滤波算法。应用自适应轴向插值器(AAI)软件对临床多层螺旋CT(MSCT)多层螺旋CT(MSCT)多层螺旋CT(MSCT)扫描机同时采集的4层螺旋CT图像的SSP和噪声进行了评价。SSP的测量采用位于旋转中心(COR)、偏离中心100 mm的直径为2 mm、厚度为50 mU/m的小金圆盘。20厘米水模内CT值的标准偏差被用作图像噪声的测量。在探测器层厚S=1 mm的条件下，螺距p以0.025为步长变化。标称重建层厚分别为1.25、1.5和2.0 mm。对于所有可能的节距值，作者找到了在与所选标称切片厚度相等的COR处各自的灵敏度分布的半高全宽(FWHM)。偏离中心100 mm处的轮廓与核心处的半高宽相比平均展宽不到7%。此外，对于p/spl LES/1.75，在COR处的第十大全宽(FWTM)的变化小于10%。在此范围内，图像噪声相对于平均噪声水平的变化小于10%。当标称切片宽度为1.25 mm和1.50 mm时，测量的切片宽度在p=1.75以上略有增加，并伴随着根据平方根倒数关系的噪声降低。作者仔细研究的MSCT系统提供了重建的层宽和图像噪声，可以认为在很大的床速范围内这些都是恒定的。在这方面，MSCT优于单层螺旋CT。在定义和优化临床方案时，可以利用这些事实：螺旋螺距几乎可以自由选择，扫描方案可以遵循诊断要求，而不受技术限制。总而言之，MSCT在提供稳定的图像质量的同时，大大减少了扫描时间。具有三维(3-D)各向同性分辨率的体积扫描对于完整的解剖区域通常是可行的。
For pt. I see ibid., vol. 19, no. 9, p. 822-34 (2000). The recently introduced multislice data acquisition for computed tomography (CT) is based on multirow detector design, increased rotation speed, and advanced z-interpolation and z-filtering algorithms. The authors evaluated slice sensitivity profiles (SSPs) and noise of a clinical multislice spiral CT (MSCT) scanner with M=4 simultaneously acquired slices and adaptive axial interpolator (AAI) reconstruction software. SSPs were measured with a small gold disk of 50 /spl mu/m thickness and 2-mm diameter located at the center of rotation (COR) and 100 mm off center. The standard deviation of CT values within a 20-cm water phantom was used as a measure of image noise. With a detector slice collimation of S=1.0 mm, the authors varied spiral pitch p from 0.25 to 2.0 in steps of 0.025. Nominal reconstructed slice thicknesses were 1.25, 1.5, and 2.0 mm. For all possible pitch values, the authors found the full-width at half maximum (FWHM) of the respective sensitivity profile at the COR equivalent to the selected nominal slice thickness. The profiles at 100 mm off center are broadened less than 7% on the average compared with the FWHM at the COR. In addition, variation of the full-width at tenth maximum (FWTM) at the COR was below 10% for p/spl les/1.75. Within this range, image noise varied less than 10% with respect to the mean noise level. The slight increase in measured slice-width above p=1.75 for nominal slice-widths of 1.25 and 1.50 mm is accompanied by a decrease of noise according to the inverse square root relationship. The MSCT system that the authors scrutinized provides reconstructed slice-widths and image noise, which can be regarded as constant within a wide range of table speeds. With respect to this, MSCT is superior to single-slice spiral CT. These facts can be made use of when defining and optimizing clinical protocols: the spiral pitch can be selected almost freely, and scan protocols can follow the diagnostic requirements without technical restrictions. In summary, MSCT offers constant image quality while scan times are reduced drastically. Volume scans with three-dimensional (3-D) isotropic resolution are routinely feasible for complete anatomical regions.
螺旋计算机断层扫描中空间变化的纵向混叠和分辨率。
影响因子：
3.8
作者：
Yen,SY;Rubin,GD;Napel,S
通讯作者：
Napel,S