Characterisation of noise and sharpness of images from four digital breast tomosynthesis systems for simulation of images for virtual clinical trials
Characterisation of noise and sharpness of images from four digital breast tomosynthesis systems for simulation of images for virtual clinical trials
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DOI：
10.1088/1361-6560/aa5dd9
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发表时间：
2017-03-21
影响因子：
3.5
通讯作者：
Young, Kenneth C.
中科院分区：
文献类型：
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作者：
Mackenzie, Alistair;Marshall, Nicholas W.;Young, Kenneth C.
对FujiFilm Innovality、GE SenoClaire、Hologic Selenia Dimensions和Siemens Inspiration数字乳腺断层合成摄影（DBT）系统的噪声和清晰度特性进行了深入评价，旨在改善虚拟临床试验的图像模拟。测量了平面模式和DBT模式的第一投影和中心投影的噪声功率谱和调制传递函数曲线。在DBT模式下，在中心投影之前，投影的X射线束被阻挡，以消除先前图像中滞后和重影的影响。在平面和DBT成像模式下，通过二次拟合的方法，可以得到噪声系数。对应于0.5的MTF（MTF 0.5）的空间频率根据在乳房支撑件上和在乳房支撑件上方40 mm处进行的MTF测量来计算。这是对第一个和中央投影进行的。使用狭缝测量从第一投影携带到后续图像的信号百分比（滞后）。还评估了与滞后相关的噪声。与相应的平面模式相比，DBT模式通常具有较低的电子噪声系数，但具有较高的结构噪声系数。在台面上方40 mm处测得的MTF 0.5对于连续扫描系统低6%至47%，而对于步进和发射系统低1%。对于广角DBT，第一次投影的MTF 0.5比中心投影低18%（FujiFilm）和28%（Siemens）。FujiFilm、GE和Hologic系统的第二次投影滞后分别为2.2%、0.3%和0.8%。在所有情况下，与滞后相关的噪声可以忽略不计。目前的乳房DBT系统的虚拟临床试验的建模框架需要进行调整，以考虑在广角MTF的滞后和变化的信号。
In-depth evaluation of the noise and sharpness characteristics of FujiFilm Innovality, GE SenoClaire, Hologic Selenia Dimensions and Siemens Inspiration digital breast tomosynthesis (DBT) systems was performed with the intention of improving image simulation for virtual clinical trials. Noise power spectra (NPS) and modulation transfer function curves (MTF) were measured for planar modes and for the first and central projections for DBT modes. In DBT mode, the x-ray beam was blocked for the projections before the central projection in order to remove the influence of lag and ghosting from the previous images. A quadratic fit between the NPS and linearised pixel value gave the noise coefficients for planar and DBT imaging modes. The spatial frequencies corresponding to an MTF of 0.5 (MTF0.5) were calculated from the MTF measurements made on the breast support and at 40 mm above the breast support. This was done for the first and the central projections. The percentage of signal carried over from the first projection to subsequent images (lag) was measured using a slit. The noise associated with lag was also evaluated. The DBT modes typically had lower electronic noise coefficients but higher structural noise coefficients compared to the respective planar mode MTF0.5 measured 40 mm above the table was between 6% and 47% lower for continuous scanning systems compared to 1% lower for step and shoot systems. For wide angle DBT, the MTF0.5 of the first projection was 18% (FujiFilm) and 28% (Siemens) lower than for the central projection. Lag in the second projection was 2.2%, 0.3%, 0.8% for the FujiFilm, GE and Hologic systems respectively. In all cases, the noise associated with lag was negligible. Current modelling frameworks for virtual clinical trials of breast DBT systems need to be adapted to account for signals from lag and variations in the MTF at wide angles.