Aslund Magnus, Cederström Björn, Lundqvist Mats, Danielsson Mats
Department of Physics, Royal Institute of Technology, AlbaNova, 106 91, Stockholm, Sweden.
Med Phys. 2007 Jun;34(6):1918-25. doi: 10.1118/1.2731032.
The physical performance of a scanning multislit full field digital mammography system was determined using basic image quality parameters. The system employs a direct detection detector comprised of linear silicon strip sensors in an edge-on geometry connected to photon counting electronics. The pixel size is 50 microm and the field of view 24 x 26 cm2. The performance was quantified using the presampled modulation transfer function, the normalized noise power spectrum and the detective quantum efficiency (DQE). Compared to conventional DQE methods, the scanning geometry with its intrinsic scatter rejection poses additional requirements on the measurement setup, which are investigated in this work. The DQE of the photon counting system was found to be independent of the dose level to the detector in the 7.6-206 microGy range. The peak DQE was 72% and 73% in the scan and slit direction, respectively, measured with a 28 kV W-0.5 mm Al anode-filter combination with an added 2 mm Al filtration.
使用基本图像质量参数确定了扫描多狭缝全场数字乳腺摄影系统的物理性能。该系统采用直接探测探测器,由边缘入射几何结构的线性硅条传感器组成,连接到光子计数电子设备。像素大小为50微米,视野为24×26平方厘米。使用预采样调制传递函数、归一化噪声功率谱和探测量子效率(DQE)对性能进行了量化。与传统的DQE方法相比,具有固有散射抑制功能的扫描几何结构对测量设置提出了额外要求,本文对此进行了研究。发现光子计数系统的DQE在7.6 - 206微戈瑞范围内与探测器的剂量水平无关。在使用28 kV钨 - 0.5毫米铝阳极 - 滤过组合并添加2毫米铝滤过的情况下,扫描方向和狭缝方向的峰值DQE分别为72%和73%。