Robert Normand, Watt Kristina N, Rochette Sophie, Desponds Lionel, Vaillant Régis, Rowlands John A
Sunnybrook Research Institute, 2075 Bayview Avenue, Room S633, Toronto, Ontario M4N 3M5, Canada.
Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, Canada.
Med Phys. 2015 Jan;42(1):521-30. doi: 10.1118/1.4903898.
The authors describe a design for prepatient region of interest attenuators (ROIAs) to reduce dose area product (DAP) for clinical use. The authors describe a model to predict DAP values from x-ray technique parameters recorded during a clinical procedure for image sequences obtained in the presence or absence of ROIAs. The model was developed primarily to determine what the DAP to a patient undergoing cardiac catheterization with a ROIA would have been if no ROIA had been used allowing a determination of DAP reduction.
Copper ROIAs with thicknesses that vary gradually so as not to cause significant image artifacts were constructed. X-ray image sequences were acquired on a clinical catheterization system with and without ROIAs with varying x-ray technique parameters. DAP values were measured for all said exposures using an ionization chamber and compared to a model the authors developed.
The model can predict DAP values within 3.5% on average with or without ROIAs when compared to ionization chamber measurements.
The proposed experimental design is adequate for measuring DAP reductions on the order of 1.5-3.5 that are expected when introducing a ROIA during patient catheterization imaging.
作者描述了一种用于患者感兴趣区预衰减器（ROIA）的设计，以降低剂量面积乘积（DAP）用于临床。作者描述了一个模型，该模型可根据临床过程中记录的X射线技术参数预测有或无ROIA时所获图像序列的DAP值。该模型主要用于确定若未使用ROIA，接受心脏导管插入术的患者的DAP会是多少，从而能够确定DAP的降低情况。
构建了厚度逐渐变化以免引起显著图像伪影的铜制ROIA。在临床导管插入术系统上，在有和无ROIA的情况下，采用不同的X射线技术参数采集X射线图像序列。使用电离室测量所有上述曝光的DAP值，并与作者开发的模型进行比较。
与电离室测量结果相比，无论有无ROIA，该模型平均能在3.5%的误差范围内预测DAP值。
所提出的实验设计足以测量在患者导管插入术成像期间引入ROIA时预期的1.5 - 3.5量级的DAP降低情况。
