Romanò Chiara, De Marco Paolo, Trivellato Sara, Ciardo Delia, Comi Stefania, Marvaso Giulia, Riva Giulia, Jereczek-Fossa Barbara Alicja, Orecchia Roberto, Cattani Federica
Unit of Medical Physics, IEO, European Institute of Oncology IRCCS, Via Ripamonti 435, I 20132 Milan, Italy; Department of Physics, University of Milan, Via Festa del Perdono, 7, 20122 Milan, Italy.
Unit of Medical Physics, IEO, European Institute of Oncology IRCCS, Via Ripamonti 435, I 20132 Milan, Italy.
Phys Med. 2020 Jul;75:19-25. doi: 10.1016/j.ejmp.2020.05.016. Epub 2020 May 27.
Evaluation of Raystation ANAtomically CONstrained Deformation Algorithm (ANACONDA) performance to different urinary bladder filling levels in male pelvis anatomic site varying the controlling Regions Of Interest (ROIs).
Different image datasets were obtained with ImSimQA (Oncology System Limited, Shrewsbury, UK) to evaluate ANACONDA performances (RaySearch Laboratories, Stockholm, Sweden). Deformation vector fields were applied to a synthetic man pelvis and a real patient computed tomography (CT) dataset (reference CTs) resulting in deformed CTs (target CTs) with various bladder filling levels. Different deformable image registrations (DIRs) were generated between each target CTs and reference CTs varying the controlling ROIs subset. Deformed ROIs were mapped from target CT to reference CT and then compared to reference ROIs. Evaluation was performed by Dice Similarity Coefficient (DSC), Correlation Coefficient (CC), Mean Distance to Agreement (MDA), maximum Distance to Agreement (maxDA) and with the introduction of global DSC (global_DSC) and global CC (global_CC) parameters.
In both synthetic and real patient CT cases, DSC scored less than 0.75 and MDA greater than 3 mm when no ROIs or only bladder were exploited as controlling ROI. DSC and CC increased by increasing the number of controlling ROIs selected whereas, an opposite behavior was observed for MDA and maxDA.
ANACONDA performances can be influenced by bladder filling fluctuation if no controlling ROIs are selected. Global_DSC and global_CC are useful parameters to quantitatively compare DIR algorithms. DIR performances improve by increasing the number of controlling ROIs selected, reaching a saturation level after a defined ROIs subset selection.
评估Raystation解剖约束变形算法（ANACONDA）在男性骨盆解剖部位不同膀胱充盈水平下，改变控制感兴趣区域（ROI）时的性能。
使用ImSimQA（英国什鲁斯伯里肿瘤系统有限公司）获取不同的图像数据集，以评估ANACONDA性能（瑞典斯德哥尔摩RaySearch实验室）。将变形向量场应用于合成男性骨盆和真实患者的计算机断层扫描（CT）数据集（参考CT），从而生成具有不同膀胱充盈水平的变形CT（目标CT）。在每个目标CT与参考CT之间生成不同的可变形图像配准（DIR），改变控制ROI子集。将变形的ROI从目标CT映射到参考CT，然后与参考ROI进行比较。通过骰子相似系数（DSC）、相关系数（CC）、平均一致距离（MDA）、最大一致距离（maxDA）以及引入全局DSC（global_DSC）和全局CC（global_CC）参数进行评估。
在合成和真实患者CT病例中，当不使用ROI或仅将膀胱作为控制ROI时，DSC得分低于0.75且MDA大于3毫米。随着所选控制ROI数量的增加，DSC和CC升高，而MDA和maxDA则呈现相反的趋势。
如果不选择控制ROI，ANACONDA性能可能会受到膀胱充盈波动的影响。全局_DSC和全局_CC是定量比较DIR算法的有用参数。通过增加所选控制ROI的数量，DIR性能会提高，在选定特定ROI子集后达到饱和水平。
