Hariyati Ika, Sulistyani Ani, Gregorius Matthew, Aribowo Harimulti, Prawoto Ungguh, Yana Defri Dwi, Salamah Thariqah, Lubis Lukmanda Evan, Soejoko Djarwani Soeharso
Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, 16424, Indonesia.
Radiology Department, Universitas Indonesia Hospital, Depok, 16424, Indonesia.
Phys Eng Sci Med. 2025 Sep 10. doi: 10.1007/s13246-025-01632-z.
This study introduces a novel optimization framework for cranial three-dimensional rotational angiography (3DRA), combining the development of a brain equivalent in-house phantom with Figure of Merit (FOM) a quantitative evaluation method. The technical contribution involves the development of an in-house phantom constructed using iodine-infused epoxy and lycal resins, validated against clinical Hounsfield Units (HU). A customized head phantom was developed to simulate brain tissue and cranial vasculature for 3DRA optimization. The phantom was constructed using epoxy resin with 0.15-0.2% iodine to replicate brain tissue and lycal resin with iodine concentrations ranging from 0.65 to 0.7% to simulate blood vessels of varying diameters. The phantom materials validation was performed by comparing their HU values to clinical reference HU values from brain tissue and cranial vessels, ensuring accurate tissue simulation. The validated phantom was used to acquire images using cranial 3DRA protocols, specifically Prop-Scan and Roll-Scan. Image quality was assessed using Signal-Difference-to-Noise Ratio (SDNR), Dose-Area Product (DAP), and Modulation Transfer Function (MTF). Imaging efficiency was quantified using the Figure of Merit (FOM), calculated as SDNR/DAP, to objectively compare the performance of two cranial 3DRA protocols. The task-based optimization showed that Roll-Scan consistently outperformed Prop-Scan across all vessel sizes and regions. Roll-Scan yields FOM values ranging from 183 to 337, while Prop-Scan FOM values ranged from 96 to 189. Additionally, Roll-Scan (0.27 lp/pixel) delivered better spatial resolution, as indicated by higher MTF 10% value than Prop-Scan (0.23 lp/pixel). Most notably, Roll-Scan consistently detecting 2 mm vessel structures among all regions of the phantom. This capability is clinically important in cerebral angiography, which is accurate visualization of small vessels, i.e. the Anterior Cerebral Artery (ACA), Posterior Cerebral Artery (PCA), and Middle Cerebral Artery (MCA). These findings highlight Roll-Scan as the superior protocol for brain interventional imaging, underscoring the significance of FOM as a comprehensive parameter for optimizing imaging protocols in clinical practice. The experimental results support the use of the Roll-Scan protocol as the preferred acquisition method for cerebral angiography in clinical practice. The analysis using FOM provides substantial and quantifiable evidence in determining the acquisition methods. Furthermore, the customized in-house phantom is recommended as a candidate to optimization tools for clinical medical physicists.
本研究引入了一种用于颅骨三维旋转血管造影（3DRA）的新型优化框架，将自制的等效脑模体的开发与品质因数（FOM）这一定量评估方法相结合。技术贡献包括开发了一种使用注入碘的环氧树脂和lycal树脂构建的自制模体，并根据临床亨氏单位（HU）进行了验证。开发了一种定制的头部模体，用于模拟脑组织和颅脑血管以优化3DRA。该模体使用含0.15 - 0.2%碘的环氧树脂复制脑组织，使用碘浓度范围为0.65%至0.7%的lycal树脂模拟不同直径的血管。通过将其HU值与脑组织和颅脑血管的临床参考HU值进行比较来进行模体材料验证，以确保准确模拟组织。使用经过验证的模体通过颅骨3DRA协议（特别是Prop - Scan和Roll - Scan）获取图像。使用信号差噪比（SDNR）、剂量面积乘积（DAP）和调制传递函数（MTF）评估图像质量。使用品质因数（FOM）对成像效率进行量化，FOM计算为SDNR/DAP，以客观比较两种颅骨3DRA协议的性能。基于任务的优化表明，在所有血管大小和区域中，Roll - Scan始终优于Prop - Scan。Roll - Scan产生的FOM值范围为183至337，而Prop - Scan的FOM值范围为96至189。此外，Roll - Scan（0.27 lp/像素）具有更好的空间分辨率，如较高的MTF 10%值所示，高于Prop - Scan（0.23 lp/像素）。最值得注意的是，Roll - Scan始终能在模体的所有区域中检测到2毫米的血管结构。这种能力在脑血管造影中具有临床重要性，即准确可视化小血管，如大脑前动脉（ACA）、大脑后动脉（PCA）和大脑中动脉（MCA）。这些发现突出了Roll - Scan作为脑部介入成像的 superior 协议，强调了FOM作为临床实践中优化成像协议的综合参数的重要性。实验结果支持在临床实践中使用Roll - Scan协议作为脑血管造影的首选采集方法。使用FOM进行的分析为确定采集方法提供了大量可量化的证据。此外，推荐定制的自制模体作为临床医学物理学家优化工具的候选者。
