Center for Radiology, University Clinical Center of Serbia, Pasterova 2, 11000 Belgrade, Serbia.
Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia.
Medicina (Kaunas). 2024 Jan 5;60(1):98. doi: 10.3390/medicina60010098.
: Total knee arthroplasty (TKA) has become the treatment of choice for advanced osteoarthritis. The aim of this paper was to show the possibilities of optimizing the Perth CT protocol, which is highly effective for preoperative planning and postoperative assessment of alignment. : The cross-sectional study comprised 16 patients for preoperative planning or postoperative evaluation of TKA. All patients were examined with the standard and optimized Perth CT protocol using advance techniques, including automatic exposure control (AEC), iterative image reconstruction (IR), as well as a single-energy projection-based metal artifact reduction algorithm for eliminating prosthesis artifacts. The effective radiation dose (E) was determined based on the dose report. Imaging quality is determined according to subjective and objective (values of signal to noise ratio (SdNR) and figure of merit (FOM)) criteria. : The effective radiation dose with the optimized protocol was significantly lower compared to the standard protocol ( < 0.001), while in patients with the knee prosthesis, E increased significantly less with the optimized protocol compared to the standard protocol. No significant difference was observed in the subjective evaluation of image quality between protocols ( > 0.05). Analyzing the objective criteria for image quality optimized protocols resulted in lower SdNR values and higher FOM values. No significant difference of image quality was determined using the SdNR and FOM as per the specified protocols and parts of extremities, and for the presence of prothesis. : Retrospecting the ALARA ('As Low As Reasonably Achievable') principles, it is possible to optimize the Perth CT protocol by reducing the kV and mAs values and by changing the collimation and increasing the pitch factor. Advanced IR techniques were used in both protocols, and AEC was used in the optimized protocol. The effective dose of radiation can be reduced five times, and the image quality will be satisfactory.
全膝关节置换术（TKA）已成为治疗晚期骨关节炎的首选方法。本文旨在展示优化珀斯 CT 方案的可能性，该方案在术前规划和术后对线评估方面非常有效。
该横断面研究包括 16 例接受 TKA 术前规划或术后评估的患者。所有患者均采用标准和优化的珀斯 CT 方案进行检查，采用先进技术，包括自动曝光控制（AEC）、迭代图像重建（IR）以及基于单能量投影的金属伪影减少算法，以消除假体伪影。有效辐射剂量（E）根据剂量报告确定。根据主观和客观（信噪比（SdNR）和品质因数（FOM）值）标准确定成像质量。
与标准方案相比，优化方案的有效辐射剂量显著降低（<0.001），而在有膝关节假体的患者中，与标准方案相比，优化方案的 E 增加明显较少。两种方案的图像质量主观评价无显著差异（>0.05）。分析优化方案的图像质量客观标准得出，SdNR 值较低，FOM 值较高。根据指定的协议和肢体部位以及假体的存在，使用 SdNR 和 FOM 确定的图像质量没有差异。
回顾“尽可能低的合理可达到”（ALARA）原则，可以通过降低 kV 和 mAs 值、改变准直和增加螺距因子来优化珀斯 CT 方案。两种方案均采用高级 IR 技术，优化方案采用 AEC。辐射有效剂量可降低五倍，图像质量将令人满意。
