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Cct228 atcm phantom was developed in cooperation with researchers at the carolineska college to assist ct operators in displaying atcm performance。
The cct228 atcm model, the cct228 atcm performance module, is made of solid catphanium flat material, allowing the measurement of signal noise in three elliptical segments of different sizes, to demonstrate the compensatory effect of atcm on body size change and dissection transition. The model also helps to assess the impact of patient alignment。
65 cm long phantom consists of three elliptical parts. Each ellipse is 15 cm long and has a ratio of 3:2; 25:16. 7 cm, 30:20 cm and 35:23. 3 cm dimensions. Provide smooth transitions between parts, with round corners at both ends. The side and top of the model are marked with a diameter of 1. 6 mm polytetrafluoroethylene to help align the model。
The cct228 atcm model, the cct228 atcm performance module, and the cct228 atcm model are designed to scan projectors x-rays (sprs) using atcm algorithms to estimate patient decay. Various scanning parameters or models can be repositioned to assess the effects of changes in parameters or errors in patient location. The resulting ct image set can be evaluated on the basis of reference scans to calculate the normalized square root error of the pipe current curve (nrmse) and to provide visual assessment of the pipe current fluctuations curve and image noise。
In order to gain a better understanding of the full effect of the different imaging parameters, the catphanium model can be used for a comprehensive image performance assessment。
The model was formed by a combination of durable catphanium flat material. Through the elliptical regions of three different sizes of the body model, both image noise can be assessed, as well as the discharge of pipe currents, thus demonstrating how atcm compensates for the effects of changes in the torso size. In addition, the module can be used to assess the impact of patients ' location deviations。
This body is 65 cm long and consists of three elliptical areas. Each elliptical area is 15 cm long, with a width ratio of 3:2 and sizes of 25:16. 7 cm, 30:20 cm and 35:23. 3 cm, respectively, and applies to modern ct scanners with a spiral diameter of up to 80 mm and a vertical and aerometric combination of atcm techniques. Transition smooth between regions, with circular designs at both ends。
The side and top of the model has 1. 6 mm diameter teflon markers, which can be supported by positioning lasers from the ct scanner。
The model is designed to be scanned first by scanning the projection radioactive image (spr), which is used by the atcm algorithm to estimate the degree of decline of the patient. Its impact on atcm can be studied by applying different scanning parameters or repositioning body models. The resulting ct image set is used to assess tube currents and resulting image noises applied along different slices of the body model. This method can be used both to provide a basis for optimizing work and in conjunction with quality control (qc) to test the stability of scanner atcm。
In order to obtain a fuller picture of the overall impact of different imaging parameters, a comprehensive image performance assessment could be conducted using catphan symmetry。
(note: teflon, a trade name for polyethylene tetrafluoroethylene, is often used for high temperature and corrosion resistant scenarios; spr, scan production radiography, is a projection obtained prior to ct scan that can be used for positioning and pre-assessment; qc, quality control, refers to quality control processes for medical equipment
The working principles of the atcm model
- Simulation of patient anatomy structure: atcm models are usually made from tissue equivalents. It is designed to be of different sizes and shapes (e. G. Steps or multiple ellipses) along the direction of length to simulate changes in the body thickness and decay of patients during scanning。
- Testing atcm system response: by scanning body models, medical physicists can assess the effectiveness of the ct scanner atcm system in regulating the current (mas) of the ct scanner when simulated "patient" size changes. Ideally, the system should increase pipe currents for larger transects to maintain image quality and reduce pipe currents for smaller transects to reduce radiation doses。
- Assessment of image quality and dosage: analysis of ct images from scanned body models to measure key performance indicators in the direction of body model length, including:
- Image noise: consistency of image noise in different cross-sections reflects the effect of atcm on maintaining constant image quality。
- Radiation dose distribution: measurement of pipe currents and radiation doses at points and comparison with different sizes of body models。
- Evaluate positioning and other variables: body modelling can also be used to test the impact of patient location errors on atcm system performance and the effects of other variable scanning settings。