Dynamic Lung Tumor Phantom Coupled with Chest Motion

摘要

Motion artifacts have always been a non-desired effect in the field of Medical Imaging. Thus new technologies are being investigated to ameliorate the damaging effects of image blurring caused by motion. The development of these new technologies requires the use of phantoms as a means of precise, repeatable and controllable source of motion for testing initial algorithms and prototypes. The objective of this project was to design a dynamic lung tumor phantom coupled with chest motion. The phantom consists of a pair of linear actuators. The complete design, excluding the actuators was built in house out of acrylic materials with low attenuation factors, making it ideal for PET studies. The linear actuator is a stepper motor coupled to a lead screw which translates rotational motion into linear displacement at a rate of 0.0254 mm/step. The system is driven by a PIC microcontroller that allows the user to select different tumor motion parameters, and is capable of performing 3D motion. The phantom is capable of providing lung tumor and chest position with an accuracy of 1.3 μm in the axis of motion, with a displacement of up to 52 mm and maximum velocity of 21.59 mm/second. The design has proven to be suitable for simulating lung tumor motion in PET studies, as well as testing motion tracking algorithms. However it can also be used in studies dealing with gated radiotherapy.