Background: The high contrast inherent in soft tissue, coupled with the capacity to implement a variety of imaging protocols and acquire functional data through magnetic resonance imaging (MRI), significantly enhances the precision of treatment planning of radiotherapy. In this study, the effect of radiotherapy positioning equipment on MR image quality of brain region was evaluated.
Methods: MRI images of homogenous phantom and 10 patients in T1 and T2 protocols with brain coil in the diagnostic MR position and using thermoplastic mask in the treatment position of radiotherapy were taken. MRI images using Medical image analysis and processing software (3D Slicer) were compared in terms of image quality with the signal-to-noise ratio (SNR) parameter.
Findings: The average percentage of SNR reduction was measured more in the T1 protocol in both phantom and patient images. The highest percentage of SNR reduction for the phantom in the posterior part was obtained for the T1 and T2 protocols, 13.23 and 11.21 percent, respectively. The lowest percentage of SNR reduction for the phantom in the anterior part was obtained for the T1 and T2 protocols, 6.81 and 4.46 percent, respectively.
Conclusion: Correcting the patient's body position using flat overlay table and thermoplastic fixation base during MRI imaging, similar to radiotherapy sessions, can increase the accuracy of CT and MRI images registration with a slight decrease in image quality and can be used in treatment planning using MRI images.