ESTRO 2025 - Abstract Book

S3631

Physics - Quality assurance and auditing

ESTRO 2025

simulators. These systems utilize radiotherapy-compatible immobilization devices and integrate external laser systems for precise patient positioning. Given the unique characteristics of these MR systems, it is essential to implement a specific quality assurance program. This study analyzes preliminary results from the implementation of a quality control protocol for an MRI simulator system. Material/Methods: Images were obtained using the medium-size ACR phantom (Pro-Project GROUP SP. Z O.O) with the MAGNETOM SOLA 1.5 T (Siemens Healthcare GmbH) MR machine. The parameters followed were described in the Large and Medium Phantom Test Guidance for the MRI Accreditation Program (ACR, 10.19.2022). Image J (1.48e) open-source software was used for image analysis. The following parameters were evaluated using different ACR Phantom modules: geometric accuracy, high-contrast spatial resolution, slice thickness accuracy, slice position accuracy, image intensity uniformity, percentage of ghosting, low-contrast object detectability, and artifact evaluation. The Syngo.via software (Siemens Healthcare GmbH) was used to verify the coincidence between the external laser system DORADOnova MR3T (LAP GmbH Laser Applikationen) isocenter and the MR machine’s isocenter through analysis of images from the Aquarius (LAP GmbH Laser Applikationen) phantom. Results: Quality control took about one hour. Results from the ACR phantom, based on five measurements (one per week), are shown in figures 1 and 2.