An MRI framework for respiratory motion modelling validation

Meschini, Giorgia; Paganelli, Chiara; Vai, Alessandro; Fontana, Giulia; Molinelli, Silvia; Pella, Andrea; Vitolo, Viviana; Barcellini, Amelia; Orlandi, Ester; Ciocca, Mario; Riboldi, Marco und Baroni, Guido (2021): An MRI framework for respiratory motion modelling validation. In: Journal of Medical Imaging and Radiation Oncology, Bd. 65, Nr. 3: S. 337-344

Abstract

Introduction Respiratory motion models establish a correspondence between respiratory-correlated (RC) 4-dimensional (4D) imaging and respiratory surrogates, to estimate time-resolved (TR) 3D breathing motion. To evaluate the performance of motion models on real patient data, a validation framework based on magnetic resonance imaging (MRI) is proposed, entailing the use of RC 4DMRI to build the model, and on both (i) TR 2D cine-MRI and (ii) additional 4DMRI data for testing intra-/inter-fraction breathing motion variability. Methods Repeated MRI data were acquired in 7 patients with abdominal lesions. The considered model relied on deformable image registration (DIR) for building the model and compensating for inter-fraction baseline variations. Both 2D and 3D validation were performed, by comparing model estimations with the ground truth 2D cine-MRI and 4DMRI respiratory phases, respectively. Results The median DIR error was comparable to the voxel size (1.33 x 1.33 x 5 mm(3)), with higher values in the presence of large inter-fraction motion (median value: 2.97 mm). In the 2D validation, the median estimation error on anatomical landmarks' position resulted below 4 mm in every scenario, whereas in the 3D validation it was 1.33 mm and 4.21 mm when testing intra- and inter-fraction motion, respectively. The range of motion described in the cine-MRI was comparable to the motion of the building 4DMRI, being always above the estimation error. Overall, the model performance was dependent on DIR error, presenting reduced accuracy when inter-fraction baseline variations occurred. Conclusions Results suggest the potential of the proposed framework in evaluating global motion models for organ motion management in MRI-guided radiotherapy.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 1754-9477
• Sprache: Englisch