A phantom based laser marking workflow to visually assess geometric image distortion in magnetic resonance guided radiotherapy

Physics and Imaging in Radiation Oncology

Axel vom Endt¹  Matthias Drobnitzky²  Andrew Dewdney³ 

[1] Siemens Healthcare GmbH, Magnetic Resonance, Erlangen, Germany;Corresponding author at: Siemens Healthcare GmbH, Magnetic Resonance, Postbox 32 60, 91050 Erlangen, Germany.;Siemens Healthcare GmbH, Magnetic Resonance, Erlangen, Germany;

关键词: Gradient nonlinearity;    MR distortion correction;    Lightweight plastic skeleton;    Silicone-based spherical fiducials;    External laser bridge;    Patient marking workflow;   

DOI  :  

来源: DOAJ

【 摘 要 】

Magnetic resonance (MR)-only workflows require quality assurance due to potential dosimetric impacts of using geometry distorted MR images in radiotherapy planning. MR-visible silicone-based fiducials were arranged in regular 3D structures to cover extended imaging volumes. The scanner’s patient marking workflow with a 2-axes movable laser bridge allowed to visually check geometric distortions of each MR reconstructed fiducial against its true position in 3D space. A measurement resolution and uncertainty of the order of 0.5 mm in sagittal and coronal, and 1 mm in transversal direction was found. The proposed workflow required 1 min of evaluation time per fiducial position, and a 9 min 3D MR volume acquisition.

【 授权许可】

Unknown