Measuring geometric accuracy in magnetic resonance imaging with 3D-printed phantom and nonrigid image registration

• DOI: 10.1007/s10334-019-00788-6
• Publication Date: 2019-10-23T23:30:56Z
• Authors: Katri Nousiainen; Teemu Mäkelä
• Keywords: Quality Control; DISTORTION CORRECTION; Phantoms, Imaging; Radiotherapy Planning, Computer-Assisted; Surgery, anesthesiology, intensive care, radiology; Quality control; Reproducibility of Results; Image Enhancement; Magnetic Resonance Imaging; 03 medical and health sciences; Magnetic resonance imaging; 0302 clinical medicine; Healthcare quality assurance; Printing, Three-Dimensional; Image Processing, Computer-Assisted; MR-IMAGES; Humans; Artifacts; Tomography, X-Ray Computed; Algorithms; Software; Research Article

Abstract

Objective We aimed to develop a vendor-neutral and interaction-free quality assurance protocol for measuring geometric accuracy of head and brain magnetic resonance (MR) images. We investigated the usability of nonrigid image registration in the analysis and looked for the optimal registration parameters.

Materials and methods We constructed a 3D-printed phantom and imaged it with 12 MR scanners using clinical sequences. We registered a geometric-ground-truth computed tomography (CT) acquisition to the MR images using an open-source nonrigid-registration-toolbox with varying parameters. We applied the transforms to a set of control points in the CT image and compared their locations to the corresponding visually verified reference points in the MR images.

Results With optimized registration parameters, the mean difference (and standard deviation) of control point locations when compared to the reference method was (0.17 ± 0.02) mm for the 12 studied scanners. The maximum displacements varied from 0.50 to 1.35 mm or 0.89 to 2.30 mm, with vendors’ distortion correction on or off, respectively.

Discussion Using nonrigid CT–MR registration can provide a robust and relatively test-object-agnostic method for estimating the intra- and inter-scanner variations of the geometric distortions.