Testing the quality of images for permanent magnet desktop MRI systems using specially designed phantoms

Abstract

Our aim was to measure the performance of desktop magnetic resonance imaging (MRI) systems using specially designed phantoms, by testing imaging parameters and analysing the imaging quality. We designed multifunction phantoms with diameters of 18 and 60 mm for desktop MRI scanners in accordance with the American Association of Physicists in Medicine (AAPM) report no. 28. We scanned the phantoms with three permanent magnet 0.5 T desktop MRI systems, measured the MRI image parameters, and analysed imaging quality by comparing the data with the AAPM criteria and Chinese national standards. Image parameters included: resonance frequency, high contrast spatial resolution, low contrast object detectability, slice thickness, geometrical distortion, signal-to-noise ratio (SNR), and image uniformity. The image parameters of three desktop MRI machines could be measured using our specially designed phantoms, and most parameters were in line with MRI quality control criterion, including: resonance frequency, high contrast spatial resolution, low contrast object detectability, slice thickness, geometrical distortion, image uniformity and slice position accuracy. However, SNR was significantly lower than in some references. The imaging test and quality control are necessary for desktop MRI systems, and should be performed with the applicable phantom and corresponding standards.

Constructing Customized Multimodal Phantoms Through 3D Printing: A Preliminary Evaluation

“…All three printing materials have a shore hardness of 90. The physical densities of these materials are 1.15 g/cm 3 , 0.76 g/cm 3 , and 1.27 g/cm 3 , respectively. The porosities are 9.09, 6.81, and 18.56%, respectively.…”

“…Medical imaging quality assurance (QA) and quality control (QC) is facilitated by well-designed physical phantoms [1][2][3][4]. Most imaging phantoms are designed for a single imaging modality, such as those accredited by the American College of Radiology (ACR) and American Association of Physicists in Medicine (AAPM) specifically for computed tomography (CT), positron emission tomography (PET), or magnetic resonance imaging (MRI) [5,6].…”