Development of a phantom for assessment of signal-to-noise ratio in whole-body diffusion-weighted MRI

Motivation: Poor signal-to-noise ratio (SNR) of whole-body diffusion-weighted images (WB-DWI) impacts the diagnostic exam quality in whole-body MRI. Evaluating SNR of WB-DWI using healthy volunteers is challenging when developing imaging protocols for multi-centre studies. Goal(s): Develop a phantom for assessing whether a proposed WB-DWI protocol will provide adequate SNR in patient examinations. Approach: A phantom was developed which replicated relevant MR properties of WB-MRI patients. We measured SNR using the phantom and qualitatively graded SNR in subjects. Results: Good correlation was found between the phantom and the subject data and a discrimination threshold between good and poor quality exams was determined. Impact: A phantom can be used to assess the SNR of WB-DWI protocols and shows good correlation with qualitative image quality, enabling faster, quantitative optimisation of SNR in WB-DWI protocols when setting up multi-centre studies.