Real-world evidence can be used to better characterize the course of multiple sclerosis (MS), care provision and outcomes in clinical practice. Magnetic resonance imaging (MRI) that occurs in the context of usual care is an important source of information that can inform clinical decision-making. Guidelines exist to enhance the clinical impact of routine MRI in MS, but it is unclear whether MRIs acquired as part of routine care in the United States adhere to these guidelines.
To describe the clinical routine brain MRIs from patients with MS across different US imaging sites.
FlywheelMS is a novel patient-centered study that aims to extract and digitize health information not readily available in existing electronic health records of patients with MS. Up to 5,000 consenting adults with a confirmed MS diagnosis will be enrolled. Brain MRI data were retrieved, and summary statistics were computed to describe the sessions, imaging sites, scanner field strengths and slice thickness of T1-weighted and FLAIR (fluid-attenuated inversion recovery) images. Longitudinal acquisition consistency (i.e. MRIs acquired from the same center with the same scanner) was also assessed.
Out of 2,389 patients enrolled, 1555 brain MRI data were retrieved from the first 492 patients (female, 81%; mean age at consent, 49±11 years). The mean number of MRI sessions per patient was 3.2±2.4, and data were captured between 1999 and 2018. Sessions were acquired at 598 different imaging sites, using mainly 1.5T scanners (61.3%), followed by 3T (32.7%) and lower field-strength magnets (3.4%; not available, 2.6%). The mean slice thickness of T1-weighted (3.1±1.7 mm) and FLAIR images (3.1±1.3 mm) was similar. Of the 352 patients (72%) that had more than one MRI session, 85 (24.1%) had consistent acquisition (i.e. same site/scanner), 153 (43.5%) had one site or scanner change, and 114 (32.4%) had more than one site and/or scanner change.
The novel, patient-centered approach of FlywheelMS can successfully extract imaging data from medical records of patients with MS across US imaging sites. These data will help us in describing the clinical routine MRI, determining the compliance to guidelines and understanding which measure (e.g. lesion volume and/or atrophy) could be potentially extracted from MRI data.