Reproducibility of quantitative susceptibility mapping in the brain at two field strengths from two vendors

Abstract

Purpose To assess the reproducibility of brain quantitative susceptibility mapping (QSM) in healthy subjects and in patients with multiple sclerosis (MS) on 1.5 and 3T scanners from two vendors. Materials and Methods Ten healthy volunteers and 10 patients were scanned twice on a 3T scanner from one vendor. The healthy volunteers were also scanned on a 1.5T scanner from the same vendor and on a 3T scanner from a second vendor. Similar imaging parameters were used for all scans. QSM images were reconstructed using a recently developed nonlinear morphology-enabled dipole inversion (MEDI) algorithm with L1 regularization. Region-of-interest (ROI) measurements were obtained for 20 major brain structures. Reproducibility was evaluated with voxel-wise and ROI-based Bland–Altman plots and linear correlation analysis. Results ROI-based QSM measurements showed excellent correlation between all repeated scans (correlation coefficient R ≥ 0.97), with a mean difference of less than 1.24 ppb (healthy subjects) and 4.15 ppb (patients), and 95% limits of agreements of within −25.5 to 25.0 ppb (healthy subjects) and −35.8 to 27.6 ppb (patients). Voxel-based QSM measurements had a good correlation (0.64 ≤ R ≤ 0.88) and limits of agreements of −60 to 60 ppb or less. Conclusion Brain QSM measurements have good interscanner and same-scanner reproducibility for healthy and MS subjects, respectively, on the systems evaluated in this study.

Age and sex related differences in subcortical brain iron concentrations among healthy adults

“…Differences in the age dependency of substantia nigra susceptibility have also been reported between L1 and L2 regularizations (Bilgic et al, 2012). A recent publication (Deh et al 2015) has shown good overall reproducibility in QSM using the algorithm employed in this study however, and such limitations should not be crucial.…”

“…Cross-sectional design relies on age-related differences between persons that are captured in a snapshot frozen in time, and cannot measure the true dynamic trajectories within a person. As in vivo imaging of susceptibility is improving and already shows good between scan reliability (Deh et al, 2015), repeated measures design becomes feasible.…”

Clinical quantitative susceptibility mapping (QSM): Biometal imaging and its emerging roles in patient care

“…QSM of biometals has been valuable in studying disease processes. QSM is shown to be reproducible across scanner makers, models, field strengths, and sites (37-40). QSM can be automated, making it ready for wide dissemination to evaluate its diagnostic and therapeutic value in clinical practice.…”

Probing neuronal activation by functional quantitative susceptibility mapping under a visual paradigm: A group level comparison with BOLD fMRI and PET

“…It also less strongly depends on data-acquisition sequence (Sun and Wilman, 2015) and parameters and should be better reproducible across scanners from different manufacturers and field strengths (Deh et al, 2015).…”

“…It can be speculated that fQSM and QSM may prove particularly useful, e.g., in future studies with an interest in layer-specific functional information (Koopmans et al, 2011), in attempts to focus on vascular components and venography of neuronally activated regions, or quantification of tissue oxygenation (Özbay et al, 2015b) and cerebral metabolic rate of oxygen consumption (Zhang et al, 2015). Such studies may also benefit from the recent achievements in accelerating the QSM processing Langkammer et al, 2015).…”