A comparison of phase imaging and quantitative susceptibility mapping in the imaging of multiple sclerosis lesions at ultrahigh field

Objective The aim of this study was to compare the use of high-resolution phase and QSM images acquired at ultra-high field in the investigation of multiple sclerosis (MS) lesions with peripheral rings, and to discuss their usefulness for drawing inferences about underlying tissue composition. Materials and methods Thirty-nine Subjects were scanned at 7 T, using 3D T2*-weighted and T1-weighted sequences. Phase images were then unwrapped and filtered, and quantitative susceptibility maps were generated using a thresholded k-space division method. Lesions were compared visually and using a 1D profiling algorithm. Results Lesions displaying peripheral rings in the phase images were identified in 10 of the 39 subjects. Dipolar projections were apparent in the phase images outside of the extent of several of these lesions; however, QSM images showed peripheral rings without such projections. These projections appeared ring-like in a small number of phase images where no ring was observed in QSM. 1D profiles of six well-isolated example lesions showed that QSM contrast corresponds more closely to the magnitude images than phase contrast. Conclusions Phase images contain dipolar projections, which confounds their use in the investigation of tissue composition in MS lesions. Quantitative susceptibility maps correct these projections, providing insight into the composition of MS lesions showing peripheral rings

Gritty Leaders: The Impact of Grit on Positive Leadership Capacity

The concepts of grit and positive leadership are central to extraordinary performance. However, to date there has been little empirical analysis of the relationship between a leader’s level of grit and their capacity to implement positive leadership strategies and practices. This correlational study explores these linkages, taking grit subfactors into consideration as well as three dimensions of positive leadership. Convenience sampling was used to survey 100 leaders across a range of industries. Respondents completed the Grit Scale and 18 questions from the Positive Leadership Practices Self-Assessment. Results indicated that grit positively correlated with positive leadership, and perseverance exhibited a stronger relationship than passion. Further, grit accounted for variance in positive leadership. These findings provide a solid evidence base for giving leaders access to development opportunities that can accelerate the growth of grit and positive leadership. Keyword