Harkins, Kevin D.; Lee, Tzu-Wei; Martin, Jonathan B.; Alderson, Hannah E.; Gore, John C.; Does, Mark D. (2026). . Journal of Magnetic Resonance, 391, 108132.
Diffusion-weighted imaging (DWI) is an MRI technique that measures the movement of water in tissue, but its image quality can be affected by magnetic field variations, electrical currents generated during scanning, and differences between repeated measurements. This study tested whether a spiral-like scanning pattern called a rosette readout trajectory could reduce these common artifacts. Multi-shot rosette DWI, which collects an image over several measurements, was evaluated in test objects and an isolated ferret brain at 7 Tesla, as well as in the spinal cords of living mice at 15.2 Tesla. The rosette approach produced consistently high-quality images at both magnetic field strengths. Correcting differences between repeated measurements also prevented unwanted loss of the diffusion-weighted signal. Overall, multi-shot rosette DWI effectively measured and corrected several important sources of MRI artifacts, demonstrating its potential for producing more reliable, high-quality diffusion images.
Fig. 1.聽A rosette readout can be divided into multiple shots, here comprised of all 5 leafs of a single rosette acquisition window, or multiple segments. Each segment consists of portions from all shots that cross the center of k-space at the same time in the acquisition window. Images reconstructed from individual segments can be used to estimate the background static聽聽field, while images reconstructed from individual shots can be used to estimate shot-to-shot phase variations. This example 5 leaf rosette contains 6 segments, as the first inout segment and the last outin segment are considered individually.