Revealing the mechanisms behind novel auditory stimuli discrimination: An evaluation of silent functional MRI using looping star

Abstract

Looping Star is a near‐silent, multi‐echo, 3D functional magnetic resonance imaging (fMRI) technique. It reduces acoustic noise by at least 25dBA, with respect to gradient‐recalled echo echo‐planar imaging (GRE‐EPI)‐based fMRI. Looping Star has successfully demonstrated sensitivity to the cerebral blood‐oxygen‐level‐dependent (BOLD) response during block design paradigms but has not been applied to event‐related auditory perception tasks. Demonstrating Looping Star's sensitivity to such tasks could (a) provide new insights into auditory processing studies, (b) minimise the need for invasive ear protection, and (c) facilitate the translation of numerous fMRI studies to investigations in sound‐averse patients. We aimed to demonstrate, for the first time, that multi‐echo Looping Star has sufficient sensitivity to the BOLD response, compared to that of GRE‐EPI, during a well‐established event‐related auditory discrimination paradigm: the “oddball” task. We also present the first quantitative evaluation of Looping Star's test–retest reliability using the intra‐class correlation coefficient. Twelve participants were scanned using single‐echo GRE‐EPI and multi‐echo Looping Star fMRI in two sessions. Random‐effects analyses were performed, evaluating the overall response to tones and differential tone recognition, and intermodality analyses were computed. We found that multi‐echo Looping Star exhibited consistent sensitivity to auditory stimulation relative to GRE‐EPI. However, Looping Star demonstrated lower test–retest reliability in comparison with GRE‐EPI. This could reflect differences in functional sensitivity between the techniques, though further study is necessary with additional cognitive paradigms as varying cognitive strategies between sessions may arise from elimination of acoustic scanner noise.

Model‐based reconstruction for looping‐star MRI

“…One other reconstruction method RF‐cycling 14 leads to reduced temporal resolution. Another appraoch is coherence‐resolved looping‐star, 18 which removes most of the overlapping echo artifacts by pushing further in k‐space before the next RF pulse is applied. This by done by increasing the gradient strength for a fixed number of RF pulses, thus increasing acquisition bandwidth, resulting in reduced SNR.…”

“…This method can increase the SNR by a $$$ \sqrt{2} $$$ at the cost of doubled scan time. The third method, 18 coherence‐resolved looping‐star, uses half as many RF pulses with increased time intervals to separate the echoes. It can be viewed as the same as the standard windowing method, but starting with fewer spokes and a higher resolution input.…”

Neurophysiological measures and correlates of cognitive load in attention‐deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and dyslexia: A scoping review and research recommendations

“…Although improving the comfort of neurodivergent participants is an ongoing topic of discussion, using simple instructions to avoid sensory overload and adjusting radiographic practice during the scans were suggested as some of many potential ways to mitigate these challenges (Stogiannos, Carlier, et al, 2022). In addition, new fMRI techniques are progressively allowing for silent imaging (Damestani et al, 2021), with the potential to make the experience less stressful for neurodivergent participants.…”

Motion corrected silent ZTE neuroimaging

“…With native FLASH‐type ZTE, further applications include variable FA T 1 mapping, 70 and PD‐weighted ZTE for bone imaging 62 and synthetic CT conversion for PET/MR attenuation correction and radiation therapy planning 71 . Similarly, MERLIN could be extended to Looping Star 72 for quiet functional BOLD imaging, 73,74 and anatomical T 2 * and susceptibility weighted imaging. MERLIN could also find applications in other parts of the body where the unique aspect of short‐T 2 imaging could be used, such as bone or lung imaging 64,75 .…”