Awake pediatric brain-MRI: a fast multi-sequence scan augmented with motion compensated single-shot 2D acquisitions.

Background: Magnetic resonance imaging (MRI) is susceptible to motion artifacts, a particular challenge in pediatric imaging. External motion tracking devices and navigator techniques have been previously explored, but challenges persist necessitating sedation.

Purpose: To establish a new awake brain-MRI exam tolerated by children with diagnostic quality images.

Materials and methods: Participants were prospectively recruited and investigated using an in-house developed multi-sequence scan called NeuroMix that produces T1-weighted, T2-weighted, T2*-weighted, T2-FLAIR, and diffusion-weighted images in under 3 minutes. Additionally, a self-created motion tracking device was attached to participants' foreheads to perform prospective motion correction (PMC) on 2D single-shot sequences that produce higher resolution images of the same contrasts as NeuroMix.Three neuroradiologists scored the completed series for artifacts. The effects of age group (<5 vs ≥5 years) and sequence type (NeuroMix vs PMC) were evaluated with a Chi²-test.

Results: Of the 64 participants recruited (mean age 6.7 years [2.7 standard deviation]) 58 completed their examination. Head motion recorded during PMC sequences revealed prevalent superior-inferior displacements [25% (67/293) exceeding 13.2 mm], and chin-up/down rotations [25% (67/293) exceeding 13.7°]. Sequence redundancy through NeuroMix and PMC scans resulted in 93% (54/58) of completed examinations having all series essential for producing an MRI-report rated as artifact-free, and therefore a report of high confidence in 84% (54/64) of participants. 22% (13/58) of completed exam reports could have been written using NeuroMix alone, the remaining required PMC- T2-weighted or T2-FLAIR sequences.

Conclusion: This protocol reliably provided diagnostic quality images and reports with high radiologist confidence and could reduce the use of procedure sedation in children.