A Comprehensive 2.5-Minute Brain MRI Protocol in the Pediatric Emergency Department: Diagnostic Evaluation of the Multicontrast NeuroMix Sequence

BACKGROUND AND PURPOSE: Prolonged acquisition times and motion artifacts limit the use of MRI in the pediatric emergency department, frequently necessitating sedation and reducing workflow efficiency, or prompting the use of CT with associated ionizing radiation. Recent MRI advances enable fast, comprehensive neuroimaging without radiation exposure. This study evaluates the diagnostic interchangeability of a fast 2.5-minute MRI multicontrast sequence (NeuroMix) with a standard MRI protocol for detecting clinically relevant intracranial findings in the pediatric emergency department. MATERIALS AND METHODS: We retrospectively identified sequential pediatric patients who underwent both a standard pediatric emergency department MRI protocol and NeuroMix over a one-year period. A finding-enriched cohort of 100 studies was constructed (44 positives and 56 controls). Three radiologists independently reviewed NeuroMix and standard protocol imaging sets in randomized batches. Diagnostic interchangeability was assessed using an agreement-based mixed-effects modeling approach using a noninferiority threshold of 10%. Acquisition times, examination completeness, artifact prevalence, interreader agreement, and diagnostic performance metrics were compared between protocols, in accordance with STARD. RESULTS: NeuroMix demonstrated diagnostic interchangeability with the standard pediatric emergency MRI protocol for detection of clinically relevant findings, with an interchangeability estimate of -3.1% (95% CI, -6.6% to +0.3%), remaining within the noninferiority margin. Overall diagnostic accuracy was identical for NeuroMix and standard imaging (87.7%). Interreader agreement for detection of clinically relevant findings was substantial for both NeuroMix (κ = 0.65) and the standard protocol (κ = 0.73). Mean acquisition time was markedly shorter for NeuroMix when compared with the standard protocol (median 2.67 minutes vs 15.26 minutes, p < 0.001). Moderate to severe artifacts and repeat sequence acquisitions occurred less frequently with NeuroMix. CONCLUSIONS: A 2.5-minute NeuroMix-based MRI protocol demonstrated diagnostic interchangeability with a standard pediatric emergency MRI protocol for clinically relevant intracranial findings with substantially reduced acquisition time and imaging artifacts. These results support NeuroMix as a fast, radiation-free approach that may serve, depending on the clinical scenario, as a supplementary or alternative neuroimaging protocol in pediatric emergency care.