Portable Bedside Low-Field MRI for Assessment of Ventricular Size

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Low-field portable MRI (pMRI) offers a potential solution for neuroimaging in critical care settings, overcoming transport challenges.
• Conventional neuroimaging (CN) is the standard, but patient transport can be difficult.

Purpose of the Study:

• To evaluate the intermodality reliability between low-field pMRI and CN for assessing ventricular size and hydrocephalus.
• To determine the accuracy of pMRI in identifying hydrocephalus compared to standard methods.

Main Methods:

• Retrospective analysis of 56 patients undergoing point-of-care 64mT pMRI and subsequent CN within 24 hours.
• Two blinded raters independently assessed pMRI for hydrocephalus, measuring bifrontal diameter, maximum skull, and Evans index.
• Interrater and intermodality agreement were calculated using intraclass coefficient (ICC) and Cohen's kappa.

Main Results:

• pMRI demonstrated excellent interrater agreement for bifrontal diameter (ICC 0.94) and Evans index (ICC 0.92), and substantial agreement for hydrocephalus (κ = 0.72).
• Intermodality agreement between pMRI and CN was near perfect for bifrontal diameter (ICC 0.94), Evans index (ICC 0.95), and hydrocephalus determination (κ = 0.95).
• pMRI achieved high sensitivity (92%) and specificity (100%) for qualitative hydrocephalus assessment and good performance (80% sensitivity, 98% specificity) for quantitative assessment.

Conclusions:

• Low-field pMRI exhibits excellent interrater reliability and strong concordance with conventional neuroimaging for ventricular size and hydrocephalus assessment.
• pMRI is a viable and effective point-of-care tool for neurocritical care applications, enhancing diagnostic capabilities at the bedside.