ABSTRACT
OBJECTIVE: A portable, low-field MRI system is now Food and Drug Administration cleared and has been shown to be safe and useful in adult intensive care unit settings. No neonatal studies have been performed. The objective is to assess our preliminary experience and assess feasibility of using the portable MRI system at the bedside in a neonatal intensive care unit (NICU) at a quaternary children's hospital. STUDY DESIGN: This was a single-site prospective cohort study in neonates ≥2 kg conducted between October and December 2020. All parents provided informed consent. Neonates underwent portable MRI examination in the NICU with support equipment powered on and attached to the neonate during the examination. A paediatric radiologist interpreted each portable MRI examination. The study outcome variable was percentage of portable MRI examinations completed without artefacts that would hinder diagnosis. Findings were compared between portable MRI examinations and standard of care examinations. RESULTS: Eighteen portable, low-field MRI examinations were performed on 14 neonates with an average age of 29.7 days (range 1-122 days). 94% (17 of 18) of portable MRI examinations were acquired without significant artefact. Significant intracranial pathology was visible on portable MRI, but subtle abnormalities were missed. The examination reads were concordant in 59% (10 of 17) of cases and significant pathology was missed in 12% (2 of 17) of cases. CONCLUSION: This single-centre series demonstrated portable MRI examinations can be performed safely with standard patient support equipment present in the NICU. These findings demonstrate that portable MRI could be used in the future to guide care in the NICU setting. TRIAL REGISTRATION NUMBER: NCT04629469.
Subject(s)
Intensive Care Units, Neonatal , Magnetic Resonance Imaging , Humans , Infant, Newborn , Clinical Competence , Feasibility Studies , Prospective StudiesABSTRACT
OBJECTIVE: Scanning time considerations have restricted routine use of 3D Fourier transform (3DFT)-encoded MRI to gradient-recalled echo sequences. We sought to combine isotropic 3DFT acquisition with fast spin-echo at a practical scan duration. This strategy offers versatile image contrast for musculoskeletal evaluation and facilitates image reformation tailored to the depiction of small anatomic features. CONCLUSION: Isotropic 3DFT fast spin-echo is feasible on current MRI scanners and has the potential to improve musculoskeletal evaluation.
Subject(s)
Algorithms , Echo-Planar Imaging/methods , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Musculoskeletal System/anatomy & histology , Adult , Anisotropy , Feasibility Studies , Humans , Male , Protons , Reproducibility of Results , Sensitivity and Specificity , Spin LabelsABSTRACT
PURPOSE: The aim of this study was to evaluate our preliminary experience at 3.0 T with imaging of the carotid bifurcation in healthy and atherosclerotic subjects. Application at 3.0 T is motivated by the signal-to-noise gain for improving spatial resolution and reducing signal averaging requirements. MATERIALS AND METHODS: We utilized a dual phased array coil and applied 2D, 3D time of flight (TOF) and turbo spin echo (TSE) sequences with comparison of two lumen signal suppression methods for black blood (BB) TSE imaging including double inversion preparation (DIR) and spatial presaturation pulses. The signal-to-noise ratios (SNR) of healthy carotid vessel walls were compared in 2D and 3D BB TSE acquisitions. The bright and black blood multi-contrast exam was demonstrated for a complex carotid plaque. RESULTS: Contrast-to-noise (CNR) greater than 150 was achieved between the lumen and suppressed background for 3D TOF. For BB, both methods provided sufficient lumen signal suppression but slight residual flow artifacts remained at the bifurcation level. As expected 3D TSE images had higher SNR compared to 2D, but increased motion sensitivity is a significant issue for 3D at high field. For multi-contrast imaging of atherosclerotic plaque, fibrous, calcified and lipid components were resolved. The CNR ratio of fibrous (bright on PDW, T2W) and calcified (dark in T1W, T2W, PDW) plaque components was maximal in the T2W images. The 3D TOF angiogram indicating a 40% stenosis was complemented by 3D multi-planar reformat of BB images that displayed plaque extent. Detection of intimal thickening, the earliest change associated with atherosclerotic progression was observed in BB PDW images at 3.0 T. CONCLUSIONS: High SNR and CNR images have been demonstrated for the healthy and diseased carotid. Improvements in RF coils along with pulse sequence optimization, and evaluation of endogenous and exogenous contrast mechanisms will further enhance carotid imaging at 3.0T.
