Clinical Indications for Rapid Sequence MRI in Pediatric Neurosurgical Patients and the Limitations and Barriers to Implementation

Summary

Here, we present a protocol to increase the use of rapid sequence magnetic resonance imaging (RS-MRI) for pediatric patients for spine, traumatic brain injury (TBI), and hydrocephalus while documenting limitations and barriers to universal implementation.

Abstract

Rapid and fast magnetic resonance imaging (MRI) protocols have become increasingly popular for pediatric neurosurgical patients as they are a great way to reduce ionizing radiation and sedation. While their popularity has increased, there are hurdles to overcome when transitioning to using them clinically, such as cost, staffing training, and motion artifact. Through this paper, we developed a protocol for clinical applications where rapid MRI can be a substitute or adjuvant in diagnostic workup. Further, we outline the relevant literature for the use of RS-MRI for the spine, TBI, and hydrocephalus pathologies while expanding upon the limitations and logistical barriers when transitioning to their use, a few of which are discussed above. Through this, we conclude that RS-MRI can be used diagnostically for spinal pathologies such as syrinx and hydrocephalus. Further, its lack of sensitivity for TBI findings makes rapid sequence magnetic resonance imaging (RS-MRI) a strong adjuvant with other advanced imaging or computed tomography (CT) for traumatic brain injury (TBI) pathologies.

Introduction

Historically, computed tomography (CT) has been a first-line imaging study in many scenarios for screening for and monitoring neurologic pathology. In the pediatric patient population, multiple studies have advocated the reduction in CT imaging to reduce radiation exposure. Kessler et al. state that the effective radiation dose of head CT (HCT) is proportionally higher in young children, and a single HCT can have a lifetime cancer mortality risk of 0.07%. Leukemias and brain malignancies are the most common pathologies associated with increased exposure to radiation¹.

Standard MRI, although without radiation, may require sedation to reduce motion artifacts in pediatric patients. Repeated sedation raises concerns and may have neurotoxic effects on the developing brain¹. Flick et al. did a large, matched cohort study that showed repeated exposure to anesthesia before age 2 may be more likely to lead to the development of learning disabilities².

With the concern for radiation exposure and sedation when performing CT and MRI, Rapid Sequence MRIs (RS-MRI) are increasingly used in the clinical environment. Early RS-MRIs were used in the evaluation of hydrocephalus. Since then, additional indications for RS-MRI have developed due to the short scan times, absence of ionizing radiation, and sedation, which is important for risk factor reduction. Through this systematic review, we aim to discuss the clinical applications where RS-MRI can be substituted or adjuvant in diagnostic workup and the limitations and barriers to implementation.

Protocol

This protocol follows the guidelines of the institutional human research ethics committee of the University of North Carolina, as it was created secondary to a literature review and did not require real human subjects. Required permissions from volunteers and for filming have been obtained. The representative RS-MRI images used in this study have been deidentified. NOTE: A review of the literature was conducted using keywords like "rapid MRI" and "fast brain". A total of 15 art…

Representative Results

Spine evaluation Ryan et al. conducted a prospective study to determine the feasibility of rapid spine MRI in the evaluation of syrinx in pediatric patients. Patients with known or suspected syrinx or Chiari malformations underwent rapid spinal MRI (HASTE) and standard non-contrast MR. Images were blindly reviewed by pediatric neuroradiologists who measured the following outcomes: Presence or absence of syrinx, syrinx measurement, clonus position, cerebellar tonsillar ectopia and degree, and filum …

Discussion

RS-MRI offers an alternative imaging diagnostic tool in pediatric patients. RS-MRI uses T2 weighted sequences to visualize cranial and spinal pathologies, with faster scan times than traditional neuroimaging modalities.

Through a literature review and observation, we developed a protocol for the use of RS-MRI. We found that the sequences most relevant for diagnosing spinal pathologies were T2 HASTE and STIR. Additionally, T2 GRE and HASTE were most likely to identify traumatic pathology. Lastl…

Materials

Alarm bell	Siemens	https://www.siemens.com/global/en/products/buildings/fire-safety/evacuation/notification-ul.html
Brain and spine coils	Siemens	https://www.siemens-healthineers.com/magnetic-resonance-imaging
Consent form to be filled out by parents or guardian	Local Health System	N/A
Ear plugs	3M Classic Ear Plugs	https://www.3m.com/3M/en_US/p/?Ntt=classic+ear+plugs
Ferroguard Metal Detector	Metrasens	https://www.metrasens.com/solution/ferroguard-assure/
Immobilization restraints	Siemens	https://www.siemens-healthineers.com/magnetic-resonance-imaging
Landmarkers, laser markers, or touch sensors	Siemens	https://www.siemens-healthineers.com/magnetic-resonance-imaging
MR power cut-off	Siemens	https://www.siemens-healthineers.com/magnetic-resonance-imaging
MR quench button	Siemens	https://www.siemens-healthineers.com/magnetic-resonance-imaging
MRI scanner	Magnetom Avanto	https://www.siemens-healthineers.com/en-us/magnetic-resonance-imaging/0-35-to-1-5t-mri-scanner/magnetom-avanto	Other brands: Discovery 750, HDXT Signa scanners, GE Healthcare, , Aera and Skyra, Siemens, Erlangen, and Germany
Radiologic technologist	Local Health System	N/A
Radiologist	Local Health System	N/A
Standard MRI hardware and software	NUMARIS	Version 4
Support pads and pillows	Medline	www.medline.com	Alternative: Quality electrodynamics