MRI evaluation and safety in the developing brain

Abstract

Magnetic resonance imaging (MRI) evaluation of the developing brain has dramatically increased over the last decade. Faster acquisitions and the development of advanced MRI sequences such as magnetic resonance spectroscopy (MRS), diffusion tensor imaging (DTI), perfusion imaging, functional MR imaging (fMRI), and susceptibility weighted imaging (SWI), as well as the use of higher magnetic field strengths has made MRI an invaluable tool for detailed evaluation of the developing brain. This article will provide an overview of the use and challenges associated with 1.5T and 3T static magnetic fields for evaluation of the developing brain. This review will also summarize the advantages, clinical challenges and safety concerns specifically related to MRI in the fetus and newborn, including the implications of increased magnetic field strength, logistics related to transporting and monitoring of neonates during scanning, sedation considerations and a discussion of current technologies such as MRI-conditional neonatal incubators and dedicated small-foot print neonatal intensive care unit (NICU) scanners.

Functional imaging of the human placenta with magnetic resonance

“…MRI in pregnancy benefits from the experience of functional MRI (fMRI) that has been gained in other specialties; specific sequences have provided a promising insight into fetal brain and placental function in vivo. 18,19 FMRI techniques allow the assessment of several functional aspects of the tissue that is being studied, which includes microvascular parameters, oxygenation, and metabolism (Table 1). This functional information can be color-coded at a voxel level to create parametric images.…”

Techniques for minimizing sedation in pediatric MRI

“…In infants and young children, SSFSE sequences can be used to address a variety of clinical needs because it can be routinely acquired during free‐breathing with no significant degradation of image quality . If SSFSE sequences use variable refocusing flip angles and short repetition time (TR), they can be even faster without adversely affecting image quality . It is important to note that SSFSE requires a prolonged readout time that results in decreased tissue contrast and might obscure focal lesions when the lesion‐to‐background contrast is low .…”

MRI evaluation of the placenta from normal variants to abnormalities of implantation and malignancies

“…These agents are classified as Category C drugs. They cross the placenta, and data describing their adverse short and long‐term effects on the human fetus are limited …”