Advances in Magnetic Resonance Imaging of the Injured Neonatal Brain

Abstract

<P>In spite of improvement in neonatal medicine, neonatal encephalopathy and resulting neonatal brain injury is a major complication that can cause long-term disability. Multiple neuroscience studies have determined potential mechanisms that underlie the vulnerability of the neonatal brain to multiple insults. In the near future, there may be new therapeutic options for both prevention and treatment of neonatal brain injury. Most pediatric centers currently use cranial ultrasound to evaluate neonatal brain injury. In the past decade, magnetic resonance imaging (MRI) techniques have been shown to be a useful additive imaging tool in the evaluation of neonatal brain injury. Conventional MRI techniques have been shown not only to provide valuable information about the pattern of brain injury in the neonatal period but also to provide information about prognosis and neurodevelopment outcome. There have been recent advances in MRI of neonatal encephalopathy with respect to the development of MR-compatible incubators. These incubators can provide an environment specifically adapted to meet the needs of critically ill preterm and term neonates when undergoing MRI. In addition, imaging resolution and signal-to-noise ratio (SNR) have been improved dramatically with the use of specifically designed neonatal coils. MR diffusion (both diffusion-weighted imaging and diffusion-tensor imaging) and MR spectroscopy are recently developed techniques that are now used routinely. The goals of this article are to provide information about the technological MR advances in the evaluation of the injured neonatal brain and to review clinical examples, which are in the major differential diagnoses of neonatal brain injury including perinatal white matter injury, hypoxic-ischemic brain injury, metabolic disease, and hemorrhage.</P> <H4>ABOUT THE AUTHORS</H4> <P>Ashok Panigrahy, MD; and Stefan Blüml, PhD, are with the Department of Radiology, Division of Neuroradiology, Institute for Maternal Fetal Health, Childrens Hospital Los Angeles (CHLA), Keck School of Medicine of USC, Los Angeles, California.</P> <P>Address correspondence to: Ashok Panigrahy, MD, Childrens Hospital Los Angeles, Department of Radiology, Mail Stop #81, 4650 Sunset Blvd., Los Angeles, CA 90027; or e-mail <a href="mailto:apanigrahy@chla.usc.edu">apanigrahy@chla.usc.edu</a>.</P> <P>Dr. Panigrahy and Dr. Bluml have disclosed no relevant financial relationships.</P> <P>The authors thank Marvin D. Nelson, MD; Istvan Seri, MD; Floyd Gilles, MD; and the Neonatal Intensive Care Unit (NICU) and Magnetic Resonance Imaging (MRI) staff at CHLA for support and advice. The authors thank Julia Cruz and Madalyn Shrier for editorial support. Grant support is from the Radiological Society of North America (RSNA), Rudi Schulte Research Institute, and National Institutes of Health (NIH) pediatric research loan repayment grant.</P> <H4>EDUCATIONAL OBJECTIVES</H4> <OL> <LI>Identify recent technological advances in the evaluation of the injured neonatal brain using magnetic resonance imaging (MRI).</LI> <LI>Propose clinical examples of neonatal brain injury as they are delineated via MRI.</LI> <LI>Differentiate the advantages of MRI evaluation of neonatal brain injury over the current standard of ultrasound imaging.</LI> </OL>