The magnetic resonance revolution in brain imaging: impact on neonatal intensive care.

T he magnetic resonance (MR) phenomenon was first described in 1946 2 but it was not until 1981 that the first transverse image through the human head was reported. In the last 20 years, MR technology has revolutionised medical and scientific neuroimaging, providing the richest source of information about the living brain available from any imaging technology and without the use of ionising radiation. MR techniques most commonly used in the neonate have been conventional MR imaging and P and H MR spectroscopy. MR imaging has allowed the observation of brain development and response to perinatal brain injury in vivo with an unprecedented sensitivity for assessment of changes in grey and white matter and an ability to differentiate unmyelinated from myelinated white matter. MR spectroscopy has provided a metabolic fingerprint of the brain during normal development and after perinatal brain injury (fig 1). Conventional MR imaging and MR spectroscopy, however, are only part of an array of methods that comprise the MR diagnostic armamentarium, which includes diffusion weighted MR imaging, diffusion tensor imaging, MR angiography, functional MR imaging (fMRI), magnetisation transfer imaging, and chemical shift imaging. These newer techniques have huge medical and scientific potential.