title: Functional Laterality of Task-Evoked Activation in Sensorimotor Cortex of Preterm Infants: An Optimized 3 T fMRI Study Employing a Customized Neonatal Head Coil.
abstract: BACKGROUND
  Functional magnetic resonance imaging (fMRI) in neonates has been introduced as a non-invasive method for studying sensorimotor processing in the developing brain. However, previous neonatal studies have delivered conflicting results regarding localization, lateralization, and directionality of blood oxygenation level dependent (BOLD) responses in sensorimotor cortex (SMC). Amongst the confounding factors in interpreting neonatal fMRI studies include the use of standard adult MR-coils providing insufficient signal to noise, and liberal statistical thresholds, compromising clinical interpretation at the single subject level.
  Here, we employed a custom-designed neonatal MR-coil adapted and optimized to the head size of a newborn in order to improve robustness, reliability and validity of neonatal sensorimotor fMRI. Thirteen preterm infants with a median gestational age of 26 weeks were scanned at term-corrected age using a prototype 8-channel neonatal head coil at 3T (Achieva, Philips, Best, NL). Sensorimotor stimulation was elicited by passive extension/flexion of the elbow at 1 Hz in a block design. Analysis of temporal signal to noise ratio (tSNR) was performed on the whole brain and the SMC, and was compared to data acquired with an 'adult' 8 channel head coil published previously. Task-evoked activation was determined by single-subject SPM8 analyses, thresholded at p < 0.05, whole-brain FWE-corrected.
  
  
  RESULTS
  Using a custom-designed neonatal MR-coil, we found significant positive BOLD responses in contralateral SMC after unilateral passive sensorimotor stimulation in all neonates (analyses restricted to artifact-free data sets = 8/13). Improved imaging characteristics of the neonatal MR-coil were evidenced by additional phantom and in vivo tSNR measurements: phantom studies revealed a 240% global increase in tSNR; in vivo studies revealed a 73% global and a 55% local (SMC) increase in tSNR, as compared to the 'adult' MR-coil.
  
  
  CONCLUSIONS
  Our findings strengthen the importance of using optimized coil settings for neonatal fMRI, yielding robust and reproducible SMC activation at the single subject level. We conclude that functional lateralization of SMC activation, as found in children and adults, is already present in the newborn period.
authors.affiliation: Department of Radiology, University of Bonn, Bonn, Germany.
authors.forename: Lukas
authors.initials: L
authors.lastname: Scheef
authors.affiliation: Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.
authors.forename: Jurek A
authors.initials: JA
authors.lastname: Nordmeyer-Massner
authors.affiliation: School of Clinical Sciences, University of Bristol, Bristol, United Kingdom.
authors.forename: Adam Pr
authors.initials: AP
authors.lastname: Smith-Collins
authors.affiliation: Department of Neonatology, University of Bonn, Bonn, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Müller
authors.affiliation: Department of Neonatology, University of Bonn, Bonn, Germany.
authors.forename: Gaby
authors.initials: G
authors.lastname: Stegmann-Woessner
authors.affiliation: Department of Radiology, University of Bonn, Bonn, Germany.
authors.forename: Jacob
authors.initials: J
authors.lastname: Jankowski
authors.affiliation: Philips Medical Systems, Hamburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gieseke
authors.affiliation: Department of Radiology, University of Bonn, Bonn, Germany.
authors.forename: Mark
authors.initials: M
authors.lastname: Born
authors.affiliation: Department of Mechanical Engineering and Marine Technology, University of Rostock, Rostock, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Seitz
authors.affiliation: Department of Neonatology, University of Bonn, Bonn, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Bartmann
authors.affiliation: Department of Radiology, University of Bonn, Bonn, Germany.
authors.forename: Hans H
authors.initials: HH
authors.lastname: Schild
authors.affiliation: Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.
authors.forename: Klaas P
authors.initials: KP
authors.lastname: Pruessmann
authors.affiliation: School of Clinical Sciences, University of Bristol, Bristol, United Kingdom.|Department of Neonatology, University of Bonn, Bonn, Germany.
authors.forename: Axel
authors.identifier: http://orcid.org/0000-0002-2380-5157
authors.initials: A
authors.lastname: Heep
authors.affiliation: Department of Radiology, University of Bonn, Bonn, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Boecker
mesh_terms: D001921:Brain / Q000254:growth & development / Q000502:physiology; D001931:Brain Mapping / Q000295:instrumentation / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D005865:Gestational Age; D006257:Head / Q000254:growth & development / Q000502:physiology; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology / Q000523:psychology; D008279:Magnetic Resonance Imaging; D008297:Male; D015997:Neonatal Screening / Q000295:instrumentation / Q000379:methods; D066191:Sensorimotor Cortex / Q000502:physiology*