Adequacy of an In-Neonatal Intensive Care Unit 1T Magnetic Resonance Imaging Compared With 3T Magnetic Resonance Imaging for Clinical Management.

BACKGROUND: This retrospective study aims to assess the added diagnostic utility and clinical value of a 3-Tesla neonatal brain magnetic resonance imaging after obtaining a 1-Tesla magnetic resonance imaging within the neonatal intensive care unit. METHODS: A cohort of 34 infants had an initial 1-Tesla magnetic resonance imaging and repeat imaging within 14 days in a 3-Tesla scanner. All infants were admitted to the level III neonatal intensive care unit at Brigham and Women's Hospital, and all images were interpreted by pediatric neuroradiologists. RESULTS: For 31 infants (91%), the 3-Tesla magnetic resonance imaging showed similar or expected evolution of known findings found on 1 Tesla. For infants with change between the 1-Tesla and 3-Tesla imaging results, there was no clinical impact. CONCLUSION: Images from 1-Tesla magnetic resonance imaging were sufficient for characterizing a wide range of neonatal brain injuries and abnormalities and repeated 3-Tesla magnetic resonance imaging did not yield further clinical benefit.

Insights from serial magnetic resonance imaging in neonatal encephalopathy in term infants.

BACKGROUND: Limited serial neuroimaging studies use magnetic resonance imaging (MRI) to define the evolution of hypoxic-ischemic insults to the brain of term infants and encompass both the primary injury and its secondary impact on cerebral development. The optimal timing of MRI to fully evaluate the impact of hypoxic-ischemic encephalopathy on brain development and associated neurodevelopmental sequelae remains unknown. METHODS: Goals: (a) review literature related to serial neuroimaging in term infants with HIE; (b) describe pilot data in two infants with HIE treated with therapeutic hypothermia who had a brain injury at day 3-5 and underwent four additional MRIs over the next 12 weeks of life and developmental evaluation at 24 months of age. RESULTS: Early MRI defines primary injury on diffusion-weighted imaging, yet the full impact may not be fully apparent until after 1 month of life. CONCLUSION: The full impact of an ischemic injury on the neonatal brain may not be fully visible until several weeks after the initial insult. This suggests the benefit of obtaining later time points for MRI to fully define the extent of injury and its neurodevelopmental impact. IMPACT: Few studies inform the nature of the evolution of brain injury with hypothermia in HIE, limiting understanding of potential neuroprotection. MRI is the standard of care for prognosis in infants with HIE, however timing for optimal prognostic prediction remains unclear. Insights from MRI after the first week of life may assist in defining the full extent of brain injury and prognostic significance. A pilot study using five MRI timepoints up to 3 months of age, is presented. More data is required with a systematic evaluation of the impact of early brain injury on brain development in term infants with HIE following TH.

Brain Injury in Infants Evaluated for, But Not Treated with, Therapeutic Hypothermia.

Defining neonatal encephalopathy clinically to qualify for therapeutic hypothermia is challenging. This study examines magnetic resonance imaging outcomes of 39 infants who were evaluated and not cooled using criteria inclusive of mild encephalopathy. Infants evaluated for therapeutic hypothermia are at risk for brain injury and may benefit from neuroimaging and follow-up.

Clinical experience with an in-NICU magnetic resonance imaging system.

OBJECTIVE: To evaluate the utility of the 1 Tesla (1 T) Embrace (Aspect Imaging) neonatal magnetic resonance imaging (MRI) scanner in a level III NICU. STUDY DESIGN: Embrace brain MRI findings for 207 infants were reviewed, including 32 scans directly compared within 5 days with imaging on a 3 T Siemens Trio. Clinical MRI scan abnormalities were also compared to cranial ultrasound findings. RESULT: Of the 207 Embrace brain MRIs, 146 (70.5%) were obtained for clinical indications and 61 (29.5%) were research cases. Abnormal findings were found in 80 scans, most commonly hemorrhage and white matter injury. Notable findings included a stroke, medullary brainstem tumor, and polymicrogyria. In the 1 T versus 3 T comparison cohort, results were discordant in only one infant with punctate foci of susceptibility noted only on the 3 T scan. CONCLUSION: The Embrace MRI scans detected clinically relevant brain abnormalities and in a subset were clinically comparable to 3 T scans.

Value of cranial ultrasound at initiation of therapeutic hypothermia for neonatal encephalopathy.

OBJECTIVE: There is variation in the clinical practice for the use of cranial ultrasound (cUS) at the time of initiation of therapeutic hypothermia (TH) for neonatal encephalopathy. The role of cUS in selecting patients who may benefit from TH or excluding those where TH may impose risk is unknown. STUDY DESIGN: A retrospective study was conducted on infants who received TH at a single tertiary center. Findings from cUS at initiation of TH were compared to findings from MRI following the completion of TH. RESULTS: One hundred and eight infants were studied. Of the 55 with abnormalities on early cUS, 50 did not have corresponding MRI abnormalities. In contrast, 16 infants had some degree of intracranial hemorrhage detected on their MRI that was not noted on earlier cUS. CONCLUSIONS: This study challenges whether cUS is an essential universal screening tool prior to the commencement of TH.