Ultra-low field (ULF) point-of-care MRI systems allow image acquisition without interrupting medical provision, with neonatal clinical care being an important potential application. The ability to measure neonatal brain tissue T1 is a key enabling technology for subsequent structural image contrast optimisation, as well as being a potential biomarker for brain development. Here we describe an optimised strategy for neonatal T1 mapping at ULF. Methods:Examinations were performed on a 64mT portable MRI system. A phantom validation experiment was performed, and total of thirty-three in-vivo exams were acquired from twentyeight neonates with postmenstrual age ranging 31 +4 to 49 +0 weeks. Multiple inversion-recovery turbo spin echo sequences were acquired with differing inversion and repetition times. An analysis pipeline incorporating inter-sequence motion correction generated proton density and T1 maps. Regions of interest were placed in the cerebral deep grey matter, frontal white matter and cerebellum. Weighted linear regression was used to predict T1 as a function of postmenstrual age. Results:Reduction of T1 with postmenstrual age is observed in all measured brain tissue; the change in T1 per week and 95% confidence intervals is given by dT1=-21ms/week [-25, -16] (cerebellum), dT1=-14ms/week [-18, -10] (deep grey matter), and dT1=-35ms/week [-45, -25] (white matter). Conclusion:Neonatal T1 values at ULF are shorter than those previously described at standard clinical field strengths, but longer than those of adults at ULF. T1 reduces with postmenstrual age and is thus a candidate biomarker for perinatal brain development.

An 840 g female baby born at 25 weeks gestation suffered a rare complication of umbilical arterial catheter (UAC) insertion, involving an accidental transection resulting in 11 cm of retained catheter inside the baby. Investigations revealed migration of the proximal tip of the catheter within 10 hours into the left subclavian artery.This complication is rare and has not frequently been described in the literature. Given the size and gestation of the patient, the risks and benefits of both conservative and non-conservative management were discussed in detail prior to any treatment decision being made. Effective multidisciplinary teamwork contributed to the successful removal of the UAC, done via a minimally invasive infraumbilical approach, associated with no further complications.

Background Infants with congenital heart disease (CHD) are at risk of neurodevelopmental impairments, which may be associated with impaired brain growth. We characterized how perioperative brain growth in infants with CHD deviates from typical trajectories and assessed the relationship between individualized perioperative brain growth and clinical risk factors. Methods and Results A total of 36 infants with CHD underwent preoperative and postoperative brain magnetic resonance imaging. Regional brain volumes were extracted. Normative volumetric development curves were generated using data from 219 healthy infants. Z‐ scores, representing the degree of positive or negative deviation from the normative mean for age and sex, were calculated for regional brain volumes from each infant with CHD before and after surgery. The degree of Z ‐score change was correlated with clinical risk factors. Perioperative growth was impaired across the brain, and it was associated with longer postoperative intensive care stay (false discovery rate P <0.05). Higher preoperative creatinine levels were associated with impaired brainstem, caudate nuclei, and right thalamus growth (all false discovery rate P =0.033). Older postnatal age at surgery was associated with impaired brainstem and right lentiform growth (both false discovery rate P =0.042). Longer cardiopulmonary bypass duration was associated with impaired brainstem and right caudate growth (false discovery rate P <0.027). Conclusions Infants with CHD can have impaired brain growth in the immediate postoperative period, the degree of which associates with postoperative intensive care duration. Brainstem growth appears particularly vulnerable to perioperative clinical course, whereas impaired deep gray matter growth was associated with multiple clinical risk factors, possibly reflecting vulnerability of these regions to short‐ and long‐term hypoxic injury.