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result(s) for
"Whyte, Hilary"
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Quantitative MRI in the very preterm brain: Assessing tissue organization and myelination using magnetization transfer, diffusion tensor and T1 imaging
by
Sled, John G.
,
Whyte, Hilary E.
,
Morris, Drew
in
Aging - pathology
,
Biological and medical sciences
,
Brain - cytology
2013
Magnetization transfer ratio (MTR), diffusion tensor imaging (DTI) parameters and T1 relaxometry values were used to create parametric maps characterizing the tissue microstructure of the neonatal brain in infants born very premature (24–32 gestational weeks) and scanned at preterm and term equivalent age. Group-wise image registration was used to determine anatomical correspondence between individual scans and the pooled parametric data at the preterm and term ages. These parametric maps showed distinct contrasts whose interrelations varied across brain regions and between the preterm and term period. Discrete patterns of regional variation were observed for the different quantitative parameters, providing evidence that MRI is sensitive to multiple independent aspects of brain maturation. MTR values showed a marked change in the pattern of regional variation at term equivalent age compared to the preterm period such that the ordinal ranking of regions by signal contrast changed. This was unlike all other parameters where the regional ranking was preserved at the two time points. Interpreting the data in terms of myelination and structural organization, we report on the concordance with available histological data and demonstrate the value of quantitative MRI for tracking brain maturation over the neonatal period.
► Quantitative MRI is sensitive to multiple independent aspects of brain maturation. ► Group-wise image registration is used to create multiple averaged parametric maps. ► Various quantitative MRI measures show distinct pattern of regional variations. ► MTR values show a marked change in the pattern of regional variation with time. ► DTI parameters preserve the same order of regional values over the neonatal period.
Journal Article
Neurodevelopmental outcome following hypoxic ischaemic encephalopathy and therapeutic hypothermia is related to right ventricular performance at 24-hour postnatal age
by
Giesinger, Regan E
,
El-Khuffash, Afif Faisal
,
Whyte, Hilary E A
in
cardiology
,
Cardiovascular system
,
Cerebral palsy
2022
ObjectiveOur aim was to determine whether right ventricular (RV) dysfunction at 24-hour postnatal age predicts adverse developmental outcome among patients with hypoxic ischaemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH).DesignNeonates≥35 weeks with HIE/TH were enrolled in a physiological study in the neonatal period (n=46) and either died or underwent neurodevelopmental follow-up at 18 months (n=43). The primary outcome was a composite of death, diagnosis of cerebral palsy or any component of the Bayley Scores of Infant Development III<70. We hypothesised that tricuspid annulus plane systolic excursion (TAPSE) <6 mm and/or RV fractional area change (RV-FAC) <0.29 would predict adverse outcome.ResultsNine patients died and 34 patients were followed up at a mean age of 18.9±1.4 months. Both indices of RV systolic performance were abnormal in 15 (35%) patients, TAPSE <6 mm only was abnormal in 4 (9%) patients and RV-FAC <0.29 only was abnormal in 5 (12%) patients (19 had with normal RV function). Although similar at admission, neonates with RV dysfunction had higher cardiovascular and neurological illness severity by 24 hours than those without and severe MRI abnormalities (70% vs 53%, p=0.01) were more common. On logistic regression, TAPSE <6 mm (OR 3.6, 95% CI 1.2 to 10.1; p=0.017) and abnormal brain MRI [OR 21.7, 95% CI 1.4 to 336; p=0.028) were independently associated with adverse outcome. TAPSE <6 mm predicted outcome with a 91% sensitivity and 81% specificity.ConclusionsThe role of postnatal cardiovascular function on neurological outcomes among patients with HIE who receive TH merits further study. Quantitative measurement of RV function at 24 hours may provide an additional neurological prognostic tool.
Journal Article
Limitations of routine neuroimaging in predicting outcomes of preterm infants
by
Whyte, Hilary E. A.
,
Blaser, Susan
in
Babies
,
Brain Diseases - diagnostic imaging
,
Brain Diseases - epidemiology
2013
Introduction
Preterm births are increasing in number and while the rates of cerebral palsy have declined, there are increasing numbers of infants who survive with handicaps. In some studies, up to 50 % of children will have morbidity when followed up to school age.
Methods
A review of current literature was conducted to determine the validity of routine cranial ultrasound scans (CUS) to predict neurodevelopmental outcomes, including motor and cognitive deficits. We also reviewed the additional benefit offered by including MRI scans in scanning protocols to enhance the reliability in predicting the neurodevelopmental sequelae of prematurity.
Results
CUS is valuable as a screening tool to determine significant brain injury when conducted regularly over the first weeks of life in preterm infants. Subtle changes on CUS are difficult to interpret and more precise information is offered by performing MRI scans. These are most often carried out at term equivalent age but earlier scans may be just as useful in predicting neurocognitive outcomes. When MRI scans are either normal or seriously abnormal, there is a very clear correlation with outcome to 2 years of age. Mild and moderate degrees of injury defined on MRI need more sophisticated scanning sequences to determine the likelihood of associated sequelae. Follow-up to school age is essential to diagnose more subtle cognitive delays.
Conclusion
CUS provides a good screening tool to detect serious brain injury resulting in motor handicaps but MRI scans are complementary and necessary to accurately predict the outcomes of preterm infants, especially cognitive delays.
Journal Article
Resilience and Vulnerability: Neurodevelopment of Very Preterm Children at Four Years of Age
by
Vandewouw, Marlee M.
,
Leijser, Lara M.
,
Taylor, Margot J.
in
brain development
,
Cerebellum
,
Children
2020
Children born very preterm (VPT) are at high-risk for altered brain development and impaired neurodevelopmental outcomes but are not well studied before school-age. We investigated 64 four-year-olds: 37 VPT children (<32 weeks gestational age [GA]; 22 males; mean GA: 28.8 weeks ± 1.6), 25 full-term (FT) children (12 males), plus two VPT cases with ventriculomegaly and exceptionally resilient outcomes. All children underwent high-resolution structural magnetic resonance imaging and developmental assessments. Measures of brain volume, cortical thickness, and surface area were obtained. Children born VPT demonstrated reduced cerebral and cerebellar white matter volumes yet increased cerebral grey matter, temporal lobe, occipital lobe and ventricle volumes after adjusting for total brain volume. Cortical thickness was greater in the VPT children compared to FT children across all lobes. On developmental assessments, the VPT children scored lower on average than FT children while the two cases had intact cognitive abilities. In addition to larger ventricle volumes, the two cases had white matter and grey matter volumes within the ranges of the FT children. The VPT children displayed distinct differences in structural brain volumes at 4 years of age, consistent with delayed maturation. The cases with persistent ventriculomegaly and good cognitive outcomes displayed typical grey matter and increased white matter volumes, indicating a potential protective developmental phenomenon contributing to their intact cognitive abilities.
Journal Article
The interfacility transport of critically ill newborns
2015
The practice of paediatric/neonatal interfacility transport continues to expand. Transport teams have evolved into mobile intensive care units capable of delivering state-of-the-art critical care during paediatric and neonatal transport. While outcomes are best for high-risk infants born in a tertiary care setting, high-risk mothers often cannot be safely transferred. Their newborns may then have to be transported to a higher level of care following birth. The present statement reviews issues relating to transport of the critically ill newborn population, including personnel, team competencies, skills, equipment, systems and processes. Six recommendations for improving interfacility transport of critically ill newborns are highlighted, emphasizing the importance of regionalized care for newborns.
Journal Article
Milrinone improves oxygenation in neonates with severe persistent pulmonary hypertension of the newborn
by
Muang-In, Sataporn
,
McNamara, Patrick J.
,
Laique, Firdous
in
Cyclic AMP - physiology
,
Cyclic GMP - physiology
,
Humans
2006
Many neonates with severe persistent pulmonary hypertension of the newborn (PPHN) are nonresponders to inhaled nitric oxide (iNO). Milrinone is a promising adjunctive therapy because of its pulmonary vasodilator properties and cardiotropic effects.
Case series of neonates with severe PPHN (defined as oxygenation index [OI] >20, failure of iNO therapy, and echocardiographic confirmation of PPHN).
Tertiary neonatal intensive care unit.
Full-term (≥37 weeks) neonates with severe PPHN who received intravenous milrinone.
The primary end point was the effect of intravenous milrinone on OI and hemodynamic stability over a 72-hour study period. Secondary end points examined included duration of iNO and degree of cardiorespiratory support.
Nine neonates at a mean gestation of 39.25 ± 2.76 weeks, birth weight of 3668 ± 649.1 g, and baseline OI of 28.1 ± 5.9 received milrinone treatment after a poor initial response to iNO treatment. Intravenous milrinone was commenced at a median age of 21 hours (range, 18-49 hours), and patients were treated for median of 70 hours (range, 23-136). Oxygenation index was significantly reduced after milrinone treatment, particularly in the immediate 24 hours of treatment (8.0 ± 6.6,
P < .001). There was a significant improvement in heart rate (179 ± 15.2 vs 149.6 ± 22.4,
P < .001) over the same period. Infants who received milrinone did not develop systemic hypotension; in fact, there was a nonsignificant trend toward improved blood pressure.
Intravenous milrinone produces early improvements in oxygenation without compromising systemic blood pressure.
Journal Article
Optimized T1- and T2-weighted volumetric brain imaging as a diagnostic tool in very preterm neonates
2011
Background
T1- and T2-W MR sequences used for obtaining diagnostic information and morphometric measurements in the neonatal brain are frequently acquired using different imaging protocols. Optimizing one protocol for obtaining both kinds of information is valuable.
Objective
To determine whether high-resolution T1- and T2-W volumetric sequences optimized for preterm brain imaging could provide both diagnostic and morphometric value.
Materials and methods
Thirty preterm neonates born between 24 and 32 weeks’ gestational age were scanned during the first 2 weeks after birth. T1- and T2-W high-resolution sequences were optimized in terms of signal-to-noise ratio, contrast-to-noise ratio and scan time and compared to conventional spin-echo-based sequences.
Results
No differences were found between conventional and high-resolution T1-W sequences for diagnostic confidence, image quality and motion artifacts. A preference for conventional over high-resolution T2-W sequences for image quality was observed. High-resolution T1 images provided better delineation of thalamic myelination and the superior temporal sulcus. No differences were found for detection of myelination and sulcation using conventional and high-resolution T2-W images.
Conclusion
High-resolution T1- and T2-W volumetric sequences can be used in clinical MRI in the very preterm brain to provide both diagnostic and morphometric information.
Journal Article
The interfacility transport of critically ill newborns
2015
The practice of paediatric/neonatal interfacility transport continues to expand. Transport teams have evolved into mobile intensive care units capable of delivering state-of-the-art critical care during paediatric and neonatal transport. While outcomes are best for high-risk infants born in a tertiary care setting, high-risk mothers often cannot be safely transferred. Their newborns may then have to be transported to a higher level of care following birth. The present statement reviews issues relating to transport of the critically ill newborn population, including personnel, team competencies, skills, equipment, systems and processes. Six recommendations for improving interfacility transport of critically ill newborns are highlighted, emphasizing the importance of regionalized care for newborns. 76 references
Journal Article
Implementation of an ultrasound-guided approach for arterial line placements in neonates—quality improvement project
by
Gardiner, Jill
,
Colangelo, Heather
,
Lee, Kyong-Soon
in
692/700/1421
,
692/700/1720
,
Arterial lines
2024
Objective
Our goal was to improve placement success rates for peripheral arterial line (PAL) placements by introducing an ultrasound-guided (USg) approach. Our aim was to maintain success rates over 70% within 18 months.
Study design
Interventions included development of a training curriculum, and procedure standardization. Among 302 patients, 115 underwent USg catheter placement; the traditional method was used in 187 patients. Outcome measures were first-attempt and overall success rates. Process measures were proportion of PALs placed under US guidance, trainer availability, and trainee sign-off. Line complications were balancing measures. Statistical process control charts were used to monitor metrics.
Results
Sustained improvement was seen with the USg approach. The USg approach had first and overall attempt success by the trainers (i.e., independent users) of 83.7% (77/92) and 96.5% (111/115), compared to 50.3% (82/163) and 73.8% (138/187) with the traditional approach.
Conclusion
Introducing the USg approach had a significant impact on PAL placement success in neonatal patients.
Journal Article