Fetal/Neonatal/Pediatric MRI

Monday 12 May 2014

Rui Vasco Simoes¹, Magdalena Sanz-Cortes¹, Nuria Bargallo², Francesc Figueras¹, and Eduard Gratacos^1
1Dept of Maternal-Fetal Medicine, Hospital Clinic, Barcelona, Barcelona, Spain, ²Dept of Radiology, Hospital Clinic, Barcelona, Barcelona, Spain

Intrauterine growth restriction (IUGR) is associated with impaired neurodevelopment. Late-onset IUGR cases are particularly difficult to diagnose in the clinic and the metabolic changes underlying their long-term brain dysfunctions remain poorly understood. We show that the NAA/Cho ratio (LCModel) is significantly lower in late-onset IUGR fetuses than in age-matched controls, independent of clinical risk factors. Our preliminary MRS pattern classification results (SpectraClassifier) suggest the existence of metabolic signatures for each group: control, IUGR without risk factors, and IUGR with risk factors. Further work will validate these results with a follow-up study in a larger population cohort.

Pavan Kumar Jella¹, Uday Krishnamurthy^1,2, Jaladhar Neelavalli^1,2, Swati Mody¹, Lami Yeo^3,4, E. Hernandez-Andrade^3,4, E. Ehterami¹, M.D. Cabrera¹, S.J. Korzeniewski³, E.M. Haacke^1,2, Sonia Hassan³, and Roberto Romero^3
1Department of Radiology, Wayne State University, Detroit, MI, United States, ²Biomedical Engineering, Wayne State University, Detroit, MI, United States, ³NICHD, NIH, DHHS, Perinatology Research Branch, Detroit, MI, United States, ⁴Obstetrics and Gynecology, Wayne State University, Detroit, MI, United States

A major issue in studying fetal hypoxic ischemic injury (HII); utero in humans and its identification is limited and often the diagnosis is postponed till the post neonatal period when the injury becomes evident in neuroimaging. Hence, non-invasive imaging methods for assessing hypoxic-ischemic brain injury in-utero are of high clinical interest. Magnetic resonance (MR) susceptibility weighted imaging (SWI), was used to measure fetal blood oxygenation that helps in assessing difference in fetal oxygen utilization between second and third trimester.

Jie Gao¹, Xianjun Li^1,2, Yumiao Zhang¹, Yanyan Li¹, Qinli Sun¹, Xue Luo^1,2, Bolang Yu¹, and Jian Yang^1,2
1Department of radiology, the first affiliated hospital of medical college, Xi'an Jiaotong University, Xi'an, Shannxi, China, ²Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shannxi, China

Diffuse excessive high signal intensity (DEHSI) is extremely common in preterm infants. It¡¯s still under debate about whether it represents a true white mater(WM) abnormality or just the relative immature in WM. Two-compartment WM model based on DKI can provides analytical expressions for the intra- and extra-axonal diffusion tensors and may be helpful in further exploring the diffusivity changes in DEHSI. So in this study, 8 preterm neonates with DEHSI and 8 matched controls who underwent MRI at term-equivalent age were enrolled. All diffusion parameters(FA=fractional anisotropy, MD=mean diffusivity, AD=axial diffusivity, RD=radial diffusivity, MK=mean kurtosis, AK=axial kurtosis, RK=radial kurtosis, AWF= axonal water fraction, Da=intra-axonal diffusivity, De¡Î=axial extra-axonal space diffusivity, De¡Í= radial extra-axonal space diffusivity, ¦Á=tortuosity) were compared between the two groups. The increased MD, AD, RD, De¡Î, De¡Í and no significantly changed MK, AK, RK, Da, AWF indicated that the diffusion changes in DEHSI were mainly due to the increased water and/or enlarged space in extra-axonal space, rather than injuries to axons or the process of myelination.

Stefan Bluml^1,2, Tai-Wei Wu^3,4, Ashok Panigrahy^1,5, John P Grimm¹, Marvin D Nelson¹, Thomas G Perkins⁶, Jonathan Chia⁶, and Jessica L Wisnowski^1,5
1Children's Hospital Los Angeles/USC, Los Angeles, CA, United States, ²Rudi Schulte Research Institute, Santa Barbara, CA, United States, ³Neonatology, Children's Hospital Los Angeles/USC, CA, United States, ⁴Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan, ⁵Children's Hospital of Pittsburgh, Pittsburgh, PA, United States, ⁶Philips Healthcare, Cleveland, OH, United States

Therapeutic hypothermia (TH) aims to lower brain temperature to prevent secondary energy failure in newborns with birth asphyxia. However, newborn brain temperature during TH is unknown as generally rectal temperatures are monitored. In this study we show, by direct brain temperature measurement using MR spectroscopy, that the brain temperatures during TH were higher in patients with poor outcome when compared with patients with mild to moderate injury. It may be necessary to measure brain temperature directly in individual patients to ascertain that the targeted level of cooling has been achieved.

Jill B. De Vis¹, Jeroen Hendrikse¹, Esben T. Petersen¹, Linda S. de Vries², Frank van Bel², Thomas Alderliesten², Floris Groenendaal², and Manon J.N.L. Benders^2
1Radiology, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, ²Neonatology, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands

Hypoxic-ischemic injury in neonates can cause impaired autoregulation of the cerebral vasculature resulting in hyperperfusion of brain tissue and probably secondary injury. In this study we investigated whether hyperperfusion, evaluated with arterial spin labeling MR imaging is associated with an adverse outcome in neonates with hypoxic-ischemic encephalopathy. We found higher perfusion in the basal ganglia and thalami of neonates with adverse compared to favorable outcome (69 ± 27 versus 31 ± 10 ml/100g/min, p < 0.01). Hyperperfusion in the basal ganglia and thalami had a sensitivity of 86% and a specificity of 100% for the prediction of adverse outcome.

Silvina L. Ferradal¹, Steve M. Liao², Adam T. Eggebrecht¹, Joshua S. Shimony¹, Terrie E. Inder³, Joseph P. Culver¹, and Christopher D. Smyser^2
1Radiology, Washington University in St. Louis, St. Louis, MO, United States, ²Pediatrics, Washington University in St. Louis, St. Louis, MO, United States,³Harvard Medical School, Boston, MA, United States

Adverse neurodevelopmental outcomes in preterm infants remain a clinical challenge. While functional connectivity (fc) using functional MRI opens a window to study brain function in neonates, frequent longitudinal monitoring is often restricted in the sickest infants. Diffuse optical tomography (DOT) provides a portable alternative modality for evaluating brain function at the bedside. Here we demonstrate that our DOT system generates resting-state maps exhibiting strong agreement with non-concurrent fcMRI maps in identical subjects. Our results suggest that fcDOT provides satisfactory spatial localization and resolution, and illustrates its potential as a viable imaging tool for bedside monitoring.

Kathryn Yvonne Manning¹, Darcy Fehlings², and Ravi S. Menon^3
1Medical Biophysics, The University of Western Ontario, London, Ontario, Canada, ²Holland Bloorview Kids Rehabilitation Hospital, University of Toronto, Toronto, Ontario, Canada, ³Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada

Hemiplegic cerebral palsy patients experience learned non-use where the hemiplegic arm is further inhibited from healthy development as most tasks are performed with the unaffected limb. Constraint-induced movement therapy (CIMT) has rendered significant functional improvement in many patients, though not all experience success and little is known about the possible neurological predictors. Resting state functional MRI and diffusion tensor imaging reveal altered global network organization and quantify white matter tract integrity. Potential predictors of clinical success are identified, and resting state network reorganization after CIMT provides evidence of neuroplasticity.

Nicolaas A Puts^1,2, Stewart H Mostofsky^3,4, Mark Tommerdahl⁵, and Richard A Edden^1,2
1Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins University, Baltimore, Maryland, United States, ²FM Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, United States, ³Department of Neurology, The Johns Hopkins University, Baltimore, Maryland, United States, ⁴Laboratory for Neurocognitive and Imaging Research, Kennedy Krieger Institute, Baltimore, Maryland, United States, ⁵Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States

GABA concentration is reduced in children with TS and is linked to behavior and diagnostic measures

Emma Muñoz-Moreno¹, Elda Fischi-Gomez^2,3, Dafnis Batalle¹, Lana Vasung³, Elisenda Eixarch^1,4, Jean-Philippe Thiran^2,5, Eduard Gratacos^1,4, and Petra Susan Huppi^3
1Fetal and Perinatal Medicine Research Group, IDIBAPS, Barcelona, Spain, ²Signal Processing Laboratory 5 (LTS5), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, ³Division of Development and Growth. Department of Pediatrics, University of Geneva, Geneva, Switzerland,⁴Maternal-Fetal Medicine Department, ICGON, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain, ⁵Department of Radiology, University Hospital Center (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland

Intrauterine Growth Restriction (IUGR) due to placental insufficiency is associated with short and long-term neurodevelopmental disorders. In this study, connectomic analysis based on diffusion magnetic resonance (dMRI) was performed in cohorts of 1-, 6- and 9-year-old children that were born preterm. Two groups were considered at each age, children with normal growth and children with IUGR. Tractography was used to infer the connections between brain regions, and estimate the connectome matrix of each subject, and graph measures were computed. Results showed that a pattern of alterations in graph measures describing brain organization in IUGR persists along childhood.

Claire E Kelly¹, Deanne K Thompson^1,2, Alexander Leemans³, Chris Adamson¹, Jian Chen¹, Terrie E Inder⁴, Jeanie LY Cheong^1,5, Lex W Doyle^1,5, and Peter J Anderson^1,6
1Murdoch Childrens Research Institute, Melbourne, VIC, Australia, ²Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia,³Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands, ⁴Brigham and Women's Hospital, Boston, MA, United States, ⁵Royal Women's Hospital, Melbourne, VIC, Australia, ⁶Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia

Very preterm birth (VPT, <32 weeks’ gestation) increases the risk of white matter injury. Tract-Based Spatial Statistics (TBSS) provides a method for studying whole brain white matter microstructure in VPT children. This study analysed diffusion tensor data from 150 VPT children and 35 term controls (born ≥37 weeks’ gestation) at 7 years of age. There were regions of higher diffusivity in the VPT children compared with controls. Increasing brain abnormality scored on neonatal MRI was associated with widespread lower fractional anisotropy and higher diffusivity in VPT children. TBSS provides a sensitive method for studying white matter microstructure in VPT children.