R G Steen

Summary

Affiliation: University of North Carolina
Country: USA

Publications

  1. ncbi request reprint Brain injury in children with sickle cell disease: prevalence and etiology
    R Grant Steen
    Department of Diagnostic Imaging, St Jude Children s Research Hospital, Memphis, TN, USA
    Ann Neurol 54:564-72. 2003
  2. ncbi request reprint Brain T1 in young children with sickle cell disease: evidence of early abnormalities in brain development
    R Grant Steen
    Department of Diagnostic Imaging, St Jude Children s Hospital, 332 N Lauderdale, Memphis, TN 38105 2794, USA
    Magn Reson Imaging 22:299-306. 2004
  3. ncbi request reprint Brain volume in pediatric patients with sickle cell disease: evidence of volumetric growth delay?
    R Grant Steen
    Department of Radiological Sciences, St Jude Children s Research Hospital, Memphis, TN, USA
    AJNR Am J Neuroradiol 26:455-62. 2005
  4. ncbi request reprint Cognitive deficits in children with sickle cell disease
    R Grant Steen
    Department of Radiological Sciences, St Jude Children s Research Hospital, Memphis, TN, USA
    J Child Neurol 20:102-7. 2005
  5. ncbi request reprint Measurement of brain metabolites by 1H magnetic resonance spectroscopy in patients with schizophrenia: a systematic review and meta-analysis
    R Grant Steen
    Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 7160, USA
    Neuropsychopharmacology 30:1949-62. 2005
  6. ncbi request reprint Brain volume in first-episode schizophrenia: systematic review and meta-analysis of magnetic resonance imaging studies
    R Grant Steen
    Department of Psychiatry, University of North Carolina at Chapel Hill, Campus Box 7160, Chapel Hill, North Carolina 27599 7160, USA
    Br J Psychiatry 188:510-8. 2006
  7. ncbi request reprint Measuring brain volume by MR imaging: impact of measurement precision and natural variation on sample size requirements
    R G Steen
    Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 7160, USA
    AJNR Am J Neuroradiol 28:1119-25. 2007
  8. ncbi request reprint Diffuse T1 reduction in gray matter of sickle cell disease patients: evidence of selective vulnerability to damage?
    R G Steen
    Department of Diagnostic Imaging, St Jude Children s Research Hospital, University of Tennessee School of Medicine, Memphis 38105 2794, USA
    Magn Reson Imaging 17:503-15. 1999
  9. ncbi request reprint Fast adipose tissue (FAT) assessment by MRI
    S A Gronemeyer
    Department of Diagnostic Imaging, St Jude s Children s Research Hospital, Memphis, TN, USA
    Magn Reson Imaging 18:815-8. 2000
  10. ncbi request reprint Abnormally high levels of brain N-acetylaspartate in children with sickle cell disease
    R Grant Steen
    Department of Radiologic Sciences, St Jude Children s Research Hospital, Memphis, TN, USA
    AJNR Am J Neuroradiol 26:463-8. 2005

Collaborators

Detail Information

Publications24

  1. ncbi request reprint Brain injury in children with sickle cell disease: prevalence and etiology
    R Grant Steen
    Department of Diagnostic Imaging, St Jude Children s Research Hospital, Memphis, TN, USA
    Ann Neurol 54:564-72. 2003
    ..The degree of vasculopathy is closely related to the degree of brain injury, implying that vasculopathy is prodromal to most forms of brain injury in hemoglobin SS...
  2. ncbi request reprint Brain T1 in young children with sickle cell disease: evidence of early abnormalities in brain development
    R Grant Steen
    Department of Diagnostic Imaging, St Jude Children s Hospital, 332 N Lauderdale, Memphis, TN 38105 2794, USA
    Magn Reson Imaging 22:299-306. 2004
    ..01) except cortical gray matter. However, patient T(1) values declined rapidly to values lower than normal by about age 4. Our findings imply that patients follow an abnormal developmental trajectory beginning early in infancy...
  3. ncbi request reprint Brain volume in pediatric patients with sickle cell disease: evidence of volumetric growth delay?
    R Grant Steen
    Department of Radiological Sciences, St Jude Children s Research Hospital, Memphis, TN, USA
    AJNR Am J Neuroradiol 26:455-62. 2005
    ..This study was designed to test a hypothesis that children with SCD have a disease-related delay in brain volumetric growth compared with healthy children...
  4. ncbi request reprint Cognitive deficits in children with sickle cell disease
    R Grant Steen
    Department of Radiological Sciences, St Jude Children s Research Hospital, Memphis, TN, USA
    J Child Neurol 20:102-7. 2005
    ..9 points lower than that of controls and decreased as a function of age (probability = .014). The findings suggest that there is diffuse brain injury in patients and that patient deficits increase with age...
  5. ncbi request reprint Measurement of brain metabolites by 1H magnetic resonance spectroscopy in patients with schizophrenia: a systematic review and meta-analysis
    R Grant Steen
    Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 7160, USA
    Neuropsychopharmacology 30:1949-62. 2005
    ..Only three of 64 studies included enough subjects to have 80% power to detect a 10% NAA reduction in patients, and no studies were adequately powered to detect a 5% NAA reduction with 80% power...
  6. ncbi request reprint Brain volume in first-episode schizophrenia: systematic review and meta-analysis of magnetic resonance imaging studies
    R Grant Steen
    Department of Psychiatry, University of North Carolina at Chapel Hill, Campus Box 7160, Chapel Hill, North Carolina 27599 7160, USA
    Br J Psychiatry 188:510-8. 2006
    ..Studies of people with schizophrenia assessed using magnetic resonance imaging (MRI) usually include patients with first-episode and chronic disease, yet brain abnormalities may be limited to those with chronic schizophrenia...
  7. ncbi request reprint Measuring brain volume by MR imaging: impact of measurement precision and natural variation on sample size requirements
    R G Steen
    Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 7160, USA
    AJNR Am J Neuroradiol 28:1119-25. 2007
    ..To determine the sample size needed to provide adequate statistical power in studies of brain volume by MR imaging, we examined the precision and variability of measurements in healthy controls...
  8. ncbi request reprint Diffuse T1 reduction in gray matter of sickle cell disease patients: evidence of selective vulnerability to damage?
    R G Steen
    Department of Diagnostic Imaging, St Jude Children s Research Hospital, University of Tennessee School of Medicine, Memphis 38105 2794, USA
    Magn Reson Imaging 17:503-15. 1999
    ..Our inability to find an effect from saturation of inflowing blood implies that rapid perfusion cannot account for T1 reduction in gray matter...
  9. ncbi request reprint Fast adipose tissue (FAT) assessment by MRI
    S A Gronemeyer
    Department of Diagnostic Imaging, St Jude s Children s Research Hospital, Memphis, TN, USA
    Magn Reson Imaging 18:815-8. 2000
    ..958), visceral adipose tissue (r(2) = 0. 753), and total adipose tissue (r(2) = 0.941). The automated method required 6 min vs 2 h for the manual method...
  10. ncbi request reprint Abnormally high levels of brain N-acetylaspartate in children with sickle cell disease
    R Grant Steen
    Department of Radiologic Sciences, St Jude Children s Research Hospital, Memphis, TN, USA
    AJNR Am J Neuroradiol 26:463-8. 2005
    ..We measured NAA levels rigorously in SCD patients to test the hypothesis that NAA is elevated in this patient population...
  11. ncbi request reprint Brain imaging findings in pediatric patients with sickle cell disease
    R Grant Steen
    Department of Diagnostic Imaging, St Jude Children s Research Hosp, 332 N Lauderdale St, Memphis, TN 38105 2794, USA
    Radiology 228:216-25. 2003
    ..To determine prevalence of imaging abnormalities in the brain of children with sickle cell disease (SCD) and to identify clinical and methodological factors that influence prevalence estimate...
  12. pmc Systematic differences between lean and obese adolescents in brain spin-lattice relaxation time: a quantitative study
    F Cazettes
    Department of Psychiatry, NYU School of Medicine, New York, NY, USA
    AJNR Am J Neuroradiol 32:2037-42. 2011
    ..In addition, obesity impacts body development during adolescence. We tested a hypothesis that T1, a marker of brain maturation, can show brain differences associated with obesity...
  13. ncbi request reprint Fat-saturated contrast-enhanced T1-weighted MRI in evaluation of osteosarcoma and Ewing sarcoma
    S A Gronemeyer
    Department of Diagnostic Imaging, St Jude Children s Research Hospital, Memphis, TN, USA
    J Magn Reson Imaging 7:585-9. 1997
    ..0001). In patients with osteosarcoma or Ewing sarcoma, FatSat T1W C+ imaging may replace T2W imaging for soft tissue mass evaluation, especially if contrast is being used for dynamic enhancement...
  14. ncbi request reprint Cognitive impairment in children with hemoglobin SS sickle cell disease: relationship to MR imaging findings and hematocrit
    R Grant Steen
    Department of Diagnostic Imaging, St Jude Children s Research Hospital, Memphis, TN 38105, USA
    AJNR Am J Neuroradiol 24:382-9. 2003
    ..We test a hypothesis that cognitive impairment in children with hemoglobin SS sickle cell disease is associated with low hematocrit and MR imaging abnormalities...
  15. ncbi request reprint The correlation between phase shifts in gradient-echo MR images and regional brain iron concentration
    R J Ogg
    Department of Diagnostic Imaging, St Jude Children s Research Hospital, Memphis, TN 38105, USA
    Magn Reson Imaging 17:1141-8. 1999
    ..Magnetic resonance phase images provide insight into the magnetic state of brain tissue and may prove to be useful in elucidating the relationship between brain iron and tissue relaxation properties...
  16. ncbi request reprint Hybrid artificial neural network segmentation of precise and accurate inversion recovery (PAIR) images from normal human brain
    J O Glass
    Department of Diagnostic Imaging, St Jude Children s Research Hospital, 332 North Lauderdale, Memphis, TN 38101, USA
    Magn Reson Imaging 18:1245-53. 2000
    ..This technique produced accurate estimates of the amounts of GM and WM while providing a reliable means of redistributing partial volume effects...
  17. ncbi request reprint Improved cerebrovascular patency following therapy in patients with sickle cell disease: initial results in 4 patients who received HLA-identical hematopoietic stem cell allografts
    R G Steen
    Department of Diagnostic Imaging, St Jude Children s Research Hospital, Memphis, TN 38105 2794, USA
    Ann Neurol 49:222-9. 2001
    ..Bone marrow transplantation may enable stenoses to heal and can substantially reduce cranial blood velocity, suggesting that allogeneic bone marrow transplantation may prevent infarction or brain damage...
  18. ncbi request reprint Age-related changes in the pediatric brain: proton T1 in healthy children and in children with sickle cell disease
    R Grant Steen
    Department of Diagnostic Imaging, St Jude Children s Research Hospital, Memphis, TN, USA
    Magn Reson Imaging 21:9-15. 2003
    ..Analysis of 141 patients with SCD shows that patients have lower T1 than normal, in both the caudate and the cortex (p < 0.001)...
  19. ncbi request reprint Kindergarten readiness skills in children with sickle cell disease: evidence of early neurocognitive damage?
    R Grant Steen
    Department of Diagnostic Imaging, St Jude Children s Research Hospital, Memphis, TN 38105 2794, USA
    J Child Neurol 17:111-6. 2002
    ..01), and there was a trend (P < .10) toward lower patient scores in language. Deficits cannot be attributed to school absence and may predict academic problems for patients with sickle cell disease...
  20. ncbi request reprint The effect of hydroxyurea on vasculopathy in a child with sickle cell disease
    Kathleen J Helton
    Department of Diagnostic Imaging, St Jude Children s Research Hospital, Memphis, TN 38105, USA
    AJNR Am J Neuroradiol 23:1692-6. 2002
    ..Hydroxyurea can be effective in treating vasculopathy, but it might not prevent the progression of parenchymal damage in advanced disease...
  21. pmc Brain volumes in psychotic youth with schizophrenia and mood disorders
    Mohamed El-Sayed
    Department of Psychiatry, University of North Carolina at Chapel Hill, NC 27599 7160, USA
    J Psychiatry Neurosci 35:229-36. 2010
    ..We sought to test the hypothesis that deficits in grey matter volume are characteristic of psychotic youth with early-onset schizophrenia-spectrum disorders (EOSS) but not of psychotic youth with early-onset mood disorders (EOMD)...
  22. ncbi request reprint Prospective brain imaging evaluation of children with sickle cell trait: initial observations
    R Grant Steen
    Department of Diagnostic Imaging, St Jude Children s Research Hospital, 332 N Lauderdale St, Memphis, TN 38105 2794, USA
    Radiology 228:208-15. 2003
    ..To determine whether sickle cell trait (hemoglobin AS) is associated with abnormalities in the brain of asymptomatic children...
  23. ncbi request reprint Single-voxel 1H PRESS at 4.0 T: precision and variability of measurements in anterior cingulate and hippocampus
    Talaignair N Venkatraman
    Brain Imaging and Analysis Center, Duke University Medical Center, Durham, NC 27710, USA
    NMR Biomed 19:484-91. 2006
    ..Simple calculations suggest that more than 200 subjects would be needed to detect a 5% difference in NAA between patients and controls...
  24. ncbi request reprint Stressing about posttraumatic stress disorder
    R Grant Steen
    Pediatrics 120:232-4; author reply 234-5. 2007