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Publications

Journal Article Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Ppublish 8 citations

PubMed: 32648323 DOI: 10.1002/jmri.27210

Transient Hypoxia Model Revealed Cerebrovascular Impairment in Anemia Using BOLD MRI and Near-Infrared Spectroscopy.

J Magn Reson Imaging 52(5):1400-1412

Authors: Julie Coloigner, Chau Vu, Matthew Borzage, Adam Bush, Soyoung Choi, Xin Miao, Yaqiong Chai, Cristina Galarza, Natasha Lepore, Benita Tamrazi, Thomas D Coates, John C Wood

Affiliations

  • CIBORG Laboratory, Department of Radiology, Children's Hospital Los Angeles, Los Angeles, California, USA.
  • Univ Rennes, CNRS, Inria, Inserm, IRISA UMR 6074, Rennes, France.
  • Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA.
  • Division of Neonatology, Fetal and Neonatal Institute, Children's Hospital Los Angeles, Los Angeles, California, USA.
  • Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
  • Department of Radiology and Department of Electrical Engineering, Stanford University, Stanford, California, USA.
  • Neuroscience Graduate Program, University of Southern California, Los Angeles, California, USA.
  • Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
  • Department of Radiology, Children's Hospital Los Angeles, Los Angeles, California, USA.
  • Division of Hematology-Oncology, Department of Pediatrics, Children's Hospital Los Angeles, Los Angeles, California, USA.
  • Department of Pediatrics and Pathology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
  • Division of Cardiology, Department of Pediatrics and Radiology, Children's Hospital Los Angeles, Los Angeles, California, USA.

Abstract

BACKGROUND

Obstructive sleep apnea and nocturnal oxygen desaturations, which are prevalent in sickle cell disease (SCD) and chronic anemia disorders, have been linked to risks of stroke and silent cerebral infarcts (SCI). Cerebrovascular response to intermittent desaturations has not been well studied and may identify patients at greatest risk.

PURPOSE

To investigate the cerebral dynamic response to induced desaturation in SCD patients with and without SCI, chronic anemia, and healthy subjects.

STUDY TYPE

Prospective.

SUBJECTS

Twenty-six SCD patients (age = 21 ± 8.2, female 46.2%), including 15 subjects without SCI and nine subjects with SCI, 15 nonsickle anemic patients (age = 22 ± 5.8, female 66.7%), and 31 controls (age = 28 ± 12.3, female 77.4%).

FIELD STRENGTH/SEQUENCE

3T, gradient-echo echo-planar imaging.

ASSESSMENT

A transient hypoxia challenge of five breaths of 100% nitrogen gas was performed with blood oxygen level-dependent (BOLD) MRI and near-infrared spectroscopy (NIRS) acquisitions. Hypoxia responses were characterized by desaturation depth, time-to-peak, return-to-baseline half-life, and posthypoxia recovery in the BOLD and NIRS time courses. SCI were documented by T fluid-attenuation inversion recovery (FLAIR).

STATISTICAL TESTS

Univariate and multivariate regressions were performed between hypoxic parameters and anemia predictors. Voxelwise two-sample t-statistic maps were used to assess the regional difference in hypoxic responses between anemic and control groups.

RESULTS

Compared to controls, SCD and chronically anemic patients demonstrated significantly higher desaturation depth (P < 0.01) and shorter return-to-baseline timing response (P < 0.01). Patients having SCI had shorter time-to-peak (P < 0.01), return-to-baseline (P < 0.01), and larger desaturation depth (P < 0.01) in both white matter regions at risk and normal-appearing white matter than patients without infarcts. On multivariate analysis, desaturation depth and timing varied with age, sex, blood flow, white blood cells, and cell-free hemoglobin (r = 0.25 for desaturation depth; r = 0.18 for time-to-peak; r = 0.37 for return-to-baseline).

DATA CONCLUSION

Transient hypoxia revealed global and regional response differences between anemic and healthy subjects. SCI was associated with extensive heterogeneity of desaturation dynamics, consistent with extensive underlying microvascular remodeling.

MeSH

White Matter, Cells, Blood, Spectroscopy, Near-Infrared, Anemia, Sickle Cell, Anemia, Magnetic Resonance Imaging, Recycling, Healthy Volunteers, Hypoxia

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