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White matter has impaired resting oxygen delivery in sickle cell patients |
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| Authors: | Yaqiong Chai MS Adam M Bush PhD Julie Coloigner PhD Aart J Nederveen PhD Benita Tamrazi MD Chau Vu MS Soyoung Choi BA Thomas D Coates MD Natasha Lepore PhD John C Wood PhD MD |
| Institution: | 1. Department of Biomedical Engineering, University of Southern California Engineering School, Los Angeles, California;2. Department of Radiology, Stanford University, California;3. Univ Rennes, CNRS, Inria, Inserm, IRISA UMR 6074, VISAGES – ERL U 1228, Rennes, France;4. Department of Radiology and Nuclear Medicine, Academic Medical Center, Amsterdam, The Netherlands;5. Department of Radiology and Nuclear Medicine, Children's Hospital Los Angeles, Los Angeles, California;6. Neuroscience Graduate Program, University of Southern California, Los Angeles, California
Division of Cardiology, Children's Hospital Los Angeles, Los Angeles, California;7. Section of Hematology, Children's Hospital Los Angeles, Los Angeles, California;8. Department of Biomedical Engineering, University of Southern California Engineering School, Los Angeles, California Department of Radiology and Nuclear Medicine, Children's Hospital Los Angeles, Los Angeles, California |
| Abstract: | Although modern medical management has lowered overt stroke occurrence in patients with sickle cell disease (SCD), progressive white matter (WM) damage remains common. It is known that cerebral blood flow (CBF) increases to compensate for anemia, but sufficiency of cerebral oxygen delivery, especially in the WM, has not been systematically investigated. Cerebral perfusion was measured by arterial spin labeling in 32 SCD patients (age range: 10-42 years old, 14 males, 7 with HbSC, 25 HbSS) and 25 age and race-matched healthy controls (age range: 15-45 years old, 10 males, 12 with HbAS, 13 HbAA); 8/24 SCD patients were receiving regular blood transfusions and 14/24 non-transfused SCD patients were taking hydroxyurea. Imaging data from control subjects were used to calculate maps for CBF and oxygen delivery in SCD patients and their T-score maps. Whole brain CBF was increased in SCD patients with a mean T-score of 0.5 and correlated with lactate dehydrogenase (r2 = 0.58, P < 0.0001). When corrected for oxygen content and arterial saturation, whole brain and gray matter (GM) oxygen delivery were normal in SCD, but WM oxygen delivery was 35% lower than in controls. Age and hematocrit were the strongest predictors for WM CBF and oxygen delivery in patients with SCD. There was spatial co-localization between regions of low oxygen delivery and WM hyperintensities on T2 FLAIR imaging. To conclude, oxygen delivery is preserved in the GM of SCD patients, but is decreased throughout the WM, particularly in areas prone to WM silent strokes. |
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