title: The severity of anaemia depletes cerebrovascular dilatory reserve in children with sickle cell disease: a quantitative magnetic resonance imaging study.
abstract: Overt ischaemic stroke is one of the most devastating complications in children with sickle cell disease (SCD). The compensatory response to anaemia in SCD includes an increase in cerebral blood flow (CBF) by accessing cerebrovascular dilatory reserve. Exhaustion of dilatory reserve secondary to anaemic stress may lead to cerebral ischaemia. The purpose of this study was to investigate CBF and cerebrovascular reactivity (CVR) using magnetic resonance imaging (MRI) in children with SCD and to correlate these with haematological markers of anaemia. Baseline CBF was measured using arterial spin labelling. Blood-oxygen level-dependent MRI in response to a CO2stimulus was used to acquire CVR. In total, 28 children with SCD (23 not on any disease-modifying treatment, 5 on chronic transfusion) and 22 healthy controls were imaged using MRI. Transfusion patients were imaged at two time points to assess the effect of changes in haematocrit after a transfusion cycle. In children with SCD, CBF was significantly elevated compared to healthy controls, while CVR was significantly reduced. Both measures were significantly correlated with haematocrit. For transfusion patients, CBF decreased and CVR increased following a transfusion cycle. Lastly, a significant correlation was observed between CBF and CVR in both children with SCD and healthy controls.
authors.affiliation: Institute of Medical Science, University of Toronto, Toronto, ON, Canada.|Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: Przemyslaw D
authors.initials: PD
authors.lastname: Kosinski
authors.affiliation: Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: Paula L
authors.initials: PL
authors.lastname: Croal
authors.affiliation: Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: Jackie
authors.initials: J
authors.lastname: Leung
authors.affiliation: Division of Haematology/Oncology, The Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: Suzan
authors.initials: S
authors.lastname: Williams
authors.affiliation: Division of Haematology/Oncology, The Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: Isaac
authors.initials: I
authors.lastname: Odame
authors.affiliation: Department of Anesthesia, St. Michael's Hospital, Toronto, ON, Canada.
authors.forename: Gregory M T
authors.initials: GM
authors.lastname: Hare
authors.affiliation: Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: Manohar
authors.initials: M
authors.lastname: Shroff
authors.affiliation: Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, ON, Canada.|Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: Andrea
authors.initials: A
authors.lastname: Kassner
mesh_terms: D000293:Adolescent; D000740:Anemia / Q000473:pathology*; D000755:Anemia, Sickle Cell / Q000503:physiopathology*; D001803:Blood Transfusion; D002560:Cerebrovascular Circulation; D002648:Child; D004106:Dilatation; D005260:Female; D006400:Hematocrit; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D013113:Spin Labels
chemical_list: D013113:Spin Labels
keywords: 
  magnetic resonance imaging
  ; haemolytic anaemia; paediatrics; sickle cell disease; stroke