The primary aim of this study is to evaluate MRI-based cerebrovascular reserve (CVR) measurements in adult patients with Sickle Cell Disease (SCD). The primary objective is to assess whether there is a correlation between CVR and silent cerebral infarcts (SCIs).
CVR is hypothesized to be impaired in SCD patients and could account for the white matter hyperintensities seen on MRI in these patients. Cerebral blood flow (CBF) alone is not sufficient to provide insight into the hemodynamic status of the brain. CVR allows us to gain insight into the capacity of the cerebrovasculature to respond to increased CBF. Vasculopathy is common in SCD and the caliber of the vessels can be assessed with 4D Flow MRI in response to actue and chronic changes in the velocity and wall shear stress on the intracranial arteries in the Circle of Willis. This study will be performed as a single center, patient-control, cross-sectional, observational study in patients with steady-state SCD and controls. The investigators expect that patients with impaired CVR will have a greater number and/or volume of SCIs.
Study Type
OBSERVATIONAL
Enrollment
60
Acetazolamide is administered to all participants to induce vasodilation, in order to assess the physiologic response on cerebral blood flow.
Academic Medical Center
Amsterdam, Netherlands
RECRUITINGCerebrovascular Reserve (CVR) from arterial spin labelling-MRI in patients compared to controls
Cerebral blood flow (CBF mL/100g/min) measurement before, during, and after, an intravenous administration of 16mg/kg acetazolamide. The percentage change in CBF will be used as a measure for CVR (%).
Time frame: 20 minutes
Cerebral Metabolic Rate of Oxygen in patients and controls
Oxygen extraction fraction and cerebral blood flow are proportional to the cerebral metabolic rate of oxygen. Using the CBF from the primary outcome, and having measured the T2 of blood (which is dependent on oxygen), we can derive the oxygen extraction fraction, which allows us to calculate the cerebral metabolic rate of oxygen (CMRO2) and compare patients with controls.
Time frame: 2 minutes
Blood markers relating to anemia will be related to MRI findings
Hematocrit, hemoglobin, hemolysis, red blood cell count, mean corpuscular hemoglobin concentration.
Time frame: Through study completion, an average of 1 year
Velocity in the circle of willis assessed with 4D Flow MRI
Velocity (m/s) before and after acetazolamide challenge will be used to indicate cerebrovascular reserve and compared between patients and controls
Time frame: 10 minutes
Silent Cerebral Infarct (SCI) on T2-weighted FLAIR MRI
Volume of SCIs will be assessed in relation to CVR
Time frame: 10 minutes
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