The Effect of Hydroxyurea on Vasculopathy in a Child with Sickle Cell Disease
Kathleen J. Heltona,e,
Winfred C. Wangb,f,
Lynn W. Wynnb,f,
Raja B. Khanc,d and
R. Grant Steena,e,f,g
a Department of Diagnostic Imaging, St Jude Children’s Research Hospital, Memphis
b Department of Hematology, St Jude Children’s Research Hospital, Memphis
c Department of Neurology, St Jude Children’s Research Hospital, Memphis
d Department of Neuro-Oncology, St Jude Children’s Research Hospital, Memphis
e Department of Radiology, University of Tennessee School of Medicine, Memphis
f Department of Pediatrics, University of Tennessee School of Medicine, Memphis
g Department of Biomedical Engineering, University of Tennessee School of Medicine, Memphis
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FIG 1. Serial MR images in a patient receiving hydroxyurea. The first examination was performed at another institution.
A, Examination 1. T1-weighted image shows mild atrophy in the left medial frontal lobe.
B, Examination 1. Fluid-attenuated inversions recovery image demonstrates a recent infarction in the right middle cerebral artery territory, as well as a remote left anterior cerebral artery infarct, bilateral deep white matter leukoencephalopathy, and a few scattered deep white matter lacunae.
C, Examination 2. Image obtained at our institution almost 1 year after the beginning of therapy shows further progression of mild diffuse cerebral atrophy.
D, Examination 5. Approximately 4 years after the beginning of hydroxyurea therapy moderate diffuse cerebral atrophy is present, with prominent sulci and further ex vacuo dilatation of the ventricular system.
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FIG 2. Summary of the clinical history of the patient. Plots show the MR imaging dates, with the percentage of fetal hemoglobin (Hb F), hemoglobin (Hgb), white blood cell (WBC) count, reticulocyte count, mean corpuscular volume (MCV), and platelet count after the initiation hydroxyurea treatment at time 0. HU indicates hydroxyurea.
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FIG 3. Serial MRA images in a patient receiving hydroxyurea. Images show progressive improvement in vascular patency.
A and B, Examination 2. One year after beginning therapy, an 8-mm severe stenosis is present in the left ICA, with a large left posterior communicating (PCOM) artery. Also present is a 10-mm stenosis in the proximal right A-1 segment of the ACA, as well as proximal segmental stenoses in both middle cerebral arteries (MCAs) (11 mm, right M-1; 9 mm, left M-1). Small moyamoya collaterals are present near the right A-1 and M-1 segments.
C and D, Examination 3. Eight months later, with the MRA examination further optimized for rapid flow, the left ICA stenosis has nearly resolved, with only a 5-mm region of tapering involving the supraclinoid segment. Stenoses involving the left M-1, right A-1, and right M-1 segments had decreased to 7, 3, and 3 mm, respectively. A short 2-mm proximal stenosis is present in the left A-1 segment. Moyamoya vasculopathy was unchanged.
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FIG 4. Serial MRA images in the patient in Figure 3. Images show progressive improvement in vascular patency.
A and B, Examination 3. The bilateral A-1 segments have become equivalent in size and the distal left ICA is less tapered. A 2-mm stenosis of the proximal left A-1 and a 1-mm stenosis of the proximal left M-1 segments persist. Also noted are the resolution of the right A-1 and M-1 stenoses and the moyamoya vasculopathy with persistent short-segmental stenoses in the proximal left A-1 and M-1 segments. The right MCA appears to be more patent; small-vessel conspicuity is lost; and both PCOMs have become smaller, suggesting a slower rate of blood flow.
C and D, Examination 4. Persistent short segment stenoses of the proximal left A-1 and M-1 segments remain.
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