Ectasia of the basilar artery in children with sickle cell disease: relationship to hematocrit and psychometric measures.
OBJECTIVE
To determine whether children with sickle cell disease (SCD), but without clinical evidence of cerebrovascular disease, have vasculopathy shown by quantitative magnetic resonance angiography (MRA).


METHODS
In a retrospective review of MRA films, we compared 47 SCD patients with 49 control patients. Time-of-flight three-dimensional T1-weighted gradient-echo images were reconstructed, by maximum-intensity projection, to show the basilar artery in coronal view, and basilar volume was calculated from measurements made on films. Basilar volume was correlated with hematocrit and with results of cognitive testing.


RESULTS
Mean basilar artery volume was 74% larger in SCD patients than in controls (P<.001). If the upper limit of normal is defined as mean adult volume +2 SD (< or =427 mm(3)), 2% (1 of 43) of controls but 37% (17 of 46) of SCD patients exceed this value (chi(2)=19.0; P<.001). Basilar volume correlated inversely with hematocrit (r=-.60; P<.0001), with full-scale IQ (r=-.62; P<.005), and with freedom from distractability (r=-.61; P<.006) in SCD patients. Analysis of basilar artery tissue from a 5-year-old SCD patient showed that basilar dilatation can be associated with pathological changes typical of hypertension.


CONCLUSIONS
Approximately 37% of a heterogenous group of pediatric SCD patients had ectasia of the basilar artery. Quantitative MRA is sensitive to subtle vasculopathy that can go undetected in the qualitative analysis more commonly done. Data suggest that there is a substantial elevation of arteriolar blood volume in pediatric SCD patients, and that such patients may share disease features in common with adult hypertension.
Steen
R G
RG
Department of Diagnostic Imaging, St Jude Children's Research Hospital, Memphis, TN, USA.
Langston
J W
JW
Ogg
R J
RJ
Manci
E
E
Mulhern
R K
RK
Wang
W
W