Patient selection: pediatric patient with sickle cell disease
Method: transcranial ultrasonography to measure maximum blood flow velocity in the left and/or right middle cerebral artery
An increased velocity is associated with:
(1) increasing levels of arterial stenosis
(2) anemia
Cutoff for increased risk: >= 170 cm/s
Additional parameters:
(1) trend in the maximum velocity, with increasing velocities associated with increasing risk
(2) history of previous stroke
(3) velocity > 200 cm/s
(4) neurological signs and symptoms suggestive of stroke
A patient at increased risk may be a candidate for:
(1) long-term transfusion therapy and/or bone marrow transplantation.
(2) angiography to define the severity and extent of vascular stenosis
Performance:
• The cutoff of >= 170 cm/s was associated with a sensitivity of 86% and specificity of 91%
