Noninvasive central nervous system imaging in sickle cell anemia: A preliminary study comparing transcranial doppler with magnetic resonance angiography

Purpose: We evaluated the accuracy of transcranial Doppler (TCD) and magnetic resonance angiography (MRA) as a screening modality for cerebral infarct in patients with sickle cell disease. Patients and Methods: Twenty-four patients with sickle cell disease were assessed for a cerebral infarct. Each patient underwent neurologic examination, psychometric evaluation, magnetic resonance imaging (MRI), MRA, and TCD. Presence of a cerebral infarct was determined by an MRI and supported by neurologic and neuropsychometric evaluation. All investigators were unaware of the patient’s status. Cerebral vasculature by MRA was categorized as being occluded, stenotic, or normal. The maximum TCD velocity of the right and left middle cerebral artery were assessed. Various cutoffs were used to determine the sensitivity and specificity of TCD. Results: MRA had a sensitivity and specificity of 100% and 92%, respectively. At a maximum velocity cutoff of 180 cm/s, the sensitivity and specificity of TCD were 20% and 67%, respectively. No maximum velocity on TCD produced both sensitivity and specificity >50%. Conclusion: MRA is more sensitive than TCD when the middle cerebral artery for maximum velocity is compared. Prospective evaluation is warranted to determine if TCD is useful as a screening technique for cerebral infarction in children with SCD.