NONINVASIVE CENTRAL-NERVOUS-SYSTEM IMAGING IN SICKLE-CELL-ANEMIA - A PRELIMINARY-STUDY COMPARING TRANSCRANIAL DOPPLER MAGNETIC-RESONANCE ANGIOGRAPHY

Purpose: We evaluated the accuracy of transcranial Doppler (TCD) and m agnetic resonance angiography (MRA) as a screening modality for cerebr al infarct in patients with sickle cell disease. Patients and Methods: Twenty-four patients with sickle cell disease were assessed for a cer ebral infarct. Each patient underwent neurologic examination, psychome tric evaluation, magnetic resonance imaging (MRI), MRA, and TCD. Prese nce of a cerebral infarct was determined by an MRI and supported by ne urologic and neuropsychometric evaluation. All investigators were unaw are of the patient's status. Cerebral vasculature by MRA was categoriz ed as being occluded, stenotic, or normal. The maximum TCD velocity of the right and left middle cerebral artery were assessed. Various cuto ffs were used to determine the sensitivity and specificity of TCD. Res ults: MRA had a sensitivity and specificity of 100% and 92%, respectiv ely. At a maximum velocity cutoff of 180 cm/s, the sensitivity and spe cificity 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 determin e if TCD is useful as a screening technique for cerebral infarction in children with SCD.