Poor Acoustic Window Limits the Diagnostic Utility of Transcranial Colour Doppler Ultrasonography for Acute Stroke in an African Population

Abstract

Background: Stroke is a major cause of death and disability. Brain computed tomography (CT) scan is used for evaluating such patients with stroke  followed by prompt interventions to reduce associated complications. Transcranial colour Doppler (TCCD) offers relatively affordable, nonionising,  noninvasive analysis of cerebral hemodynamics.

Aim: The aim of this study was to provide preliminary data on the utility of TCCD in adult acute stroke in  sub‑Saharan Africa, specifically to correlate Doppler assessed vascular flow dynamics with morphological CT variables observed in patients with stroke.

Patients, Materials and Methods: A prospective study on fifty adult patients with acute stroke (25 ischemic and 25 hemorrhagic) who had computed  tomography scans and duplex ultrasonography performed within 24 h of the onset of acute stroke. The Doppler variables from TCCD were correlated  with the brain CT data.

Results: For ischemic stroke, the middle cerebral artery (MCA) and anterior cerebral artery (ACA) were visualised bilaterally in 8  (32%) of patients, while the posterior cerebral artery (PCA) was seen bilaterally in only 1 (4%) case. For the hemorrhagic stroke category, the MCA and ACA  were visualised bilaterally in 16 (64%) of patients, while the PCA was seen bilaterally in only 6 (24%) cases. The ACA asymmetry index showed a  strong negative correlation (r = −0.938, P = 0.046) with the total stroke volume and a strong correlation with the amount of midline shift (r = 0.993, P =  0.0006). There was no correlation between the other indices of asymmetry and the CT scan quantitative data.

Conclusion: This study shows that  evaluating adult patients with acute stroke using TCCD with the currently available two‑dimensional ultrasound transducers may be limited by poor acoustic window in a sub‑Saharan African population. In future, the application of three‑dimensional transducers with lower frequencies and the  introduction contrast enhanced TCCD might bring about a positive outcome.