CORRELATION BETWEEN MRI PERFUSION PARAMETERS AND TRANSCRANIAL DOPPLER ULTRASOUND FINDINGS IN THE DIAGNOSIS OF ACUTE ISCHEMIC STROKE

Abstract

Background: Acute ischemic stroke (AIS) is a leading cause of morbidity and mortality worldwide. Rapid and accurate assessment of cerebral perfusion is crucial for guiding therapeutic interventions such as thrombolysis and thrombectomy. Magnetic resonance imaging (MRI) perfusion provides quantitative measures of cerebral blood flow (CBF), volume (CBV), mean transit time (MTT), and time-to-maximum (Tmax), while transcranial Doppler (TCD) ultrasound offers real-time bedside assessment of intracranial arterial flow and pulsatility. Objective: To evaluate the correlation between MRI perfusion parameters and TCD ultrasound findings in patients with acute middle cerebral artery (MCA)-territory ischemic stroke and assess whether combined imaging improves diagnostic performance. Materials and Methods: In this prospective observational study, 80 patients (mean age 67.4 ± 9.3 years; 46 males, 34 female) with MCA-territory AIS within 12 hours of symptom onset underwent MRI perfusion and TCD within one hour of each other. MRI perfusion metrics (CBF, CBV, MTT, Tmax) were obtained using dynamic susceptibility contrast (DSC) imaging. TCD parameters (peak systolic velocity [PSV], mean flow velocity [MFV], pulsatility index [PI]) were recorded. Patients were classified into infarct core, penumbra, and normal perfusion groups based on MRI criteria. Spearman correlations assessed relationships between TCD and MRI parameters. ANOVA compared groups, and ROC analysis evaluated diagnostic accuracy of MRI alone versus MRI+TCD combined. Results: Significant correlations were observed between TCD and MRI metrics: PSV vs MTT (r = –0.62, p < 0.001), PSV vs Tmax (r = –0.59, p < 0.001), PI vs CBF (r = –0.57, p < 0.001), and MFV vs CBF (r = 0.51, p < 0.001). Group comparisons showed a gradient: infarct core exhibited the lowest CBF and MFV, highest MTT and PI, followed by penumbra, then normal perfusion (p < 0.001 for all). ROC analysis demonstrated that MRI+TCD combined (AUC = 0.89) improved diagnostic performance compared with MRI alone (AUC = 0.84; p = 0.03). Conclusion: TCD parameters correlate with MRI perfusion metrics and can serve as bedside surrogates for cerebral perfusion. Combining TCD with MRI improves diagnostic accuracy in acute MCA-territory stroke, offering a practical, rapid, and complementary approach for clinical decision-making, particularly in settings with limited MRI accessibility.