Value of contrast-enhanced transcranial color-coded sonography for diagnosing middle cerebral artery stenosis in...

Transcranial color-coded sonography (TCCS) is widely used to detect middle cerebral artery (MCA) stenosis in clinical settings; however, the image quality can be affected by temporal bone window acoustic transmission conditions. In this study, we evaluated the value of contrast-enhanced (CE)-TCCS for diagnosing MCA stenosis in patients with poor temporal bone windows.

In total, 77 patients with 154 MCA images were assessed. The clinical symptoms were classified as symptomatic (n=28, 36.4%) and asymptomatic (n=49, 63.6%). The flow velocity parameters of the MCA images were measured, including the peak systolic velocity (PSV), end diastolic velocity (EDV), and mean flow velocity (MFV), with computed tomography angiography (CTA) used as a reference. The best cutoff value for the various velocity parameters measured by CE-TCCS for diagnosing MCA stenosis and its severity was determined based on the maximum Youden's index through receiver operating characteristic (ROC) curve analysis.

Symptomatic patients had a high prevalence of MCA stenosis [odds ratio (OR) =4.386; 95% confidence interval (CI): 1.110-17.324]. Out of the 154 MCA images with a poor temporal bone window under the TCCS modality, 133 (86.4%) had a good temporal bone window under the CE-TCCS modality. In the stenosis group, the PSV, EDV, and MFV values measured via CE-TCCS were significantly greater than those in the normal group (P<0.001). The flow velocity increases gradually with worsening stenosis severity (P<0.001). The optimal cutoff values for the mild stenosis and normal groups were as follows: PSV ≥173.5 cm/s (sensitivity: 96.7%, specificity: 95.2%), EDV ≥66.6 cm/s (sensitivity: 76.7%, specificity: 87.3%), MFV ≥102.5 cm/s (sensitivity: 83.3%, specificity: 95.2%); the optimal cutoff values for the moderate and mild stenosis were as follows: PSV ≥213 cm/s (sensitivity: 91.7%, specificity: 100%), EDV ≥84.5 cm/s (sensitivity: 83.3%, specificity: 80.0%), MFV ≥130.5 cm/s (sensitivity: 87.5%, specificity: 100%); the optimal cutoff values for the severe and moderate stenosis were as follows: PSV ≥261.5 cm/s (sensitivity: 93.8%, specificity: 100%), EDV ≥105 cm/s (sensitivity: 93.8%, specificity: 83.3%), MFV ≥159.5 cm/s (sensitivity: 93.8%, specificity: 95.8%).

CE-TCCS can enhance the temporal bone window visualization in patients with poor temporal window under TCCS, providing diagnostic value for varying degrees of MCA stenosis.