What is the approximate velocity described for the middle cerebral artery in this data set?

• A. 55 cm/s
• B. 39 cm/s
• C. 21 cm/s
• D. 47 cm/s

Answer: (A)

In transcranial Doppler, the middle cerebral artery’s velocity is typically described by its peak systolic velocity, which in a healthy adult usually falls around the mid-50s cm/s. The data set showing a peak near 55 cm/s matches this normal systolic velocity range, making it the best description of the MCA flow in this context. Mean velocity in the MCA tends to be lower, around 40 cm/s, and end-diastolic values are typically 15–20 cm/s, so the other numbers reflect different aspects of the waveform rather than the peak systolic velocity. Thus, 55 cm/s aligns with the expected peak systolic velocity for the MCA.