I Need Help Understanding My Carotid Duplex Scan Results. It

I need help understanding my Carotid Duplex Scan results. It says: Findings: mild atherosclerotic disease near the left carotid bifurcation/bulb. It appears calcified with less than 50% luminal narrowing. Right CCA PSV 90 cm/sec. ICA PSV 101 cm/sec. PDV 37 cm/sec. IC.CC PSV ratio 1.21. Vertebral flow antegrade. Spectral waveforms are normal. Left CCA PSV 110 cm/sec. ICA PSV 128 cm/sec. PDV 53 cm/sec. IC/CC PSV ration 1.16. Vertebral flow antegrade. Spectral waveforms are normal.
Impression: Left ICA peak systolic velocity is slight elevated in the 50-60% narrowing range. Other parameters are less than 50% luminal narrowing including the gray scale. Thank you.