In this study, we demonstrated a technique that could non-invasively quantify lenticulostriate artery (LSA) flow velocities in cerebral small vessel disease (CSVD). With phase-contrast magnetic resonance angiography (PC-MRA) at 7T, LSA blood flow velocities were detected in patients with CADASIL (a hereditary CSVD). LSA flow velocities decreased in patients compared with healthy individuals. We also found good associations between velocities and clinical characteristics among patients with CADASIL. These results suggest that PC-MRA at 7T is a valuable technique to assess small arterial dysfunction in patients with CSVD.