Figure 1

Examples of chronic cerebrospinal venous insufficiency venous hemodynamic criteria on Doppler sonography. (A) Flap anomalies noted in internal jugular vein (IJV) lumen; (B) annulus in the left IJV: circumferential thickened vein wall that is restricting the vein from fully expanding with respiratory or positional changes; (C) thrombus noted in IJV; (D) severe stenosis of left IJV: CSA measurement of ≤3 mm²; (E and F) Reflux/bidirectional flow directed towards the brain for a duration of >0.88 seconds in the right IJV in the supine position (E demonstrates reflux using color flow, while F demonstrates reflux using spectral analysis - waveform noted above baseline for more than 0.88 seconds).