Fig. 6From: Percutaneous endoscopic lumbar discectomy combined with platelet-rich plasma injection for lumbar disc herniation: analysis of clinical and imaging outcomesSchematic diagram of RVG measurement. The cerebrospinal fluid grey scale of sacral one segment (b) was selected as a reference, and the grey scale of the responsible segmental disc (a) was measured, RVG = (a / b) * 100%. Comparison of RVG on MRI preoperatively (A), 3 months (B) and 12 months (C) postoperativelyBack to article page