The disc height index (DHI) measurement method using a section of a lumbar spine standing sagittal EOS image is demonstrated The DHI is calculated using the disc height anterior (Ha), the disc height posterior (Hp), the disc width superior (Ds) and the disc width inferior (Di). The variables are entered into the following equation [(Ha + Hp)/(Ds + Di)] × 100. In addition, all disc compartments that were calculated are numbered (L1/2 to L5/S1) in the image shown