Image Type lumbar lordosis Sacral Slope (SS) Disc Height Index (DHI) Segmental Lordosis Pelvic Tilt (PT) Slip Angle/Lumbosacral Kyphosis Lumbosacral Angle (Ferguson’s Angle/Sacral Inclination) PI-LL Mismatch Boxall’s Angle (Sacral Inclination) X-Ray CT Scan MRI Scan Lumbar Spine Pelvic Incidence-Slip Angle Relationship Ferguson’s Line George’s Line (Posterior Vertebral Body Line) Ullman’s Line Pelvic Incidence Mcnab's Line