====== Central Sacral Vertical Line ====== {{ ::csvl.png?400|}} (On AP standing scoliosis x-ray) vertically oriented line which bisects the sacrum perpendicular to a tangent drawn across the iliac crests. The central sacral vertical line (CSVL) is used in the assessment of spinal scoliosis. It is a line constructed on frontal films of the spine and pelvis to measure coronal balance, drawn as follows: a line connecting the top of the iliac crests is drawn a second line is drawn perpendicular to the first, which bisects the sacrum. Normal: For coronal balance, a plumb line from the middle of C7 VB should be < 4 cm from [[CSVL]]. Alignment objective: Plumb line from the middleof C7 VB < 4 cm from CSVL. Positive numbers are to the right, negative to left.