Detailed Description Spondylolisthesis is a spinal condition in which one vertebral body has slid forward in relation to the vertebrae below and is sometimes associated with spinal instability. Lumbar spondylolisthesis is a relatively common problem and is generally diagnosed from radiographs. MRI is often used to evaluate the condition further and to determine if there is nerve root compression involved. One potential disadvantage with traditional MRI to evaluate spondylolisthesis is imaging is performed with the patient lying supine in the scanner. This creates a potential for the superior vertebra to slide posteriorly so that the extent of the slip may not be fully appreciated, if seen at all. Use of upright weight bearing MRI provides the opportunity to image the spine in the position that patients are most likely to experience symptoms and is similar to standing radiographs.