Systems, computer-readable media, and methods are described for assessing physiological condition of spinal intervertebral discs in a quantitative manner using magnetic resonance imaging (MRI) data A simple, objective, continuous measurement of disc health or degeneration/pathology is provided, using routinely acquired or other digital magnetic resonance imaging (MRI) sequences. The measurement includes calculation of a value based on one or more ratios from signal-based measurements of spinal disc structures or regions, which can be obtained either through manual tracing or automated through programming of image analysis software. The measurement can be implemented by a computer and/or stored on a computer readable storage medium.