Chronic low back pain, affecting up to 58% of the population, often stems from intervertebral disc degeneration. Although magnetic resonance imaging (MRI) is commonly used for diagnostics, challenges arise in pinpointing pain sources due to frequent asymptomatic findings. Single-photon emission tomography (SPECT) integrated with computed tomography (CT) offers a promising approach, enhancing sensitivity and specificity. In this retrospective study, spanning 2016 to 2022, SPECT/CT imaging was performed on 193 patients meeting specific criteria. We correlated SPECT/CT findings with lumbar MRI results, utilizing Pfirrmann and Rajasekaran classifications for disc degeneration and endplate damage assessment. Logistic regression analysis adjusted for age and sex evaluated associations. Of 965 spinal levels assessed, SPECT/CT positivity strongly correlated with higher Pfirrmann grades and Rajasekaran endplate classifications. Notably, Modic changes (MCs) on MRI displayed a nonsignificant relationship with SPECT/CT positivity. Significant associations were observed in older patients with positive MCs, Pfirrmann grades, and Rajasekaran classifications. This comprehensive study, the largest of its kind, establishes a significant link between SPECT/CT positivity and advanced lumbar degenerative changes. Higher Pfirrmann grades and increased Rajasekaran endplate damage demonstrated substantial correlations with SPECT/CT positivity. Notably, MCs did not exhibit such association. Our findings underscore the potential of SPECT/CT in identifying pain generators in degenerative spinal conditions, offering valuable insights for future interventions.