Diagnosing intervertebral disc pain by CT-guided discography and MRI

Objective: To discuss the values of CT-guided discography and MRI respectively in diagnosing intervertebral disc pain. Methods: CT-guided discography was performed in 55 cases of the suspicious intervertebral disc pain who examined lumbar MRI preciously , the positive discs were classified according to Dallas Discogram Description(DDD), then diagnosed definitely positive discs and the degree of degeneration and rupture of corresponding anulus fibrosus. Results: 33 cases were positive by CT-guided discography , the positive rate in the elder group (≥50 year) was 35.7% , that in the younger group was 68.3%. According to the evaluation on degree and level of disc degeneration and rupture with DDD. 1,2,3 degree of disc degeneration was 26.3%,34.2%,39.5%; 1,2,3 degree of disc rupture was 23.7%,73.7%,2.6%. Degenerative changes on MR image existed in all positive discs .10 cases were positive in 11 cases existing HIZ on MR , the positive rate of which was 90.9% . Conclusion: (1) The positive rate of discography is higher in the younger group of chronic lumbar pain. (2)Abnormal morphology of discography(rupture within anulus fibrosus) is the basis of inducing pain.(3) Diffuse factor of contrast media within intervertebral disc .(4) It has high sensitivity but low specificity to diagnose intervertebral disc pain by MR , so we have to utilize discography to identify the responsible disc.(5)HIZ on MRI has higher specificity to diagnose intervertebral disc pain .