Comparative Study of Lumbar Magnetic Resonance Imaging and Myelography in Young Soldiers with Herniated Lumbar Disc

Objective : This study was undertaken to compare the diagnostic performances of magnetic resonance imaging (MRI), MR myelography (MRM) and myelography in young soldiers with a herniated lumbar disc (HLD). Methods : Sixty-five male soldiers with HLD comprised the study cohort. A visual analogue scale for low back pain (VAS-LBP), VAS for leg radiating pain (VAS-LP) and Oswestry disability index (ODI) were applied. Lumbar MR, MRM, and myelographic findings were checked and evaluated by four independent radiologists, respectively. Each radiologist was asked to score (1 to 5) the degree of disc protrusion and nerve root compression using modified grading systems devised by the North American Spine Society and Pfirrmann and the physical examination rules for conscription in the Republic of Korea. Correlated coefficients between clinical and radiological factors were calculated. Interpretational reproducibility between MRI and myelography by four bases were calculated and compared. Results : Mean patient age was 20.5 +/- 1.1. Mean VAS-LBP and VAS-LP were 6.7 +/- 1.6 and 7.4 +/- 1.7, respectively. Mean ODI was 48.0 +/- 16.2%. Mean MRI, MRM, and myelography scores were 3.3 +/- 0.9, 3.5 +/- 1.0, and 3.9 +/- 1.1, respectively. All scores of diagnostic performances were significantly correlated (p<0.05). However, none of these scores reflected the severity of patients' symptoms. There was no statistical difference of interpretational reproducibility between MRI and myelography. Conclusion : Although MRI and myelography are based on different principles, they produce similar interpretational reproducibility in young soldiers with a HLD. However, these modalities do not reflect the severity of symptoms.