Comparative Study of the Clinically Diagnosed Herniated Nucleus Pulposus with the Computed Tomographic and Myelographic Finding

Suh, Jung Tak; Yoo, Chong Il; Kim, Hui Taeg

Abstract

79 patients with suspected H.N.P. of lumbar vertebrae were studied from June 1983 to June 1986 who had had both metrizamide myelography and computed tomography. Comparative study of the findings from clinical examination, CT and myelography of them are as follows. l. In physical examination, S.L.R.T. was most common sign, 58 patient(73.4% of study group) showed positive in S.L.R.T.(30~70 range). Of these positive patients in S.L.R.T. 41.4% was the patients who were younger than 30 years of age and also had pressure sign of nerve root on CT and myelography. These group showed highest positive rate in S.L.R.T. 2. In CT and myelographic study, the most frequent occurence of H.N.P. were seen in L4-5, L5-S1, L3-4 in order and myelography showed higher positive rate in L4-5 intervertebral space while CT showed higher positive rate in LS-S1. 3. On CT, facet joint arthritis or stenosis were seen in 49.4% of the study group and 53.7% of computed tomographic positive patients of H.N.P. 4. Corresponding rate of positive sign of H.N.P. between CT and myelographic findings were seen 71 intervertebral spaces, which means 84.5% of 84 positive spaces on CT and 88.8% of 80 positive spaces on myelography. 5. In 49 intervertebral spaces clinical sign, CT and myelographic findings were all positive. In another words 58.3% of 84 positive intervertebral spaces on CT and 61.3% of 80 positive spaces on myelography showed all positive sign on clinical examentation, CT and myelography. 6. L5-Sl intervertebral spaces showed most controversial results in comparative study of CT and myelography. 7. 25 of 26 positive spaces on CT(96.2%) and 23 of 26 positive spaces of myelography(88.5%) were confirmed by operation and all 3 false-negative on myelography were found in L5-Sl intervertebral space. 8. Most diagnostic differences were seen in L5-S1, which has wider epidural space. CT showed higher sensitivity than myelography in this study. For its higher sensitivity and non-invasiveness CT is thought to be first recommendable method for diagnosis of H.N.P. and myelography is recommended as second best choice where diagnostic differences are seen.