Correlative study between MRI signal intensity of the lumbar intervertebral disc and collagen content in the nucleus pulposus

Abstract

Objective To study correlation between MRI signal intensity of the lumbar intervertebral disc and collagen content in the nucleus pulposus.Methods Thirty-one cases with lumbar intervertebral disc herniation(male 21,female 10)received percutaneous lumbar disketetomy.Thirty-one specimens of nucleous pulposus were obtained from percutaneous lumbar disketctomy procedure and collagen content in them was measured with reformed hydroxyproline measurement method.The signal intensity(SI) of lumbar intervertebral disc and cerebrospinal fluid was measured in T_2 WI sagittal image and then ratio of disc SI to cerebrospinal fluid SI was calculated.The Pearson analysis was used to analyze the correlation between the collagen content and SI ratio and disc SI on T_2 WI.Results Collagen content and SI ratio were (231.0±63.5)mg/g and 0.19±0.07,respectively.There was negative correlation between them (r=-0.61,P0.01).Disc T_2 WI SI was 80.5±31.7.Collagen content was correlated inversely with Disc T_2 WI SI(r=-0.53,P0.01).Conclusion There exits moderately negative correlation between MRI signal intensity and collagen content in the nucleous pulposus.The increasing of collagen content is one of factors to cause signal intensity of disc decreasing.