THE MAGNETIC RESONANCE IMAGING OF THE LUMBAR SPINE IN OUT-PATIENTS WITH LOW BACK PAIN

Abstract

This paper aims to estimate the prevalence rates of MRI change in LBP out-patients and to determine the relationship between abnormalities in an MRI and personal and occupational factors. The MRI records were obtained from 200 out-patients with LBP (114 males and 86 females) who received a diagnostic MRI at St. Luke's Medical Center. The mean and standard deviation of this sample's age were 43.8 years and 14.8 years, respectively. Based on the MRI, each lumbar disc was scored as normal or degenerated. Bulging and herniated were also recorded. Each patient completed a short questionnaire that included the measures of height, weight, age, and present occupation and any history of "heavy manual labor". Occupations were grouped into white collar sedentary, white collar professional, blue collar exposed to prolonged sitting and vibration, blue collar exposed to heavy, unemployed or retired, and homemaker. Chi-square tests were used to determine the statistical significance of these trends. A multiple logistic regression was used to develop a predictive model of spine pathology based on a subject's individual characteristics and occupational classification.Normal discs were found in 26% of the patients and degenerated discs in 47.5%. There were bulging/herniated disks in 26.5%. In men who were younger than 29 years, 50% had herniated disks, and 50% were normal. Three fourth of the women in the same age group showed normal discs. Forty-three percent of the subjects reported a history of performing heavy labor. Using the logistic regression model there were two variables predictive of observable MRI pathology: age and prior history of heavy labor. The analysis indicated that an older individual who had a history and heavy labor was more likely to show one or more pathological model discs in an MRI scan.