The therapeutic impact of lumbar spine MRI on patients with low back and leg pain

Abstract

The influence of lumbar spine magnetic resonance imaging (MRI) on the management of patients with low back and leg pain, with a clinical diagnosis of neural compression, has been investigated by a controlled prospective observational study. The clinical features of the patients at the time of request for MRI have been compared with the subsequent management in order to define the clinical indications for lumbar spine MRI. Clinical history, physical examination findings and tests of functional and psychological disability were all recorded at the time of request for MRI. Following MRI, patients were assessed without knowledge of the MRI findings and a diagnosis and management plan recorded. Immediate access to the MRI report and hard copy films was then provided and a revised diagnosis and management plan made. The clinical features and MRI findings were compared with the subsequent management. Seventy-two patients were examined, 65 (90.3%) had leg pain as a predominant feature and abnormalities in neurological examination were found in 31 (43%). Twenty-three of 48 (47.9%) of patients with a pre MRI management plan of surgery were changed to conservative management following the MRI. The diagnosis altered in 50 % of cases with the largest change in diagnosis occurring in 13 patients where MRI did not confirm the clinical impression of nerve root compression. Seventeen patients with no abnormality of neurological testing were subsequently treated by surgery which included all 12 patients treated by spinal fusion. The major impact of MRI was to move patients towards conservative treatment. A variety of features in the history and physical examination as well as MRI findings are predictors for surgical treatment. The variety of diagnoses and surgical options available make it difficult to define clear clinical guidelines for the use of MRI.