A controlled comparison of myelography, computed tomography, and magnetic resonance imaging in clinically suspected lumbar disc herniation

STUDY DESIGN. A controlled prospective blinded study. OBJECTIVES. To compare the diagnostic power of myelography, computed tomography and magnetic resonance imaging in the diagnosis of low lumbar disc herniation. METHODS. Eighty patients with monoradicular sciatica were examined by myelography, computed tomography, and magnetic resonance imaging, and all underwent subsequent surgery. The images were evaluated twice in a blinded fashion, and the diagnostic power of the modalities was expressed by a decision-analytic regret function. RESULTS. In 57 patients (71%) a disc herniation at the expected level was disclosed at surgery. The largest amount of diagnostic information was gained from computed tomography, followed by magnetic resonance imaging and myelography. Both computed tomography and magnetic resonance imaging were significantly informative, whereas this was not the case for myelography. CONCLUSION. The results indicate that computed tomography or magnetic resonance imaging should be the first choice for imaging in patients with suspected lumbar disc herniation.