The effect of gadolinium on the sensitivity and specificity of MR in the initial diagnosis of multiple sclerosis.

PURPOSE To determine whether gadolinium can improve the sensitivity and specificity of MR imaging for the initial diagnosis of multiple sclerosis. METHODS Patients (n = 57) with neurologic symptoms suggesting multiple sclerosis were studied prospectively. MR imaging consisted of T2-weighted and gadolinium-enhanced T1-weighted spin-echo images. Lumbar puncture was performed for cerebrospinal fluid analysis in 34 patients. RESULTS After imaging, 17 patients (35%) had clinically definite multiple sclerosis. Cerebrospinal fluid examination had a sensitivity of 69% and specificity of 38%. Using liberal criteria, the sensitivity of T2-weighted MR imaging was 94% and the specificity 55%; using more strict criteria, the specificity increased to 65% with a sensitivity of 88%. Gadopentetate dimeglumine enhancement increased the specificity further to 80% with a loss of sensitivity (59%). CONCLUSION Gadolinium enhancement increases the specificity of MR imaging in the early diagnosis of multiple sclerosis.