Intrathoracic lymph node evaluation by CT and MRI with histopathologic correlation in non-small cell bronchogenic carcinoma.

Twenty patients with non-small cell bronchogenic carcinoma were prospectively studied for intrathoracic lymphadenopathy using computed tomography (CT) and magnetic resonance imaging (MRI). The CT and MRI results were correlated with the surgical histopathology results of 103 harvested lymph nodes. Based on node dimension (utilizing a 1-cm cutoff value), neither imaging modality was accurate in predicting the histopathology of the nodes. CT had a sensitivity of 21%, specificity of 95%, and an overall accuracy of 85%; MRI had a sensitivity of 14%, specificity of 97%, and an overall accuracy of 85%. Moreover, CT and MRI detected preoperatively only 17% and 14%, respectively, of the harvested nodes. In summary, lymph node sizes measured by CT and MRI are inaccurate in predicting the benignity or malignancy of lymph nodes. Lymphadenopathy can be present even with a "negative" CT or MRI scan of the thorax.