PURPOSE: To evaluate the usefulness of a new computed tomographic (CT) criterion for diagnosing hilar lymph node metastases on the basis of the margin between hilar interstitium and lung parenchyma. MATERIALS AND METHODS: The morphology of normal and metastatic hilar nodes was analyzed in seven inflated and fixed human lung specimens. Thin-section, incremental, dynamic CT was then performed preoperatively in 95 patients with lung cancer, and the margins of peribronchovascular hypoattenuated areas were evaluated in 22 of the patients with normal hila. CT-pathologic comparisons were performed at 179 locations where interstitium touched lung parenchyma. The comparison was based on a new CT criterion in which convex interstitial margins indicate nodal metastases. RESULTS: The margins of the interstitia with normal nodes were concave or straight at 94.8% (183 of 193) of the contact sites in the six normal specimens and at 97.3% (436 of 448) of the contact sites on CT scans, whereas the margins of the interstitia with abnormal nodes were convex at 94.7% (54 of 57) of the contact sites in the abnormal specimen. Sensitivity, specificity, and accuracy of three reviewers who used the new criterion were 87.3%, 88.3%, and 88.1%, respectively. CONCLUSION: The new CT criterion is useful for the diagnosis of hilar node metastases in lung cancer.
PURPOSE: To evaluate the usefulness of a new computed tomographic (CT) criterion for diagnosing hilar lymph node metastases on the basis of the margin between hilar interstitium and lung parenchyma. MATERIALS AND METHODS: The morphology of normal and metastatic hilar nodes was analyzed in seven inflated and fixed human lung specimens. Thin-section, incremental, dynamic CT was then performed preoperatively in 95 patients with lung cancer, and the margins of peribronchovascular hypoattenuated areas were evaluated in 22 of the patients with normal hila. CT-pathologic comparisons were performed at 179 locations where interstitium touched lung parenchyma. The comparison was based on a new CT criterion in which convex interstitial margins indicate nodal metastases. RESULTS: The margins of the interstitia with normal nodes were concave or straight at 94.8% (183 of 193) of the contact sites in the six normal specimens and at 97.3% (436 of 448) of the contact sites on CT scans, whereas the margins of the interstitia with abnormal nodes were convex at 94.7% (54 of 57) of the contact sites in the abnormal specimen. Sensitivity, specificity, and accuracy of three reviewers who used the new criterion were 87.3%, 88.3%, and 88.1%, respectively. CONCLUSION: The new CT criterion is useful for the diagnosis of hilar node metastases in lung cancer.