title: Improving specificity of computed tomography in diagnosis of malignant mediastinal lymph nodes.
abstract: Four parameters of lymph node appearance on computed tomography were studied to improve specificity for malignancy in bronchogenic carcinoma: 1) node location, 2) homogeneity, 3) border definition, and 4) delineation by fat. Of 54 carcinoma patients, nodes were pathologically malignant in 21. Computed tomography showed enlarged nodes (over 1 cm) in 20 of these (true-positive rate, 96%), but also in 13 of the 33 patients with pathologically benign lymph nodes (false-positive rate, 39%). A combination of all four computed tomography parameters reduced the false-positive rate from 39 to 21% and decreased the true-positive rate from 96 to 86%. The criterion of border definition alone reduced the false-positive rate from 39 to 6%, but decreased the true-positive rate from 96 to 61%. The most useful computed tomography parameter was delineation, which reduced the false-positive rate to 15% and decreased the true-positive rate only to 86%. The computed tomography appearance of enlarged lymph nodes may be used to improve selection of patients with enlarged nodes for preoperative biopsy.
mesh_terms: D002283:Carcinoma, Bronchogenic / Q000000981:diagnostic imaging / Q000556:secondary*; D006801:Humans; D008175:Lung Neoplasms; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging*; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary*; D009367:Neoplasm Staging / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*