HILAR LYMPH-NODES - IDENTIFICATION WITH SPIRAL CT AND HISTOLOGIC CORRELATION

PURPOSE: To determine the appearance of normal hilar lymph nodes and associated soft tissue at spiral computed tomography (CT). MATERIALS AND METHODS: At spiral CT in 50 healthy patients, peribronchovascular hypoattenuated areas of 42 right and 45 left hila were systematically evaluated. Histologic results were correlated in five additional cases. RESULTS: Hilar lymph nodes were depicted (a) in the right hilum (lateral to A2 [n = 33 {79%}], medial [n = 29 {69%}] or lateral [n = 11 {26%}] to the interlobar pulmonary artery, and medial to the lower-lobe pulmonary artery [n = 30 {71%}], A7 [n = 9 {21%}], and A8-10 [n = 8 {19%}]); and (b) in the left hilum (lateral to A2 [n = 22 {49%}], medial to the interlobar pulmonary artery [n = 45 {100%}], and the lower-lobe pulmonary artery [n 27 {60%}], and in the angles of bifurcation of A7+8 and A9+10 [n = 18 {40%}]). Hilar lymph nodes were seen to be triangular or linear and to be less than 3 mm wide except around the left-lower-lobe pulmonary artery. CONCLUSION: Spiral CT accurately depicts normal hilar lymph nodes and their major anatomic relationships.