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.