New image characteristics in endobronchial ultrasonography for differentiating peripheral pulmonary lesions.

Endobronchial ultrasonography (EBUS) rapidly and accurately localizes peripheral pulmonary lesions. It can aid differential diagnosis by characterizing lesions and discriminating between neoplastic and non-neoplastic disease. From July 2005 through December 2006, patients with peripheral lesions underwent EBUS examination in a tertiary-referral teaching hospital. Image characteristics were subsequently correlated with definite histopathologic diagnosis. Three current-issued image patterns of EBUS were assayed from 40 initial patients, including (a) hypoechoic areas, (b) anechoic areas and (c) luminant areas around the probe. Excluding 22 cases because of inconsistent typing, 193 patients possessing definite diagnoses were enrolled in the investigation, of which 107 cases (55.4%) were neoplastic diseases. Hypoechoic areas appeared to be unrelated to the nature of the lesions (p = 0.288). Most lesions with anechoic areas were neoplasms (18 of 21 cases, 85.7%) and lesions without luminant areas suggested non-neoplastic disease (19 of 24 cases, 79.2%). Anechoic and luminant areas were significantly different between neoplasm and non-neoplasm groups (p = 0.003 and p < 0.001, respectively). The average additional time for EBUS required was 3.85 +/- 2.36 min (range 1 to 13 min). In conclusion, this uncomplicated and time-saving method of using EBUS image patterns could provide additional information to facilitate differential diagnoses.