Abstract: Objective To explore the value of contrast-enhanced ultrasound(CEUS) in diagnosis of pulmonary space-occupying lesions. Methods Forty patients with 40 pulmonary space-occupying lesions found by using computed tomography(CT) and/or X ray, visible at US, were enrolled in this study, including 38 peripheral pulmonary lesions and 2 central pulmonary lesions with obstructive atelectasis. Of the 40 patients, 25 were male and 15 female, the mean age was (64.8±12.5)years (range from 35 to 84 years). Firstly, the lesions' dimension, shape, echo and blood flow characteristic were recorded by traditional ultrasound, then CEUS was performed, and time to enhancement(TE), time to peak(TTP) and net enhancement(NE) were recorded. Finally, percutaneous puncture biopsy was performed under the guidance of ultrasound, taking care to avoid the no-enhanced necrotic areas displayed by CEUS, and all specimens were examined pathologically. Results All the 40 cases underwent percutaneous puncture biopsy, 1 case developed the complication of hemoptysis. In 40 lesions, 34 were malignant,of which 1 was indefinite by percutaneous puncture biopsy pathology but was confirmed as malignant tumor by pathology of specimen obtained via surgery, the other 6 were benign lesions. So the rate of final diagnosis using percutaneous puncture biopsy was 97.5%(39/40). TE was slightly shorter in malignant lesion group than in benign lesion group using CEUS〔(9.50±1.05)s & (10.85±1.67)s, respectively〕 and with no significant difference(P>0.05), however, a seriously short or delayed TE may be helpful for different diagnosis in pulmonary space-occupying lesions. There was no significant difference regarding NE and TTP between two groups(P>0.05 & P>0.05, respectively); Sixteen(47.1%) were discovered non-enhanced necrosis areas in 34 malignant lesions, and 3(50.0%) in 6 benign lesions(P>0.05). The time intensity curve(TIC) of different pulmonary space-occupying lesions was characterized by "ascending slowly and descending slowly" pattern. Conclusion CEUS is a valuable method for diagnosis and guiding percutaneous puncture biopsy in pulmonary space-occupying lesions.

Key words: ultrasound, contrast-enhanced ultrasound, pulmonary, biopsy