【Abstract】Objective To investigate whether modified pulmonary ultrasonography combined with serum salivary liquefaction carbohydrate antigen-6 (KL6) and matrix metalloproteinase-7 (MMP7) is helpful in evaluating pulmonary fibrosis. Methods: Thirty 3.0 ~ 4.0 kg male New Zealand white rabbits were randomly divided into experimental group (n = 15) and control group (n = 15). The rabbit model of pulmonary fibrosis was established by intratracheal injection of bleomycin hydrochloride in the experimental group

and the same amount of saline was perfused in the control group. After modeling

5 animals in the experimental group and 5 animals in the control group were randomly selected for lung ultrasound scanning and determination of the contents of serum KL6 and MMP7 on days 14

21

and 42

respectively

and sacrificed for pathological examination. The correlation between modified lung ultrasound scoring method

serum KL6 and MMP7 and pulmonary fibrosis was analyzed. Results ①Compared with the control group

there were significant differences in the modified pulmonary ultrasound score

lung histopathological score and serum Kl6 and MMP7 expression in the experimental group (P < 0.05)

which increased with time. ②There was a strong positive correlation between modified lung ultrasound score

rabbit serum Kl6 level and MMP7 level and pathological tissue score (r = 0.925

0.892

0.808

respectively

P < 0.05). There was a strong positive correlation between the modified lung ultrasound score and serum Kl6 and MMP7 levels in rabbits (r = 0.884

0.831

respectively

P < 0.05 for all). Conclusion The modified lung ultrasound scoring method combined with serum kl6 and MMP7 detection may be helpful for the assessment of the severity of pulmonary interstitial fibrosis.