Study On The Formation Mechanism Of B Line In Lung Ultrasound

Objective:To explore the formation condition and influencing factors of B line.Methods:1.Foam was made,mixing 50g/L soda solution with white vinegar in a 1:1 ratio,and foam size was measured with a microscope.2.The injection were given of the same amount of oscillation of physiological saline,contrast agent,and baking soda solution+white vinegar,in these five types of models respectively,namely physiological saline model,coupling agent,in vitro bovine liver(injection via the liver parenchyma),in vitro bovine liver(injection via the portal vein/bile duct),and stomach tube approaching the cardia of living rabbit.Each model was tested 20 times repeatedly,B line formation was observed with ultrasound,and the ultrasonic images were saved.Results:1.The foam diameter of the baking soda solution+white vinegar under the microscope was about 10~2～10~3μm,and the foam diameter of the contrast agent was<10μm.2.B line was not detected in any types of model in which the injections were given of the oscillating physiological saline and contrast agent.3.The occurrence rate of B line in 5 models in the process of the injection of the foam,produced by baking soda solution+white vinegar,was as follows:physiological saline model(0%)<in vitro bovine liver(injection via the liver parenchyma)model(70%)<coupling agentsaline model(85%)<stomach tube approaching the cardia in living rabbit(90%)<in vitro bovine liver(injection via the portal vein/bile duct)model(100%).There were significant differences in occurance rate between physiological saline model and other four modles(P<0.01).There was a significant difference between in vitro bovine liver(injection via the liver parenchyma)model,and in vitro bovine liver(injection via the portal vein/bile duct)model(P<0.05).Conclusion:The formation of B line is related to the size of foam,the amount and shape of foam aggregation and the movement of foam.Objective: To investigate the correlation between B line in lung ultrasound and severity of pulmonary edema.Methods:1.The 20 rabbits were randomly divided into the control group and the experimental group with 5 rabbits per group.The experimental group was randomly divided into 3 subgroups according to the oleic acid dose.Before the intervention,ultrasound examination was performed on transthoracic bilateral lungs to record the presence of B line signs and to store ultrasonic dynamic images(3 ~ 5s).2.The control group was given 10ml/kg of saline injection via ear vein,and the experimental group was given different doses of oleic acid via ear vein,and the same amount of saline was injected after 10 mins.50 mins after the injection of saline,the left-sided transthoracic lung ultrasound was performed and the ultrasonic images were saved.3.Right thoracic cavity was opened after deep anesthesia,the lesion degree of the lung tissue was observed with the naked eye,and the ultrasound examination of the lung in the corresponding region under direct vision was conducted and the ultrasonic images were saved.After the rabbit was executed,the lung tissue of the corresponding region was collected and histopathological examination was performed.The left lung was taken out and the wet/dry lung ratio was measured.Results:1.There were significant differences in wet/dry ratio between the heavy oleate dosage group,and non-oleic acid dosage,and mild acid dosage group(P<0.05).There were significant differences in B line score of transthoracic lung ultrasound between non-oleic acid dosage group and moderate oleate dosage group,and severe oleate dosage group,also between the mild acid dosage group and moderate oleic acid dosage groups.Different oleic acid dosage was positively correlated with wet/dry lung ratio(r=0.574;P=0.020)and B line score(r=0.954;P = 0.000).Wet/dry lung ratio was positively correlated with the transthoracic lung ultrasonographic B line score(r=0.690;P = 0.003).2.There was no significant difference in the lung ultrasound of the B line score between moderate lesion group and severe lesion group(P>0.05),but significant differences were observed between other groups(P<0.05).There were significant differences in the pathological histological scores of lung histology between no lesion group and mild lesion group,moderate lesion group and severe lesion group(P<0.05).Moreover,The degree of lesion with naked eyes was positively correlated with the B line score of the lung ultrasound under direct vision(r=0.893;P=0.000),and histopathological score(r=0.690;P = 0.000);The histopathological score was positively correlated with the B line score of the lung ultrasound under direct vision(r=0.647;P = 0.000).Conclusion: B line in the ultrasonography can reflect the severity of pulmonary edema and the severity of histopathology,so it can be used for semi-quantitative evaluation.