An Animal Experimental Study On The Multiple Comet Tail Sign And Early Abdominal Visceral Injury

Objective To study on the correlation between multiple comet tail sign and the early abdominal visceral injury and explore the clinical application of the multiple comet tail sign in prompting the early abdominal visceral injury in an oleic acid animal model.Methods The experimental animals were divided into experimental and control groups. Before establishing model, all the sonograms of the lungs, livers, and kidneys were stored, and then the rabbits of control group were put to death. The oleic acid animal model of multiple comet tail sign were made in the experimental group. The successful model was defined as at least one lung area shows varying degrees of multiple comet tail sign in breast sonogram. The sonograms of lungs,livers and kidneys were stored in successful model and then the rabbits were put to death. The two groups of rabbits were dissected and the lungs, livers, kidneys, and spleens were removed to make the tissue slices. The gross pathologic findings and microscopic histological changes of the two groups were observed and recorded.According to the chest sonogram, the ultrasound scores were defined as: 1 point for short comet tail sign, 2 points for isolated comet tail sign, 3 points for mild multiple comet tail sign, 4 points for moderate multiple comet tail sign, 5 points for falls sign(severe multiple comet tail sign). The degrees of organs injury were assessed according to the percentage of pathologic lesion area, to compare the correlation between the multiple comet tail sign and abdominal organ injury.Results The successful rate of multiple comet tail sign model in experimental group is 100%. The sonograms of liver and kidney have no significant change before and after the experiment, the spleen dose not display. The common gross pathologic findings of the two groups are as follows: rice-sized white nodules are scattered on the surface of liver. The common microscopic pathologic findings of two groups are as follows: parasites are seen in liver, chronic inflammatory diseases are found out in both lung and liver, and congestion is found out in lung, liver, kidney and spleen.The incidence of lung’s positive pathologic changes in experimental group is 100%(11/11), the gross pathologic findings are full shape with dark red hemorrhagic area on surface; the microscopic pathologic findings are pulmonary edema(11/11,100%)and pulmonary hemorrhage(9/11, 81.8%). The incidence of liver’s positive pathologic changes in experimental group is 45.5%(5/11), the gross pathologic findings are full shape with reddish brown surface and flexible texture; the microscopic pathologic findings are cellular swelling of hepatocytes(5/11, 45.5%).The incidence of kidney’s positive pathologic changes in experimental group is18.2%(2/11), the gross pathology has no obvious changes, and the microscopic pathologic findings are cellular swelling of renal tubular epithelial cells(5/11,45.5%). No obvious positive pathologic change is found in spleen. Results show that the lung ultrasound scores of rabbits with liver injury are obviously higher than those with no liver injury, and there is significant differences(p=0.011). There is a statistically significant positive correlation between the lung ultrasound scores of rabbits with liver injury and the microscopic pathologic area of liver lesion(r=0.893,p=0.041), the higher the lung ultrasound score, the more severity of the liver injury.Conclusions The appearance of multiple comet tail sign is earlier than the sonogram changes of liver and kidney. The most sensitive pathologic changes of abdominal organ appear in liver, followed by kidney, spleen has no obvious specific changes over the same period. The scope and extent of the multiple comet tail sign can prompt the early injury in liver and kidney.