To study 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.

The experimental animals were divided into an experimental group and a control group. The sonograms of the lungs, livers and kidneys of control group were collected, and then the rabbits were executed. The animals of experimental group were made into multiple comet tail sign models. The thorax sonogram of successful model showed at least one lung area with varying degrees of multiple comet tail sign. Collect the sonograms of lungs, livers and kidneys were collected, and then the rabbits were executed. The two groups of rabbits were dissected, and the lungs, livers, kidneys, and spleens were removed to make the tissue sections. The gross pathologic findings and microscopic histological changes of the two groups were observed and noted. The ultrasound scores of chest sonograms were recorded: short comet tail sign for 1 point, isolated comet tail sign for 2 points, mild multiple comet tail sign for 3 points, moderate multiple comet tail sign for 4 points, and falls sign (severe multiple comet tail sign) for 5 points. The degree of organ injury was assessed by the percentage of pathologic injury area under microscope, and the correlation between the multiple comet tail sign and abdominal organ injury was analyzed.

The successful rate of multiple comet tail sign model in experimental group was 100%. The sonograms of liver and kidney have no significant change after the experiment. The incidence of positive pathologic changes in experimental group was 100% (11/11). The gross pathologic findings of lung were complete shape with dark red hemorrhagic area at surface; the microscopic pathologic findings were pulmonary edema (11/11, 100%) and pulmonary hemorrhage (9/11, 81.8%). The incidence of positive pathologic changes in the liver of experimental group was 45.5% (5/11). The gross pathologic findings of liver were complete shape with reddish brown surface and flexible texture; the microscopic pathologic findings were cellular swelling of hepatocytes (5/11, 45.5%). The incidence of positive pathologic changes in the kidneys of experimental group was 18.2% (2/11). The gross pathology had no obvious changes, and the microscopic pathologic findings were cellular swelling of renal tubular epithelial cells (2/11, 18.2%). Results showed that the lung ultrasound scores of rabbits with liver injury were obviously higher than those of rabbits with no liver injury, and there was significant differences (Z=-2.529, P=0.011). There was 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), and the higher the lung ultrasound score, the more severity of the liver injury.

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. The scope and extent of the multiple comet tail sign can prompt the early injury in liver and kidney.