Establishment Of Acute Hepatic Trauma CT Model And Its Clinical Significance

IntroductionIn the recent years, the rates of hepatic contusion-laceration and acute hepatic trauma are obviously risen in parallel to traffic incidence increase. CT is one of major imaging methods for diagnosis of acute hepatic trauma. However, there is relatively higher false diagnostic ratio in acute hepatic trauma by using CT technique. For improving radiological accurate for acute hepatic trauma diagnosis, we established an acute hepatic trauma model in rabbits for studying the generation mechanism of the disease, which also laying a foundation for other techniques such as MRI to research hepatic trauma.ObjectiveIn this study, an rabbit model acute hepatic trauma was established to reveal the generation mechanism of the disease and to analyze CT findings in the model and its clinical significance.Materials and MethodsThe 30 experimental white rabbits were randomly assigned into 3 groups including simple hepatic contusion-laceration group (n=6), blood-itself injection group (n=12) and plasm-itself injection group (n=12). We programmed the experiment as follow: firstly, rabbits anaesthesia by chloraminetone, secondly, positioning by CT, then, setting up the hepatic trauma models and spontaneously CT scanning, and repeat CT scan 1 ?> 3^ 5^ 7 days later respectively, finally, CT findings were analyzed.1. CT scan: Routine abdominal scan were done with SIEMENS Volume Zoon helix CT and scanning parameters of 120Kv/140mAs, pitch 1.0mm, collimation 1.0mm, reconstruction slice 1.0mm. Contrast mediums -Ominpaque were injected with bolus 2.0ml/kg. Examination ranged from diaphragm to the bottom of the liver, finally, we analyze all of CT findings.2. Methods of CT model creation: ?simple hepatic contusion-laceration group: This kind of experimental CT models of acute hepatic trauma can be created successfully by scarification and stir within hepatic parenchyma. The aspiration needle was positioned on the upper edge of hepatic hilar. ? blood-itself injection group: Blood collection were performed from ear veins of the experimental rabbits with each 8ml and 15ml. The blood collection were injected into the traumatic region at the same time. (D plasm-itself injection group: Blood collection were also from ear veins of the rabbits with each 15ml and 30ml. Blood serums were removed after 30 minutes. Then the plasm solidifications were injected slowly into the traumatic part of the simple hepatic contusion-laceration groups. In addition, the attenuation values of blood> serum and plasm were recorded through CT.The 30 experimental white rabbits were randomly assigned into 3 groups including simple hepatic contusion-laceration group (n=6), blood-itself injection group (n=12) and plasm-itself injection group (n=12). Those acute hepatictrauma models, which were set up with scarification and stir within hepatic parenchyma by paracentetic needles, blood-itself or plasm-itself injection, were examined with CT scans and the CT findings were analyzed.ResultsResults CT findings of three experimental hepatic trauma models were as follows: ?simple hepatic contusion-laceration group: iso-density lesions (n=4) or ambiguously stripe low-density lesions (n=2) on CT unenhanced scans, and stripe, fissured or mottled low-density lesions after contrast medium. All lesions were disappeared 1-3 days later, ?blood-itself injection group: irregular, slightly low- and iso-density lesions. The lesions became fusiform, ellipse or round one days later and disappeared 3-5 days later, ?plasm-itself injection group: iso-density lesions or slightly high-density lesions with irregular margin on CT unenhanced scans, and irregular low-density lesions after contrast medium. The low-density lesions remained irregular shope or became fusiform, ellipse or round with 1.0 ~ 2.0 cm in size one day later and less than 1.0 cm in size and three days later. All the lesions were disappeared 5-7 days later. Subcapsular hematoma was seen in 7 cases out of 24 cases of blood-itself injection group and plasm-itself injection group, and pseudonaeurysm was found in one case in the plasm-itself injection group.ConclusionDifferent kinds of experimental CT models of acute hepatic trauma can be created successfully by scarification and stir within hepatic parenchyma, blood-itself or plasm-itself injection. Those models may be important for other imaging techniques to study acute hepatic trauma.