| Avascular necrosis of femoral head ( ANFH) is one of the most common or-thopaedical diseases, involving 20 millions people in the world. ANFH could cause damage and collapse of femoral head in late stage, which directly affect life quality of the patient. In all factors, over - dose usage of hormone is one of the most important and frequent etiopathogenisis. Although the exact pathogene-sis has not been defined, the possible pathogenesis is related with disorder of fat metabolism, which induces hyperlipemia and coagulation in blood vessels. While effect of cytokine on ANFH, specially VEGF, has received more and more attention, and its important impact on development and repairing processes of ANFH had been found.In both patient and animal model study of Steroid - induced ANFH, Hyper-lipidemia are by far the earliest blood - biochemical change, and decrease of blood flow is the earliest pathological changes. Nowadays, the common imaging techniques are MR and Radionuclides to investigate blood supply of femoral head; but some disadvanges of these techniques, such as the relatively low specificity and high price, lead to the requirement of a new method which could be used to detect changes of blood flow as early as possible. Recently, CT perfu-sion has become a new technique in the detection of microcirculation of living tissues, and the principle of which is identical with that of scintigraphy. CT perfusion , which is one of the functional imaging techniques, could provid some information of microcirculatory changes of tissues, such as volume of blood flow (perfusion) , time to peak (TIP) ,and mean transmit time(MTT). Such a technique has been used to investigate the perfusion of diseases in solid organs such as brain, liver, or kidney. But as far as we are concerned, no documents about bone diseases have been reported until today.In our experimental study, the model of ANFH in rabbits was induced using Methylprednisolone. The correlations among the blood biochemical changes,MSCT perfusion imaging , as well as histopathology of induced model of ANFH were observed. Among them, the pivotal study was to investigate characteristic of MSCT perfusion Imaging and expression of VEGF of Steroid - induced ANFH, and establish correlation among blood biochemiology, MSCT perfusion imaging, as well as histopathology. The result of our research may be helpful for demonstration of the pathogenesis of Steroid - induced ANFH, and providing a new imaging technique to detect abnormity of blood supply of femoral head as early as possible.Materials and Methods1. Establishment of animal model22 rabbits with 1-1.5 years old were included in this study, and divided into two groups. As an experimental group, 18 rabbits were injected 8mg/kg Methylprednisolone and penicillin twice a week until the eighth weekend, while 4 rabbits were only injected penicillin twice a week as a control group. In 2,4,6, 8 weekend of timepoint after injection, both four rabbits of experimental group and one rabbit of control group were killed respectively.2. Blood biochemical examinationIn every weekend, all animals were fasting, then blood samples were obtained from eight rabbits of experimental group and one of control group at random , to observe factors of blood lipid and hemorrheology.3. MSCT perfusion imagingMSCT perfusion imaging were performed using philips MX8000 CT scanner in four rabbits of experimental group and one rabbit of control gourp in 2 4 6 8 weekend of timepoint respectively.After a conventional examination, Onmipaque 350mgI/ml were injected through ear vein with a dosage of 2ml/kg ( rate; 1ml/s; scan time: 0.75s; cycle time: 2s) during CT perfusion were performed, consecutive 100 images were obtained.All perfusion images were transferred to CT workstation for data analysis u-sing FUNCTIONAL CT software. In two scans, where bilateral femoral headwere displayed perfectly, the artery beside right Femoral head were used as the reference artery, then acquiring time - density curves of artery an...
|
PDF Full Text Request