Objective To review the principles and techniques of CT perfusion imaging and its applications in the imaging diagnosis of abdominal disorders. Methods All the relevant literatures were reviewed. The principles and techniques of CT perfusion imaging were described and summarized in detail. The functional information of a target abdominal organ (e.g. the liver and pancreas) revealed by CT perfusion imaging, such as hemodynamics and microcirculation status, was also evaluated. Results In addition to the morphologic information, CT perfusion imaging can also provide functional information about the circulation parameters of target abdominal organs. Moreover, such functional information can be generated for the neovasculature and microcirculation of tumor lesions of abdominal organs, which is very helpful for not only the diagnosis, but also the evaluation of tumor invasiveness and response to treatment. Conclusion CT perfusion imaging offers an effective method for studying abdominal disorders by providing functional information that is quite useful for the differential diagnosis and assessment of therapeutic response.
We established acute cholangitis and endotoxiemia in 18 rabbits by ligating the common bile duct and injecting E coli(O111B4 strain)into the common bile duct. After perfusion through activated charcoal via femoral artery-vein pathway, the average blood levels of endotoxin decreased sighificantly from 2.24Eu/ml to 0.17Eu/ml(Plt;0.001). This result suggested that blood perfusion through activated charcoal may be a promising therapy for acute endotoxemia.
【Abstract】 Objective The present study employed both static and dynamic imaging modal ities to study bothintra- and extravascular events attributing to steroid-associated osteonecrosis (ON) using an experimental protocol with a single low-dose l i ppolysaccharide (LPS) injection and subsequently three injections of high-dose methylprednisolone (MPS). Methods Fourteen 28-week-old male New Zealand white rabbits received one intravenous injection of LPS (10 μg/ kg). After 24 hours, three injections of 20 mg/kg of MPS were given intramuscularly at a time interval of 24 hours. Additional 6 rabbits were used as controls. Dynamic MRI was performed on bilateral femora for local intraosseous perfusion before and after LPS injection. Blood samples were collected for haematological examinations before and after LPS injection. Bilateral femora were dissected and decalcified for microCT-based microangiography. ON lesion, intravascular thrombus and extravascular marrow fat cell size were examined histopathologically. Results Intravascular thrombus was observed in all ON rabbits. Extravascular marrow fat cell size was significantly increased in ON rabbits than that of the controls (P lt; 0.05). Compared to basel ine, a significant decrease in ratio of tissue-type-plasminogen-activator/plasminogen-activator inhibitor 1,activated-partial- thromboplatin-time, and a significant increase in ratio of low-density-l ipoprotein/high-density-l ipoprotein were only found in ON rabbits (P lt; 0.05). Dynamic MRI showed a significant decrease in the perfusion index ‘maximum enhancement’ in the ON rabbits (P lt; 0.05) and microCT-based microangiography showed blocked stem vessels in ON samples.Overall, 93% of the rabbits (13/14) developed ON and no rabbits died throughout the experiment period. Conclusion Bothintra- and extravascular events were found attributing to the steroid- associated ON based on our experimental protocol with a single low-dose LPS injection and subsequent three injections of high-dose MPS. Both high ON incidence and no mortal ity in rabbits treated with this inductive protocol suggested its effectiveness for future studies on evaluation of therapeutic efficacy of interventions developed for prevention of steroid-associated ON.