| PrefaceVarious liver diseases lead to significant alterations of the hepatic microcirculation. Therefore, quantification of hepatic perfusion has the potential to improve the assessment and management of liver diseases. Most methods used to quantify liver perfusion are invasive or controversial. Quantification of liver perfusion by means of dynamic single section CT was first described by Miles et al in 1993. Because of its a-bility to combine quantifiable information about perfusion with detailed anatomic information in one image, this technique becomes a study hot in modern medicine . The purpose of this study is to analyse hepatic perfusion parameters in rats with cirrhosis using dynamic CT , and further study the value of this method in liver diseases.Materials and MethodsMale Sprague - Dawley rats weighing 80 - 120g,supplied by the experimental animal center of the Second Affiliated Hospital of China Medical University, were included in this study and divided into .two groups at random . Experimental group, 30 rats were administered 0. 03% thioacetamide for six weeks and then 0. 04% thioacetamide foranother six - week time. In the thirteenth week the liver scanning was applied and all the work was done in one week.After intraperitoneal injection of sodium pentothal the tail vein was used as transfusion circuit of perfusion scanning.With supine position of the rats, the routine horizontal scanning of the middle - upper abdomen was applied with MX8000 ( Marconi Co. ). The axial scanning was applied after the intended scanning coverage was selected centered in portal hepatic with at least one lamina passing through kidney. Then perfusion scanning was applied after getting the satisfactory results.Scanning parameters; voltage: 80KV , Electric current; 120mAs, thickness of lamina;5. 0mm , Interval time; 1. 5s/lamina, Visual field;65 -80mm , Matrix; 512 512,Continual scanning 42 -43. 5s after injection of contrast medium,Injection rate; 0. 2ml/s with total dosage of 0. 4 - 0. 6ml after Contrast medium (Omnipaque 350mg/ml) was diluted.The rats were killed after perfusion scanning and the liver was taken out. After fixed in formalin HE dying and pathologic observation were applied under microscope.After the intended area in aorta, portal vein, parenchyma of hepatic right lobe and cortex of kidney were analyzed with PerfXProject software( Xie Xueqian , Department of radiation, the Second affiliated Hospital CMU) , the mean value of HAP, HPP, HPI were obtained.Statistical Analysis; Measurement data was analyzed by independent T test between two groups, and paired - samples T test was used between left and right liver in the same group. P valve of less than 0. 05 and 0. 01 was considered statistically significant, and verysignificant.Result17 rats were excluded from this study , including 14 dead rats during model - making period , 1 rat for anaesthesia and 2 rats fault vein injection. At last 12 rats in experimental group and 10 rats in control group were completed hepatic perfusion CT examination. All rats in experimental group were demonstrated cirrhosis with pathology and normal livers in control group.In hepatic perfusion parameters , Hepatic arterial perfusion and hepatic perfusion index were significantly increased in experimental group. Hepatic portal perfusion and total liver perfusion were decreased in experimental group. There was no differentiation between left half liver and right half liver in two groups.DiscussionAs show in this study , HAP and HPI were increased in rats with cirrhosis and there were statistical difference between two groups (P < 0.05 ,P <0.01 respectively ) . On the contrary , HPP and TLP were decreased in experimental group with statistical difference too between two groups ( P < 0. 01, P < 0. 05 respectively ) . The changes of hepatic haemodynamics were similar with literature and can be explained by the morphologic alterations that occur in cirrhosis. The increased vascular resistance in the cirrhotic liver reduces the portal perfus... |
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