A Comparative Study Of Five Urography Methods In Canine By Computed Tomography(CT)

Imaging examination plays an important role in the diagnosis of small animal urinary system diseases.CT urography has been gradually applied to small animal clinical practice because of its excellent high resolution and high diagnostic efficiency.Research on methods of CT urography has rarely been reported.In this paper,the application effects of the traditional fast-injection method,the fast-injection method of abdominal pressure,the fast-injection method of low-dose furosemide contrast agent,the fast-injection method of small-dose furosemide batch injection of contrast agent and the fast-injection method of low-tension pressure-free contrast agent in canine CT urography were compared.Four 12-month-old Chinese garden dogs,half male and half female,with no medical history,were selected for CT urography with five methods.During the experiment,propofol induction,isoflurane maintenance anesthesia and iodohydrin angiography were used.16-row CT scanning was performed in 30 s renal cortex phase,1 min renal medulla phase,5 min early renal excretion,10 min middle renal excretion and 20 min late renal excretion.The images obtained are post-processed by Linux software,using Multiple Planar Reconstruction,Multiple Planar Reconstruction,Volume Rendering and Curved Planar Reformation imaging modes.The development density of each tissue structure of the experimental urinary system was analyzed in the same group,and the urinary anatomy structure display quality,ureteral continuity,lumen CT value and ureteral lumen maximum diameter were compared in the renal excretion period,aiming to evaluate the advantages and disadvantages of the five methods applied in canine CT urography.Blood pressure pulse,whole blood count and liver and kidney biochemical indicators were measured and compared in the early,middle and late stages of the experiment.The test results are as follows:(1)The iohexol used in the experiment had no effect on the blood pressure pulse,whole blood cell count and liver and kidney biochemical indexes of the experimental dogs(P>0.05).(2)The optimal development density of renal cortex and renal medulla is 5 min early in renal excretion;the optimal development density of renal pelvis,renal pelvis and ureter was in the middle of 10 min renal excretion;the optimal development density of the bladder was 20 min late in the renal excretion.(3)In the urinary system anatomical structure display quality:fast-injection method of low-dose furosemide contrast agent and fast-injection method of small-dose furosemide batch injection of contrast agent in the whole kidney excretion period is not statistically different(P>0.05);in the whole kidney excretion period,it is superior to the traditional fast-injection method,the fast-injection method of abdominal pressure and the low tension pressure-free contrast agent fast injection method,and there is statistical difference(P<0.05);There was no statistical difference between the traditional fast-injection method,the fast-injection method of abdominal pressure and the low tension pressure-free contrast agent fast injection method(P>0.05).(4)In terms of ureteral continuity:fast-injection method of low-dose furosemide contrast agent,fast-injection method of small-dose furosemide batch injection of contrast agent were not statistically different in the whole renal excretion period(P>0.05);in the whole kidney excretion period,it is superior to the traditional fast injection method and the low tension and pressure-free contrast agent fast injection method,and there is statistical difference(P<0.05);the early renal excretion at 5 min and the late renal excretion at 20 min were better than the fast intravenous injection of abdominal pressure,with statistical difference(P<0.05).Abdominal pressurization and rapid injection method in the middle of 10 minutes of renal excretion to untie the abdominal pressure band,and fast-injection method of low-dose furosemide contrast agent and fast-injection method of small-dose furosemide batch injection of contrast agent is not statistically significant(P>0.05);it is superior to the traditional fast injection method and the low tension and pressure-free contrast agent fast injection method,and there is statistical difference(P<0.05).The traditional fast injection method and the low tension and pressure-free contrast agent rapid injection method were not statistically different during the whole renal excretion period(P>0.05);There was no significant difference between early renal excretion at 5 min and late renal excretion at 20 min and fast injection of abdominal pressure(P>0.05).(5)In terms of CT value of the lumen in the middle stage of renal excretion at 10 min,there was no statistical difference between the fast-injection method of low-dose furosemide contrast agent and fast-injection method of small-dose furosemide batch injection of contrast agent in the upper segment of renal pelvis and ureter(P>0.05).It was significantly lower than the traditional fast-injection method,the fast-injection method of abdominal pressure and the fast-injection method of low-tension pressure-free contrast agent,with statistical difference(P<0.05).There was no statistically significant difference between the traditional fast-injection method,the fast-injection method of abdominal pressure and the fast-injection method of low-tension pressure-free contrast agent(P>0.05).In the middle segment of the ureter,the fast intraperitoneal compression injection method was higher than the fast intravenous injection method of low-dose furosemide contrast agent and the fast-injection method of small-dose furosemide batch injection of contrast agent,with statistical difference(P<O.OS),and no statistical difference compared with the traditional fast intravenous injection method and the fast intravenous injection method of low-tension pressure-free contrast agent(P>0.05).There were no statistically significant differences between traditional fast injection,low dose furosemide contrast agent fast injection,low dose furosemide group contrast agent fast injection and low tension pressure-free contrast agent fast injection(P>0.05).In the lower segment of the ureter,there were no statistically significant differences between the traditional fast-injection method,the fast-injection method of abdominal pressure,the fast-injection method of low-dose furosemide contrast agent,the fast-injection method of small-dose furosemide batch injection of contrast agent and the fast-injection method of low-tension pressure-free contrast agent(P>0.05).(6)In the middle of the 10th minute renal excretion,the maximum diameter of the ureteral lumen:in the entire ureter,there were no statistically significant differences between the traditional fast-injection method,the fast-injection method of abdominal pressure,the fast-injection method of low-dose furosemide contrast agent,the fast-injection method of small-dose furosemide batch injection of contrast agent and the fast-injection method of low-tension pressure-free contrast agent(P>0.05).Based on the above experimental conclusions,the application of low-dose furacemide in canine CTU has the advantages of thinner contrast agent concentration,clearer image,better tissue structure display quality,full ureter and better ureteral continuity,which facilitates the observation of canine urinary system.The fast-injection method of low-dose furosemide contrast agent and the fast-injection method of small-dose furosemide batch injection of contrast agent of two kinds of methods in dog CTU image display quality and continuity of urinary system and so on are no statistical differences,which are better than the traditional fast injection method,fast abdominal pressure injection method and low tension free of pressure contrast medium injection method,so the two methods are worth applying in clinical trials.