The Relationship Between Peak Time And Peak Value Of Contrast Media Reaching Abdominal Aorta And Patients' Factors

Purpose: 1 To explore a suitable way to get the peak time and peakvalue of the contrast media reaching the abdominal aorta. 2 Toinvestigate the relationship between peak time of contrast mediareaching abdominal aorta and influencing factors. 3 To investigatethe relationship between peak value of contrast media reachingabdominal aorta and patients' factors.Methods: 1 5 cases having plain CT scan and then had contrast CTscan of the arterial phase in the upper abdomen at 25s after contrastmedia administration. Another case were dynamically studied at thelevel of the upper border of the second lumber vertebrae by the testbolus at 12s after administration of contrast media Omnipaque 300mgⅠ/ml at the rate of 2.5ml/1. Images of the arterial phase and of the testbolus were analyzed by the software Dynamic Evaluation to know thealteration of density in the abdominal aorta and to get the highestdensity and its corresponding time. 2 Ominpaque 300mg/ml 20mlwas injected at a rate of 2.5ml/s into 110 patients and after 12s wastracked by test bolus in the abdominal aorta at the level of celiac trunk, then the peak time of abdominal aorta was achieved by the softwaredynamic evaluation. Regression analysis and stepwise regressionanalysis were used to study how the peak time of contrast mediareaching abdominal aorta influenced by the factors including patients'gender, age, height, weight, heart rate, blood pressure, injection siteand with or without heart disease, diabetes mellitus or chemotherapy.3 Ominpaque 300mg/ml 20ml was injected at a rate of 2.5ml/s into108 patients and after 12s was tracked by test bolus in the abdominalaorta at the level of celiac trunk, then the peak value in the abdominalaorta was achieved by the software dynamic evaluation. Regressionanalysis and stepwise regression analysis were used to study how thepeak value of contrast media reaching abdominal aorta influenced bythe patients' factors including patients' gender, age, height, weight,heart rate, blood pressure, injection site, peak time, and whether beingwith heart disease, diabetes mellitus or chemotherapy.Results: 1 The density-time curves of abdominal aorta gottenfrom the Dynamic Evaluation in the arterial phase of the 5 casesshowed that there were no rapid increase and sharp decrease and noaccurate peak value or its corresponding time could be reached. Thedensity-time curve of the abdominal aorta by the test bolus offered anobvious increase and evident decrease, so the peak value and itscorresponding time could be obtained. 2 It was in our study shown that the peak time of contrast media in abdominal aorta wasshorter in female than that in male averagely and shorter as the heartrate and mean arterial blood pressure increased relatively. The peaktime of the injection site in the vein of hand back was longer than thatin the vein of cubitus generally, the older, the longer of the peak timeand it was not influenced by the patients' height, weight or with orwithout subtle diabetes mellitus or chemo. Recommended formula:PT(s)=28.0760+A×0.0789+G×2.1630-HR×0.1086-IS×2.4206-MABP(mmHg)×0.0468(The exact value of G and IS areshown in the full text below). 3 The peak value of contrast mediareaching abdominal aorta was lower in male than that in femaleaveragely, decreased gradually as the patients' height, weight and peaktime increased. The peak value of the injection site in the vein of handback was lower than that of the cubitus generally and it was notinfluenced by the patients' heart rate, blood pressure or whether beingwith heart disease, diabetes mellitus or chemo. Recommended formulaof PV(Hu)=383.8400-H(cm)×1.0909-W(kg)×0.6760+IS×16.7878-PT(s)×1.6882(The exact value of IS is offered in the fulltext below).Conclusion: 1 The peak time and peak value of the contrast mediareaching the abdominal aorta can't be achieved from the arterial phaseafter contrast media administration in the upper abdomen. Dynamical scan of the abdominal aorta after contrast media administration withTest bolus can elicit the peak time and peak value by the softwareDynamic Evaluation. 2 The delayed time after contrast mediumadministration in CT enhanced scan should be adjusted individuallyaccording to the patients' age, gender, heart rate, mean arterial bloodpressure and injection site. 3 The volume of contrast media used inpatients needing exam of enhanced CT scan could be adjusted accordingto the patients' age, gender, height, weight, injection site and peak time.