The Study On CT Image Quality In Abdominal Examination With Different Parameters Of Contrast Medium Usage

Objects: The enhancement CT scan with contrast medium can increase the density difference between the lesion and normal tissue, so it can improve the detection and diagnosis accuracy of the lesion. Due to characteristics of the contrast medium, they would produce some side effects for the patients. In order to use the contrast medium reasonablely, this study analyzed the concentration and injection rate of the contrast medium, observed the side effects caused by the contrast medium, then,obtained a group of optimized contrast medium injection scheme.Methods: 120 patients who were selected undertook abdominal CT enhanced scan, not including of the patients with serious liver cirrhosis, diffuse liver cancer, large ascites,heart failure,which could affect the hemodynamic changes. Choosed 7 sites in the liver of the patient as ROIS. Measured the strengthening value of the 7 fixed ROIS (contrast CT value minus non-contrast CTvalue). Then, evaluated the strengthening value of the abdominal aorta, the trunk of portal vein and 5 sites in liver parenchyma in each group. To compared the difference of image enhancement degree in the scans which were applied with different concentration and injection rate of contrast medium in patients.Results: The abdominal CT images with the contrast medium of 370mg/ml and 350mg/ml are better than those with the contrast medium of 300mg/ml. But there were no significant differences in side effects between high concentration and low concentration contrast medium. There was no significant influence in imaging quality in abdominal CT with the injection rate of contrast medium of 3ml/s or 4ml/s. But incidence rate of the side effects in the scan whose contrast medium injection rate was 4ml/s was more than whose contrast medium injection rate was 3ml/s. 17 of 120 patients in the experimental study were produced the side effects after contrast medium injection,which contained as local swelling, thermal pain, numb with different degree, including of 3ml/s injection flow rate in 5 cases, 4ml/s injection flow rate in 12 cases.All of the 120 patients in this study have been done the serologic examinations urea nitrogen (BUN), creatinine (Cr) before and after CT examination within 48 hours .No rise of the results of plasma BUN, Cr. No significant changes of blood pressure, temperature and pulse before and after contrast medium injection.Conclusion: This study analysised the contrast-enhanced abdominal CT image quality and side effects caused by contrast medium in 120 patients, then,found that the CT images with contrast medium concentration of 370mg/ml and 350mg/ml, injection rate of 3ml/s had higher quality ,meantime it could guarantee the safety of patients to the maximum extent. So one set of reasonable parameters of contrast medium usage in abdominal CT imaging was obtained.