Examination of patient factors and contrast medium factors that exert influence on contrast enhancement

PURPOSE: To determine the relationship between patient factors and contrast medium factors, both of which influence contrast enhancement. Our goal was to achieve improved standardization and reproducibility of enhancement based on the findings of this study. METHODS: Enhancement units(EU) and the contrast enhancement index(CE index) were calculated in the areas of the hepatic parenchyma and abdominal aorta in 370 subjects who underwent our hepatic dynamic study. We analyzed the obtained values in terms of differences in age, sex, body weight, iodine volume per body weight, and volume and concentration of contrast medium. RESULTS: Changes in EU values were dependent on total iodine volume and body weight, showing a positive correlation with iodine volume per body weight. When assessed in terms of fixed total volume, the values were found to show a negative correlation with body weight. The obtained CE index values were closely distributed on a fixed iodine volume per weight, with slight variations that were related to sex, body weight, and age. Particularly, in the analysis of changes in enhancement levels according to age, a notable increase in contrast enhancement in inverse relationship with decline in glomerular filtration rate(GFR) with aging was observed.