Comparison of Enhancement, Image Quality, Cost, and Adverse Reactions Using 2 Different Contrast Medium Concentrations for Routine Chest CT on 16-Slice MDCT

Objective: To evaluate the degree of enhancement and image quality of chest computed tomographic (CT) examinations on 16-slice multidetector CT using low-concentration [300 milligrams of iodine per milliliter (mg I/mL)] and high-concentration (370 mg I/mL) contrast media; to assess the impact on cost and adverse reactions of the use of high-iodine concentration contrast medium. Materials and Methods: A total of 100 patients scheduled for routine chest CT examinations were administered nonionic contrast medium of 2 strengths: low-iodine concentration contrast medium (300 mg I/mL) [group A: n = 50; male-female ratio, 28:22; mean age, 58.4 years] and high-iodine concentration contrast medium (370 mg I/mL) (group B: n = 50; male-female ratio, 18:32; mean age, 57.6 years) with a constant amount of iodine (400 mg) injected per kilogram of body weight. Contrast media were injected using a dual injector at 2.5 mL/s followed by a 30-mL saline at 2.5 mL/s. The degree of enhancement was quantified by measuring Hounsfield unit values in different arteries and veins and was also rated on a 5-point scale for qualitative assessment. We also evaluated perivenous contrast-related artifacts. The data were compared using Mann-Whitney U test for both qualitative and quantitative enhancement ratings. A P value of less than 0.05 was considered statistically significant. The P value was adjusted using Bonferroni correction for statistical significance when multiple comparisons were performed. The difference in cost and the incidence of adverse reactions in both groups were calculated. Results: The mean enhancement values in group B were significantly greater (P < 0.05) than those in group A. The mean Hounsfield units and standard deviation in groups A and B were aorta = 153 ± 4, 216 ± 20; pulmonary artery = 147 ± 10, 208 ± 20; superior vena cava = 155 ± 27, 299 ± 72; and pulmonary vein = 134 ± 10, 215 ± 30, respectively. The mean enhancement on a 5-point scale was greater in group B (4.2) than in group A (3.3) (P < 0.01). No significant difference between groups in perivenous artifacts was seen. Up to 5.5% savings in cost resulted from the use of a higher concentration of iodine, with no increase in adverse reactions. Conclusions: Use of higher-concentration contrast media provides a higher degree of contrast enhancement and image quality for a routine chest CT on a 16-slice multidetector CT. It also contributes to considerable cost savings with no increased risk of adverse reactions compared with low-concentration contrast media.