Intraindividual comparison of contrast media concentrations for combined abdominal and thoracic MDCT

OBJECTIVE. The purpose of this study was an intraindividual comparison of the degrees of MDCT contrast enhancement achieved with agents containing 300 and 370 mg I/mL. SUBJECTS AND METHODS. Seventy-five patients underwent baseline and follow-up MDCT of the chest and abdomen with contrast media containing a high concentration of iodine (iopromide 370 mg I/mL) and standard iodine concentration (iopromide 300 mg I/mL). The total iodine load (37 g) and the iodine delivery rate (1.29 g/s) were identical for the two protocols. Contrast enhancement in the chest ( right and left ventricles, pulmonary trunk, descending aorta) and the abdomen (aorta, inferior vena cava, portal vein, and liver) was determined. Results were compared by use of paired Student's t tests, and p was adjusted with Bonferroni correction for multiple comparisons (p <= 0.0056). RESULTS. Contrast enhancement was significantly higher for the 300 mg I/mL protocol than for the 370 mg I/mL protocol at all anatomic sites in the chest except the left ventricle ( right ventricle, 359 +/- 100 H vs 320 +/- 102 H, p = 0.003; pulmonary trunk, 334 +/- 96 H vs 303 +/- 89 H, p = 0.003; left ventricle, 310 +/- 54 H vs 300 +/- 51 H, p = 0.036; descending aorta, 300 +/- 63 H vs 277 +/- 57 H, p = 0.0002). No statistically significant differences were found in the abdomen (all p > 0.0056). CONCLUSION. Given equivalent iodine load and delivery rate, the use of 300 mg I/mL contrast medium results in better contrast enhancement than use of 370 mg I/mL contrast medium in CT of the chest. For the portal venous phase of CT of the abdomen, there was no significant difference in contrast enhancement for the two concentrations of iodine.