Effect of intravenous injection site on contrast enhancement of CT thorax – Comparison between injection on two sides of cubital

Objective: To investigate the relationship between left or right cubital veins as intravenous contrast injection sites and the quality of enhanced CT thorax images. Materials and Methods: 332 consecutive patients who underwent contrast enhanced MDCT thorax were included. Subjects were divided into three age groups: Group 1- <40 years, group 2- 40-60 years, and group 3- >60 years, who were administered contrast injection into either left or right cubital veins based on stratified randomization. Anteroposterior distance (APD) is defined as the distance between posterior border of manubrium and anterior border of aortic arch or brachiocephalic artery, where left brachiocephalic vein traverses, which was measured and compared against image quality. Results: Contrast enhanced images obtained with injection into the right cubital vein showed better quality than those obtained with injection through the left (P < 0. 05). APD showed a statistically significant difference between group 1 and group 3. No significant difference was found between group 1 and 2, and between group 2 and 3. APD correlated with image quality of scans obtained with injection on left cubital vein (P < 0. 05). Conclusion: Better contrast enhanced CT thorax image quality was seen with injection into right cubital vein by avoiding passage through possibly compressed left brachiocephalic vein, especially in older patients.