Abstract: 【Abstract】Objective To evaluate the repeatability of infiltration and contact ultrasound examinations in measuring cephalic vein diameter. Methods Thirty-nine patients were subjected to radial artery-cephalic vein internal fistula angioplasty in left forearm in University-Town Hospital of Chongqing Medical University. Before the surgery, their cephalic vein diameters were measured using infiltration ultrasound and contact ultrasound methods at the same position and at different time points by two professional physicians working in the ultrasonic diagnosis field for more than 10 years. Interclass correlation coefficient (ICC) was used to evaluate the intra- and inter-group consistency of the measurement. Bland-Altman plot analysis was performed to rEevaluate the repeatability. Results The intra- and inter- group consistency of the measurements were quite satisfactory using infiltration ultrasound, with the ICC values of 0.968 (95% CI : 0.939～0.983, P＜0.001) and 0.960 (95% CI : 0.924～0.979, P＜0.001) respectively. The intra- and inter-group consistency of the measurements were 0.718 (95% CI: 0.521～0.843, P<0.001) and 0.692 (95% CI: 0.482～0.827, P＜0.001) respectively using contact ultrasound. In the Bland- Altman cephalic vein diameter scattergrams of intra- and intergroups, the points falling within the 95% LIMITS of agreement (LOA) were 97% in infiltration ultrasound group, and were 94% in contact ultrasound group. The two-dimensional images of cephalic vein, including the structure of proximal field, the anterior wall and intracavitary structure, were clearer in infiltration ultrasound group. Additionally, infiltration ultrasound had the advantages of bigger examination field and simultaneous display of cephalic vein and radial artery. Conclusion The repeatability of cephalic vein diameter measurement and the two-dimensional images of cephalic vein including the structure of proximal field and the scanning scope were better using infiltration ultrasound than using contact ultrasound. Therefore, infiltration ultra-sound is a preferential method for cephalic vein diameter measurement before radial artery-cephalic vein internal fistula angioplasty.

Key words: Infiltration, Contact, Ultrasound, Cephalic vein