A comparison of brachial artery reactivity measured by external and intravascular ultrasound.
External ultrasound (US), EXUS, is widely used to measure brachial artery (BA) diameter changes in the assessment of vascular function; however, it has not been compared with other imaging modalities. We simultaneously measured BA diameter responses to hyperaemic flow and nitrate using EXUS and intravascular ultrasound (US), IVUS, in 10 patients. Mean diameters measured across all time periods correlated closely (r = 0.67, p < 0.001). Percent diameter change to hyperaemia and nitrate also correlated well (r = 0.67, p < 0.01). IVUS cross-sectional area (CSA) was significantly different from that calculated from EXUS using pir(2) (23.95 +/- 4.89 vs. 20.35 +/- 4.51 mm(2), respectively, p < 0.001). Orthogonal diameters measured by IVUS were significantly different (5.45 +/- 0.85 vs. 5.17 +/- 0.79 mm, respectively, p < 0.005). In conclusion, EXUS and IVUS BA diameter measurements correlated well; however, discrepancies in absolute measurements were revealed. The cross-section of the BA is oval; therefore, deriving CSA by pir(2) is inaccurate.
Ong
Paul J L
PJ
Cardiac Medicine, National Heart and Lung Institute, Imperial College of Science, Technology and Medicine and Royal Brompton Hospital, London, UK.
Webb
Carolyn M
CM
Sorensen
Morten B
MB
Hayward
Christopher S
CS
Collins
Peter
P
D000328:Adult; D000368:Aged; D001916:Brachial Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018084:Ultrasonography, Interventional / Q000295:instrumentation*