Cross-section imaging with M-mode as an alternative method for the measurement of brachial artery flow-mediated vasodilation.
OBJECTIVE
Endothelial dysfunction is well known as a risk marker for initiation and progression of atherosclerosis. Flow-mediated vasodilation (FMD) of the brachial artery induced by postischemic forearm hyperemia is a widely used noninvasive method for evaluating endothelial function. M-mode ultrasonography offers high spatial and temporal resolution and is therefore suitable for diameter measurement of pulsatile vessels. We intended to compare FMD values obtained by M-mode on cross-section images and by the conventional method, ie, measurement with B-mode ultrasonography on longitudinal images.


METHODS
We recruited 37 subjects (19 women, mean age: 48.3 ± 15.2 years; range: 23-71 years) in whom we measured the brachial artery diameters at baseline and at maximum dilation after forearm ischemia. FMD was calculated as the percentage of postischemic dilation.


RESULTS
Baseline (3.92 ± 0.72 versus 3.91 ± 0.58 mm; p = 0.97) and maximal dilated diastolic diameter (4.26 ± 0.76 versus 4.23 ± 0.61 mm; p = 0.84), FMD (8.98 ± 3.84 versus 8.14 ± 1.99%; p = 0.84), and time to maximum dilation (48.7 ± 9.0 versus 49.3 ± 6.4 seconds, p = 0.64) were not different between the two methods.


CONCLUSIONS
M-mode brachial artery diastolic and systolic diameter measurement is feasible, suitable, and accurate for the assessment of FMD without the need for electrocardiography.
Department of Neurology, Gachon University Gil Hospital, Incheon, South Korea.
Dong Hoon
DH
Shin
Jin Soo
JS
Lee
Ji Man
JM
Hong
Sun Yong
SY
Kim
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001916:Brachial Artery / Q000000981:diagnostic imaging* / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography / Q000379:methods*; D014664:Vasodilation