Journal of Ultrasound in Medicine, Vol 15, Issue 6 459-464, Copyright © 1996 by American Institute of Ultrasound in Medicine
Digital tapping of the superficial temporal artery: significance in carotid duplex sonography
N. E. Budorick, W. Rojratanakiat, M. K. O'Boyle, D. E. Engelbrecht and B. B. Gosink
Department of Radiology, University of California, San Diego, La Jolla, USA.
To determine whether tapping on the superficial temporal artery correctly
identifies the ECA during carotid sonography, prospective evaluation of the
reflection of the temporal tap on the spectral waveform was recorded and
graded as 3+, 2+, 1+, or 0 in each ECA, ICA, and CCA, with 3+ being the
most brisk response in each carotid system (ipsilateral CCA, ICA, and ECA).
The pattern of response was evaluated in patients with and without
hemodynamically significant (> than 50% diameter) stenoses in CCA, ICA,
and ECA. The most frequent pattern of response to tapping on the
superficial temporal artery was 3+ in the ECA, 2+ in the CCA, and 1+ or 0
in the ICA. This pattern was found in 41% (82/200) of systems overall.
Whether or not stenoses were present in any branch of the extracranial
carotid system, the strongest response (3+) was found in the ECA (58/200
[87%] with stenosis; 119/200 [89%] without stenosis, and lesser responses
in the other arteries: 2+ in the CCA 31/200 [46%] with stenosis; 63/200
[47%] without stenosis, and 1+ or 0 in the ICA 58/200 [87%] with stenosis
and 103/200 [77%] without stenosis). This pattern was unaltered by the
degree of stenosis in the ECA or in the ICA. In 92.5% of the systems
interrogated, the response was greater in the ECA than in the ICA. Tapping
on the superficial temporal artery may be used as a reliable method of
identifying the ipsilateral ECA even in instances of significant
atherosclerotic disease in the ECA, CCA, or ICA.
