Morphological features of the internal carotid artery: advantages of combining linear and convex probes in duplex ultrasonography.
RATIONALE AND OBJECTIVES
Previous research has determined that carotid abnormalities (CAs) are partly located >3 cm above the carotid bifurcation. However, identifying CAs occurring in this location using high-frequency linear probes is difficult. The aim of this study was to explore the efficacy of a combination of high-frequency and low-frequency probes in duplex ultrasonography for identifying morphologic features of the internal carotid artery (ICA).


MATERIALS AND METHODS
A total of 1055 ICAs from 532 patients were analyzed. CAs were classified prospectively according to the criteria of Wain et al, Weibel and Fields, and Metz et al. The diagnostic rates of high-frequency ultrasonography alone and a combination of high-frequency and low-frequency ultrasonography were compared. The distances from the carotid bifurcation to the initial point of the CA and to the mandibular angle were also measured.


RESULTS
High-frequency ultrasonography detected 23.2% of CAs, and the combination detected 32.2% of CAs (P < .001) in the 1055 ICAs. Of these CAs, 32.4% and 16.8% began >2.5 and >3 cm above the carotid bifurcation, respectively. The distance between the carotid bifurcation and the mandibular angle was <1.5 cm in 100 arteries (9.48%). The diameter of the distal ICA was larger in patients with CAs than in those without CAs (4.33 ± 0.52 vs 4.13 ± 0.49 mm, P < .001).


CONCLUSIONS
Combining high-frequency and low-frequency probes is better than high-frequency probes alone to assess morphologic features of the ICA in duplex ultrasonography. Low-frequency convex probes should be added to traditional ultrasonography for the evaluation of morphologic features of the ICA before carotid endarterectomy, carotid artery stenting, and CA angioplasty.
['Xiong|Jian-Qun|JQ|', 'Yu|Chen|C|', 'Shi|Yu-Wen|YW|', 'Li|Ying-Hua|YH|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D002340:Carotid Artery Diseases D002343:Carotid Artery, Internal D004867:Equipment Design D019544:Equipment Failure Analysis D005260:Female D006801:Humans D007089:Image Enhancement D008297:Male D008875:Middle Aged D015203:Reproducibility of Results D012680:Sensitivity and Specificity D014159:Transducers D018616:Ultrasonography, Doppler, Duplex
morphologic Internal carotid artery convex probes ultrasonography