Measurement of common carotid artery intima-media thickness in clinical practice: comparison of B-mode and RF-based technique.
OBJECTIVE
The common carotid artery intima-media thickness (CCA-IMT) is usually measured using B-mode ultrasound images. A different approach for CCA-IMT detection is based on radio frequency (RF) multiple M-line analysis.


METHODS
The present study explores the relationship between B-mode and RF measurement of CCA-IMT, as well as the reproducibility of both methods in 136 patients recently diagnosed with cardiovascular disease. Within one session, repeated measurements were made in the distal CCA bilaterally, using the B-mode (averaged over 10 mm) and RF technique (averaging 12 M-lines over 14 mm).


RESULTS
The two methods correlate well (Pearson r = 0.765). The CCA-IMT values measured with B-mode and RF were 0.779 +/- 0.196 mm and 0.734 +/- 0.172 mm, respectively. B-mode CCA-IMT is significantly larger than RF CCA-IMT (mean difference of 0.045 mm, SEM 7.8 microm; t = 5.82; p < 0.001). In the multivariate regression analysis, carotid artery stenosis, inhomogeneous IMT and diabetes mellitus were the main predictors of differences between B-mode and RF CCA-IMT. The intrapatient variation for B-mode and RF-based CCA-IMT is comparable (0.05 +/- 0.04 mm and 0.07 +/- 0.05 mm, respectively).


CONCLUSIONS
CCA-IMT values measured with RF and B-mode have similar reproducibility and exhibit acceptable correlation, but RF CCA-IMT is significantly smaller. The difference between both methods is mainly due to advanced atherosclerosis. Hence, both methods can be used reliably to measure CCA-IMT in clinical practice.
Schreuder
F H
FH
Department of Clinical Neurophysiology, Maastricht University Medical Centre, 6202 AZ Maastricht, Netherlands. fschreuder@gmail.com
Graf
M
M
Hameleers
J M
JM
Mess
W H
WH
Hoeks
A P
AP
D000368:Aged; D016477:Artifacts; D050197:Atherosclerosis / Q000000981:diagnostic imaging*; D001331:Automation; D002318:Cardiovascular Diseases / Q000453:epidemiology; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging*; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011846:Radio Waves; D012016:Reference Values; D015203:Reproducibility of Results; D012307:Risk Factors; D012984:Software; D017539:Tunica Intima / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000473:pathology; D017540:Tunica Media / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000473:pathology; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods*