Does B-mode common carotid artery intima-media thickness differ from M-mode?

An Increased intima-media thickness of the common carotid artery Is thought to be an early sign of atherosclerosis. Both B- and M-mode ultrasonographi c techniques are used to measure the intima-media thickness of the common c arotid artery (B-IMT and M-IMT, respectively). The present study compares i ntima-media thickness of the common carotid artery measured with the two te chniques. Intima-media thickness was measured in a random population sample of 250 subjects. Comparison was made by mean and 95% confidence intervals of differences between B-IMT and M-IMT, by linear regression analysis, and by intraclass and concordance correlation coefficients. M-IMT was + 0.011 /- 0.091 mm (95% confidence intervals: -0.167 to + 0.188 mm) larger than B- IMT, which was 0.661 +/- 0.136 rum (range: 0.380 to 1.120 mm). Intraclass a nd concordance correlation coefficients were 0.802 and 0.801, respectively. In conclusion, acceptable agreement exists between the two methods and the re was no important systematic difference between B-IMT and M-IMT. (C) 2001 World Federation for Ultrasound in Medicine & Biology.