Assessment of the spatial homogeneity of artery dimension parameters with high frame rate 2-D B-mode

To elicit vessel wall inhomogeneities in diameter and distension along an a rterial segment, a 2-D vessel wall-tracking system based on fast B-mode has been developed, The frame rate of a 7.5-MHz linear-array transducer (lengt h 36 mm) is enhanced by increasing the pulse-repetition frequency to 10 kHz , decreasing the number of echo lines per frame from 128 to 64, or increasi ng the interspacing between echo lines with a factor of two or four. Dedica ted software has been developed to extract for each echo-line the end-diast olic diameter from the B-mode image and the 2-D distension waveform from th e underlying radiofrequency (RF) information, The method is validated in tu bes with various focal lesion sizes. Straight segments of presumably homoge neous common carotid arteries have also been tested. The temporal and spati al SD of diameter or distension reveals inhomogeneities in time or space (i .e., inhomogeneities in artery characteristics). The method can be implemen ted in echo systems supporting high frame rates and real-time processing of radiofrequency data. (C) 2001 World Federation for Ultrasound in Medicine & Biology.