Journal of Ultrasound in Medicine, Vol 20, Issue 4 371-378, Copyright © 2001 by American Institute of Ultrasound in Medicine
Carotid artery involvement in Takayasu's arteritis: evaluation of the activity by ultrasonography
S. H. Park, J. W. Chung, J. W. Lee, M. H. Han and J. H. Park
Department of Radiology, Seoul National University College of Medicine, Institute of Radiation Medicine, Korea.
The purpose of this study was to investigate the ultrasonographic criteria
for determining the activity of carotid lesions in Takayasu's arteritis. In
10 consecutive patients, common carotid arteries with active lesions (n =
8) and inactive lesions (n = 9) were included in the study. The activity of
the carotid lesions was determined on the basis of clinical and laboratory
findings and computed tomographic scans. Special focus was placed on
thickness and echogenicity of the involved arterial wall and outer diameter
of the involved arterial segment. All 17 common carotid arteries evaluated
showed segmental or diffuse circumferential thickening of the involved
wall. The wall thickness was 2.5 to 5.0 mm (mean +/- SD, 3.3 +/- 0.8 mm) in
active lesions and 1.1 to 2.0 mm (mean, 1.6 +/- 0.4 mm) in inactive
lesions. The outer diameter of the involved segment was 7.0 to 15.0 mm
(mean, 10.0 +/- 2.4 mm) in active lesions and 4.9 to 9.5 mm (mean, 6.8 +/-
1.4 mm) in inactive lesions. Active lesions showed hyperechogenicity in the
full thickness of the involved wall (n = 6) or concentric triple layers
with a hyperechoic middle layer (n = 2). Inactive lesions showed
hyperechogenicity (n = 7) or isoechogenicity (n = 2) of the involved wall.
One active lesion showed intramural arteries. Although precise measurement
to tenths of a millimeter is impossible with the transducer used, prominent
wall thickening with a maintained outer diameter in the common carotid
artery suggests an active lesion, whereas mild wall thickening with a
decreased outer diameter suggests an inactive lesion. Triple layers of a
thickened wall with intramural arteries can be an ultrasonographic finding
of an active lesion.
