Ultrasound Features in the Diagnosis of Takayasu's Arteritis with Carotid Artery Involvement and Evaluation of Disease Activity

  Objective  To investigate the ultrasonographic characteristics of the Takayasu's arteritis (TA) with carotid artery involvement and explore the role of carotid wall thickness in the assessment of disease activity.

  Methods  Totally 58 consecutive TA patients in our hospital were examined by carotid ultrasonography. The sonographic features were investigated and the wall thicknesses were measured.They were further divided into active TA group and inactive TA group. In addition, 58 healthy subjects were enrolled as the control group.The wall thicknesses of the carotid arteries were compared among the active TA group, inactive TA group, and control group. The receiver operating characteristic (ROC) curve was drawn to evaluate the efficacy of the wall thickness of carotid artery in the assessment of disease activity.

  Results  Of these 116 common carotid arteries (CCAs) in 58 patients, 106 CCAs were affected.A characteristic homogeneous isoechoic/hypoechoic, circumferential thickening was shown in 76 involved CCAs(71.7%).In addition, 35 CCAs (33.0%)showed a typical "macaroni" sign, while 67 (63.2%) showed quadri-layer changes and a "target" sign in cross section. The CCA wall was significantly thicker in the TA patients than that in control group (P < 0.001), and it was also thicker in the active TA group than in inactive TA group(P < 0.05). When the ROC analysis was performed with 2.25 mm taken as the cutoff value of wall thickness to evaluate TA activity, the sensitivity was 71.4% and specificity was 66.0%. In stenosis group, the sensitivity rose to 90.0% when 2.40 mm was used as the cutoff value; in non-stenosis group, the specificity rose to 81.5% when 2.25 mm was used as the cutoff value.

  Conclusions  The target sign may become a new sonographic feature for the diagnosis of TA in carotid ultrasonography, and increased wall thickness may be a useful indicator of active disease.