The value of real - time sonoelastography on achilles tendon in patients with ankylosing spondylitis

JIAO Rui-rui; NIE Hong-juan; YU Jing; TU Ji-zheng

Abstract：Objective:Real - time sonoelastography(SE)was performed in healthy controls(HC)and patients with anky-losing spondylitis(AS)and the results was contrasted. To investigate the efficacy of SE for assessing achilles tendon abnormali-ties. Methods:B - mode ultrasound and SE was longitudinally and transversely performed in achilles tendons of 30 asymptomat-ic healthy controls and patients with AS. Tendon was divided into proximal(musculotendinous junction),middle(2 ~ 6 cm a-bove insertion at the calcaneus)and distal( insertion at the calcaneus)segments. B - mode examinations included tendon thicknesses,widths,echotextures,and enthesopathic findings. Ultrasound images were graded into three grades:grade 1,normal- appearing tendon( parallel margins,homogeneous echotexture);grade 2,enlarged tendon( bowed margins,homogeneous echotexture);grade 3,hypoechoic area with or without tendon enlargement. SE images were evaluated by the following experi-mentally proven color grading system:grade 1,blue(hardest tissue)to green(hard tissue);grade 2,yellow(intermediate tis-sue);grade 3,red(soft tissue). Results:B - mode recorded the thickness and width of every segment of achilles tendon,then calculated the thickness and width ratio. No significant differences was observed in proximal segment between the 2 groups(P= 0. 495),meanwhile patients with AS performed significant differences with HC at distal and middle segment(P < 0. 001,P =0. 001). The number of abnormal cases of each segment detected by B - mode is not statistically significant between the 2 groups( P = 0 . 298 ,P = 0 . 464 ,P = 0 . 315 ),neitherinproximalandmiddlesegmentbetween2 groupsexaminedbySE( P =0. 298,P = 0. 464,P = 0. 315). There is significant differences in distal part between 2 groups examined by SE(P = 0. 001). B - mode and SE were moderately to well correlated with regard to assessing Achilles tendon abnormalities( Κ = 1 . 0 0 0 ,Κ =0. 674,Κ = 0. 574). Interesting,SE abnormalities were more common in the middle third of the Achilles tendon in the HC group and in the distal third of the Achilles tendon in the AS group. Conclusion:SE and B - mode were moderately to well cor-related with regard to assessing Achilles tendon abnormalities and SE has superior sensitivity in assessing Achilles lesions com-pared with B - mode. SE may be a new valuable method for detecting AS activity or treatment effect and assessing other inf lammatory rheumatic disorders.