Reliability of shear wave ultrasound elastography for neck lesions identified in routine clinical practice.
OBJECTIVE
To evaluate the reliability of shear wave ultrasound elastography (SWE) in the neck.


METHODS
176 neck lesions (40 thyroid, 56 lymph nodes, 46 salivary, 34 miscellaneous) identified in a routine US clinic underwent SWE by one or two blinded radiologists. For this study, SWE required the operator to acquire three 10 second dynamic colour-coded SWE cineloops per lesion, select one static image per cineloop, and place circular regions-of-interest within the entire lesion and stiffest part to generate 3 SWE measurements per static image. For logistical reasons, one radiologist evaluated all 176 lesions and the other evaluated 58 lesions. Both radiologists also reviewed 27 archived cineloops independently to assess SWE excluding practical technique. Reliability was assessed using intraclass correlation coefficients (ICCs) concordance correlation coefficients (CCCs) and coefficients of repeatability (CORs).


RESULTS
Test-retest ICCs for the radiologist evaluating 176 lesions were 0.78 - 0.85 (fair-excellent agreement), CCCs were 0.85 - 0.88 (substantial agreement), and CORs were 14.9 - 36.1 kPa. For both radiologists evaluating 58 lesions, intra-rater and inter-rater ICCs were 0.65 - 0.78 and 0.72 - 0.77 respectively. For SWE excluding practical technique, inter-rater ICCs were 0.97 - 0.98 (excellent agreement). ICCs differed according to tissue, being higher in thyroid lesions than lymph nodes (p < 0.001), and higher in benign than malignant lesions (p values < 0.001).


CONCLUSIONS
Intra- and inter-rater reliability of SWE is fair to excellent according to ICCs. SWE reliability is influenced appreciably by acquisition technique. Nevertheless, CORs for SWE are not negligible. To determine whether these results are acceptable clinically, further research is required to establish SWE stiffness values of normal and pathological tissues in the neck.
Diagnostic Imaging and Interventional Radiology, Chinese University of Hong Kong, The Prince of Wales Hospital, 30-32 Ngan Shing Street, NT Shatin, Hong Kong. drkbhatia@cuhk.edu.hk
K
K
Bhatia
C S L
CS
Tong
C C M
CC
Cho
E H Y
EH
Yuen
J
J
Lee
A T
AT
Ahuja
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000000981:diagnostic imaging*; D015588:Observer Variation; D010038:Otorhinolaryngologic Diseases / Q000000981:diagnostic imaging*; D012466:Salivary Gland Diseases / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity; D033081:Shear Strength / Q000502:physiology*; D013223:Statistics as Topic; D013959:Thyroid Diseases / Q000000981:diagnostic imaging; D055815:Young Adult