Added value of two-dimensional shear wave elastography to ultrasonography for staging common femoral vein thrombi.

Unlabelled: prove the performance for staging common femoral vein thrombi (CFVT).

Material And Methods: A total of 194 consecutive patients with CFVT who underwent US and 2D-SWE were enrolled. These patients were categorized into three groups according to CFVT duration: Stage A (≤14 days), Stage B (14 days to 6 months), and Stage C (≥6 months). The diagnostic performance was assessed by the area under the receiver operating characteristic curve (AUC).

Results: Among all US features, CFV diameter ratio of thrombosed leg to contralateral leg (CFVD_ratio) showed the highest AUC in predicting Stage A and Stage C (0.87 and 0.84, respectively). The diagnostic performance of 2D-SWE value of CFVT (CFVT_E) is comparable with that of CFVD_ratio for Stage A (AUC: 0.85, p=0.630), whereas inferior to that of CFVD_ratio for Stage C (AUC: 0.73, p=0.026). Combining CFVD_ratio with CFVT_E showed lower performance in predicting Stage A (AUC: 0.81, p=0.021) and Stage C (AUC: 0.67, p<0.0001) relative to CFVD_ratio alone. However, this combination increased the specificity from 80.3% to 92.7% (p<0.0001) without a significant reduction of sensitivity (from 77.2% to 70.2%, p=0.371) for predicting Stage A.

Conclusions: Adding 2D-SWE to US did not improve the diagnostic performance for staging CFVT compared with US alone. However, the combination improved the specificity in predicting CFVT less than 14 days without loss of sensitivity.