B-Flow Twinkling Sign in Preoperative Evaluation of Cervical Lymph Nodes in Patients with Papillary Thyroid Carcinoma

Table 2

The diagnostic performance of the combination of each conventional ultrasound signs with the BFI-TS.

Combined US features	Total lymph nodes (604)	Metastatic lymph nodes (298)	Sensitivity; (%)	Specificity; (%)	𝑃	PPV	NPV
Round shape; Short to long axis (diameter ratio > 0.5); + BFI-TS	126	125	41.9	99.7	𝜒^2 158.4; 𝑃 0.0000	99.2	63.8
Abnormal echogenicity; + BFI-TS	200	200	67.1	100	𝜒^2 307; 𝑃 0.0000	100	75.7
Absence of the hilum; + BFI-TS	221	221	74.2	100	𝜒^2 357.9; 𝑃 0.0000	100	78.9
Calcification; + BFI-TS	92	92	30.9	100	𝜒^2 111.4; 𝑃 0.0000	100	59.8
Cystic change; + BFI-TS	61	61	20.5	100	𝜒^2 69.7; 𝑃 0.0000	100	56.4
Peripheral vascularity; + BFI-TS	117	116	39.9	99.7	𝜒^2 144; 𝑃 0.0000	99.1	62.6

US: ultrasound; LNs: lymph nodes; PPV: positive predictive value; NPV: negative predictive value; BFI-TS: B-flow imaging twinkling sign.