Thyroid Imaging Reporting and Data System(TI-RADS):Interobserver variability and positive predictive value for assessment of thyroid nodules / 中华超声影像学杂志

ABSTRACT

Objective To retrospectively evaluate interobserver variability between radiologists by using lexicon of the Thyroid Imaging Reporting and Data System ( TI-RADS ) to classify lesions on ultrasonography and retrospectively determine the positive predictive value ( PPV) of each TI-RADS level. Methods Five radiologists retrospectively reviewed 188 consecutive thyroid nodules with known pathologic diagnosis of 172 patients from June,2016 to November,2016. Each observer described each lesion with TI-RADS terminology and final TI-RADS level were assigned by adding the points from all categories. Cohen κ statistic was used to assessed the interobserver variability for each ultrasonographic ( US ) descriptors and final TI-RADS level. PPV for all TI-RADS levels were determined for all readers combined. Results For each US descriptor,composition,echogenicity,shape,margin,echogenic foci,their κ were 0.743 (0.713－0.772),0.418 (0.319－0.517),0.468 (0.389－0.547),0.397 (0.291－0.503) and 0.566 (0.514－0.617) respectively ( data in parentheses are 95% confidential intervals). The κ for TI-RADS level was 0.782 (0.749 －0.81). PPV for TI-RADS level 1 to 5 were 0(0/8),0(0/23),14.3% (4/28),29.7%(11/37) and 85.7% (78/91). Conclusions Interobserver agreement with the TI-RADS terminology is substantial for composition, moderate for echogenicity, shape and echogenic foci, fair for margin. Interobserver agreement is substantial for TI-RADS level. Consequently different understanding in US images has little influence in patient management,justifying the use of ACR-TIRADS in clinical practice.