Retrospective Cohort Study
Copyright ©The Author(s) 2022.
World J Radiol. Jan 28, 2022; 14(1): 19-29
Published online Jan 28, 2022. doi: 10.4329/wjr.v14.i1.19
Table 1 Pooled inter-reader agreement with the reference standard
Pre-training, kPost-training, kP value of the difference
Composition0.46 (95%CI: 0.37 to 0.54), moderate0.52 (95%CI: 0.44 to 0.61), moderate0.32
Echogenicity0.36 (95%CI: 0.29 to 0.44), fair0.44 (95%CI: 0.37 to 0.52), moderate0.30
Shape0.09 (95%CI: 0.02 to 0.21), slight0.67 (95%CI: 0.56 to 0.78), substantial< 0.001
Margins0.03 (95%CI: -0.14 to 0.08), slight0.05 (95%CI: -0.05 to 0.15), slight0.71
Echogenic Foci0.28 (95%CI: 0.19 to 0.37), fair0.45 (95%CI: 0.36 to 0.53), moderate0.004
TI-RADS Level0.14 (95%CI: 0.08 to 0.20), slight0.36 (95%CI: 0.30 to 0.42), fair< 0.001
Recommendations0.36 (95%CI: 0.27 to 0.45), fair0.50 (95%CI: 0.41 to 0.59), moderate0.02
Table 2 Percentage reader agreement with the reference standard for sonographic features
Sonographic feature
RS
R1 pre
R1 post
R2 pre
R2 post
R3 pre
R3 post
Composition
n
n (%)





Spongiform40 (0)1 (25)1 (25)1 (25)3 (75)4 (100)
Cystic or almost completely cystic 113 (27.3)5 (45.5)7 (63.6)8 (72.7)10(90.9)10(90.9)
Mixed cystic and solid 129 (75)6 (50)5 (41.7)7 (58.3)5 (58.3)6 (50)
Solid2726 (96.3)26 (96.3)25 (92.6)26 (96.3)18 (66.7)19 (70.4)
Echogenicity
Anechoic113 (27.3)5 (45.5)5 (45.5)5 (45.5)9 (81.8)8 (72.7)
Hyperechoic or isoechoic2723 (85.2)23 (85.2)19 (70.4)21 (77.8)19 (70.4)20 (74.1)
Hypoechoic122 (16.7)4 (33.3)9 (75)8 (66.7)4 (33.3)4 (33.3)
Shape
Wilder than tall4238 (90.5)39 (92.9)7 (16.7)39 (92.9)41 (97.6)40 (95.2)
Taller than wide87 (87.5)7 (87.5)7 (87.5)7 (87.5)6 (75)4 (50)
Margins
Smooth or ill defined4736 (76.6)35 (74.5)35 (74.5)33 (70.2)43 (91.5)45 (95.7)
Lobulated or irregular31 (33.3)2 (66.7)1 (33.3)2 (66.7)0 (0)0 (0)
Echogenic foci
None or large comet tail artifact4120 (48.8)36 (87.8)29 (70.7)39 (95.1)29 (70.7)29 (70.7)
Macrocalcification31 (33.3)1 (33.3)0 (0)2 (66.7)2 (66.7)2 (66.7)
Punctate echogenic foci65 (83.3)4 (66.7)2 (33.3)5 (83.3)3 (50)3 (50)
Table 3 Percentage reader agreement with the reference standard for American College of Radiology Thyroid Imaging Reporting and Data System levels
ACR TI-RADS levelRS, nR1 pre, n (%)R1 post, n (%)R2 pre, n (%)R2 post, n (%)R3 pre, n (%)R3 post, n (%)
1111 (9.1)5 (45.5)1 (9.1)7 (63.6)10 (90.9)8 (72.7)
293 (33.3)4 (44.4)0 (0)4 (44.4)3 (33.3)3 (33.3)
394 (44.4)5 (55.5)1 (11.1)6 (66.7)4 (44.4)6 (66.7)
4134 (30.8)5 (38.5)5 (38.5)9 (69.2)5 (38.5)5 (38.5)
587 (87.5)4 (50)6 (75)5 (62.5)3 (37.5)3 (37.5)
Table 4 Percentage reader agreement with the reference standard for American College of Radiology Thyroid Imaging Reporting and Data System recommendations
Recommendations
RS, n
R1 pre, n (%)
R1 post, n (%)
R2 pre, n (%)
R2 post, n (%)
R3 pre, n (%)
R3 post, n (%)
No follow up2513 (52)17 (68)10 (40)19 (76)21 (84)22 (88)
Follow up53 (60)1 (20)1 (20)3 (60)3 (60)3 (60)
FNA2017 (85)15 (75)18 (90)17 (85)11 (55)13 (65)
Table 5 The relative sensitivity, specificity, positive predictive value, and negative predictive value per Thyroid Imaging Reporting and Data System Level on the pre-training assessment compared to the reference standard
Pre-training, StatisticsTI-RADS 1, %TI-RADS 2, %TI-RADS 3, %TI-RADS 4, %TI-RADS 5, %
Sensitivity
R19.1 (0.2-41.3)33.3 (7.5-70.1)44.4 (13.7-78.8)30.8 (9.1-61.4)87.5 (47.4-99.7)
R29.1 (0.2-41.3)0 (0-33.6)11.1 (0.3-48.3)38.5 (13.9-68.4)75 (34.9-96.8)
R390.9 (58.7-99.8)33.3 (7.5-70.1)44.4 (13.7-78.8)38.5 (13.9-68.4) 37.5 (8.5-75.5)
Pooled36.4 (20.4-54.9)22.2 (8.6-42.3)33.3 (16.5-54)35.9 (21.2-52.8)66.7 (44.7-84.4)
Specificity
R1100 (91.0-100)90.2 (76.9-97.3)92.7 (80.1-98.5)62.2 (44.8-77.5)76.2 (60.6-88)
R2100 (91-100)97.6 (87.1-99.9)80.5 (65.1-91.2)81.1 (64.8-92)50 (34.2-65.8)
R366.7 (49.8-80.9)97.6 (87.1-99.9)95.1 (83.5-99.4)89.2 (74.6-97)90.5 (77.4-97.3)
Pooled88.9 (81.8-94)95.1 (89.7-98.2)89.4 (82.6-94.3)76.6 (67.6-84.1)72.2 (63.5-79.8)
Positive predictive value
R110042.9 (16.8-73.6)57.1 (26.4-83.2)22.2 (10.3-41.6)41.2 (27.7-56.1)
R2100011.1 (1.8-46.8)41.7 (21.5-65.1)22.2 (14.8-32.1)
R343.5 (32.2-55.5)75 (26-96.2)66.7 (30.1-90.3)55.6 (28.3-79.8)42.9 (17.1-73.2)
Pooled48 (31.8-64.6)50 (25.9-74.1)40.9 (24.8-59.2)35 (23.9-48)31.4 (23.5-40.5)
Negative predictive value
R179.6 (76.4-82.5)86.1 (79.4-90.8)88.4 (80.8-93.2)71.9 (62.2-79.9)97 (83.5-99.5)
R279.6 (76.4-82.5)81.6 (80.9-82.4)80.5 (75.8-84.5)79 (70.4-85.6)91.3 (75.3-97.3)
R396.3 (79.8-99.4)87 (80.7-91.4)88.6 (81.2-93.4)80.5 (72.6-86.5)88.4 (81.5-92.9)
Pooled83.2 (79.2-86.6)84.8 (81.9-87.3)85.9 (82.3-88.9)77.3 (72.5-81.5)91.9 (86.5-95.3)
Table 6 The relative sensitivity, specificity, positive predictive value, and negative predictive value per Thyroid Imaging Reporting and Data System Level on the post-training assessment compared to the reference standard
Post-training, Statistics
TI-RADS 1, %
TI-RADS 2, %
TI-RADS 3, %
TI-RADS 4, %
TI-RADS 5, %
Sensitivity
R145.5 (16.8-76.6)44.4 (13.7-78.8)55.6 (21.2-86.3)38.5 (13.9-68.4)50 (15.7-84.3)
R263.6 (30.8-89.1)44.4 (13.7-78.8)66.7 (29.9-92.5)69.2 (38.6-90.9)62.5 (24.5-91.5)
R372.7 (39-94)33.3 (7.5-70.1)66.7 (29.9-92.5)38.5 (13.9-68.4) 37.5 (8.5-75.5)
Pooled60.6 (42.1-77.1)40.7 (22.4-61.2)63 (42.4-80.6)48.7 (32.4-65.2)50 (29.1-70.9)
Specificity
R192.3 (79.1-98.4)97.6 (87.1-99.9)90.2 (76.9-97.3)70.3 (53-84.1)81 (65.9-91.4)
R294.9 (82.7-99.4)97.6 (87.1-99.9)95.1 (83.5-99.4)73 (38.6-90.9)90.5 (77.4-97.3)
R366.7 (49.8-80.9)95.1 (83.5-99.4)97.6 (87.1-99.9)86.5 (71.2-95.5)90.5 (77.4-97.3)
Pooled84.6 (76.8-90.6)96.8 (91.9-99.1)94.3 (88.6-97.7)76.6 (67.6-84.1)87.3 (80.2-92.6)
Positive predictive value
R162.5 (32-85.5)80 (33.6-96.9)55.6 (29.4-79)31.3 (16.3-51.5)33.3 (16.5-56)
R277.8 (45.8-93.6)80 (33.6-96.9)75 (41.8-92.6)47.4 (32.2-63.1)55.6 (29.9-78.6)
R338.1 (25.8-52.2)60 (22.6-88.5)85.7 (45.1-97.8)50 (25.6-74.4)42.9 (17.1-73.2)
Pooled 52.6 (40.1-64.8)73.3 (48.6-88.9)70.8 (52.8-84.1)42.2 (31.5-53.8)42.9 (29-57.9)
Negative predictive value
R185.7 (77.6-91.2)88.9 (81.7-93.5)90.2 (81.6-95.1)76.5 (66.8-84)89.5 (80.7-94.5)
R290.2 (80.8-95.3)88.9 (81.7-93.5)92.9 (83.7-97)87.1 (74.5-94)92.7 (83.7-96.9)
R389.7 (76.3-95.9)86.7 (80.3-91.2)93 (84.1-97.1)80 (71.9-86.2)88.4 (81.5-92.9)
Pooled 88.4 (83.2-92.1)88.2 (84.5-91.1)92.1 (87.6-95)81 (75.5-85.4)90.2 (85.9-93.2)