Objective:

To explore the value of strain elastography (SE) and shear wave elastography (SWE) in the differential diagnosis of Thyroid Imaging Reporting and Data System (TI-RADS) 4 thyroid nodules with a maximum diameter 1 cm.

Methods:

The ultrasonic imaging results of 263 thyroid nodules in 251 patients who underwent conventional ultrasound

SE and SWE before surgery were retrospectively analyzed

and the pathological results of surgical resection or fine-needle aspiration biopsy were the gold standard. On the SE image

the thyroid tissue around the nodule at the same depth was used as a reference to measure the strain ratio (SR); on the SWE image

the

E

ratio

was similarly measured. The diagnostic cutoff values of SR and

E

ratio

were obtained by receiver operating characteristic (ROC) curve to evaluate the diagnostic efficacy of different examination methods.

Results:

A total of 144 malignant lesions and 119 benign lesions were included in the study. The SR and

E

ratio

values of the malignant group were higher than those of the benign group (SR: 3.14

vs

1.20;

E

ratio

: 2.13

vs

1.21;

P

＜0.05). The areas under the ROC curves of SR

E

ratio

and ultrasound were 0.896

0.840 and 0.746

respectively (

P

＜0.05). The sensitivity

specificity and diagnostic accuracy of SR 2.32 in the diagnosis of TI-RADS 4 malignant nodules with a maximum diameter 1 cm were 87.5%

88.2% and 87.8%

respectively; combined with ultrasound and SR

the diagnostic specificity was increased to 90.8%; ultrasound combined with SRand

E

ratio

improved the diagnostic specificity to 97.8%.

Conclusion:

For TI-RADS 4 thyroid nodules with a maximum diameter 1 cm

compared with the

E

ratio

index

the SR index has higher efficacy in the differential diagnosis of benign and malignant. The combination o

f SR with conventional ultrasound

or further combined with

E

ratio

in SWE

can improve the diagnostic specificity and avoid the possibility of invasive procedures in patients with benign nodules.