Sonographic Characteristics and Interval Changes of Subacute Thyroiditis.
OBJECTIVE
This study aimed to assess the sonographic characteristics and interval changes of subacute thyroiditis using follow-up sonography.


METHODS
From January 2008 to December 2014, 85 patients with clinically suspected subacute thyroiditis underwent sonographic examinations by a single radiologist. Subacute thyroiditis was confirmed on the basis of the clinical, sonographic, and cytohistopathologic findings. On the initial and follow-up sonograms, the individual sonographic findings and interval changes were retrospectively investigated by the same radiologist. According to the sonographic configuration, subacute thyroiditis lesions were categorized as nodular or non-nodular. The interval changes in the lesions were classified as follows: "disappeared," "decreased," "increased," "eventually smaller," "eventually larger," or "no interval change."


RESULTS
Subacute thyroiditis was confirmed in 64 of the 85 patients. In these 64 patients, nodular (n = 39) and non-nodular (n = 35) lesions were found; 10 patients had both nodular and non-nodular lesions. Of the 64 patients, 41 underwent sonographic follow-up. In both nodular and non-nodular lesions, the common interval changes included disappeared, decreased, and eventually smaller patterns. Although the increased pattern was found only in 4 nodular lesions, there was no significant difference in the interval changes between nodular and non-nodular lesions. On follow-up sonography, a new lesion was detected in 6 patients.


CONCLUSIONS
The prevalence rate of nodular subacute thyroiditis lesions on sonography was high, and the interval changes in the lesions were variable.
Department of Radiology, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea.
Yoo Jin
YJ
Lee
Department of Radiology, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea dwultra@lycos.co.kr.
Dong Wook
DW
Kim
D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013961:Thyroid Gland / Q000000981:diagnostic imaging; D013968:Thyroiditis, Subacute / Q000000981:diagnostic imaging*; D014463:Ultrasonography / Q000379:methods*; D055815:Young Adult
configuration; follow-up; head and neck ultrasound; sonography; subacute thyroiditis; thyroid