Hippo-YAP/TAZ signalling coordinates adipose plasticity and energy balance by uncoupling leptin expression from fat mass.

Adipose tissues serve as an energy reservoir and endocrine organ, yet the mechanisms that coordinate these functions remain elusive. Here, we show that the transcriptional coregulators, YAP and TAZ, uncouple fat mass from leptin levels and regulate adipocyte plasticity to maintain metabolic homeostasis. Activating YAP/TAZ signalling in adipocytes by deletion of the upstream regulators Lats1 and Lats2 results in a profound reduction in fat mass by converting mature adipocytes into delipidated progenitor-like cells, but does not cause lipodystrophy-related metabolic dysfunction, due to a paradoxical increase in circulating leptin levels. Mechanistically, we demonstrate that YAP/TAZ-TEAD signalling upregulates leptin expression by directly binding to an upstream enhancer site of the leptin gene. We further show that YAP/TAZ activity is associated with, and functionally required for, leptin regulation during fasting and refeeding. These results suggest that adipocyte Hippo-YAP/TAZ signalling constitutes a nexus for coordinating adipose tissue lipid storage capacity and systemic energy balance through the regulation of adipocyte plasticity and leptin gene transcription.

YAP/TAZ direct commitment and maturation of lymph node fibroblastic reticular cells.

Fibroblastic reticular cells (FRCs) are immunologically specialized myofibroblasts of lymphoid organ, and FRC maturation is essential for structural and functional properties of lymph nodes (LNs). Here we show that YAP and TAZ (YAP/TAZ), the final effectors of Hippo signaling, regulate FRC commitment and maturation. Selective depletion of YAP/TAZ in FRCs impairs FRC growth and differentiation and compromises the structural organization of LNs, whereas hyperactivation of YAP/TAZ enhances myofibroblastic characteristics of FRCs and aggravates LN fibrosis. Mechanistically, the interaction between YAP/TAZ and p52 promotes chemokine expression that is required for commitment of FRC lineage prior to lymphotoxin-ß receptor (LTßR) engagement, whereas LTßR activation suppresses YAP/TAZ activity for FRC maturation. Our findings thus present YAP/TAZ as critical regulators of commitment and maturation of FRCs, and hold promise for better understanding of FRC-mediated pathophysiologic processes.

The association between thyroid echogenicity and thyroid function in pediatric and adolescent Hashimoto's thyroiditis.

In this study, we evaluated the association between thyroid echogenicity on ultrasonography (US) and thyroid function in pediatric and adolescent Hashimoto's thyroiditis (HT) patients.In 86 pediatric and adolescent HT patients, the association between echogenicity and thyroid function and microsomal autoantibody status was evaluated. Among patients with overt hypothyroidism, 89.2% (33/37) showed a US grade of 3 or 4. All of the patients at grade 4 presented with overt hypothyroidism. In contrast, 97.8% (44/49) of the patients with subclinical hypothyroidism or euthyroidism showed grades 1 or 2. Patients with increased thyroid-stimulating hormone titer also tended to have increased US grades (P < .001). In contrast, free thyroxine levels were significantly decreased with increasing US grade (P < .001).In conclusion, patients with higher US grades had decreased thyroid function (P < .001).

Correction to: Effect of training on ultrasonography (US) BI-RADS features for radiology residents: a multicenter study comparing performances after training.

The original version of this article, published on 07 January 2019, unfortunately contained a mistake.

Effect of training on ultrasonography (US) BI-RADS features for radiology residents: a multicenter study comparing performances after training.

OBJECTIVES: To evaluate the effect of training radiology residents on breast ultrasonography (US) according to the Breast Imaging Reporting And Data System (BI-RADS) and the factors that influence the training effect. METHODS: This multicenter, prospective study was approved by eight institutional review boards. From September 2013 to July 2014, 248 breast masses in 227 women were included for US image acquisition. Representative B-mode and video images of the breast masses were recorded, among which 54 cases were included in the education set and 66 in the test set. Sixty-one radiology residents scheduled for breast imaging training individually reviewed the test set, immediately before, 1 month after, and 6 months after training. Diagnostic performances and US descriptors of the residents were evaluated and compared against those of expert radiologists. RESULTS: Agreements between residents and experienced radiologists showed improvement after training, while agreements between post-training and post-6-month training descriptors did not show significant differences (all p > 0.05, respectively). Sensitivity, negative predictive value (NPV), and AUC were significantly improved for residents post-training and post-6-month training (all p < 0.05), while approximating the performances of expert radiologists except for AUC (0.836, 0.840, and 0.908, respectively, p < 0.05). Low levels of pre-training AUC, total number of breast US examinations, and the number of sessions per week that residents were involved in were factors influencing the improvement of AUC. CONCLUSION: Training using education material dedicated for breast US imaging effectively improved the diagnostic performances of radiology residents and agreements with experienced radiologists on US BI-RADS features. KEY POINTS: • Agreements on lesion descriptors between residents and experienced radiologists showed improvement after training, regardless of test point. • Sensitivity, NPV, and AUC were significantly improved for residents in post-training and post-6-month training (all p < 0.05). • Low levels of pre-training AUC, total number of breast US examinations, and the number of sessions per week that residents were involved in were factors influencing the improvement of AUC.

Insulin receptor substrate 2: a bridge between Hippo and AKT pathways.

NAFLD induces the development of advanced liver diseases such as NASH and liver cancer. Therefore, understanding the mechanism of NAFLD development is critical for its prevention and treatment. Ablation of PTEN or Hippo pathway components induces liver cancer in a murine model by hyperactive AKT or YAP/TAZ, respectively. Although the regulation of these two pathways occurs in the same hepatocyte, the details of crosstalk between Hippo-YAP/TAZ and PTEN-AKT pathways in liver homeostasis and tumorigenesis still remain unclear. Here, we found that depletion of both PTEN and SAV1 in liver promotes spontaneous NAFLD and liver cancer through hyperactive AKT via YAP/TAZmediated up-regulation of IRS2 transcription. Conversely, NAFLD is rescued by both ablation of YAP/TAZ and activation of the Hippo pathway. Furthermore, human HCC patients with NAFLD showed strong correlation between YAP/TAZ and IRS2 or phospho-AKT expression. Finally, the inhibition of AKT by MK-2206 treatment attenuates NAFLD development and tumorigenesis. Our findings indicate that Hippo pathway interacts with AKT signaling during the intervention with IRS2 to prevent NAFLD and liver cancer. [BMB Reports 2018; 51(5): 209-210].

Thyroid nodules and cancer in children and adolescents affected by Hashimoto's thyroiditis.

OBJECTIVE: To investigate the rates of thyroid nodules and cancer in pediatric cases of Hashimoto's thyroiditis (HT) in Korea. METHODS: We retrospectively reviewed 89 pediatric and adolescent patients (age, 3-18.0 years) with HT who underwent thyroid ultrasonography (US) at our institution from February 2006 to July 2016. The diagnosis of HT was based on the presence of thyroid autoantibodies. The presence of any thyroid nodules with US and cytopathologic features was analyzed. The malignancy rate was also determined. RESULTS: Thyroid nodules were in 20 of the 89 patients (22.4%). Eight of these 20 patients (40%) had colloid cysts, two (10%) had nodular hyperplasia, one (5%) had follicular adenoma, and two (10%) had lymphocytic thyroiditis. Seven of the 89 patients (7.9%) were confirmed to have a malignancy, all of which were papillary thyroid carcinoma (PTC); of those, five patients had diffuse sclerosing variant PTC, and two had conventional PTC on pathology. CONCLUSION: The prevalence of thyroid nodules in children and adolescents with HT was 22.4%. The malignancy rate of children with HT was 7.9%. The malignancy rate among thyroid nodules was 35%, which is higher than the 26% rate generally reported for children with nodules. Therefore, using thyroid US to survey known or suspected thyroid nodules might be helpful in children and adolescents with HT and may provide further useful diagnostic information. Advances in knowledge: Thyroid US could help to assess HT patients who have known or suspected thyroid nodules.

Hippo-mediated suppression of IRS2/AKT signaling prevents hepatic steatosis and liver cancer.

Nonalcoholic fatty liver disease (NAFLD) is a major risk factor for liver cancer; therefore, its prevention is an important clinical goal. Ablation of phosphatase and tensin homolog (PTEN) or the protein kinase Hippo signaling pathway induces liver cancer via activation of AKT or the transcriptional regulators YAP/TAZ, respectively; however, the potential for crosstalk between the PTEN/AKT and Hippo/YAP/TAZ pathways in liver tumorigenesis has thus far remained unclear. Here, we have shown that deletion of both PTEN and SAV1 in the liver accelerates the development of NAFLD and liver cancer in mice. At the molecular level, activation of YAP/TAZ in the liver of Pten-/- Sav1-/- mice amplified AKT signaling through the upregulation of insulin receptor substrate 2 (IRS2) expression. Both ablation of YAP/TAZ and activation of the Hippo pathway could rescue these phenotypes. A high level of YAP/ TAZ expression was associated with a high level of IRS2 expression in human hepatocellular carcinoma (HCC). Moreover, treatment with the AKT inhibitor MK-2206 or knockout of IRS2 by AAV-Cas9 successfully repressed liver tumorigenesis in Pten-/- Sav1-/- mice. Thus, our findings suggest that Hippo signaling interacts with AKT signaling by regulating IRS2 expression to prevent NAFLD and liver cancer progression and provide evidence that impaired crosstalk between these 2 pathways accelerates NAFLD and liver cancer.

Normative Values for Tonsils in Pediatric Populations Based on Ultrasonography.

OBJECTIVES: Pediatric tonsillar infections are common, particularly in adolescents. Ultrasonography (US) has high sensitivity and specificity for diagnosing peritonsillar abscesses and can diagnose tonsillitis by enlargement of the gland. In this study, we established normal tonsillar measurements and volumes according to age in pediatric populations. METHODS: Transcervical US of the peritonsillar region to measure tonsillar size and volume was performed in patients who had undergone neck US without throat symptoms from October 2016 to May 2017. Transverse and anteroposterior diameters, length, and volume were measured. RESULTS: In total, 161 patients (age range, 1 month-18 years) were enrolled in the study. The mean tonsillar volumes ± SD were 1.58 ± 1.26 (total), 0.30 ± 0.14 (<1 year), 1.27 ± 0.57 (1-<5 years), 2.06 ± 1.09 (5-<10 years), and 2.19 ± 1.48 (>10 years) cm3 . Mean measurements for the sums of both tonsils for the transverse diameter, anteroposterior diameter, and length were 1.98 ± 0.61, 2.17 ± 0.66, and 2.28 ± 0.69 cm, respectively. Tonsillar size and volume increased according to age. Simplified models for volume estimation showed that anteroposterior diameters had the highest coefficients of determination (R2 = 0.71 and 0.74). Regression models for the tonsillar volume of 6 measurements in the multiple linear regression models showed an R2 of 0.89. Regression models for log(volume) showed an improved coefficient of determination (R2 = 0.96). CONCLUSIONS: These normal tonsillar sizes on transcervical ultrasound in pediatric patients can be used to diagnose tonsillar lesions.

Analysis of RAS mutation in thyroid nodular hyperplasia and follicular neoplasm in a Korean population.

BACKGROUND: To investigate the difference in frequency of RAS mutations between nodular hyperplasia (NH), follicular thyroid adenomas (FTAs) and follicular thyroid carcinomas (FTCs) in a Korean population. METHODS: RAS mutations in 50 NH, 57 FTAs and 39 FTCs between January 2002 and May 2015 were analysed by pyrosequencing. RESULTS: Nine nodules of 50 NHs (18%), 18 nodules of 39 FTCs (46.2%) and 19 nodules of 57 FTAs (33.3%) harboured RAS mutations. Three FTCs and three FTAs showed two point mutations simultaneously. N-RAS codon 61 (n = 6 of 9, 66.7%) and H-RAS codon 61 (n = 3 of 9, 33.3%) were found in NHs. K-RAS codons 12-13, K-RAS codon 61, N-RAS codons 12-13 and H-RAS codons 12-13 were not found in NHs. N-RAS codon 61 (n = 7 of 21, 33.3%), K-RAS codons 12-13 (n = 6 of 21, 28.6%), H-RAS codon 61 (n = 4 of 21, 19.0%), K-RAS codon 61 (n = 3 of 21, 14.3%) and N-RAS codons 12-13 (n = 1 of 21, 4.7%) were found in FTCs, and N-RAS codon 61 (n = 10 of 22, 45.5%), K-RAS codons 12-13 (n = 5 of 22, 22.7%), H-RAS codon 61 (n = 5 of 22, 22.7%), K-RAS codon 61 (n = 1 of 22, 4.5%) and N-RAS codons 12-13 (n = 1 of 22, 4.5%) were observed in FTAs. CONCLUSIONS: The frequencies of RAS mutations among our Korean population were 18% in NHs, 46.2% in FTC and 33.3% in FTAs. N-RAS codon 61 was the most frequent mutation in NHs, FTCs and FTAs, and the frequency was not significantly different among the three groups. K-RAS codons 12-13 were the second most commonly involved site in FTCs and FTAs, whereas no mutation was detected at this site in NHs.

Papillary Thyroid Carcinoma Arising Within a Follicular Adenoma: A Case Report, Ultrasound Features, and Considerations.

Papillary thyroid carcinoma (PTC) arising within a follicular adenoma is an exceptionally rare histopathological subtype that shows the nuclear features of PTC within a benign-appearing, circumscribed follicular adenoma. Although it is clinically significant because of its malignant nature, its ultrasonographic features have not been described previously. A 26-year-old man presented with a heterogeneous isoechoic solid nodule with a marked hypoechoic solid focus and a low echoic peripheral rim in the right thyroid gland on ultrasonography. On color Doppler images, markedly increased vascularity was seen in the hypoechoic solid component. An ultrasound-guided gun biopsy suggested a follicular neoplasm. In the evaluation of a hemithyroidectomy specimen, thyroid follicles and a thin fibrous capsule were seen, which favored a follicular adenoma with tumor cells in a focal area indicating papillary carcinoma. Here, we report a case of PTC arising within a follicular adenoma and discuss possible considerations in thyroid ultrasonographic examinations.

Can Nodular Hyperplasia of the Thyroid Gland be Differentiated From Follicular Adenoma and Follicular Carcinoma by Ultrasonography?

OBJECTIVES: The aim of this study was to evaluate the ultrasonographic features for differentiation of follicular thyroid lesions. METHODS: Ultrasonographic features of surgically confirmed 56 follicular adenoma (FA), 22 follicular carcinoma (FC), and 100 nodular hyperplasia (NH) were evaluated using univariable and multivariable multinomial logistic regression analyses, receiver operating characteristic analyses, and areas under the curve. RESULTS: Tumor diameter, margin, echotexture, cystic changes, calcification, hypoechoic rim, and vascularity were significant on univariable analysis. On multivariable logistic regression analyses, tumor diameter (FA, P = 0.002; odds ratio [OR], 0.75; FC, P = 0.001; OR, 2.02), absence of cystic changes (FA, P = 0.127; OR, 2.21; FC, P ≤ 0.001; OR, 17.74), absence of spongiform appearance (FA, P = 0.234; OR, 0.31; FC, P < 0.001; OR,  1673.46), and peripheral vascularity (FA, P = 0.004; OR, 26.64; FC, P < 0.001; OR, 145060.38) differed significantly among the 3 follicular lesions, with NH as a reference. The areas under the curve for NH, FA, and FC were 0.844, 0.858, and 0.705, respectively, and diagnostic accuracy was 72.6%. CONCLUSIONS: Tumor diameter, cystic changes, spongiform appearance, and peripheral vascularity differed significantly among follicular lesions. The diagnostic capability was moderate.

Diagnostic Utility of Acoustic Structure Quantification for Evaluation of Radiation Sialadenitis after Radioactive Iodine Therapy.

Acoustic structure quantification (ASQ) software was used to analyze statistical information on acquired echo signals, to determine the ability of ASQ to distinguish normal salivary glands of asymptomatic patients from glands of patients with radiation sialadenitis (RS) after radioactive iodine therapy. The ASQ values of 192 salivary glands were compared by multinomial logistic regression analysis, and receiver operating characteristic curves were constructed. Between-observer agreement was assessed by calculating the intra-class correlation coefficient. The mean ASQ values of patients with chronic RS or asymptomatic patients who had undergone radioactive iodine therapy were greater than those of patients with normal glands (p < 0.001). The ratio was associated with the highest odds ratio in patients with chronic RS compared with normal patients. Diagnostic performance was moderate; the intra-class correlation coefficient between observers was very good. ASQ can objectively differentiate RS-affected tissue from normal salivary tissue and is thus valuable for clinically diagnosing RS after radioactive iodine therapy.

Comparison of Inter-Observer Variability and Diagnostic Performance of the Fifth Edition of BI-RADS for Breast Ultrasound of Static versus Video Images.

Our aim was to compare the inter-observer variability and diagnostic performance of the Breast Imaging Reporting and Data System (BI-RADS) lexicon for breast ultrasound of static and video images. Ninety-nine breast masses visible on ultrasound examination from 95 women 19-81 y of age at five institutions were enrolled in this study. They were scheduled to undergo biopsy or surgery or had been stable for at least 2 y of ultrasound follow-up after benign biopsy results or typically benign findings. For each mass, representative long- and short-axis static ultrasound images were acquired; real-time long- and short-axis B-mode video images through the mass area were separately saved as cine clips. Each image was reviewed independently by five radiologists who were asked to classify ultrasound features according to the fifth edition of the BI-RADS lexicon. Inter-observer variability was assessed using kappa (κ) statistics. Diagnostic performance on static and video images was compared using the area under the receiver operating characteristic curve. No significant difference was found in κ values between static and video images for all descriptors, although κ values of video images were higher than those of static images for shape, orientation, margin and calcifications. After receiver operating characteristic curve analysis, the video images (0.83, range: 0.77-0.87) had higher areas under the curve than the static images (0.80, range: 0.75-0.83; p = 0.08). Inter-observer variability and diagnostic performance of video images was similar to that of static images on breast ultrasonography according to the new edition of BI-RADS.

Validation of the fifth edition BI-RADS ultrasound lexicon with comparison of fourth and fifth edition diagnostic performance using video clips.

PURPOSE: The aim of this study was to evaluate the positive predictive value (PPV) and the diagnostic performance of the ultrasonographic descriptors in the fifth edition of BI-RADS, comparing with the fourth edition using video clips. METHODS: From September 2013 to July 2014, 80 breast masses in 74 women (mean age, 47.5±10.7 years) from five institutions of the Korean Society of Breast Imaging were included. Two radiologists individually reviewed the static and video images and analyzed the images according to the fourth and fifth edition of BI-RADS. The PPV of each descriptor was calculated and diagnostic performances between the fourth and fifth editions were compared. RESULTS: Of the 80 breast masses, 51 (63.8%) were benign and 29 (36.2%) were malignant. Suspicious ultrasonographic features such as irregular shape, non-parallel orientation, angular or spiculated margins, and combined posterior features showed higher PPV in both editions (all P<0.05). No significant differences were found in the diagnostic performances between the two editions (all P>0.05). The area under the receiver operating characteristics curve was higher in the fourth edition (0.708 to 0.690), without significance (P=0.416). CONCLUSION: The fifth edition of the BI-RADS ultrasound lexicon showed comparable performance to the fourth edition and can be useful in the differential diagnosis of breast masses using ultrasonography.

The Diffuse Sclerosing Variant of Papillary Thyroid Cancer Presenting as Innumerable Diffuse Microcalcifications in Underlying Adolescent Hashimoto's Thyroiditis: A Case Report.

Hashimoto's thyroiditis is the most common diffuse thyroid disease and is characterized by diffuse lymphocytic infiltration. However, the ultrasonographic findings of papillary thyroid carcinomas that arise from Hashimoto's thyroiditis in the pediatric and adolescent population are not well known.We report a rare ultrasonographic finding in a 22-year-old woman diagnosed with the diffuse sclerosing variant of papillary thyroid carcinoma that arose from underlying Hashimoto's thyroiditis: innumerable diffuse microcalcifications instead of a typical malignant-appearing nodule.

Papillary Thyroid Carcinoma Arising in Children and Adolescent Hashimoto's Thyroiditis: Ultrasonographic and Pathologic Findings.

Objectives. We compared the ultrasonography and pathology features of papillary thyroid carcinoma (PTC) in pediatric and adolescents with Hashimoto's thyroiditis (HT) with those of non-HT patients. Materials and Methods. Eleven patients who were surgically confirmed to have pediatric or adolescent PTC from 2006 to 2014 were included in this study. We retrospectively analyzed the preoperative ultrasonography and pathology features of PTC arising in HT and non-HT patients. Results. On ultrasonography, thyroid gland was lobulated and enlarged, with many scattered microcalcifications in four of five HT patients. Four of six non-HT patients had suspicious masses with calcifications. The diffuse sclerosing variant of PTC (DSVPTC) was found in three of five HT patients, but none in non-HT patients. Macroscopic or microscopic extrathyroidal extension was evident in all of the HT patients and four of the non-HT patients. Neck lymph node metastases were in all HT patients and five of non-HT patients. Conclusions. Three of five PTCs in pediatric and adolescent HT patients were DSVPTC, whereas all PTCs of the non-HT patients were classic type. On ultrasonography, thyroid gland was diffusely enlarged with scattered microcalcifications in four of five HT patients. All five HT cases had aggressive disease, including extrathyroidal extension and cervical lymph node metastases.

Investigation of Acoustic Structure Quantification in the Diagnosis of Thyroiditis.

OBJECTIVE: The objective of this study was to evaluate the ability of acoustic structure quantification (ASQ) to diagnose thyroiditis. MATERIALS AND METHODS: The echogenicity of 439 thyroid lobes, as determined using ASQ, was quantified and analyzed retrospectively. Thyroiditis was categorized into five subgroups. The results were presented in a modified chi-square histogram as the mode, average, ratio, blue mode, and blue average. We determined the cutoff values of ASQ from ROC analysis to detect and differentiate thyroiditis from a normal thyroid gland. We obtained data on the sensitivity and specificity of the cutoff values to distinguish between euthyroid patients with thyroiditis and patients with a normal thyroid gland. RESULTS: The mean ASQ values for patients with thyroiditis were statistically significantly greater than those for patients with a normal thyroid gland (p < 0.001). The AUCs were as follows: 0.93 for the ratio, 0.91 for the average, 0.90 for the blue average, 0.87 for the mode, and 0.87 for the blue mode. For the diagnosis of thyroiditis, the cutoff values were greater than 0.27 for the ratio, greater than 116.7 for the mean, and greater than 130.7 for the blue average. The sensitivities and specificities were as follows: 84.0% and 96.6% for the ratio, 85.3% and 83.0%, for the average, and 79.1% and 93.2% for the blue average, respectively. The ASQ parameters were successful in distinguishing patients with thyroiditis from patients with a normal thyroid gland, with likelihood ratios of 24.7 for the ratio, 5.0 for the average, and 11.6 for the blue average. With the use of the aforementioned cutoff values, the sensitivities and specificities for distinguishing between patients with thyroiditis and euthyroid patients without thyroiditis were 77.05% and 94.92% for the ratio, 85.25% and 82.20% for the average, and 77.05% and 92.37% for the blue average, respectively. CONCLUSION: ASQ can provide objective and quantitative analysis of thyroid echogenicity. ASQ parameters were successful in distinguishing between patients with thyroiditis and individuals without thyroiditis, with likelihood ratios of 24.7 for the ratio, 5.0 for the average, and 11.6 for the blue average.

Using Acoustic Structure Quantification During B-Mode Sonography for Evaluation of Hashimoto Thyroiditis.

OBJECTIVES: This study aimed to evaluate the usefulness of Acoustic Structure Quantification (ASQ; Toshiba Medical Systems Corporation, Nasushiobara, Japan) values in the diagnosis of Hashimoto thyroiditis using B-mode sonography and to identify a cutoff ASQ level that differentiates Hashimoto thyroiditis from normal thyroid tissue. METHODS: A total of 186 thyroid lobes with Hashimoto thyroiditis and normal thyroid glands underwent sonography with ASQ imaging. The quantitative results were reported in an echo amplitude analysis (Cm(2)) histogram with average, mode, ratio, standard deviation, blue mode, and blue average values. Receiver operating characteristic curve analysis was performed to assess the diagnostic ability of the ASQ values in differentiating Hashimoto thyroiditis from normal thyroid tissue. Intraclass correlation coefficients of the ASQ values were obtained between 2 observers. RESULTS: Of the 186 thyroid lobes, 103 (55%) had Hashimoto thyroiditis, and 83 (45%) were normal. There was a significant difference between the ASQ values of Hashimoto thyroiditis glands and those of normal glands (P < .001). The ASQ values in patients with Hashimoto thyroiditis were significantly greater than those in patients with normal thyroid glands. The areas under the receiver operating characteristic curves for the ratio, blue average, average, blue mode, mode, and standard deviation were: 0.936, 0.902, 0.893, 0.855, 0.846, and 0.842, respectively. The ratio cutoff value of 0.27 offered the best diagnostic performance, with sensitivity of 87.38% and specificity of 95.18%. The intraclass correlation coefficients ranged from 0.86 to 0.94, which indicated substantial agreement between the observers. CONCLUSIONS: Acoustic Structure Quantification is a useful and promising sonographic method for diagnosing Hashimoto thyroiditis. Not only could it be a helpful tool for quantifying thyroid echogenicity, but it also would be useful for diagnosis of Hashimoto thyroiditis.