Sonographic differentiation of asymptomatic diffuse thyroid disease from normal thyroid: a prospective study

Malignancy risk of indeterminate lymph node at the central compartment in patients with thyroid cancer and concomitant sonographic thyroiditis

BACKGROUND

To evaluate the malignancy risk of sonographic (US) indeterminate lymph node (LN)s at the central compartment in thyroid cancer patients with US-thyroiditis (ST).

METHODS

Among the central compartments of suspicious, indeterminate, and probably benign LN US categories, the malignancy rates were compared between ST and non-US-thyroiditis (non-ST) groups. Those of indeterminate category were compared with suspicious and probably benign categories.

RESULTS

At 531 central compartments from 349 patients, the malignancy rate was lower in ST group (34.4% [44/128]) than non-ST group (43.4% [175/403]), although statistically not significant (p = 0.08). The malignancy rate of indeterminate category in ST group (35.7% [5/14]) was lower than non-ST group (71.9% [23/32]) (p = 0.047). Within ST group, the malignancy rate of indeterminate category (35.7% [5/14]) did not differ from probably benign category (29.1% [30/103]) (p = 0.756), but was lower than suspicious category (81.8% [9/11]) (p = 0.042).

CONCLUSIONS

The malignancy risk of US indeterminate LNs at the central compartment in thyroid cancer patients with US thyroiditis was lower than that in patients without US thyroiditis.

Predictors of lateral lymph node metastasis and skip metastasis in patients with papillary thyroid microcarcinoma

Background

Papillary thyroid microcarcinoma (PTMC) is characterized by its favorable prognosis and potential for active surveillance (AS) as a management option. However, the presence of cervical lymph node (LN) metastasis, especially lateral LN metastasis, significantly impacts management and prognosis. Previous studies have focused on post-surgery risk factors for cervical LN metastasis. This study aims to identify predictors of lateral LN metastasis by analyzing pre-operative ultrasonographic findings alongside clinicopathological factors.

Methods

A retrospective review of medical records was conducted for patients with PTMC who underwent surgery at Chonnam National University Hwasun Hospital between 2004 and 2013. This is a case-control study that compares patients with lateral LN metastasis (N1b) to age- and sex-matched patients without LN metastasis (N0). Subgroup analysis was performed to evaluate risk factors of skip metastasis.

Results

The study included 90 patients with PTMC with lateral LN metastasis (N1b) and 268 age- and sex-matched patients without LN metastasis (N0). The mean age was 49.3 years, and female patients were dominant in both groups. Structural recurrences of 4.4% (4/90) were observed only in the N1b group. The N1b group exhibited a higher frequency of upper lobe tumor location compared to the N0 group (38.9% vs. 16.0%, p < 0.001). There was no significant difference in the locations with the presence of invasion to adjacent organs. A higher proportion of non-parallel shape was observed in the N1b group than the N0 group (80.0% vs. 66.0%, p = 0.013). There were no differences in echogenicity, sonographic feature, margin, and AP diameter of the thyroid gland between the two groups. In multivariate analysis, independent risk factors for lateral LN metastasis included extrathyroidal extension, multiplicity, upper lobe tumor location, and non-parallel shape. Skip metastasis in patients with PTMC was associated with upper lobe tumor location.

Conclusion

Detailed ultrasound examinations, evaluating tumor location, number, orientation, and the presence of ETE, are crucial in accurately predicting lateral LN metastasis especially when primary tumor was in the upper lobe to avoid missing skip metastasis. These evaluations can help guide the decision between AS and immediate surgery in patients with PTMC.

US Predictors of Papillary Thyroid Microcarcinoma Progression at Active Surveillance

Background Active surveillance (AS) is an accepted strategy for patients with low-risk papillary thyroid microcarcinoma (PTMC). While previous studies have evaluated the prognostic value of US features, results have been inconsistent. Purpose To determine if US features can help predict tumor progression in patients with low-risk PTMC undergoing AS. Materials and Methods This prospective study enrolled 1177 participants with PTMC from three hospitals between June 2016 and January 2021. Participants were self-assigned to either immediate surgery or AS, and those with two or more US examinations in the absence of surgery were included in the analysis. A χ2 test was used to compare estimated tumor progression rate at 4 years between participants stratified according to US features. Multivariable Cox regression analysis was used to assess the association of clinical and US features with overall tumor progression and specific progression criteria. Results Among 699 participants included in the analysis, 68 (mean age, 49 years ± 12 [SD]; 40 female participants) showed tumor progression (median follow-up, 41.4 months ± 16 [SD]). Tumor progression was associated with the US features of diffuse thyroid disease (DTD) (hazard ratio [HR], 2.3 [95% CI: 1.4, 3.7]; P = .001) and intratumoral vascularity (HR, 1.7 [95% CI: 1.0, 3.0]; P = .04) and the participant characteristics of male sex (HR, 2.8 [95% CI: 1.7, 4.6]; P < .001), age less than 30 years (HR, 2.9 [95% CI: 1.2, 6.8]; P = .01), and thyroid-stimulating hormone level of 7 µU/mL or higher (HR, 6.9 [95% CI: 2.7, 17.4]; P < .001). The risk of tumor progression was higher for participants with DTD (14%, P = .001) or intratumoral vascularity (14%, P = .02) than for participants without these features (6%). DTD and intratumoral vascularity were associated with tumor enlargement (HR, 2.7 [95% CI: 1.4, 5.1]; P = .002) and new lymph node metastasis (HR, 5.0 [95% CI: 1.3, 19.4]; P = .02), respectively. Conclusion DTD and intratumoral vascularity were associated with an increased risk of tumor progression in participants with PTMC undergoing AS. Clinical trial registration no. NCT02938702 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Reuter and the review "International Expert Consensus on US Lexicon for Thyroid Nodules" by Durante et al in this issue.

Clinical application of a 5G-based telerobotic ultrasound system for thyroid examination on a rural island: a prospective study

PURPOSE

To evaluate the feasibility of a 5G-based telerobotic ultrasound (US) system for thyroid examination on a rural island.

METHODS

From September 2020 to March 2021, this prospectively study enrolled a total of 139 patients (average age, 58.6 ± 12.7 years) included 33 males and 106 females, who underwent 5G-based telerobotic thyroid US examination by a tele-doctor at Shanghai Tenth People's Hospital and a conventional thyroid US examination at Chongming Second People's Hospital 84 km away. The clinical feasibility of 5G-based telerobotic US for thyroid examination were evaluated in terms of safety, duration, US image quality, diagnostic results, and questionnaire survey.

RESULTS

92.8% of patients had no examination-related complaints. The average duration of the 5G-based telerobotic US examination was similar as that of conventional US examination (5.57 ± 2.20 min vs. 5.23 ± 2.1 min, P = 0.164). The image quality of telerobotic US correlated well with that of conventional US (4.63 ± 0.60 vs. 4.65 ± 0.61, P = 0.102). There was no significant difference between two types of US examination methods for the diameter measurement of the thyroid, cervical lymph nodes, and thyroid nodules. Two lymphadenopathies and 20 diffuse thyroid diseases were detected in two types of US methods. 124 thyroid nodules were detected by telerobotic US and 127 thyroid nodules were detected by conventional US. Among them, 122 were the same thyroid nodules. In addition, there were good consistency in the US features (component, echogenicity, shape, and calcification) and ACR TI-RADS category of the same thyroid nodules between telerobotic and conventional US examinations (ICC = 0.788-0.863). 85.6% of patients accepted the telerobotic US, and 87.1% were willing to pay extra fee for the telerobotic US.

CONCLUSION

The 5G-based telerobotic US system can be a routine diagnostic tool for thyroid examination for patients on a rural island.

Validation of Ultrasound Risk Stratification Systems for Cervical Lymph Node Metastasis in Patients with Thyroid Cancer

Simple Summary

Ultrasound (US) malignancy risk stratification systems (RSS) for cervical lymph nodes (LNs) have not been fully established in patients with thyroid cancer. In this study, we assessed the malignancy risks of each US feature and risk category from the Korean Society of Thyroid Radiology (KSThR) and the European Thyroid Association (ETA). Both systems effectively classified malignancy risks; however, 15.1% of LNs were unclassifiable in ETA RSS. Suspicious US features of hyperechogenicity, cystic change, echogenic foci, and abnormal vascularity were independently associated with metastasis. When the primary tumor characteristics were assessed, tumor multiplicity was associated with metastasis in the indeterminate LN group. We refined this system and proposed an RSS based on the KSThR system for cervical LNs in patients with thyroid cancer.

Abstract

A malignancy risk stratification system (RSS) for cervical lymph nodes (LNs) has not been fully established. This study aimed to validate the current RSS for the diagnosis of cervical LN metastasis in thyroid cancer. In total, 346 LNs from 282 consecutive patients between December 2006 and June 2015 were included. We determined the malignancy risk of each ultrasound (US) feature and performed univariable and multivariable logistic regression analyses. Each risk category from the Korean Society of Thyroid Radiology (KSThR) and the European Thyroid Association (ETA) was applied to calculate malignancy risks. The effects of size, number of suspicious features, and primary tumor characteristics were analyzed to refine the current RSS. Suspicious features including echogenic foci, cystic change, hyperechogenicity, and abnormal vascularity were independently predictive of malignancy (p ≤ 0.045). The malignancy risks of probably benign, indeterminate, and suspicious categories were 2.2–2.5%, 26.8–29.0%, and 85.8–87.4%, respectively, according to the KSThR and ETA criteria. According to the ETA criteria, 15.1% of LNs were unclassifiable. In indeterminate LNs, multiplicity of the primary tumor was significantly associated with malignancy (odds ratio, 6.53; p = 0.004). We refined the KSThR system and proposed a US RSS for LNs in patients with thyroid cancer.

Can ultrasound echogenicity of normal parotid and submandibular glands be used as a reference standard for normal thyroid echogenicity?

Purpose

This study aimed to determine whether the normal parotid gland (PG) and submandibular gland (SMG) can be used as reference standards for normal thyroid echogenicity.

Methods

In total, 1,302 consecutive patients with normal salivary glands were included in this study. The echogenicity of the SMG and PG was assessed during real-time ultrasound examinations, and the glands were categorized as hyperechogenic, isoechogenic, and hypoechogenic relative to the thyroid parenchyma in patients without diffuse thyroid disease (group 1, n=1,106) and with diffuse thyroid disease (group 2, n=196). The frequency of the echogenicity categories of the normal PG and SMG was assessed according to patients’ age.

Results

In group 1, the normal PG showed isoechogenicity in 94.0% and hypoechogenicity or hyperechogenicity in 6.0%, and the normal SMG showed isoechogenicity in 73.6% and hypoechogenicity in 26.4% of patients (P<0.001). There was no significant association of the frequency of isoechoic PG with age (P=0.834); however, there was a trend for an increasing frequency of isoechoic SMG with aging (22.9%-81.4%) (P<0.001). Similar findings were found in group 2 patients without decreased thyroid echogenicity.

Conclusion

The normal PG was mostly isoechoic to the normal thyroid parenchyma, whereas the normal SMG showed hypoechogenicity at various frequencies according to age. The echogenicity of the normal PG can be used as an alternative reference standard for normal thyroid echogenicity; however, the normal SMG is not suitable for a reference standard when assessing thyroid nodule echogenicity in patients who have diffuse thyroid disease with decreased parenchymal echogenicity.

Role of ultrasound and Doppler findings as a predictor of thyroid hormonal levels in cases of Hashimoto thyroiditis

Background

Chronic lymphocytic thyroiditis or Hashimoto’s thyroiditis (HT) is a common form of organ specific autoimmune disease mediated by anti-thyroid autoantibodies. Ultrasound including Doppler is helpful diagnostic tool in the diagnosis of Hashimoto’s thyroiditis. This study aimed to evaluate the ultrasound and Doppler characters of Hashimoto thyroiditis and to analyze the relationship between these ultrasound, Doppler features and thyroid hormones level.

Results

Thyroid gland sonographic parenchymal abnormalities (septations, undulation, micronodularity, gland hyper vascularity, hypoechogenicity, sizable nodules as well as enlarged para-tracheal lymph nodes) were significantly higher in Hashimoto cases compared to control group (P value is < 0.001). Undulation of thyroid gland margin was the most sensitive sonographic sign seen in about 72% of studied cases. Thyroid stimulating hormone (TSH) level was significantly high in cases with grade 2 echogenicity compared to cases with grade 0 and grade 1 echogenicity and was significantly high in cases with para-tracheal abnormal enlarged lymph nodes (p < 0.05). TSH & thyroxine (T4) levels were significantly high in cases with high gland vascularity in Doppler study (p < 0.05).

Conclusions

Ultrasound is a very good diagnostic tool in HT with established signs. It can suggest hypothyroidism (high TSH) in cases of grade 2 parenchymal echogenicity, high vascularity and para-tracheal lymph nodes enlargement. These finding could be helpful in patient management and can contribute in better understanding the disease progression.

Validation of Diagnostic Performance and Interobserver Agreement of DTD-TIRADS for Diffuse Thyroid Disease on Ultrasound: A Single-Center Study

OBJECTIVE. This retrospective study aimed to investigate the capability of the already-proposed thyroid imaging reporting and data system for detecting diffuse thyroid disease (DTD-TIRADS) on ultrasound (US) by assessing interobserver agreement and diagnostic performance. MATERIALS AND METHODS. A total of 180 patients who underwent thyroid US before thyroid surgery were included. Three radiologists blinded to the pathologic and serologic data independently categorized the US features according to a four-category DTD-TIRADS classification system. On the basis of the pathologic results of thyroid parenchyma, diagnostic performance values were calculated using ROC curve analyses. Interobserver agreements of each US feature and DTD-TIRADS category among the three radiologists were also assessed. RESULTS. Of the 180 patients, 143 (79.4%) had normal thyroid parenchyma and 37 (20.6%) had diffuse thyroid disease (DTD). The areas under the ROC curve for DTD were not significantly different among the three radiologists: 0.876 (95% CI, 0.819-0.920) for radiologist 1, 0.883 (95% CI, 0.827-0.926) for radiologist 2, and 0.861 (95% CI, 0.801-0.908) for radiologist 3 (p > .05). The cutoff for the diagnosis of DTD was category III DTD-TIRADS. The sensitivity, specificity, and accuracy of DTD-TIRADS for detecting DTD were 86.5%, 81.1%, and 82.2% for radiologist 1; 86.5%, 83.2%, and 83.9% for radiologist 2; and 83.8%, 82.5%, and 82.8% for radiologist 3, respectively. Interobserver agreement of DTD-TIRADS categorization was almost perfect (κ = 0.81). CONCLUSION. DTD-TIRADS has high diagnostic performance and almost-perfect interobserver agreement. Thus, DTD-TIRADS can be considered to be an effective classification system for diagnosing DTD.

The Presence of Hypoechoic Micronodules in Patients with Hashimoto's Thyroiditis Increases the Risk of an Alarming Cytological Outcome

The aim of the study was to identify a possible relation between various ultrasonographic (US) appearances of Hashimoto's thyroiditis (HT) and the risk of obtaining an alarming cytology of coexisting nodules. The study included 557 patients with HT, who had been referred for fine needle aspiration biopsy (FNA). We divided US patterns of HT (UP-HT) into eight groups: (a) Hypoechoic (compared to submandibular glands), homogeneous/fine echotexture; (b) hypoechoic, heterogeneous/coarse echotexture; (c) marked hypoechoic (darker than strap muscles), heterogeneous/coarse echotexture; (d) heterogeneous echotexture with hyperechoic, fibrous septa; (e) multiple, discrete marked hypoechoic areas (sized as 1 to 6 mm); (f) normoechoic pseudo-nodular areas; (g) echostructure similar to connective tissue; (h) thyroid parenchyma with no signs of HT. Indications for a surgical treatment resulting from the FNA outcome (categories IV-VI of Bethesda System for Reporting Thyroid Cytopathology) were identified only in patients with variants b, c, and e of UP-HT, but merely the "multiple, discrete marked hypoechoic areas" variant significantly increased the odds of obtaining such cytology (OR:5.7). The presence of the "normoechoic pseudo-nodular areas" variant significantly increased the odds for the benign cytology (OR:1.7). There are significant differences in the frequency of obtaining an alarming cytology in relation to the UP-HT variant.

Thyroid Ultrasound: Diffuse and Nodular Disease

Thyroid ultrasound with gray-scale and color Doppler is the most helpful imaging modality to differentiate normal thyroid parenchyma from diffuse or nodular thyroid disease by evaluating glandular size, echogenicity, echotexture, margins, and vascularity. The various causes of diffuse thyroid disease often have overlapping sonographic imaging features. Thyroid nodules may be hyperplastic or neoplastic, with most due to benign hyperplastic changes in architecture and benign follicular adenomas; only a small percentage are malignant. A systematic approach to nodule morphology that includes evaluation of composition, echogenicity, margin, shape, and any echogenic foci can guide decision to biopsy or follow nodules.

Clinical applications of Doppler ultrasonography for thyroid disease: consensus statement by the Korean Society of Thyroid Radiology

Doppler ultrasonography (US) is widely used for the differential diagnosis of thyroid nodules, metastatic cervical lymph nodes in patients with thyroid cancer, and diffuse parenchymal disease, as well as for guidance in various US-guided procedures, including biopsy and ablation. However, controversies remain regarding the appropriate use and interpretation of Doppler US. Therefore, the Korean Society of Thyroid Radiology organized a taskforce to develop a consensus statement on the clinical use of Doppler US for thyroid disease. The review and recommendations in this article are based on a comprehensive analysis of the current literature and the consensus of experts.

Comparison of Real-Time and Static Ultrasonography Diagnoses for Detecting Incidental Diffuse Thyroid Disease: A Multicenter Study

This study aimed to compare diagnostic accuracy of real-time and static ultrasonography (US) for differentiating diffuse thyroid disease (DTD) from normal thyroid parenchyma (NTP). At 4 participating institutions, 203 patients underwent real-time thyroid US before thyroid surgery. For static US, the same radiologists retrospectively evaluated US findings on a picture archive and communication system after 4 weeks. In real-time and static US diagnoses, US category included no DTD, indeterminate, suspicious for DTD, and DTD. We investigated the diagnostic accuracy of real-time and static US with a receiver operating characteristic curve analysis using histopathologic results as the reference standard. Histopathologic results exhibited NTP (n = 139), Hashimoto thyroiditis (n = 24), non-Hashimoto lymphocytic thyroiditis (n = 33), and diffuse hyperplasia (n = 7). Of 203 patients, there were significant differences in echogenicity, echotexture, glandular margin, and vascularity of the thyroid gland and US category between NTP and DTD groups in both real-time and static US diagnoses (P < 0.001). The diagnostic indices of real-time and static US were highest when the cutoff criterion was chosen as 1 or more abnormal US features. In addition, US category was the only feature with a significant difference between DTD and NTP groups regardless of the practical experience. The receiver operating characteristic curve analysis showed that real-time US was superior to static US in the diagnostic accuracy; however, there was no significant difference (P = 0.09). In conclusion, real-time and static US can be helpful for detecting incidental DTD by using US classification based on abnormal US features.

Value of the New Elastography Technique using Acoustic Radiation Force Impulse in Differentiation between Hashimoto's Thyroiditis and Graves' Disease

Background and Aim:

This study was performed to evaluate the role and accuracy of shear wave elastography in the differentiation between Graves’ disease (GD) and Hashimoto’s thyroiditis (HT), in comparison with the B-mode ultrasound and color Doppler ultrasound.

Materials and Methods:

This study was non-randomized prospective study. The study included 30 patients with GD, 65 patients with HT, and 35 patients with normal thyroid glands. Assessment of ultrasonographic criteria, color Doppler flow pattern, and shear patterns differed significantly between the control group and the group of diffuse thyroid disease (P < 0.001). The most specific sign for diagnosing HT was nodularity (97.87%), and the most sensitive sign was coarse echotexture (81.54%). Color Doppler flow (CDF) showed sensitivity of 91.8%, specificity of 56.92%, positive predictive value of 52.54%, negative predictive value of 92.5%, and diagnostic accuracy of 68.69% in the differentiation between GD and HT. The mean shear wave velocity (SWV) was 2.61 ± 0.32 m/s in the GD group (range: 2.1–3.21 m/s), 2.85 ± 0.52 m/s in the HT group (range: 2.31–3.82 m/s), and 1.75 ± 0.37 m/s in the control group (range: 1.24–2.36 m/s). The mean SWVs in the GD and HT groups were significantly higher than that in the control group (P < 0.001). The mean SWV in the HT group was higher than that in the GD group (P = 0.03).

Conclusion:

Quantitative and qualitative SWE is useful for diagnosing diffuse thyroid disease and evaluating the degree of fibrosis in autoimmune thyroiditis. However, acoustic radiation force impulse techniques cannot differentiate between HT and GD reliably.

Ultrasound detection of incidental diffuse parotid disease: A single-center study

In this study, we compared ultrasound (US) features between normal parotid parenchyma (NPP) and incidental diffuse parotid disease (DPD). From January 2008 to December 2017, 180 patients underwent neck US before parotid surgery at our hospital. From these, 82 were excluded because of the lack of histopathological data concerning the parotid parenchyma or inadequate US images. A single radiologist blinded to the clinicoserological data and histopathological results, retrospectively investigated all US features and categorizations for the parotid glands using a picture archiving and communication system. Retrospective histopathological analysis of the parotid parenchyma was performed by a single pathologist. On the basis of the histopathological analyses, the 98 patients were divided into NPP (n = 70) and DPD (n = 28) groups. Among US features, parenchymal echogenicity and echotexture showed statistically significant differences between the two groups (p < 0.0001), whereas the gland size, margin, and vascularity showed no significant differences (p > 0.05). The US-based categorization significantly differentiated between NPP and DPD (p < 0.0001), and receiver operating characteristic curve analysis revealed that US categorization based on ≥2 abnormal US features showed the best diagnostic performance for detecting DPD. Thus, US can aid in differentiating DPD from NPP.

Sonographic Evaluation of Thyroid Size: A Review of Important Measurement Parameters

An accurate evaluation of thyroid volume, in patients of all ages, is important for the correct diagnosis of a goiter and for sonographic monitoring of thyroid diseases. It is especially important in pediatrics because the linear measurements of a developing thyroid gland do not correlate well with age, sex, or body composition variables. Diverse methods are used to estimate thyroid size and volume. Sonographic volumetry and visual inspection and palpation are used to evaluate the thyroid. Although thyroid size can be easily assessed on physical examination, due to the superficial location of the gland, palpation has low sensitivity and specificity for the management and diagnosis of thyroid disorders. Therefore, thyroid volume measured sonographically is more accurate than thyroid size assessed with a physical examination. Imprecise calculation of thyroid size and volume may lead to false-positive or false-negative diagnoses of thyromegaly, which may result in unnecessary or delayed care.

Thyroid Imaging Reporting and Data System for Detecting Diffuse Thyroid Disease on Ultrasonography: A Single-Center Study

Objective: This study aimed to compare the ultrasonography (US) features of diffuse thyroid disease (DTD) and normal thyroid parenchyma (NTP), and to propose a structured imaging reporting system for detecting DTD. Methods: This retrospective study assessed the findings for 270 consecutive patients who underwent thyroid US before thyroid surgery. The following US data were analyzed: DTD-specific features, parenchymal echotexture and echogenicity, anteroposterior diameter, glandular margin, and parenchymal vascularity. Univariate and multivariate analyses with generalized estimating equations were performed to investigate the relationship between US features and DTD. The fitted probability of DTD was analyzed by using a regression equation. Results: Of the 270 patients, there were NTP (n = 193), Hashimoto thyroiditis (n = 24), non-Hashimoto lymphocytic thyroiditis (n = 51), Graves' disease (n = 1), and diffuse hyperplasia (n = 1). The following US features were significantly associated with DTD: decreased or increased parenchymal echogenicity, coarse parenchymal echotexture, increased anteroposterior diameter, lobulated glandular margin, and increased parenchymal vascularity. Of these, coarse parenchymal echotexture was the most significant independent predictor of DTD. The numbers of abnormal US features were positively correlated with the fitted probability and risk of DTD. The diagnostic indices were highest when the chosen cut-off criterion was category III with the largest Az value (0.867, 95% confidence interval: 0.820-0.905), yielding a sensitivity of 68.8%, specificity of 92.2%, positive predictive value of 77.9%, negative predictive value of 88.1%, and accuracy of 85.6% (p < 0.001). Conclusions: Our sonographic reporting and data system may be useful for detecting DTD.

Diagnostic accuracy of computed tomography for differentiating diffuse thyroid disease from normal thyroid parenchyma: A multicenter study

This study aimed to assess the diagnostic performance of computed tomography (CT) for differentiating diffuse thyroid disease (DTD) from normal thyroid parenchyma (NTP) using multicenter data. Between January 2016 and June 2016, 229 patients underwent preoperative neck CT and subsequent thyroid surgery at five participating institutions. The neck CT images of each patient were retrospectively reviewed and classified into the following four categories: no DTD, indeterminate, suspicious for DTD, and DTD. The results of the CT image evaluations were compared with the histopathological results to determine the diagnostic accuracy of CT at each institution. According to the histopathological results, there were NTP (n = 151), Hashimoto thyroiditis (n = 24), non-Hashimoto lymphocytic thyroiditis (n = 47), and diffuse hyperplasia (n = 7). The CT categories of the 229 patients were "no DTD" in 89 patients, "indeterminate" in 40 patients, "suspicious for DTD" in 42 patients, and "DTD" in 58 patients. The presence of two or more CT features of DTD, which was classified as "suspicious for DTD" by all radiologists, had the largest area under the receiver-operating characteristic curve (Az = 0.820; 95% confidence interval: 0.764, 0.868), with sensitivity of 85.9% and specificity of 78.2%. However, no statistical significance between readers' experience and their diagnostic accuracy was found. In conclusion, evaluations of CT images are helpful for differentiating DTD from NTP.

Diagnostic Accuracy of Real-Time Sonography in Differentiating Diffuse Thyroid Disease From Normal Thyroid Parenchyma: A Multicenter Study

OBJECTIVE

The purpose of this multicenter study was to assess the diagnostic accuracy of real-time sonography (US) for differentiating diffuse thyroid disease (DTD) from normal thyroid parenchyma among radiologists blinded to patients' clinical, serologic, and imaging history and to determine the differences in diagnostic accuracy among radiologists from different institutions.

MATERIALS AND METHODS

From January to March 2017, 214 patients underwent preoperative thyroid US and subsequent thyroid surgery at four participating institutions. Real-time US was performed at each institution by an attending radiologist, who classified US diagnoses into one of the following four categories based on US findings: no DTD, indeterminate, suspicious for DTD, and DTD. The outcomes of US diagnoses were compared with histopathologic results to determine the diagnostic accuracy of real-time US at each institution.

RESULTS

Histopathologic results included normal thyroid parenchyma (n = 143), Hashimoto thyroiditis (n = 29), non-Hashimoto lymphocytic thyroiditis (n = 37), and diffuse hyperplasia (n = 5). Normal thyroid parenchyma and DTD exhibited statistically significant differences in echogenicity, echotexture, size, glandular margin, vascularity of thyroid, and US classification. There was positive correlation between US classification and histopathologic results at all institutions for detecting DTD. The highest diagnostic indexes were obtained when the cutoff criterion was suspicious for DTD. There was favorable diagnostic accuracy, with statistically significant differences, at all institutions for the diagnosis of DTD.

CONCLUSION

Real-time US can be helpful for differentiating DTD from normal thyroid parenchyma.

Association of obesity and diabetes with thyroid nodules

AIM

There are conflicting data concerning the possibility that obesity and diabetes raise the risk of thyroid nodules. The incidence of thyroid nodules is increasing, as is that of obesity and diabetes; therefore, understanding whether these metabolic and nutritional disorders influence nodular thyroid disease is important for organizing prevention strategies. This study investigated the association between thyroid nodules, obesity, diabetes, and dietary habits.

MATERIALS AND METHODS

A cohort of randomly selected adults (455 males, 746 females; age: 18-90 years) living in Palermo (Italy), a mild iodine deficiency area, was cross-sectionally investigated. Participants underwent high-resolution ultrasonographic evaluation of the thyroid, and answered a food frequency questionnaire. Laboratory blood measurements were obtained in 587 participants.

RESULTS AND DISCUSSION

Thyroid nodules were detected in 475 (39.5%) participants. The number of thyroid nodules was correlated with age (r = 0.19; P < 0.001), gender (r = 0.08; P = 0.005), and body mass index (r = 0.07; P = 0.02). No significant correlation was observed between the number of nodules and glycated hemoglobin, serum insulin concentrations, and homeostasis model assessment of insulin resistance. Age-adjusted and gender-adjusted prevalence of both overweight/obesity and type 2 diabetes of each group of participants divided according to the number of nodules significantly increased with the number of nodules (P < 0.05 in both cases). The group of participants with nodules exhibited a significantly lower age-adjusted and gender-adjusted habitual intake of milk (P = 0.02). Multivariate regression analysis showed that age, gender, body mass index, diabetes, and habitual consumption of milk were independently correlated with presence of thyroid nodules.

CONCLUSION

This study seems to indicate that an association exists between obesity, diabetes, and thyroid nodules.

Screening for thyroid diseases among students of applied medical sciences at King Abdulaziz University, Saudi Arabia

OBJECTIVES

To identify the occurrence rate of thyroid ultrasound abnormalities in asymptomatic subjects, and describe the features of detected nodules among university students.

METHODS

The study is based on an observational research design that was conducted from April 2015 to May 2015. The study included 166 individuals, aged between 19 and 23 years. The subjects had their glands examined by ultrasound (US) scanning, using Philips ultrasound machine (5-12 MHz linear transducer).

RESULTS

We recruited 90 (57.8%) females and 76 (42.2%) males without any indications of thyroid disease. Data estimated that 41 (24.7%) subjects had positive results on thyroid disease screening, 24 (70.6%) participants had solitary nodules, and 10 (29.4%) had multiple nodules. Thirty-four subjects revealed nodular presentation in the screening, among which 24 (70.6%) indicated solitary nodules and 10 (29.4%) had multiple nodules. Among 3 subjects, who indicated hypoechoic nodules, 2 (66.7%) underwent US-fine needle aspiration biopsy and received histological confirmation that they had papillary carcinomas.

CONCLUSION

Ultrasonography is a useful and effective technique for screening thyroid related diseases, and can be utilized as a routine practice for general population screening.

Comparison of ultrasonography and computed tomography for diagnosing diffuse thyroid disease: a multicenter study

PURPOSE

To compare the diagnostic performance of ultrasonography (US) and computed tomography (CT) for diagnosing incidentally detected diffuse thyroid disease (DTD) in patients who underwent thyroid surgery using multicenter data.

METHODS

Between July and December 2016, a total of 177 patients who underwent preoperative thyroid US and neck CT, and subsequent thyroid surgery at 4 participating institutions, were reviewed. US and CT images in each case were retrospectively reviewed by a radiologist at each institution, and classified into one of the following four categories based on US and CT features: no DTD; indeterminate; suspicious for DTD; and DTD. The diagnostic accuracy of US and CT were calculated at each institution by comparison with histopathological results.

RESULTS

Respective US and CT classifications in the 177 patients were no DTD in 75 and 71, indeterminate in 46 and 34, suspicious for DTD in 28 and 31, and DTD in 28 and 41. Among the histopathological results, 113 patients had normal thyroid parenchyma, 23 had Hashimoto thyroiditis, 36 had non-Hashimoto lymphocytic thyroiditis, and 5 had diffuse hyperplasia. The presence of ≥ 2 US and CT features of DTD, which was classified as suspicious for DTD or DTD, had the largest area under the receiver operating characteristic curve (0.866 and 0.893, respectively), with sensitivity and specificity of 71.9 and 91.2% in US, and 84.4 and 84.1% in CT, respectively. However, there was no statistically significant difference between readers' experience and their diagnostic performance.

CONCLUSION

US and CT imaging may be helpful for detecting incidental DTD.

Magnetic Resonance Imaging Features of Normal Thyroid Parenchyma and Incidental Diffuse Thyroid Disease: A Single-Center Study

Background: No previous studies have investigated the feasibility of magnetic resonance imaging (MRI) diagnosis for detecting incidental diffuse thyroid disease (DTD). This study investigated MRI features of normal thyroid parenchyma and incidental DTD. Methods: From January 2008 to December 2017, 387 patients underwent neck MRI in our hospital due to tumor/nodal staging (n = 137), lymphadenopathy (n = 122), inflammatory neck lesion (n = 85), congenital neck lesion (n = 12), and patient request (n = 31). Among them, 375 patients were excluded because of a lack of appropriate histopathological data on the thyroid parenchyma. Results: Among the patients included, 10 had normal thyroid parenchyma, 1 had Hashimoto thyroiditis, and 1 had diffuse hyperplasia. The common MRI features of normal thyroid parenchyma include iso-/slightly high and homogeneous signal intensity on T1/T2-weighted images, normal anteroposterior diameter of the thyroid gland, smooth margin, and homogeneously increased enhancement as compared to adjacent muscle. Hashimoto thyroiditis exhibited high and inhomogeneous signal intensity on T2-weighted images, while diffuse hyperplasia revealed an increased anteroposterior diameter and lobulated margin of the thyroid gland, and inhomogeneous enhancement. Conclusions: MRI may be helpful for detection of incidental DTD.

Updated guidelines on the preoperative staging of thyroid cancer

Recent studies have provided prognostic information and recommendations for staging thyroid cancers that have changed the staging and management guidelines for the disease. Consequently, minimal extrathyroidal extension (ETE) was removed from the T3 stage classification in the eighth edition of the TNM staging system by the American Joint Committee on Cancer. New T categories have been subsequently added, including T3a, defined as a tumor >4 cm in its greatest dimension, limited to the thyroid gland, and T3b, defined as a tumor of any size with gross ETE invading only the strap muscles. In this article, the author reviews the changes in the TNM staging system for thyroid cancer, with an emphasis on ultrasonography in preoperative staging.

Thyroid Ultrasonography in Differentiation between Graves' Disease and Hashimoto's Thyroiditis

OBJECTIVE

Graves' disease and Hashimoto's thyroiditis are the most common causes of hyper and hypothyroidism, respectively. Differentiation of these 2 diseases, if the patient is euthyroid, may sometimes be extremely difficult on the basis of clinical and laboratory findings. The purpose of this study was to determine the sensitivity and specificity of gray scale sonography in differentiation of Graves' disease from Hashimoto's thyroiditis.

METHODS

This study included 149 patients divided into three groups, patients with Graves' disease (34 patients, mean age = 36.8 ± 10.17 years), Patients with Hashimoto's thyroiditis (62 patients, mean age = 33.4 ± 12.16 years) and control group (53 healthy people, mean age = 34.74 ± 16.87 years). Members of all groups were referred to a single radiologist for thyroid sonography for evaluation of thyroid echogenicity pattern.

RESULTS

A total of 117 women and 32 men were examined by sonography. The most common sonographic pattern in Hashimoto and Graves' was homogenous hypo-echogenicity which was observed in 45.2% and 47.1% of cases, respectively. Peripheral hypo-echogenicity pattern was seen in 40.3% of Hashimoto's group with 100% specificity and 40.3% sensitivity. Central-hypoechogenic pattern was observed in 17.6% of Graves' group with 100% and 17.6% specificity and sensitivity, respectively.

CONCLUSION

Our findings indicate that sonography has high specificity but low sensitivity in the diagnosis of either Graves' disease or Hashimoto's thyroiditis. It is therefore not possible to differentiate between these two diseases using sonography alone. Confirmation by laboratory data is also needed.

Evaluation of Diagnostic Performance of Screening Thyroid Ultrasonography and Imaging Findings of Screening-Detected Thyroid Cancer

Purpose

The purpose of this study was to evaluate the diagnostic performance and cost of screening thyroid ultrasonography (US) in an asymptomatic population and determine the US features of screening-detected thyroid cancer.

Materials and Methods

This study included 1,845 asymptomatic participants who underwent screening thyroid US between March and August 2012 at the screening center in our hospital. We evaluated the diagnostic performance of screening thyroid US for thyroid cancer and the average cost of diagnosis for each patient. We also determined the characteristic US features of screening-detected thyroid cancer.

Results

Of the 1,845 subjects, 661 showed no abnormalities, 1,155 exhibited benign thyroid nodules, and 29 exhibited thyroid cancer. Imaging features such as solid composition, hypoechogenicity, taller-than-wide axis, and ill-defined or spiculated margins of nodules were suggestive of malignancy. The rate of detection of cancer was 1.6% (29/1,845), and the sensitivity, specificity, and positive and negative predictive values were 100% (18/18), 98.7% (1,051/1,065), 56.3% (18/32), and 100% (1,051/1,051), respectively. Of 18 patients who underwent thyroidectomy, three (16.7%) had a pathological tumor staging of T3, and four (22.2%) had a pathological nodal staging of N1a. The average cost of diagnosis for each patient with cancer was $7,319.

Conclusion

Screening thyroid US exhibited a good diagnostic performance, with a feasible social cost of use. This modality demonstrated significant differences in sonographic features between screening-detected cancer and benign nodules.

Association between Bethesda Categories and Ultrasound Features of Conventional Papillary Thyroid Carcinoma

The association between categories 3, 5 and 6 of the Bethesda System for Reporting Thyroid Cytopathology and the clinical and ultrasonography (US) features of conventional papillary thyroid carcinoma (PTC) was evaluated. We included 2005 patients diagnosed with conventional PTC at surgery and Bethesda categories 3, 5 and 6 at pre-operative US-guided fine-needle aspiration. Multinomial regression analysis was performed to determine the odds ratio (ORs) of each US feature associated with category 3 or 5, with category 6 as reference. Category 3 and 5 PTCs were smaller (ORs = 0.925 and 0.937) and did not exhibit marked hypo-echogenicity (ORs = 0.341 and 0.268) compared with category 6 PTCs. Category 3 and 5 PTCs exhibited significant macrocalcification (ORs = 2.372 and 1.594) and heterogeneous parenchyma (OR = 1.265 in category 5). In conclusion, conventional PTCs pre-operatively aspirated as Bethesda category 3, 5 or 6 significantly differ in size, macrocalcification, underlying thyroid parenchymal echogenicity and final assessment of US features.

Ultrasonographic features and clinical characteristics of Warthin-like variant of papillary thyroid carcinoma

Warthin-like variant of papillary thyroid carcinoma (WVPTC) is a rare entity recently characterized. We evaluated ultrasonographic (US) features and clinical characteristics of WVPTC. Nine patients were diagnosed with WVPTC through surgery in our institution from May 2005 to January 2015. Eight of nine patients had available preoperative US images. A retrospective review of the US and clinical characteristics was performed. WVPTC compromised of 0.06% of 14,071 PTCs surgically confirmed. A mean age of nine patients was 53.2 years (range, 32-75 years). The mean nodule size of nine WVPTCs was 0.9 cm (range, 0.5-1.5 cm). Two patients showed central nodal metastasis and one patient with conventional PTC as an index tumor underwent central and lateral neck dissection. No one showed recurrence or distant metastasis during the follow-up period (mean, 4.6 years; range, 0.6-10 years). The most common US features of WVPTCs were solid composition (62.5%), hypoechogenicity (75%), and wider-than-tall shape (100%), respectively. Four (50%) of eight nodules showed well-defined margin and three (37.5%) of them had cystic component. One of eight resembled focal thyroiditis. Three nodules were considered as probably benign with US. All nine cases demonstrated underlying heterogeneous parenchymal echogenicity and accompanied chronic lymphocytic thyroiditis in permanent sections. Thyroid function tests in all patients were normal except for one with subclinical hypothyroidism. WVPTC is an uncommon subtype of PTC and has favorable prognosis, which can be misdiagnosed as a probably benign nodule or focal thyroiditis with US. All cases are associated with heterogeneous parenchyma in the background.

Importance of Delphian Lymph Node Evaluation in Autoimmune Thyroiditis: Fact or Fiction?

Background

Our main objective was to evaluate the association between autoimmune thyroiditis and the Delphian lymph node during different stages of thyroiditis.

Material/Methods

The relationships between the ultrasonography (US) results of thyroiditis and characteristics of the Delphian lymph node in different stages of AT were evaluated. Thyroid hormone and antibody levels were assessed. A total of 126 patients were divided into four groups according to the thyroid US findings: Group 1: control cases; Group 2: indeterminate cases; Group 3: established thyroiditis cases; Group 4: advanced-late stage thyroiditis cases.

Indeterminate cases attended a 1-year follow-up, and the cases with a sonographic finding matching thyroiditis formed Group 2.

Results

The rate of Delphian lymph node presence in Group 4 was significantly higher than in Groups 1 and 2 (p<0.01). In addition, its presence was significantly higher in Group 3 than in Group 1 (p<0.05). Although there was a difference in Delphian lymph node presence between Groups 2 and 3, it was not significant (p=0.052), nor was there a significant difference between Groups 1 and 2 (p>0.05). Both the long and short axis measurements were significantly higher in Groups 2, 3, and 4 compared to those in the control group. However, the same increase was not observed in the long/short axis ratio.

Conclusions

Both the presence and dimensions of the Delphian lymph node were highly correlated with the progress of autoimmune thyroiditis. Evaluating the Delphian lymph nodes might prevent missing a diagnosis of autoimmune thyroiditis.

Evaluation of Underlying Lymphocytic Thyroiditis With Histogram Analysis Using Grayscale Ultrasound Images

OBJECTIVES

The purpose of this study was to evaluate diagnostic performance of histogram analysis using grayscale ultrasound (US) images in the diagnosis of lymphocytic thyroiditis.

METHODS

Three radiologists reviewed a total of 505 US images and classified the images according to the presence/existence of lymphocytic thyroiditis. After 2 months, each reviewer repeated the process with the same 505 images in a randomly mixed order. The intraobserver and interobserver variability was analyzed with a generalized κ value. Four histogram parameters (mean value, standard deviation, skewness, and kurtosis) were obtained, and an index was calculated from principal component analysis. Diagnostic performances were compared.

RESULTS

Of 505 patients, 125 (24.8%) had lymphocytic thyroiditis, and 380 (75.2%) had normal thyroid parenchyma on pathologic analysis. The κ value for intraobserver variance ranged from -0.002 to 0.781, and the overall κ values for interobserver variance were 0.570 and 0.214 in the first and second tests, respectively. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for the 3 reviewers versus the principal component analysis index were 28.0% to 83.2%, 43.7% to 82.6%, 53.5% to 79.0%, 24.6% to 56.2%, and 75.2% to 88.9% versus 58.4%, 72.4%, 68.9%, 41.0%, and 84.1%.

CONCLUSIONS

Histogram analysis of grayscale US images provided confirmable and quantitative information about lymphocytic thyroiditis and was comparable with performers' assessments in diagnostic performance.

Acoustic Structure Quantification Analysis of the Thyroid in Patients with Diffuse Autoimmune Thyroid Disease

The aim of this study was to assess whether acoustic structure quantification (ASQ) can differentiate normal from pathological thyroid parenchyma in patients with diffuse autoimmune thyroid disease (AITD). We evaluated 83 subjects (72 [87%] women and 11 [13%] men) aged 19 to 94 years with a mean age of 53 years. We performed a prospective study (from March 2011 to November 2014) that included 43 (52%) patients with chronic autoimmune thyroiditis (CAT), 22 (26%) patients with Graves' disease (GD), and 18 (22%) healthy volunteers. The ASQ values were significantly lower in normal subjects than in subjects with CAT and GD (p < 0.001). In contrast, the differences between the GD and the CAT patients (p = 0.23) were not statistically significant. The optimal cutoff ASQ value for which the sum of sensitivity and specificity was the highest for the prediction of diffuse thyroid pathology was 103 (95% confidence interval = [0.79, 0.95]). At this cutoff value, the sensitivity was 83% and the specificity was 89%. Our findings suggest that ASQ is a useful method for the assessment of the thyroid in patients with AITD.

Diagnostic performance of thyroid ultrasonography screening in pediatric patients with a hypothyroid, hyperthyroid or euthyroid goiter

BACKGROUND

Goiter is frequently the first indicator of thyroid disease in children.

OBJECTIVE

To evaluate the usefulness of ultrasonography (US) in the identification of potential malignant nodules and autoimmune thyroiditis in children with diffuse goiter.

MATERIALS AND METHODS

This study consisted of 113 patients <20 years with a diffuse goiter who underwent thyroid US. Parenchymal echogenicity and the presence of nodules and abnormal lymph nodes were evaluated on US; if a thyroid nodule was detected, its characteristics were analyzed. The diagnostic accuracy of the US findings in the diagnosis of autoimmune thyroid disease was assessed.

RESULTS

Thyroid nodules were detected on US in 72 of the 113 (63.7%) patients. Of these, 65 (90.3%) had probably benign nodules and 4 (5.6%) patients had nodules suspicious of malignancy. The remaining had indeterminate nodules only. In one child with suspected malignant nodules, papillary thyroid cancer with coexisting autoimmune thyroiditis was confirmed. Hypoechogenicity was visualized in 23 (88.5%) patients with autoimmune thyroiditis and 12 (85.7%) with Graves disease. The sensitivity and specificity of micronodulation for autoimmune thyroiditis were 53.9% and 98.3%, respectively.

CONCLUSION

Although the potential for malignant nodules is relatively low in children with diffuse goiter, US can detect focal thyroid disease and characterize the nodules. US thus plays a useful role in excluding autoimmune thyroiditis in this population.

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.

Correlation of normal thyroid ultrasonography with thyroid tests

BACKGROUND

Thyroid disorders are frequently seen in the community. Thyroid ultrasonography (US) is commonly used in the diagnosis of thyroid diseases. The relationship between heterogeneous echogenicity of thyroid gland and thyroid tests are well known.

METHODS

The aim of this study is to evaluate the correlation of normal US with the thyroid tests. A total of 681 individuals were enrolled in the study. Individuals were separated into two groups as normal (group 1) and hypoechoic (group 2) according to the echogenicity in US. Subjects with nodular thyroid lesions were excluded from the study. Thyroid stimulating hormone (TSH), free T4 (fT4), thyroid peroxidase antibody (TPOAb) and anti-thyroglobulin antibody (TgAb) values were recorded in both groups and thyroid stimulating hormone receptor antibody (TRAb) was recorded in individuals with low TSH.

RESULTS

86.1% of individuals in group 1 had normal TSH, 93.7% had normal thyroid antibodies and in 77.6% of individuals, all thyroid tests performed were normal. In the 6.9% of the group 2, all reviewed thyroid tests were normal (P<0.001).

CONCLUSIONS

Our study shows that US is correlated with normal thyroid function tests and is a valuable tool in the prediction of normal thyroid function.

Acoustic radiation force impulse elastography for differentiation of benign and malignant thyroid nodules with concurrent Hashimoto's thyroiditis

The purpose of the study was to explore the diagnostic performance of acoustic radiation force impulse (ARFI) elastography in differential diagnosis between benign and malignant thyroid nodules in patients with coexistent Hashimoto's thyroiditis (HT). A total of 141 pathological proven nodules in 141 HT patients (7 males and 134 females, mean age 50.1 years, range 23-75 years) received conventional ultrasound (US), elasticity imaging (EI) and ARFI elastography, including virtual touch tissue imaging (VTI) and virtual touch tissue quantification (VTQ), before surgery. Shear wave velocity (SWV) and SWV ratio were measured for each nodule on VTQ. The US, EI and ARFI elastography features were compared between benign and malignant nodules in HT patients. Receiver operating characteristic curve (ROC) analyses and area under curve (AUC) were performed to assess the diagnostic performance. Pathologically, 70 nodules were benign and 71 nodules were malignant. Significant differences were found between benign and malignant nodules in HT patients for EI (EI score) and ARFI (VTI grade and SWV) (all P value <0.05). The AUCs for EI, VTI, SWV and SWV ratio were 0.68 [95% confidence interval (CI): 0.59-0.77], 0.90 (95% CI: 0.84-0.95), 0.77 (95%CI: 0.70-0.85) and 0.74 (95%CI: 0.66-0.82), respectively. The cut-off points were EI score ≥3, VTI grade ≥4, SWV ≥2.58 m/s and SWV ratio ≥1.03, respectively. In conclusion, ARFI elastography is useful for differentiation between benign and malignant thyroid nodules in HT patients. The diagnostic performance of ARFI elastography is better than EI.

Roles of ultrasound and power Doppler ultrasound for diagnosis of Hashimoto thyroiditis in anti-thyroid marker-positive euthyroid subjects

PURPOSE

The present study was performed to investigate the contribution of ultrasonographic (US) findings to diagnosis in anti-thyroid marker-positive patients with normal hormone levels among euthyroid subjects with Hashimoto's thyroiditis (HT).

METHODS

Forty premenopausal euthyroid patients with a median age of 32 years (range, 20-44 years) with normal levels of free triiodothyronine (FT3) and free thyroxine (FT4), and elevated anti-thyroid peroxidase (TPO) antibodies were enrolled in this study. A control group of 46 healthy individuals with a median age of 29 years (range, 18-43 years) was composed of randomly selected volunteers. The examinations included basic morphometric (measurement of thyroid gland dimensions in three axes, the volume of each thyroid lobe, and the total thyroid volume), morphological grayscale imaging (echogenicity, nodularity, septations, undulation of the margins, and reactive lymph nodes), and thyroid gland vascularity.

RESULTS

There were no statistically significant differences in morphometric parameters of the thyroid gland between the study and control groups. There were significant differences in the presence of nodularity, undulation of the gland margins, septations inside the glands, infrathyroidal and/or pretracheal reactive lymph nodes, and increased vascularity on power Doppler imaging between the groups. The use of all parameters together yielded a sensitivity of 90%, specificity of 84.8%, positive predictive value (PPV) of 83.7%, negative predictive value (NPV) of 90.7%, and accuracy of 87.2% for diagnosis of HT.

CONCLUSIONS

US and power Doppler US are helpful for the diagnosis of HT in anti-thyroid marker-positive patients with normal thyroid hormone levels.

Comparative study of ultrasound and computed tomography for incidentally detecting diffuse thyroid disease

The aim of this study was to compare the diagnostic values of thyroid ultrasound (US) and neck computed tomography (CT) in incidentally detecting diffuse thyroid disease (DTD). A single radiologist made US and CT diagnoses of incidentally detected DTD in 130 consecutive patients before thyroidectomy for various malignancies. Histopathologic examinations confirmed normal thyroid (n = 80), Hashimoto thyroiditis (n = 20), non-Hashimoto lymphocytic thyroiditis (n = 28) and diffuse hyperplasia (n = 2). Receiver operating characteristic curves revealed that the best diagnostic indices of both imaging methods were achieved on the basis of two or more abnormal imaging findings. The sensitivity, specificity and accuracy of US and CT in incidentally detecting DTD by this classification were 72% and 72%, 87.5% and 91.3% and 81.5% and 83.8%, respectively. Thyroid US and neck CT have similar diagnostic values for differentiating incidental DTD from normal thyroid.

Repeat Fine-Needle Aspiration Biopsy within a Short Interval Does Not Increase the Atypical Cytologic Results for Thyroid Nodules with Previously Nondiagnostic Results

OBJECTIVE

The purpose of this study was to determine whether the recommended waiting period of 3 months is necessary for repeat fine-needle aspiration biopsy (FNAB).

STUDY DESIGN

A retrospective review of 128 nodules from 126 patients with initial nondiagnostic (ND) results was performed for the period between January 2009 and December 2012. Demographic and clinical factors were recorded including age, sex, time interval between FNABs, and ultrasound (US) factors, i.e. nodule size, location, consistency, suspicious malignant findings and thyroiditis. The time interval was subdivided into </≥5, 10, 15 and 20 weeks after the initial FNAB. The effects on the nuclear atypia were analyzed using the Fisher exact test and the Mann-Whitney U test.

RESULTS

None of the demographic, clinical or US variables was significantly related to the atypical diagnosis of repeat FNAB. The time interval until repeat FNAB was also not related to the atypical diagnosis (p = 0.63, 0.57, 0.23 and 0.48 for 5, 10, 15 and 20 weeks, respectively).

CONCLUSION

The timing of repeat FNAB for thyroid nodules with previous ND results did not increase the nuclear atypia on repeat FNAB.

Heterogeneous echogenicity of the thyroid parenchyma does not influence the detection of multi-focality in papillary thyroid carcinoma on preoperative ultrasound staging

Heterogeneous echogenicity and micro-nodulations of diffuse thyroid disease on ultrasonography (US) might influence the diagnostic performance of pre-operative US staging, especially the detection of multi-focality. This study was designed to determine whether heterogeneous echogenicity of the thyroid parenchyma influences the diagnostic performance of US in the detection of multi-focality in papillary thyroid carcinoma. Between December 2010 and April 2011, 811 patients underwent pre-operative staging US for papillary thyroid carcinoma and surgery. Twelve radiologists performed the pre-operative US for T and N staging. Underlying parenchymal echogenicity and unilateral and bilateral multi-focality of the thyroid nodules were also evaluated. Patients were divided into two groups on the basis of the underlying echogenicity of the thyroid gland. To evaluate the diagnostic accuracy of US with respect to underlying echogenicity, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated and compared between the two groups. Among the 811 patients included, US revealed underlying heterogeneous echogenicity of the thyroid parenchyma in 204 (25.2%) and underlying homogeneous echogenicity of the thyroid parenchyma in 607 (74.8%). There were no significant differences between the two groups in the diagnostic performance of pre-operative staging US in predicting unilateral multi-focality and bilaterality. Underlying heterogeneous echogenicity in a thyroid gland with Hashimoto's thyroiditis does not significantly influence the detection of multi-focality in papillary thyroid cancer on pre-operative US staging.

Diagnostic role of conventional ultrasonography and shearwave elastography in asymptomatic patients with diffuse thyroid disease: initial experience with 57 patients

PURPOSE

Thyroid ultrasonography (US) is a useful diagnostic tool in the evaluation of diffuse thyroid disease (DTD), whereas shearwave elastography is a dynamic technique that can provide information about tissue hardness by using acoustic shearwaves remotely induced by a focused ultrasonic beam. This study aims at investigating the role of conventional US and shearwave elastography in the diagnosis of asymptomatic patients with DTD.

MATERIALS AND METHODS

Fifty-seven patients who underwent both conventional US and shearwave elastography were included in this study. Interobserver variability of the three radiologists in assessment of underlying thyroid echogenicity on conventional US was analyzed. Diagnostic performances for diagnosing DTD on conventional US and shearwave elastography were calculated and compared.

RESULTS

Fair agreement was observed in the identification of DTD with conventional US (kappa value= 0.27). The area under the receiver operating characteristic curve (Az) were 0.52-0.585 on conventional US by three radiologists. The Az values when using the mean and maximum elasticity values as a diagnostic criteria for DTD were 0.619 and 0.59 on shearwave elastography. Patients with DTD showed higher mean [24.1±10 kilo-Pascals (kPa)] and maximum (36.4±13.3 kPa) elasticity values on shearwave elastography when compared to the normal group (23.4±10.8 kPa and 33.7±12.4 kPa, respectively), although without statistical significance (p=0.802 and p=0.452, respectively).

CONCLUSION

Conventional US did not show reliable interobserver agreement in the diagnosis of DTD. Although not statistically significant, shearwave elastography may provide additional information in the diagnosis of DTD. Therefore, larger prospective studies are needed to define the values of shearwave elastography for diagnosing DTD.

Computed tomography features of incidentally detected diffuse thyroid disease

Objective. This study aimed to evaluate the CT features of incidentally detected DTD in the patients who underwent thyroidectomy and to assess the diagnostic accuracy of CT diagnosis. Methods. We enrolled 209 consecutive patients who received preoperative neck CT and subsequent thyroid surgery. Neck CT in each case was retrospectively investigated by a single radiologist. We evaluated the diagnostic accuracy of individual CT features and the cut-off CT criteria for detecting DTD by comparing the CT features with histopathological results. Results. Histopathological examination of the 209 cases revealed normal thyroid (n = 157), Hashimoto thyroiditis (n = 17), non-Hashimoto lymphocytic thyroiditis (n = 34), and diffuse hyperplasia (n = 1). The CT features suggestive of DTD included low attenuation, inhomogeneous attenuation, increased glandular size, lobulated margin, and inhomogeneous enhancement. ROC curve analysis revealed that CT diagnosis of DTD based on the CT classification of "3 or more" abnormal CT features was superior. When the "3 or more" CT classification was selected, the sensitivity, specificity, positive and negative predictive values, and accuracy of CT diagnosis for DTD were 55.8%, 95.5%, 80.6%, 86.7%, and 85.6%, respectively. Conclusion. Neck CT may be helpful for the detection of incidental DTD.

Heterogeneous echogenicity of the underlying thyroid parenchyma: how does this affect the analysis of a thyroid nodule?

Background

Heterogeneous echogenicity of the thyroid gland has been associated with diffuse thyroid disease and benign and malignant nodules can coexist with diffuse thyroid disease. Underlying heterogeneous echogenicity might make it difficult to differentiate between benign and malignant nodules on US. Thus, the aim of this study was to evaluate the influence of underlying thyroid echogenicity on diagnosis of thyroid malignancies using US.

Methods

A total of 1,373 patients who underwent US-guided fine needle aspiration of 1,449 thyroid nodules from June 2009 to August 2009 were included. The diagnostic performance of US assessment for thyroid nodules was calculated and compared according to underlying thyroid echogenicity. The diagnostic performance of US assessments in the diagnosis of thyroid malignancy according to the underlying parenchymal echogenicity was compared using a logistic regression with the GEE (generalized estimating equation) method. Each US feature of malignant and benign thyroid nodules was analyzed according to underlying echogenicity to evaluate which feature affected the final diagnosis.

Results

Among the 1,449 nodules, 325 (22.4%) were malignant and 1,124 (77.6%) were benign. Thyroid glands with heterogeneous echogenicity showed significantly lower specificity, PPV, and accuracy compared to thyroid glands with homogeneous echogenicity, 76.3% to 83.7%, 48.7% to 60.9%, and 77.6% to 84.4%, respectively (P = 0.009, 0.02 and 0.005, respectively). In benign thyroid nodules, microlobulated or irregular margins were more frequently seen in thyroid glands with heterogeneous echogenicity than in those with homogenous echogenicity (P < 0.001).

Conclusion

Heterogeneous echogenicity of the thyroid gland significantly lowers the specificity, PPV, and accuracy of US in the differentiation of thyroid nodules. Therefore, caution is required during evaluation of thyroid nodules detected in thyroid parenchyma showing heterogeneous echogenicity.

Role of sonographic diagnosis in managing Bethesda class III nodules

BACKGROUND AND PURPOSE

Bethesda class III cytology is an important limitation of the US-FNA in assessing thyroid nodules. This study aimed to assess the diagnostic efficacy of US in evaluating thyroid nodules with Bethesda class III cytology.

MATERIALS AND METHODS

From January 2008 to December 2009, 1036 patients with 1289 thyroid nodules diagnosed by US and subsequent US-FNA biopsy were enrolled in the study. On the basis of US features, each thyroid nodule was prospectively classified by a single radiologist into 1 of 5 diagnostic categories: benign, probably benign, borderline, possibly malignant, and malignant. Solid nodules were classified by using all 5 categories, whereas partially cystic nodules were classified by using 4 (borderline was omitted). We calculated the diagnostic efficacy of thyroid US by comparing the US diagnoses with the histopathology results of Bethesda class III nodules.

RESULTS

Of the 51 Bethesda class III nodules, 35 were surgically confirmed and 8 were histologically diagnosed, and a malignancy rate of 46.5% (20/43) was determined. From the 43 nodules, the sensitivity, specificity, positive and negative predictive values, and accuracy were calculated with 9 borderline nodules excluded (100%, 94.7%, 93.3%, 100%, and 97.0%, respectively) and with the 9 when reclassified as benign (63.6%, 95.2%, 93.3%, 71.4%, and 79.1%, respectively) and malignant (100%, 85.7%, 88.0%, 100%, and 93.0%, respectively). The values obtained with exclusion and malignancy reclassification of 9 borderline nodules were not significantly different (P = .250).

CONCLUSIONS

US diagnosis by using the present US classification system can be helpful for managing Bethesda class III nodules.

Staging of papillary thyroid carcinoma with ultrasonography: performance in a large series

BACKGROUND

This study was designed to evaluate the performance of ultrasonography (US) for the preoperative staging of papillary thyroid carcinoma (PTC) in a large series according to the TNM classification.

METHODS

Preoperative US was performed for the evaluation of primary tumors and lymph node metastasis in 722 consecutive patients with cytologically proven PTC. Three experienced radiologists prospectively determined T and N categories of PTC. N categorization was based on compartments, including left and right lateral compartments (levels II-V) and central compartment (level VI). All patients underwent surgery and central compartment dissection. Lateral compartment dissection was selectively performed. We assessed the diagnostic performance of preoperative US for staging of PTC on the basis of pathologic findings of surgical specimens. Subgroup analysis according to suspicion of diffuse thyroid disease (DTD) on US was performed to compare US accuracies for N categorization.

RESULTS

US predicted 61.7% (142/230) of patients with multifocal PTC and 67.1% (100/149) of patients with bilateral malignancy. Overall accuracy of US for T categorization was 69.7% (503/722) and that of US for N categorization was 59% (426/722). Accuracies of sonographic categorization for N0, N1a, and N1b were 66% (276/418), 33.3% (70/210), and 85.1% (80/94), respectively. Overall US accuracy for prediction of an N category was significantly lower in patients with US-indicated DTD (51.1%, 67/131) than it was in patients without DTD (60.7%, 359/591; P = 0.043).

CONCLUSIONS

Preoperative US is a feasible technique for the preoperative staging of PTC and is helpful for the detection of lateral compartment metastasis. Presence of DTD can affect the staging of lymph node metastasis.