Standards of the Polish Ultrasound Society - update. Ultrasound examination of thyroid gland and ultrasound-guided thyroid biopsy

Alteration in kynurenine pathway metabolites in young women with autoimmune thyroiditis

The kynurenine pathway (KP) of tryptophan degradation includes several compounds that reveal immunomodulatory properties. The present study aimed to investigate the alteration in KP metabolites in young women with autoimmune thyroiditis (AIT) and their associations with thyroid function. The thyroid function tests, antithyroid antibodies measurement and ultrasonography of the thyroid gland have been performed in 57 young women with AIT and 38 age-matched healthy controls. The serum levels of tryptophan, kynurenine (KYN) and its metabolites were determined, and the activity of KP enzymes was calculated indirectly as product-to-substrate ratios. KP was activated and dysregulated in AIT, along with significantly elevated levels of KYN and anthranilic acid (AA), at the expense of the reduction of kynurenic acid (KYNA), which was reflected by the increase in the AA/KYNA ratio (p < 0.001). In univariate and multiple regression analyses, peripheral deiodinase (SPINA-GD) activity in AIT was positively associated with KYNA, AA, and quinolinic acid (QA). The merger of AA, AA/KYNA ratio, QA and SPINA-GD exhibited the highest sensitivity and specificity to predict AIT (p < 0.001) in receiver operating characteristic (ROC) analysis. In conclusion, the serum KYN metabolite profile is dysregulated in young women with AIT and could serve as a new predictor of AIT risk.

Markedly hypoechoic: a new definition improves the diagnostic performance of thyroid ultrasound

OBJECTIVES

To determine the contribution of a modified definition of markedly hypoechoic in the differential diagnosis of thyroid nodules.

METHODS

A total of 1031 thyroid nodules were included in this retrospective multicenter study. All of the nodules were examined with US before surgery. The US features of the nodules were evaluated, in particular, the classical markedly hypoechoic and modified markedly hypoechoic (decreased or similar echogenicity relative to the adjacent strap muscles). The sensitivity, specificity, and AUC of classical/modified markedly hypoechoic and the corresponding ACR-TIRADS, EU-TIRADS, and C-TIRADS categories were calculated and compared. The inter- and intraobserver variability in the evaluation of the main US features of the nodules was assessed.

RESULTS

There were 264 malignant nodules and 767 benign nodules. Compared with classical markedly hypoechoic as a diagnostic criterion for malignancy, using modified markedly hypoechoic as the criterion resulted in a significant increase in sensitivity (28.03% vs. 63.26%) and AUC (0.598 vs. 0.741), despite a significant decrease in specificity (91.53% vs. 84.88%) (p < 0.001 for all). Compared to the AUC of the C-TIRADS with the classical markedly hypoechoic, the AUC of the C-TIRADS with the modified markedly hypoechoic increased from 0.878 to 0.888 (p = 0.01); however, the AUCs of the ACR-TIRADS and EU-TIRADS did not change significantly (p > 0.05 for both). There was substantial interobserver agreement (κ = 0.624) and perfect intraobserver agreement (κ = 0.828) for the modified markedly hypoechoic.

CONCLUSION

The modified definition of markedly hypoechoic resulted in a significantly improved diagnostic efficacy in determining malignant thyroid nodules and may improve the diagnostic performance of the C-TIRADS.

CLINICAL RELEVANCE STATEMENT

Our study found that, compared with the original definition, modified markedly hypoechoic significantly improved the diagnostic performance in differentiating malignant from benign thyroid nodules and the predictive efficacy of the risk stratification systems.

KEY POINTS

• Compared with the classical markedly hypoechoic as a diagnostic criterion for malignancy, the modified markedly hypoechoic resulted in a significant increase in sensitivity and AUC. • The C-TIRADS with the modified markedly hypoechoic achieved higher AUC and specificity than that with the classical markedly hypoechoic (p = 0.01 and  < 0.001, respectively).

Conventional ultrasonography and elastosonography in diagnosis of malignant thyroid nodules: A systematic review and meta-analysis

Purpose

To evaluate the diagnostic value of conventional ultrasound and elastosonography in malignant thyroid nodules by meta-analysis.

Methods

The literature included in the Cochrane Library, PubMed, and Embase were searched by using "elastosonography, ultrasonography, thyroid nodules" as the keywords. The clinical studies using elastosonography and conventional ultrasound to diagnose thyroid nodules were selected, and histopathology of thyroid nodules was used as reference standards. The quality evaluation and heterogeneity test were performed on the literature that met the requirements, the combined specificity and sensitivity were pooled, and a comprehensive ROC curve analysis was performed. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool was utilized to evaluate the quality of each included study. Meta-DiSc version 1.4, StataSE 12 and Review Manager 5.4 were used.

Results

A total of nine studies assessed 3066 thyroid nodules (2043 benign and 1023 malignant). The pooled sensitivity, specificity, PLR, NLR, and DOR of conventional ultrasound for the diagnose of malignant thyroid nodules were 0.833 (95% CI 0.809-0.855), 0.818 (95% CI 0.801-0.835), 4.85 (95% CI 4.36-5.39), 0.20 (95% CI 0.17-0.23), and 29.38 (95% CI 23.28-37.08), respectively, with an AUC of 0.9068. Also, the pooled sensitivity, specificity, PLR, NLR, and DOR of elastosonography were 0.774 (95% CI 0.741-0.804), 0.737 (95% CI 0.715-0.758), 3.14(95% CI 2.85-3.47), 0.29 (95% CI 0.25-0.34), and 9.35 (95% CI 7.63-11.46), respectively, with an AUC of 0.8801. Three studies provided data regarding the conventional ultrasound and elastosonography. The pooled sensitivity, specificity, PLR, NLR, DOR, and AUC were 0.902 (95% CI 0.870-0.928), 0.649 (95% CI 0.616-0.681), 2.72 (95% CI 2.46-3.00), 0.14 (95% CI 0.11-0.19), 25.51 (95%CI 17.11-38.03), and 0.9294.

Conclusion

The existing evidence shows that elastosonography cannot completely replace conventional ultrasound in the diagnosis of malignant thyroid nodules, and the combination of elastosonography and conventional ultrasound gives a better diagnostic precision.

Systematic review registration

www.crd.york.ac.uk, identifier PROSPERO CRD42022375808.

Finite element analysis to predict temperature distribution in the human neck with abnormal thyroid: A proof of concept

BACKGROUND AND OBJECTIVE

Hyperthyroidism, hypothyroidism, goiter and cancer are some of the dysfunctions that can occur concerning the thyroid, an important body homeostasis regulatory gland located in the cervical region. These disorders are mostly caused by changes in metabolism and can impair quality of life. This study presents a non-invasive approach that can detect changes in thyroid metabolism through the finite element analysis and medical images. The objective of this work was to develop a numerical model to represent the temperature distribution in the human neck with and without the presence of thyroid nodules. The patient-specific computational model for the case with thyroid nodules was calibrated with infrared thermography.

METHODS

A three-dimensional geometrical model of the neck was constructed based on the segmentation of magnetic resonance (MR) images. The Finite Element Method (FEM) was used to simulate heat diffusion and convection in the cervical region. The infrared thermography image was used to calibrate the heat transfer constants to obtain the surface temperature of the human neck model containing the enlarged thyroid with nodules. Subsequently, another case for the entire neck with an abnormally large thyroid without the nodules was simulated using the calibrated physical constants.

RESULTS

Results of the simulations with and without the presence of thyroid nodules were compared, showing the influence of the generation of heat from the nodules, allowing observation of the thermal differences on the cervical surface and at the thyroid itself. The model with nodules presented higher skin temperature distribution in the anterior triangle region when compared to the case without nodules. An average of 0.36^∘C of absolute error and 1% of relative error was obtained for the calibration between the simulated model and the infrared image.

CONCLUSIONS

This research consists of an innovative approach by comparing the results obtained via FEM simulation and the corresponding infrared image of the same neck region under study. Since there are great variability and uncertainties in the determination of the thermal constants, we applied a procedure for calibrating them based on a patient-specific case, which involves a multinodular goiter accompanied by hyperthyroidism. This proof-of-concept study allows the creation of comparative scenarios between the FEM simulations and the corresponding infrared image. Thus, it is expected that, in the future, this approach could be used to include the effect of drugs in the treatment strategies of thyroid diseases and disorders.

Head and Neck Ultrasound - EFSUMB Training Recommendations for the Practice of Medical Ultrasound in Europe

Different surgical and medical specialists increasingly use head and neck ultrasound and ultrasound-guided interventions as part of their clinical practice. We need to ensure high quality and standardized practice across specialties, and this position paper of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) describes the training requirements for head and neck ultrasound. Traditionally, a minimum number of ultrasound examinations indicates competence, but this is unreliable, and a general shift towards competence-based training is ongoing. For each EFSUMB level, we will outline the theoretical knowledge and skills needed for clinical practice. The recommendations follow the three EFSUMB competency levels for medical ultrasound practice. Level 1 describes the skills required to perform essential head and neck ultrasound examinations independently, level 2 includes ultrasound-guided interventions, while level 3 involves the practice of high-level neck ultrasound and use of advanced technologies. Our goal is to ensure high quality and standardized head and neck ultrasound practice performed by different clinical specialists with these recommendations.

Sirtuin 1, Visfatin and IL-27 Serum Levels of Type 1 Diabetic Females in Relation to Cardiovascular Parameters and Autoimmune Thyroid Disease

The loss of cardioprotection observed in premenopausal, diabetic women may result from the interplay between epigenetic, metabolic, and immunological factors. The aim of this study was to evaluate the concentration of sirtuin 1, visfatin, and IL-27 in relation to cardiovascular parameters and Hashimoto’s disease (HD) in young, asymptomatic women with type 1 diabetes mellitus (T1DM). Thyroid ultrasound, carotid intima-media thickness (cIMT) measurement, electrocardiography, and echocardiography were performed in 50 euthyroid females with T1DM (28 with HD and 22 without concomitant diseases) and 30 controls. The concentrations of serum sirtuin 1, visfatin and IL-27 were assessed using ELISA. The T1DM and HD group had higher cIMT (p = 0.018) and lower left ventricular global longitudinal strain (p = 0.025) compared to females with T1DM exclusively. In women with a double diagnosis, the sirtuin 1 and IL-27 concentrations were non-significantly higher than in other groups and significantly positively correlated with each other (r = 0.445, p = 0.018) and thyroid volume (r = 0.511, p = 0.005; r = 0.482, p = 0.009, respectively) and negatively correlated with relative wall thickness (r = –0.451, p = 0.016; r = –0.387, p = 0.041, respectively). These relationships were not observed in the control group nor for the visfatin concentration. These results suggest that sirtuin 1 and IL-27 contribute to the pathogenesis of early cardiac dysfunction in women with T1DM and HD.

Prevention of Iodinated Contrast Media-Induced Hyperthyroidism in Patients with Euthyroid Goiter

INTRODUCTION

Iodinated contrast media (ICM)-induced hyperthyroidism is an underestimated, potentially severe condition; however, its prevention has not been sufficiently investigated. The aim of this study was to evaluate the influence of ICM on thyroid status, the advantages of prophylactic therapy for iodine-induced hyperthyroidism (IIH) in patients with euthyroid goiter and cardiovascular comorbidities, and the association between the incidence of IIH and thyroid volume.

METHODS

Thirty-six euthyroid patients undergoing procedures involving ICM administration were divided into 2 groups: the first group (n = 13) received prophylactic treatment with thiamazole or thiamazole combined with sodium perchlorate during ICM exposure; the second group (n = 23) did not receive prophylaxis. Thyroid-stimulating hormone levels were evaluated before and after ICM, and thyroid hormone levels were assessed after ICM at different points in time. The morphology of the thyroid was evaluated by ultrasonography.

RESULTS

Twenty-one patients (58%) developed hyperthyroidism after ICM. Hyperthyroidism was observed more frequently in the group without prophylactic treatment than in the group with prophylaxis (65 vs. 15%, respectively; p = 0.006). No cases of overt hyperthyroidism were observed in the group receiving thiamazole with sodium perchlorate. IIH persisted for a median time of 52.5 days. Larger thyroid volume was associated with a significantly higher occurrence of ICM-induced hyperthyroidism (p = 0.04).

CONCLUSIONS

Patients with euthyroid goiter receiving ICM are at risk of developing hyperthyroidism. The occurrence of hyperthyroidism after ICM in euthyroid patients with goiter is higher in those with larger thyroid volume. The frequency of ICM-induced hyperthyroidism in euthyroid patients with goiter is lower in those receiving prophylactic therapy with thiamazole in monotherapy or in combination with sodium perchlorate than in those not receiving prophylactic treatment.

"Small Thyroid Gland" in Reproductive Women without Autoimmune Thyroid Disease-Ultrasonographic Evaluation as a Useful Screening Tool for Hypothyroidism

Proper thyroid function is important for women of childbearing age, as hypothyroidism affects fertility, pregnancy and offspring. The upper reference limit for thyrotropin (TSH) in pregnancy was defined as <2.5 mU/L in the first trimester. Recommendations include either universal screening of TSH before pregnancy, or identifying individuals at “high risk” for thyroid illness. “Small thyroid gland” not associated with autoimmune thyroid disease (AITD) seems to be a reason for hypothyroidism and probably should be included in target case finding procedure before pregnancy. The purpose of this cross-sectional study was to analyze relationships between the thyroid volume and its function, and to determine the thyroid volume as a predictive factor for TSH levels above 2.5 µIU/mL in reproductive women without AITD. We included 151 women without AITD, and aged 18–40. Blood and urine samples were analyzed for parameters of thyroid function. Ultrasound examination of the thyroid was performed. The thyroid volume was negatively correlated with TSH. Women with a thyroid volume in the 1st quartile for the study population presented higher TSH levels versus women in the 4th quartile (p = 0.0132). A thyroid volume cut-off point of 9 mL was the predictive factor for TSH levels above 2.5 µIU/mL (p = 0.0037).

Exposure to Bisphenol A Analogs and the Thyroid Function and Volume in Women of Reproductive Age-Cross-Sectional Study

Bisphenols (BPs) are commonly known plastifiers that are widely used in industry. The knowledge about the impact of BPs on thyroid function is scarce. Proper thyroid functioning is especially important for women of reproductive age, as hypothyroidism affects fertility, pregnancy outcomes and the offspring. There are no studies analyzing the influence of BPs on thyroid function and volume in non-pregnant young women. The aim of this cross-sectional study was to evaluate the relationship between bisphenol A and its 10 analogs (BPS, BPC, BPE, BPF, BPG, BPM, BPP, BPZ, BPFL, and BPBP) on thyroid function and volume in women of reproductive age. Inclusion criteria were: female sex, age 18-40 years. Exclusion criteria were history of any thyroid disease, pharmacotherapy influencing thyroid function, pregnancy or puerperium, and diagnosis of autoimmune thyroid disease during this study. Venous blood was drawn for measurement of thyrotropin (TSH), free thyroxine, thyroid peroxidase antibodies, thyroglobulin antibodies, BPs. Urine samples were analyzed for: ioduria and BPs. Ultrasound examination of thyroid gland was performed. One hundred eighty participants were included into the study. A negative correlation was found between urine BPC and the thyroid volume (R = -0.258; p = 0.0005). Patients with detected urine BPC presented smaller thyroid glands than those with not-detected urine BPC (p = 0.0008). A positive correlation was found between TSH and urine BPC (R = 0.228; p = 0.002). Patients with detected urine BPC presented higher concentrations of TSH versus those with not-detected urine BPC (p = 0.003). There were no relationships between any of serum BPs as well as the other urine BPs and thyroid function and its volume. The only BP that demonstrated the relationship between thyroid function and its volume was BPC, probably because of its chemical structure that most resembles thyroxine. Exposure to this BP may result in the development of hypothyroidism that could have a negative impact on pregnancy and the offspring.

Accuracy of the European Thyroid Imaging Reporting and Data System (EU-TIRADS) in the valuation of thyroid nodule malignancy in reference to the post-surgery histological results

Purpose

To assess the clinical usefulness of the European Thyroid Imaging and Reporting Data System (EU-TIRADS) in the valuation of thyroid nodules malignancy in reference to post-surgery histological results.

Material and methods

Pre-operative ultrasound was performed in consecutive patients admitted for thyroid surgery between June 2017 and January 2018. Thyroid nodules were classified according to EU-TIRADS to five groups: 1-5. At least one fine-needle aspiration biopsy (FNAB)/patient (dominant or suspected nodule) was performed in an outpatient clinic. The final diagnosis was based on the histological result. The percentage of cancers in each EU-TIRADS group was evaluated. Finally, sensitivity, specificity, accuracy, as well as positive and negative predictive values for malignancy were assessed.

Results

Fifty-two patients with a total of 140 thyroid nodules (median: 3 nodules/thyroid [minimum-maximum: 1-6]) were enrolled in the study. Thyroid cancer was diagnosed in 0% (0/6) in EU-TIRADS 2; 0% (0/92) in EU-TIRADS 3; 5.9% (2/34) in EU-TIRADS 4, and 75% (6/8) in EU-TIRADS 5. In nodules assessed as EU-TIRADS ≥ 4 sensitivity, specificity, positive and negative predictive values for malignancy were, respectively: 75% (CI 95%: 40.7-93.5), 94.1% (CI 95%: 86.0-98.5), 75% (CI 95%: 40.7-93.5), and 94.1% (CI 95%: 86.0-98.5).

Conclusions

EU-TIRADS is a valuable and simple tool for assessment of the risk of malignancy of thyroid nodules and demonstrates a high ultrasound correlation with histological post-surgery results. FNAB should be performed in all nodules assessed as EU-TIRADS ≥ 4, due to higher risk of malignancy.

Use of the Kwak Thyroid Image Reporting and Data System (K-TIRADS) in differential diagnosis of thyroid nodules: systematic review and meta-analysis

PURPOSE

The purpose of this systematic literature review was to assess the usefulness of the Thyroid Image Reporting and Data System (K-TIRADS) classification proposed by Kwak for differentiation of thyroid nodules.

MATERIAL AND METHODS

Four literature databases were searched for relevant articles through early January 2017. A meta-analysis was performed to calculate pooled sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-) and diagnostic odds ratio (DOR). The area under the curve (AUC) from the pooled receiver operating characteristic (ROC) was used to assess the usefulness of this classification for differentiation of thyroid nodules. Meta-analysis was conducted by using meta-analysis software.

RESULTS

We analysed six publications describing 10,926 nodules. Pooled sensitivity, specificity, LR+, LR-, DOR, and AUC for pooled ROC were 0.983 (95 % CI 0.976-0.989), 0.552 (95 % CI 0.542-0.562), 2.666 (95 % CI 1.692-4.198), 0.05 (95 % CI 0.035-0.072), 51.020 (95 % CI 15.241-170.79) and 0.938, respectively.

CONCLUSIONS

Kwak TIRADS has high sensitivity and low specificity. Thus, it is very useful to discard the benign cases and to reduce the number of biopsies.

KEY POINTS

• Routine, adequate standardization of thyroid nodules ultrasound classification is mandatory. • Kwak TIRADS parameters are accurate for differentiating focal thyroid lesions. • Kwak TIRADS system is simple to apply. • Kwak TIRADS system may become a useful diagnostic tool.

Ultrasound image of the thyroid gland in obese children

Obesity as a disease of affluence also affects younger children. Numerous observations suggest a link between excessive body weight and thyroid function disorders. Subclinical hypothyroidism has been diagnosed increasingly frequently in patients with obesity. A growing number of papers also point to morphological changes of the thyroid gland in the ultrasound examination in obese children. These reports mainly concern changes in echogenicity. The present paper discusses the most important aspects of this topic on the basis of the literature as well as containing a brief analysis based on own experiences.

Shear wave elastography in medullary thyroid carcinoma diagnostics

Shear wave elastography (SWE) is a modern method for the assessment of tissue stiffness. There has been a growing interest in the use of this technique for characterizing thyroid focal lesions, including preoperative diagnostics.

AIM

The aim of the study was to assess the clinical usefulness of SWE in medullary thyroid carcinoma (MTC) diagnostics.

MATERIALS AND METHODS

A total of 169 focal lesions were identified in the study group (139 patients), including 6 MTCs in 4 patients (mean age: 45 years). B-mode ultrasound and SWE were performed using Aixplorer (SuperSonic, Aix-en-Provence), with a 4-15 MHz linear probe. The ultrasound was performed to assess the echogenicity and echostructure of the lesions, their margin, the halo sign, the height/width ratio (H/W ratio), the presence of calcifications and the vascularization pattern. This was followed by an analysis of maximum and mean Young's (E) modulus values for MTC (EmaxLR, EmeanLR) and the surrounding thyroid tissues (EmaxSR, EmeanSR), as well as mean E-values (EmeanLRz) for 2 mm region of interest in the stiffest zone of the lesion. The lesions were subject to pathological and/or cytological evaluation.

RESULTS

The B-mode assessment showed that all MTCs were hypoechogenic, with no halo sign, and they contained micro- and/ or macrocalcifications. Ill-defined lesion margin were found in 4 out of 6 cancers; 4 out of 6 cancers had a H/W ratio > 1. Heterogeneous echostructure and type III vascularity were found in 5 out of 6 lesions. In the SWE, the mean value of EmaxLR for all of the MTCs was 89.5 kPa and (the mean value of EmaxSR for all surrounding tissues was) 39.7 kPa Mean values of EmeanLR and EmeanSR were 34.7 kPa and 24.4 kPa, respectively. The mean value of EmeanLRz was 49.2 kPa.

CONCLUSIONS

SWE showed MTCs as stiffer lesions compared to the surrounding tissues. The lesions were qualified for fine needle aspiration biopsy based on B-mode assessment. However, the diagnostic algorithm for MTC is based on the measurement of serum calcitonin levels, B-mode ultrasound and FNAB.

Errors and mistakes in ultrasound diagnostics of the thyroid gland

Ultrasound examination of the thyroid gland permits to evaluate its size, echogenicity, margins, and stroma. An abnormal ultrasound image of the thyroid, accompanied by other diagnostic investigations, facilitates therapeutic decision-making. The ultrasound image of a normal thyroid gland does not change substantially with patient's age. Nevertheless, erroneous impressions in thyroid imaging reports are sometimes encountered. These are due to diagnostic pitfalls which cannot be prevented by either the continuing development of the imaging equipment, or the growing experience and skill of the practitioners. Our article discusses the most common mistakes encountered in US diagnostics of the thyroid, the elimination of which should improve the quality of both the ultrasound examination itself and its interpretation. We have outlined errors resulting from a faulty examination technique, the similarity of the neighboring anatomical structures, and anomalies present in the proximity of the thyroid gland. We have also pointed out the reasons for inaccurate assessment of a thyroid lesion image, such as having no access to clinical data or not taking them into account, as well as faulty qualification for a fine needle aspiration biopsy. We have presented guidelines aimed at limiting the number of misdiagnoses in thyroid diseases, and provided sonograms exemplifying diagnostic mistakes.