Benign and malignant thyroid nodules: US differentiation--multicenter retrospective study

A Study to Evaluate TIRADS Scoring in the Management of Thyroid Nodules

INTRODUCTION

Thyroid nodules pose a frequent clinical dilemma, requiring the use of precise and expedient diagnostic methods. The effectiveness of the Thyroid Imaging Reporting and Data System (TIRADS) in relation to histopathology, which is considered the standard method, continues to be a prominent area of investigation. TIRADS provides a systematic evaluation based on ultrasound imaging. The primary objective of this study was to evaluate the reliability of the Thyroid Imaging Reporting and Data System (TIRADS) in the assessment of thyroid nodules, in comparison with histopathological findings.

METHODS

A retrospective design was employed to analyze data obtained from a sample of 100 patients, ranging in age from 19 to 82 years. The main objective of the study was to assess ultrasonography (USG) findings using the Thyroid Imaging Reporting and Data System (TIRADS) as the major outcome measure. The secondary outcome measure was based on histological evaluations. Multiple statistical tests were utilized, such as linear regression and the kappa statistic.

RESULTS

The outcomes of this study indicate a significant association between TIRADS and histopathology results, particularly in the higher risk groups. The study findings indicate that the diagnostic value of TIRADS III, IV, and V is supported by the respective malignancy risks of 4.1%, 90%, and 100%.

CONCLUSION

The appropriate utilization of TIRADS can function as a dependable first method for evaluating thyroid nodules, although it is essential to supplement this approach with histological examinations in order to obtain a thorough understanding.

[Thyroid nodules as an incidental finding : Value of sonography and scintigraphy in primary diagnostics]

Due to the widespread use of high-resolution sonography, numerous thyroid nodules are diagnosed, often as incidental findings. The challenge lies in evaluating various criteria such as size, shape, and echogenicity to assess the nodules' malignancy risk. Risk stratification systems have been developed to enable systematic assessment as well as to avoid unnecessary medical interventions and malignant findings being overlooked. This article provides an overview of the current diagnostic standards in primary assessment of thyroid nodules.

Thyroid Nodule Characterization: Overview and State of the Art of Diagnosis with Recent Developments, from Imaging to Molecular Diagnosis and Artificial Intelligence

Ultrasound (US) is the primary tool for evaluating patients with thyroid nodules, and the risk of malignancy assessed is based on US features. These features help determine which patients require fine-needle aspiration (FNA) biopsy. Classification systems for US features have been developed to facilitate efficient interpretation, reporting, and communication of thyroid US findings. These systems have been validated by numerous studies and are reviewed in this article. Additionally, this overview provides a comprehensive description of the clinical and laboratory evaluation of patients with thyroid nodules, various imaging modalities, grayscale US features, color Doppler US, contrast-enhanced US (CEUS), US elastography, FNA biopsy assessment, and the recent introduction of molecular testing. The potential of artificial intelligence in thyroid US is also discussed.

Bilateral papillary thyroid cancer: pitfalls of ACR TI-RADS and evaluation of modified parameters

PURPOSE

To explore modified parameters of the American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) for evaluating contralateral nodules based on preoperative ultrasound features of papillary thyroid carcinoma (PTC) in the suspected lobe, thus guiding the management of bilateral PTC.

METHODS

We retrospectively analyzed 389 consecutive patients with PTC (272 in training set, 117 in validation set) who underwent total thyroidectomy from March 2020 to March 2022. According to their postoperative pathological data, the patients were divided into unilateral and bilateral PTC groups. The clinicopathological features and sonographic characteristics of suspected nodules were compared between the groups, and further ultrasonic characteristics of TI-RADS grade (TR grade)-underestimated nodules were analyzed.

RESULTS

Patients with a body mass index of ≥25 kg/m2 (P < 0.001), multifocality in the suspected lobe (P < 0.001), and TR > 3 isthmus nodules (P = 0.003) tended to have bilateral PTC. After modifying the TI-RADS classification for contralateral nodules using these three parameters, the area under the curve for diagnosing contralateral lesions increased from 0.79 (95% confidence interval, 0.74-0.84) to 0.83 (0.78-0.87) in the training set. The missed diagnosis rate of contralateral PTC decreased in both the training set [21.1% (28/133) to 4.5% (6/133)] and validation set [11.4% (8/70) to 2.9% (2/70)]. Preoperative ultrasound tended to underestimate the contralateral nodules with the presence of cystic components [100% (6/6)] and halo sign [73.3% (11/15)].

CONCLUSION

The modified TI-RADS classification based on the suspected lobe may facilitate effective preoperative malignant risk stratification of contralateral nodules in bilateral PTC.

Cancer rates and characteristics of thyroid nodules with macrocalcification

AIMS

The aim of this study was to determine the malignant potential of thyroid nodules with macrocalcifications and to evaluate the role of other sonographic findings in the diagnosis of malignancy in thyroid nodules besides macrocalcifications.

METHODS

The findings of 8250 patients who applied to our outpatient clinic and underwent thyroid ultrasonography(US) between 2008 and 2021 were retrospectively reviewed. We included a total of 296 patients with 296 macrocalcified nodules (macrocalcification group) and an age- and sex matched group of 300 patients (control group) with the cytopathologic and/or histopathologic data of fine-needle aspiration biopsy (FNAB) of thyroid nodules without calcification. Demographic characteristics of these patients, US characteristics of the nodules, and thyroid function tests were recorded. Cytopathological data of FNAB were classified according to BETHESDA.

RESULTS

The malignancy rate was 14.2% (42/296) in the macrocalcification group and 5.3% (16/300) in the control group (p < 0.001). There was no significant relationship between interrupted peripheral calcification and malignancy. Hypoechoic or markedly hypoechoic appearance, irregular border, solid structure, presence of accompanying pathological lymphadenopathy on sonographic examination and upper and middle zone localization were other sonographic features that increased the risk of malignancy of a nodule. The presence of autoimmunity was not found to be associated with the risk of malignancy. TSH and calcitonin levels of malignant nodules were higher than benign nodules. There was no significant difference between gender and malignancy. In the univariate analysis, it was found that the presence of macrocalcification increased the risk of malignancy 2.935 times. (OR:2.935, p < 0.001.95% CI for OR 1.611-5.349) In addition, being younger, being in the high TIRADS category, and being in the upper and middle zones were factors that increased the risk of malignancy. Gender, TSH level, nodule volume and structure were not associated with malignancy. However, after multivariate analysis, factors that significantly increased the risk of malignancy were younger age, higher TIRADS category, and nodule localization.

CONCLUSION

In our study, the malignancy rate was higher in the macrocalcification group than in the control group. However, no correlation was found after multivariate analysis. In the multivariate analysis, younger age, higher TIRADS category, and nodules located in the upper and middle zone were other factors associated with malignancy. There was no association between peripheral interrupted calcification and malignancy risk.

Mapping the lymph node metastasis landscape: A bibliometric Odyssey of papillary thyroid carcinoma publications (2012-2022)

Objective

Lymph node metastasis in papillary thyroid carcinoma (PTC) has become an area of great interest in the study of thyroid diseases. The aim of this study was to elucidate the research trends and impact of lymph node metastasis of PTC in the study of thyroid diseases through a comprehensive bibliometric analysis.

Methods

We conducted an extensive bibliometric review of the literature on lymph node metastasis in PTC using the Web of Science Core Database (WOSCC), which included approximately 3292 publications from 2012 to 2022. Data analysis and visualization were performed, using advanced bibliometric tools including VOSviewer, CiteSpace, and bibliometrix R software packages.

Results

A total of 3292 publications from 81 one countries were identified. The analysis showed a pattern of growth in the number of publications per year from 2012 to 2022, with China having the highest number of papers. Outstanding contributions were made by China, Korea, USA, Italy and Japan, with Thyroid being the most important journal. The author who published the most papers was Jingqiang Zhu. The institutions that published the most papers were Shanghai Jiao Tong University and Yonsei University. The analysis found that prognosis, recurrence, and ultrasound were the keywords with the highest frequency of occurrence in addition to those related to the title of this article.

Conclusion

Our bibliometric analysis outlines the current state of research on lymph node metastasis in PTC, highlighting significant contributions, trends, and future research directions.

Impact of ultrasound elastography in evaluating Bethesda category IV thyroid nodules with histopathological correlation

Introduction

Fine needle aspiration (FNA) is the gold standard method recommended in the diagnosis of thyroid nodules. Bethesda IV cytology results are identified in 7-9% of nodules investigated through FNA, with reported malignancy rate in a wide range of 10-40%. The recommended treatment is either surgical or risk additional molecular testing before surgery. However, a large number of nodules belonging to this category (60-80%) are observed to be benign after surgical excision, which can put the patient at risk of unnecessary surgical morbidity. This study aimed to assess the diagnostic performance of conventional ultrasound, the ACR TI-RADS score and elastography in cases of Bethesda IV cytology on FNA.

Methods

We evaluated ninety-seven consecutive cases with Bethesda category IV results on FNA by using conventional B-mode ultrasound, qualitative strain or shear-wave elastography (Hitachi Preirus Machine, Hitachi Inc., Japan and Aixplorer Mach 30 Supersonic Imagine, Aix-en-Provence, France) and all nodules were classified according to the ACR TI-RADS system. Conventional ultrasound was used to categorize the nodules as potentially malignant based on the following features: hypoechogenicity, inhomogeneity, a taller than wide shape, irregular margins, presence of microcalcifications, an interrupted thyroid capsule and suspicious cervical lymph nodes. Elastography classified nodules with increased stiffness as suspicious for malignancy.

Results

We considered pathology results as the gold standard diagnosis, finding that 32 out of 97 nodules were carcinomas (33%) and 65 out of 97 were benign nodules (67%). The benign group included twenty cases of non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). Finally, we compared ultrasound data with pathology results, which showed that nineteen out of the 32 malignant nodules presented with increased stiffness on elastography (p=0.0002). On conventional ultrasound, we found that microcalcifications (p=0.007), hypoechogenicity and irregular margins (p=0.006) are features which can distinguish between benign and malignant nodules with statistical significance.

Discussion

Integrating elastography as a parameter of the ACR TI-RADS score in the evaluation of Bethesda category IV nodules showed a sensitivity of 90.62% in detecting thyroid cancer cases (p=0.006). We can conclude that elastographic stiffness as an addition to high risk features observed on conventional ultrasound improves the detection of malignant nodules in cases with Bethesda IV cytology.

Fully-Automatic Detection and Diagnosis System for Thyroid Nodules Based on Ultrasound Video Sequences by Artificial Intelligence

Background

Interpretation of ultrasound findings of thyroid nodules is subjective and labor-intensive for radiologists. Artificial intelligence (AI) is a relatively objective and efficient technology. We aimed to establish a fully automatic detection and diagnosis system for thyroid nodules based on AI technology by analyzing ultrasound video sequences.

Patients and Methods

We prospectively acquired dynamic ultrasound videos of 1067 thyroid nodules (804 for training and 263 for validation) from December 2018 to January 2021. All the patients underwent hemithyroidectomy or total thyroidectomy. Dynamic ultrasound videos were used to develop an AI system consisting of two deep learning models that could automatically detect and diagnose thyroid nodules. Average precision (AP) was used to estimate the performance of the detection model. The area under the receiver operating characteristic curve (AUC) was used to measure the performance of the diagnostic model.

Results

Location and shape were accurately detected with a high AP of 0.914 in the validation cohort. The AUC of the diagnostic model was 0.953 in the validation cohort. The sensitivity and specificity of junior and senior radiologists were 76.9% vs 78.3% and 68.4% vs 81.1%, respectively. The diagnostic performance of the AI diagnostic model was superior to that of junior radiologists (P = 0.016) and was not significantly different from that of senior radiologists (P = 0.281).

Conclusion

We established a fully automatic detection and diagnosis system for thyroid nodules based on ultrasound video using an AI approach that can be conveniently applied to optimize the management of patients with thyroid nodules.

Diagnostic value of contrast-enhanced ultrasound in the diagnosis of papillary thyroid microcarcinoma: A systematic review and meta-analysis

BACKGROUND

Using meta-analysis to evaluate the diagnostic value of contrast-enhanced ultrasound (CEUS) in the diagnosis of papillary thyroid microcarcinoma (PTMC).

METHODS

For this systematic review and meta-analysis, we searched PubMed, Cochrane Library, Web of Science, WanFang Data, VPCS Data, and China National Knowledge Infrastructure electronic databases for diagnostic studies on PTMC by CEUS from January 2013 to November 2022. Data were not available or incomplete such as case reports, nonhuman studies, etc, were excluded. Random-effects meta-analyses were used to evaluate the diagnostic accuracy of CEUS in diagnosing PTMC. The quality of the evidence was assessed with the QUADAS-2 scale. This study is registered on PROSPERO, number CRD42023409417.

RESULTS

Of 1064 records identified, 33 were eligible. The results showed that the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio of CEUS in diagnosing PTMC were 0.84 (95% confidence interval [CI] = 0.83-0.86), 0.82 (95% CI = 0.80-0.83), 3.90 (95% CI = 3.23-4.72), 0.21 (95% CI = 0.18-0.25), and 20.01 (95% CI = 14.97-26.74), respectively, and the area under the summary receiver operating characteristic curve was 0.8930 (the Q index was 0.8239). The Deek funnel plot indicated publication bias (P ˂.01).

CONCLUSION

This meta-analysis provides an overview of diagnostic accuracy of CEUS in diagnosing PTMC which indicates CEUS has a good diagnostic value for PTMC. The limitations of this study are publication bias and strong geographical bias.

Challenges in Risk Stratification of Solid Atypical Mixed Echogenicity Thyroid Nodules

Background: To determine the prevalence and risk of malignancy (ROM) in solid atypical mixed echogenicity thyroid nodules (SAMENs) with sonographic patterns not classifiable by the 2015 American Thyroid Association Ultrasound Risk Stratification System (NC ATA). Methods: We searched our prospectively collected endocrine surgery thyroid nodule (TN) database, with particular attention to those solid nodules that were NC ATA. An algorithm assigned each into one of the five ATA risk groups per the 2015 American Thyroid Association Ultrasound Risk Stratification System (ATA USRSS). TNs that the algorithm could not assign to a risk group were deemed NC ATA and were subsequently analyzed. Additionally, we categorized this group using an algorithm based on the 2017 American College of Radiology Thyroid Imaging Reporting and Data System (ACR-TIRADS). We were specifically interested in the characteristics that resulted in non-classification by the 2015 ATA USRSS and the fine needle aspiration biopsy (FNAB) cytology and surgical pathology results from the group. Results: We evaluated data from 5,040 nodules, of which 1,772 had surgical pathology. There were 150 solid nodules not classified by 2015 ATA USRSS, all of which demonstrated atypical features along with iso-, hetero-, hyper-and mixed echogenicity (solid atypical mixed echogenicity nodules-SAMENs). Sixty of these nodules were excised and sent for surgical pathology, while 90 were followed without surgical excision. Out of the 90 that did not undergo surgery, 82 underwent FNAB with cytologic evaluation. Of our 150 SAMENs, 40 were malignant by surgical histology and six were likely malignant by cytology (total SAMEN ROM without noninvasive follicular thyroid neoplasm with papillary-l ike nuclear features 31%). The most common sonographic pattern present in our SAMEN group consisted of an isoechoic solid component with microcalcifications (28/40-70% of all excised malignant nodules). In our excised malignant SAMENs, 50% demonstrated follicular-patterned neoplastic architecture while 48% displayed papillary architecture. Conclusion: Our study demonstrates that SAMENs with at least one suspicious sonographic feature: including (1) microcalcifications; (2) irregular or other suspicious margins,;opulation, and a higher ROM (31%) than the intermediate-risk group of the 2015 ATA USRSS (10-20%).

Correlation of TIRADS scoring in thyroid nodules with preoperative fine needle aspiration biopsy and postoperative specimen pathology

INTRODUCTION

The aim of our study is to determine the value of Thyroid Imaging Reporting and Data Systems (TIRADS) scoring in predicting malignancy in thyroid nodules by examining its relationship with fine needle aspiration biopsy and postoperative histopathological results.

MATERIALS AND METHODS

In this study, patients who underwent surgery after ultrasonographic examination and fine needle aspiration biopsy for thyroid nodules at the General Surgery Clinic of Çukurova University Faculty of Medicine between January 2014 and November 2021 were retrospectively analyzed. The thyroid ultrasonography and fine needle aspiration biopsy of the included patients were performed by a clinician with 15 years of experience. The ultrasonographic features of the nodules were re-evaluated by the same clinician, and the American College of Radiology (ACR) TIRADS score was determined. Fine needle aspiration biopsy results were grouped according to Bethesda criteria. Postoperative histopathological examination results were divided into two groups: benign and malignant. The ACR TIRADS score was compared with fine needle aspiration biopsy and histopathological results. The performance of the ACR TIRADS score in predicting malignancy was determined.

RESULTS

79.8% of the 397 patients were female, and the mean age was 50.9 ± 12.8 years. The mean diameter of the nodules was 27.4 ± 15.8 mm. There was a significant, positive, but weak correlation between ACR TIRADS and Bethesda (p < 0.001) (r = 0.33). When the ACR TIRADS score was compared with histopathological results, it was found that the rate of malignancy increased as the TIRADS score increased (p < 0.001). The rates of malignancy diagnosis were 0% for TR1, 13.2% for TR2, 21.7% for TR3, 50.3% for TR4, and 72.4% for TR5. The area under the receiver operating characteristic curve for TIRADS in predicting malignancy was 0.747 (95% CI: 0.699-0.796, p < 0.001). TIRADS can distinguish malignancy with 75% accuracy. The optimal cutoff point was determined as TR4 with 80.3% sensitivity and 60.8% specificity.

CONCLUSION

The ACR TIRADS scoring system is an effective risk classification system for thyroid nodules, providing 75% accuracy in predicting malignancy, with 80.3% sensitivity and 60.8% specificity values.

Role of ultrasonography (USG) and color Doppler in the evaluation of thyroid nodules and its association with USG-guided FNAC - A cross-sectional study

Introduction

Thyroid diseases affect approximately 42 million people in India. The majority (15%-40%) of these cases remain asymptomatic and benign and warrant special investigations such as ultrasonography (USG) and fine-needle aspiration cytology (FNAC) for diagnosis. Early diagnosis and management of thyroid disorders determine the disease course in many patients.

Objective

To determine the role of USG and color Doppler in the evaluation of thyroid nodules and its association with USG-guided FNAC.

Methods

We did a cross-sectional analytical study over 2 years, where we recruited 108 patients with thyroid swelling attending the OPD. We used a semi-structured data collection proforma that captured information on sociodemographic details, clinical symptoms, physical examination, and all ne cessary laboratory investigations. All patients underwent USG, color Doppler, and FNAC as a part of the investigation of thyroid nodules. The diagnostic value of ultrasound and Doppler parameters was assessed in terms of sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy for detection of malignancy in comparison to FNAC.

Results

Approximately 155 nodules were identified from the selected 108 cases, and the prevalence of malignancy among the selected thyroid nodule patients was found to be 9.1%. We observed that malignant tumors were likely to be solitary with lobulated margins, >2 cm in size with <50% peripheral halo, with markedly hypoechoic, predominantly solid, with nodal involvement and extrathyroidal extension, microcalcifications, and central vascularity. We also observed that tumors that had USG characteristics of being taller than wide (91%), poorly defined margins (92%), marked hypoechoic (95%), and microcalcifications (96%) had the highest diagnostic accuracy in detecting malignancy when compared to FNAC.

Conclusion

Thus, through our study findings, we conclude that USG and color Doppler can serve as vital tools for the evaluation of thyroid nodules with high sensitivity and specificity.

A Novel Interpretable Radiomics Model to Distinguish Nodular Goiter From Malignant Thyroid Nodules

OBJECTIVES

The purpose of this study is to inquire about the potential association between radiomics features and the pathological nature of thyroid nodules (TNs), and to propose an interpretable radiomics-based model for predicting the risk of malignant TN.

METHODS

In this retrospective study, computed tomography (CT) imaging and pathological data from 141 patients with TN were collected. The data were randomly stratified into a training group (n = 112) and a validation group (n = 29) at a ratio of 4:1. A total of 1316 radiomics features were extracted by using the pyradiomics tool. The redundant features were removed through correlation testing, and the least absolute shrinkage and selection operator (LASSO) or the minimum redundancy maximum relevance standard was used to select features. Finally, 4 different machine learning models (RF Hybrid Feature, SVM Hybrid Feature, RF, and LASSO) were constructed. The performance of the 4 models was evaluated using the receiver operating characteristic curve. The calibration curve, decision curve analysis, and SHapley Additive exPlanations method were used to evaluate or explain the best radiomics machine learning model.

RESULTS

The optimal radiomics model (RF Hybrid Feature model) demonstrated a relatively high degree of discrimination with an area under the receiver operating characteristic curve (AUC) of 0.87 (95% CI, 0.70-0.97; P < 0.001) for the validation cohort. Compared with the commonly used LASSO model (AUC, 0.78; 95% CI, 0.60-0.91; P < 0.01), there is a significant improvement in AUC in the validation set, net reclassification improvement, 0.79 (95% CI, 0.13-1.46; P < 0.05), and integrated discrimination improvement, 0. 20 (95% CI, 0.10-0.30; P < 0.001).

CONCLUSION

The interpretable radiomics model based on CT performs well in predicting benign and malignant TNs by using quantitative radiomics features of the unilateral total thyroid. In addition, the data preprocessing method incorporating different layers of features has achieved excellent experimental results.

CLINICAL RELEVANCE STATEMENT

As the detection rate of TNs continues to increase, so does the diagnostic burden on radiologists. This study establishes a noninvasive, interpretable and accurate machine learning model to rapidly identify the nature of TN found in CT.

Improved cancer risk stratification of isoechoic thyroid nodules to reduce unnecessary biopsies using quantitative ultrasound

Objective

Gray-scale ultrasound (US) is the standard-of-care for evaluating thyroid nodules (TNs). However, the performance is better for the identification of hypoechoic malignant TNs (such as classic papillary thyroid cancer) than isoechoic malignant TNs. Quantitative ultrasound (QUS) utilizes information from raw ultrasonic radiofrequency (RF) echo signal to assess properties of tissue microarchitecture. The purpose of this study is to determine if QUS can improve the cancer risk stratification of isoechoic TNs.

Methods

Patients scheduled for TN fine needle biopsy (FNB) were recruited from the Thyroid Health Clinic at Boston Medical Center. B-mode US and RF data (to generate QUS parameters) were collected in 274 TNs (163 isoechoic, 111 hypoechoic). A linear combination of QUS parameters (CQP) was trained and tested for isoechoic [CQP(i)] and hypoechoic [CQP(h)] TNs separately and compared with the performance of conventional B-mode US risk stratification systems.

Results

CQP(i) produced an ROC AUC value of 0.937+/- 0.043 compared to a value of 0.717 +/- 0.145 (p >0.05) for the American College of Radiology Thyroid Imaging, Reporting and Data System (ACR TI-RADS) and 0.589 +/- 0.173 (p >0.05) for the American Thyroid Association (ATA) risk stratification system. In this study, CQP(i) avoids unnecessary FNBs in 73% of TNs compared to 55.8% and 11.8% when using ACR TI-RADS and ATA classification system.

Conclusion

This data supports that a unique QUS-based classifier may be superior to conventional US stratification systems to evaluate isoechoic TNs for cancer and should be explored further in larger studies.

Integrated Diagnostics of Thyroid Nodules

Thyroid nodules are common findings, particularly in iodine-deficient regions. Our paper aims to revise different diagnostic tools available in clinical thyroidology and propose their rational integration. We will elaborate on the pros and cons of thyroid ultrasound (US) and its scoring systems, thyroid scintigraphy, fine-needle aspiration cytology (FNAC), molecular imaging, and artificial intelligence (AI). Ultrasonographic scoring systems can help differentiate between benign and malignant nodules. Depending on the constellation or number of suspicious ultrasound features, a FNAC is recommended. However, hyperfunctioning thyroid nodules are presumed to exclude malignancy with a very high negative predictive value (NPV). Particularly in regions where iodine supply is low, most hyperfunctioning thyroid nodules are seen in patients with normal thyroid-stimulating hormone (TSH) levels. Thyroid scintigraphy is essential for the detection of these nodules. Among non-toxic thyroid nodules, a careful application of US risk stratification systems is pivotal to exclude inappropriate FNAC and guide the procedure on suspicious ones. However, almost one-third of cytology examinations are rendered as indeterminate, requiring "diagnostic surgery" to provide a definitive diagnosis. 99mTc-methoxy-isobutyl-isonitrile ([99mTc]Tc-MIBI) and [18F]fluoro-deoxy-glucose ([18F]FDG) molecular imaging can spare those patients from unnecessary surgeries. The clinical value of AI in the evaluation of thyroid nodules needs to be determined.

Modified American College of Radiology Thyroid Imaging Reporting and Data System and Modified Artificial Intelligence Thyroid Imaging Reporting and Data System for Thyroid Nodules: A Multicenter Retrospective Study

Background: Risk stratification systems for thyroid nodules are limited by low specificity. The fine-needle aspiration (FNA) biopsy size thresholds and stratification criteria are based on evidence from the literature and expert consensus. Our aims were to investigate the optimal FNA biopsy size thresholds in the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) and artificial intelligence (AI) TI-RADS and to revise the stratification criteria in AI TI-RADS. Methods: A total of 2596 thyroid nodules (in 2511 patients) on ultrasound examination with definite pathological diagnoses were retrospectively identified from January 2017 to September 2021 in 6 participating Chinese hospitals. The modified criteria for ACR TI-RADS were as follows: (1) no FNA for TR3; (2) FNA threshold for TR4 increased to 2.5 cm. The modified criteria for AI TI-RADS were as follows: (1) 6-point nodules upgraded to TR5; (2) no FNA for TR3; (3) FNA threshold for TR4 increased to 2.5 cm. The diagnostic performance and the unnecessary FNA rate (UFR) of modified versions were compared with the original ACR TI-RADS. Results: Compared with the original ACR TI-RADS, the modified ACR (mACR) TI-RADS yielded higher specificity (73% vs. 46%), accuracy (74% vs. 51%), area under the receiver operating characteristic curve (AUC; 0.80 vs. 0.70), and lower UFR (25% vs. 48%; all p < 0.001), although the sensitivity was slightly decreased (87% vs. 93%, p = 0.057). Compared with the original ACR TI-RADS, the modified AI (mAI) TI-RADS yielded higher specificity (73% vs. 46%), accuracy (75% vs. 51%), AUC (0.81 vs. 0.70), and lower UFR (24% vs. 48%; all p < 0.001), although the sensitivity tended to be slightly decreased (89% vs. 93%, p = 0.13). There was no significant difference between the mACR TI-RADS and mAI TI-RADS in the diagnostic performance and UFR (all p > 0.05). Conclusions: The revised FNA thresholds and the stratification criteria of the mACR TI-RADS and mAI TI-RADS may be associated with improvements in specificity and accuracy, without significantly sacrificing sensitivity for malignancy detection.

Use of ultrasound elastography in differentiating benign from malignant thyroid nodules: a prospective study

Purpose

Elastography is a real-time non-invasive ultrasonography modality wherein the tissue stiffness is evaluated by calculating the degree of tissue distortion in response to an external force. This study was undertaken to assess the diagnostic value of elastography in differentiating benign from malignant thyroid nodules.

Methodology

In this prospective comparative study, a total of 52 thyroid nodules from 44 euthyroid patients undergoing fine needle aspiration cytology were assessed. Elastography was performed by a single experienced sonologist, wherein the nodules were graded as per elastography scoring (ES), and the strain ratio (SR) for each nodule was computed. Final histopathology findings of the patients undergoing surgery were compared to elastography findings, and measures of diagnostic accuracy to differentiate between benign and malignant nodules were determined for ES and SR.

Results

Thirty (68.2%) females and 14 (31.8%) males, with a mean age of 45.18 ± 11.23 years, were assessed. Fourteen (31.8%) patients underwent thyroidectomy, and histopathology was reported for 18 (34.6%) nodules. In all, nine (17.3%) nodules were malignant, and 43 (82.7%) nodules were considered benign. ES demonstrated a sensitivity of 88.9%, specificity of 88.3%, PPV of 61.5%, NPV of 97.4%, and accuracy of 88.5% to identify benign thyroid nodules. The mean SR for benign nodules was significantly lower as compared to malignant nodules (2.72 ± 0.62 vs. 4.52 ± 0.75, P < 0.0001). The optimal cut-point value for SR to differentiate benign and malignant thyroid nodules was determined to be 3.8, with the sensitivity, specificity, PPV, NPV, and accuracy being 88.9%, 95.4%, 80%, 94.6%, and 94.2%, respectively.

Conclusion

Ultrasound elastography (ES and SR) demonstrated good diagnostic efficacy to differentiate benign thyroid nodules from the malignant ones, and can be a good supplementary tool to gray-scale ultrasonography. It can also help in reducing the rates of unnecessary fine needle-aspiration biopsy.

A novel approach to quantify calcifications of thyroid nodules in US images based on deep learning: predicting the risk of cervical lymph node metastasis in papillary thyroid cancer patients

OBJECTIVE

Based on ultrasound (US) images, this study aimed to detect and quantify calcifications of thyroid nodules, which are regarded as one of the most important features in US diagnosis of thyroid cancer, and to further investigate the value of US calcifications in predicting the risk of lymph node metastasis (LNM) in papillary thyroid cancer (PTC).

METHODS

Based on the DeepLabv3+ networks, 2992 thyroid nodules in US images were used to train a model to detect thyroid nodules, of which 998 were used to train a model to detect and quantify calcifications. A total of 225 and 146 thyroid nodules obtained from two centers, respectively, were used to test the performance of these models. A logistic regression method was used to construct the predictive models for LNM in PTCs.

RESULTS

Calcifications detected by the network model and experienced radiologists had an agreement degree of above 90%. The novel quantitative parameters of US calcification defined in this study showed a significant difference between PTC patients with and without cervical LNM (p < 0.05). The calcification parameters were beneficial to predicting the LNM risk in PTC patients. The LNM prediction model using these calcification parameters combined with patient age and other US nodular features showed a higher specificity and accuracy than the calcification parameters alone.

CONCLUSIONS

Our models not only detect the calcifications automatically, but also have value in predicting cervical LNM risk of PTC patients, thereby making it possible to investigate the relationship between calcifications and highly invasive PTC in detail.

CLINICAL RELEVANCE STATEMENT

Due to the high association of US microcalcifications with thyroid cancers, our model will contribute to the differential diagnosis of thyroid nodules in daily practice.

KEY POINTS

• We developed an ML-based network model for automatically detecting and quantifying calcifications within thyroid nodules in US images. • Three novel parameters for quantifying US calcifications were defined and verified. • These US calcification parameters showed value in predicting the risk of cervical LNM in PTC patients.

Deep learning approaches for differentiating thyroid nodules with calcification: a two-center study

BACKGROUND

Calcification is a common phenomenon in both benign and malignant thyroid nodules. However, the clinical significance of calcification remains unclear. Therefore, we explored a more objective method for distinguishing between benign and malignant thyroid calcified nodules.

METHODS

This retrospective study, conducted at two centers, involved a total of 631 thyroid nodules, all of which were pathologically confirmed. Ultrasound image sets were employed for analysis. The primary evaluation index was the area under the receiver-operator characteristic curve (AUROC). We compared the diagnostic performance of deep learning (DL) methods with that of radiologists and determined whether DL could enhance the diagnostic capabilities of radiologists.

RESULTS

The Xception classification model exhibited the highest performance, achieving an AUROC of up to 0.970, followed by the DenseNet169 model, which attained an AUROC of up to 0.959. Notably, both DL models outperformed radiologists (P < 0.05). The success of the Xception model can be attributed to its incorporation of deep separable convolution, which effectively reduces the model's parameter count. This feature enables the model to capture features more effectively during the feature extraction process, resulting in superior performance, particularly when dealing with limited data.

CONCLUSIONS

This study conclusively demonstrated that DL outperformed radiologists in differentiating between benign and malignant calcified thyroid nodules. Additionally, the diagnostic capabilities of radiologists could be enhanced with the aid of DL.

Combining Clinicopathologic and Ultrasonic Features for Predicting Skip Metastasis of Lateral Lymph Nodes in Papillary Thyroid Carcinoma

Background

Skip metastasis, regarded as lateral lymph node metastasis (LLNM) without involving the central lymph node metastasis (CLNM), in papillary thyroid carcinoma (PTC) patients is commonly unpredictable. The purpose of the present research was to investigate the independent risk factors of skip metastasis in patients with PTC.

Methods and Materials

In the present research, 228 consecutive PTC patients who experienced total thyroidectomy coupled with central and lateral lymph node dissection from May 2020 to September 2022 at the Affiliated hospital of Jiangsu University were included in our research. Univariate and multivariate analysis were then applied to investigate the risk factors of skip metastasis in patients with PTC. Furthermore, a predictive model of skip metastasis was then constructed based on risk factors.

Results

The skip metastasis rate was 11.8% (27/228) in the current research. After the univariate and multivariate analysis, tumor size ≤ 10 mm, unilaterality, microcalcification, and upper tumor location were determined to be predictive factors of skip metastasis. The risk score of skip metastasis was calculated: risk score = 1.229 × (if tumor nodule ≤ 10mm) + 1.518 × (if unilaterality nodule) + 1.074 × (if microcalcification in nodule) + 2.332 × (if nodule in upper location).

Conclusion

Tumor size ≤ 10 mm, unilaterality, microcalcification, and upper tumor location can increase the occurrence of skip metastasis in patients with PTC, which is expected to provide useful information to guide the suitable intraoperative window.

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).

Predicting Malignancy of Thyroid Micronodules: Radiomics Analysis Based on Two Types of Ultrasound Elastography Images

RATIONALE AND OBJECTIVES

To develop a multimodal ultrasound radiomics nomogram for accurate classification of thyroid micronodules.

MATERIALS AND METHODS

A retrospective study including 181 thyroid micronodules within 179 patients was conducted. Radiomics features were extracted from strain elastography (SE), shear wave elastography (SWE) and B-mode ultrasound (BMUS) images. Minimum redundancy maximum relevance and least absolute shrinkage and selection operator algorithms were used to select malignancy-related features. BMUS, SE, and SWE radiomics scores (Rad-scores) were then constructed. Multivariable logistic regression was conducted using radiomics signatures along with clinical data, and a nomogram was ultimately established. The calibration, discriminative, and clinical usefulness were considered to evaluate its performance. A clinical prediction model was also built using independent clinical risk factors for comparison.

RESULTS

An aspect ratio ≥ 1, mean elasticity index, BMUS Rad-score, SE Rad-score, and SWE Rad-score were identified as the independent predictors for predicting malignancy of thyroid micronodules by multivariable logistic regression. The radiomics nomogram based on these characteristics showed favorable calibration and discriminative capabilities (AUCs: 0.903 and 0.881 for training and validation cohorts, respectively), all outperforming clinical prediction model (AUCs: 0.791 and 0.626, respectively). The decision curve analysis also confirmed clinical usefulness of the nomogram. The significant improvement of net reclassification index and integrated discriminatory improvement indicated that multimodal ultrasound radiomics signatures might work as new imaging markers for classifying thyroid micronodules.

CONCLUSION

The nomogram combining multimodal ultrasound radiomics features and clinical factors has the potential to be used for accurate diagnosis of thyroid micronodules in the clinic.

International Expert Consensus on US Lexicon for Thyroid Nodules

Multiple US-based systems for risk stratification of thyroid nodules are in use worldwide. Unfortunately, the malignancy probability assigned to a nodule varies, and terms and definitions are not consistent, leading to confusion and making it challenging to compare study results and craft revisions. Consistent application of these systems is further hampered by interobserver variability in identifying the sonographic features on which they are founded. In 2018, an international multidisciplinary group of 19 physicians with expertise in thyroid sonography (termed the International Thyroid Nodule Ultrasound Working Group) was convened with the goal of developing an international system, tentatively called the International Thyroid Imaging Reporting and Data System, or I-TIRADS, in two phases: (phase I) creation of a lexicon and atlas of US descriptors of thyroid nodules and (phase II) development of a system that estimates the malignancy risk of a thyroid nodule. This article presents the methods and results of phase I. The purpose herein is to show what has been accomplished thus far, as well as generate interest in and support for this effort in the global thyroid community.

[Clinical Approach for Thyroid Radiofrequency Ablation]

Radiofrequency ablation (RFA) is a non-surgical treatment for symptomatic, benign thyroid nodules. This treatment works by heating and destroying the nodule tissue, which results in reduction of its size and alleviation of the symptoms involved. RFA is indicated for nodules which are confirmed to be benign on two or more cytological or histological examinations, and which result in clinical symptoms requiring medical treatment. It is associated with good short-term outcomes on one-year follow-up; however, 20%-30% of the nodules regrow after more than three years. Therefore, on the basis of long-term follow-up, management of regrowth is key to patient care following RFA. Regrowth is more likely to occur in nodules that are large in size prior to RFA, and in those with high or increased vascularity. Recently, new techniques such as hydrodissection, artery-first ablation, and venous ablation have been introduced to inhibit regrowth. In addition, appropriate criteria for additional RFA should be applied to manage regrowth and prolong its therapeutic effects. RFA is essentially an alternative to surgery; therefore, the ultimate goal of this procedure is to avoid surgery permanently, rather than to achieve temporary effects.

Ultrasound characteristics of follicular and parafollicular thyroid neoplasms: diagnostic performance of artificial neural network

BACKGROUND

Ultrasound is the first-line imaging modality for detection and classification of thyroid nodules. Certain features observable by ultrasound have recently been equated with potential malignancy. This retrospective cohort study was conducted to test the hypothesis that radiomics of the four categorical divisions (medullary [MTC], papillary [PTC], or follicular [FTC] carcinoma and follicular thyroid adenoma [FTA]) demonstrate distinctive sonographic characteristics. Using an artificial neural network model for proof of concept, these sonographic features served as input.

METHODS

A total of 148 patients were enrolled for study, all with confirmed thyroid pathology in one of the four named categories. Preoperative ultrasound profiles were obtained via standardized protocols. The neural network consisted of seven input neurons; three hidden layers with 50, 250, and 100 neurons, respectively; and one output layer.

RESULTS

Radiomics of contour, structure, and calcifications differed significantly according to nodule type (p = 0.025, p = 0.032, and p = 0.0002, respectively). Levels of accuracy shown by artificial neural network analysis in discriminating among categories ranged from 0.59 to 0.98 (95% confidence interval [CI]: 0.57-0.99), with positive and negative predictive ranges of 0.41-0.99 and 0.78-0.97, respectively.

CONCLUSIONS

Our data indicate that some MTCs, PTCs, FTCs, and FTAs have distinctive sonographic characteristics. However, a significant overlap of these characteristics may impede an explicit classification. Further prospective investigations involving larger patient and nodule numbers and multicenter access should be pursued to determine if neural networks of this sort are beneficial, helping to classify neoplasms of the thyroid gland.

Predictors and a prediction model for positive fine needle aspiration biopsy in C-TIRADS 4 thyroid nodules

Objectives

To screen out the predictors and establish a prediction model of positive fine needle aspiration biopsy (FNAB) in the Chinese Guidelines for Malignant Risk Stratification of Thyroid Nodule Ultrasound (C-TIRADS) 4 thyroid nodules, and this nomogram can help clinicians evaluate the risk of positive FNAB and determine if FNAB is necessary.

Methods

We retrospectively analyzed data from 547 patients who had C-TIRADS 4 thyroid nodules and underwent fine-needle aspiration biopsy (FNAB) at the Second Affiliated Hospital of Chongqing Medical University between November 30, 2021 and September 5, 2022. Patients who met our inclusion criteria were divided into two groups based on positive or negative FNAB results. We compared their ultrasound (US) features, BRAF V600E status, thyroid function, and other general characteristics using univariate and multivariate logistic regression analyses to identify independent predictors. These predictors were then used to construct a nomogram. The calibration plot, area under the curve (AUC), and decision curve analysis were employed to evaluate the calibration, discrimination, and clinical utility of the prediction model.

Results

Out of 547 patients, 39.3% (215/547) had a positive result on fine-needle aspiration biopsy (FNAB), while 60.7% (332/547) had a negative result. Univariate logistic regression analysis revealed no significant differences in TPOAb, TgAb, TSH, Tg, nodule location, sex, or solid status between the two groups (P>0.05). However, age, nodule size, internal or surrounding blood flow signal, microcalcifications, aspect ratio, morphology, and low echo showed significant differences (P<0.05). Multivariate logistic regression analysis was conducted to explore the correlation between potential independent predictors. The results showed that only age (OR=0.444, 95% Cl=0.296~0.666, P<0.001), low echo (OR=3.549, 95% Cl=2.319~5.432, P<0.001), microcalcifications (OR=2.531, 95% Cl=1.661~3.856, P<0.001), aspect ratio (OR=3.032, 95% Cl=1.819~5.052, P<0.001), and morphology (OR=2.437, 95% Cl=1.586~3.745, P<0.001) were independent predictors for a positive FNAB. These variables were used to construct a prediction nomogram. An ROC curve analysis was performed to assess the accuracy of the nomogram, and AUC=0.793, which indicated good discrimination and decision curve analysis demonstrated clinical significance within a threshold range of 14% to 91%.

Conclusion

In conclusion, 5 independent predictors of positive FNAB, including age (≤45 years old), low echo (yes), microcalcifications (yes), aspect ratio (>1) and morphology (irregular), were identified. A nomogram was established based on the above 5 predictors, and the nomogram can be used as a complementary basis to help clinicians make decisions on FNAB of C-TI-RADS 4 thyroid nodules.

The possibilities of ultrasound imaging in the diagnosis of follicular neoplasia of the thyroid gland

Thyroid cancer is the most common cancer of the endocrine system. The diagnosis of thyroid cancer has taken a step forward due to the introduction of fine-needle biopsy of the thyroid gland with subsequent evaluation of cytological material using the Bethesda system. One category of this classification traditionally remains a gray area of diagnosis. The detection of a follicular tumor in the cytological material (category IV according to Bethesda) does not allow one to reliably classify the neoplasia as benign or malignant and requires surgical intervention. The traditional informative and widely used method for diagnosing thyroid tumors is ultrasound. However, the sensitivity and specificity of the method varies over a wide range. This review analyzes the literature on the possibilities of ultrasound diagnostics in assessing the malignant potential of follicular tumors of the thyroid gland.

Analysis of 665 thyroid nodules using both EU-TIRADS and ACR TI-RADS classification systems

BACKGROUND

Ultrasound-based classification systems allow stratification of thyroid nodules to recommend fine-needle aspiration (FNA) based on their malignancy risk. However, these have discrepancies that may have an impact in thyroid cancer detection. We aimed to compare European Thyroid Association (EU-TIRADS) and American College of Radiology (ACR TI-RADS), in terms of FNA indication and diagnostic performance.

METHODS

Retrospective study of 665 thyroid nodules from 598 patients who underwent ultrasound and fine-needle aspiration at a tertiary-care institution between January 1st of 2016 and July 31st of 2019. Based on their sonographic features they were classified according to the EU-TIRADS and ACR TI-RADS classification and then their cytological results were obtained. Differences in FNA indications according to these two classifications were analysed. In patients who underwent surgical removal of the nodules, the final pathological diagnosis was obtained.

RESULTS

A statistically significant association was found between EU-TIRADS and ACR TI-RADS classification systems (p < 0.001). ACR TI-RADS allowed greatest reduction in FNA performed (32% vs 24.5%). A different risk category was obtained in 174 (26.1%) nodules, mostly higher with EU-TIRADS. The indication to FNA changed in 54 (8.1%) nodules (49 only indicated following EU-TIRADS recommendations), of which 4 had Bethesda IV and 5 had Bethesda III cytology. The FNA indication in a higher number of nodules using EU-TIRADS was due to difference in the dimensional threshold for FNA on low-risk nodules; to the fact that hypoechogenicity in a mixed nodule ascribes it moderate risk, while using ACR TI-RADS it would only be considered of low risk, and to the use of isolated sonographic features, namely marked hypoechogenicity, microcalcifications and irregular margins, to automatically categorize a nodules as high risk in EU-TIRADS, while ACR TI-RADS requires a group of potentially suspicious features to consider a nodule of high risk. The analysis of pathology proven nodules revealed equally good sensitivity of both systems in the detection of malignancy, but weak specificity, slightly greater with ACR TI-RADS (27.1% vs 18.6%).

CONCLUSIONS

The EU-TIRADS and ACR TI-RADS are both suitable to assess thyroid nodules and through risk stratification avoid unnecessary FNA. FNA was less performed using ACR TI-RADS, which was slightly more efficiency in excluding malignancy.

B-mode Ultrasound Characteristics of Thyroid Nodules With High-Benign Probability and Nodules With Risk of Malignancy

INTRODUCTION

Thyroid nodules are commonly found on clinical examination or diagnostic imaging of the neck. Malignant thyroid nodules are increasing worldwide, making thyroid cancer one of the most common endocrine malignancies worldwide. The aim of this study was to determine B-mode ultrasound characteristics of benign thyroid nodules and nodules with risk of malignancy.  Material and methods: This retrospective study was conducted on subjects (n=99) who underwent thyroid ultrasound. Data were retrieved from the Thyroid Digital Image Database of Universidad Nacional de Colombia, a published open-access dataset, in which B-mode ultrasound images were interpreted by expert radiologists providing a complete diagnostic description of thyroid lesions using the Thyroid Imaging Reporting and Data System.

RESULTS

Sponge-like appearance (Pearson Chi-Square 4.6, p=0.02), cystic (Pearson Chi-Square 27.3, p<0.001), isoechoic (Pearson Chi-Square 26, p<0.001), and well-defined (Pearson Chi-Square 13.7, p<0.001) thyroid nodules were more likely to be observed in benign nodules (risk of malignancy <5%). On the other hand, predominately solid (Pearson Chi-Square 5.9, p=0.01), microcalcifications (Pearson Chi-Square 50.7, p<0.001), hypoechoic (Pearson Chi-Square 27.7, p<0.001), irregular shape (Pearson Chi-Square 6.6, p=0.01), and ill-defined (Pearson Chi-Square 8.8, p=0.003) thyroid nodules were more likely to be observed in nodules with risk of malignancy (>5%).

CONCLUSION

Ultrasound characteristics could be used to determine thyroid nodules with risk of malignancy and avoid over-diagnosing nodules with benign features. Further research evaluating the use of multiparametric ultrasound to distinguish between benign thyroid nodules and thyroid nodules with risk of malignancy is required.

The diagnostic value of a new ultrasonographic method for the measurement of a taller-than-wide shape of benign and malignant thyroid nodules

PURPOSE

To evaluate the diagnostic value of a new ultrasonographic method in the measurement of thyroid nodules with a taller-than-wide (TTW) shape.

METHODS

A total of 982 thyroid nodules were analysed, 571 of which were malignant thyroid nodules and 411 of which were benign nodules. Nodules were divided into two groups by size: Group A (<1 cm, n = 627) and Group B (≥1 cm, n = 355). The angle between the maximum diameter of each nodule and the horizontal axis was measured by image analysis software. The best cut-off value for distinguishing between benign and malignant thyroid nodules and the diagnostic accuracy of the new ultrasonographic method in the measurement of TTW shapes were determined by receiver operating characteristic (ROC) curve analysis.

RESULTS

The cut-off value for distinguishing benign and malignant thyroid nodules was 44.5 degrees. The area under the ROC curve (AUC) was 0.849 (95% CI: 0.822~0.875), and the sensitivity and specificity of the diagnosis of malignant thyroid nodules were 86.9% and 84.4%, respectively. Regarding the angle between the maximum diameter and the transverse axis of the thyroid nodules, an angle greater than 45 degrees was a significant indicator of a diagnosis of malignant thyroid nodules. The AUC for distinguishing malignant from benign thyroid nodules with the new ultrasonographic method in the measurement of TTW shapes was higher than that with the first method (FM) in the whole group, Group A and Group B (respectively, 0.849 vs. 0.812, 0.853 vs. 0.808, 0.852 vs. 0.828). The diagnostic sensitivity of a TTW shape measured by the new ultrasonographic method for predicting thyroid malignancy was significantly higher than that measured by the FM in the whole group, Group A and Group B (respectively, 0.858 vs. 0.760, 0.764 vs. 0.669, 0.890 vs. 0.815).

CONCLUSION

A TTW shape measured by our new ultrasonographic method showed superior performance for predicting thyroid malignancy.

Considerable interobserver variation calls for unambiguous definitions of thyroid nodule ultrasound characteristics

Objective

Thyroid nodule ultrasound characteristics are used as an indication for fine-needle aspiration cytology, usually as the basis for Thyroid Imaging Reporting and Data System (TIRADS) score calculation. Few studies on interobserver variation are available, all of which are based on analysis of preselected still ultrasound images and often lack surgical confirmation.

Methods

After the blinded online evaluation of video recordings of the ultrasound examinations of 47 consecutive malignant and 76 consecutive benign thyroid lesions, 7 experts from 7 thyroid centers answered 17 TIRADS-related questions. Surgical histology was the reference standard. Interobserver variations of each ultrasound characteristic were compared using Gwet's AC1 inter-rater coefficients; higher values mean better concordance, the maximum being 1.0.

Results

On a scale from 0.0 to 1.0, the Gwet's AC1 values were 0.34, 0.53, 0.72, and 0.79 for the four most important features in decision-making, i.e. irregular margins, microcalcifications, echogenicity, and extrathyroidal extension, respectively. The concordance in the discrimination between mildly/moderately and very hypoechogenic nodules was 0.17. The smaller the nodule size the better the agreement in echogenicity, and the larger the nodule size the better the agreement on the presence of microcalcifications. Extrathyroidal extension was correctly identified in just 45.8% of the cases.

Conclusions

Examination of video recordings, closely simulating the real-world situation, revealed substantial interobserver variation in the interpretation of each of the four most important ultrasound characteristics. In view of the importance for the management of thyroid nodules, unambiguous and widely accepted definitions of each nodule characteristic are warranted, although it remains to be investigated whether this diminishes observer variation.

Combined fine-needle aspiration with core needle biopsy for assessing thyroid nodules: a more valuable diagnostic method?

PURPOSE

This study aimed to evaluate the diagnostic value of combined fine-needle aspiration (FNA) with core needle biopsy (CNB) in thyroid nodules.

METHODS

FNA and CNB were performed simultaneously on 703 nodules. We compared the proportions of inconclusive results and the diagnostic performance for malignancy among FNA, CNB, and combined FNA/CNB for different nodule sizes.

RESULTS

Combined FNA/CNB showed lower proportions of inconclusive results than CNB for all nodules (2.8% vs. 5.7%, P<0.001), nodules ≤1.0 cm (4.9% vs. 7.3%, P=0.063), nodules >1.0 cm (2.0% vs. 5.0 %, P<0.001), nodules ≤1.5 cm (3.8% vs. 7.9 %, P<0.001), and nodules >1.5 cm (2.1% vs. 3.9 %, P=0.016). The sensitivity of combined FNA/CNB in predicting malignancy was significantly higher than that of CNB (89.0% vs. 80.0%, P<0.001) and FNA (89.0% vs. 58.1%, P<0.001) for all nodules. Within American College of Radiology Thyroid and Imaging Reporting and Data System grades 4-5, in the subgroup of nodules ≤1.5 cm, combined FNA/ CNB showed the best sensitivity in predicting malignancy (91.4%), significantly higher than that of CNB (81.0%, P<0.001) and FNA (57.8%, P<0.001). However, in the subgroup of nodules >1.5 cm, the difference between combined FNA/CNB and CNB was not significant (84.2% vs. 78.9%, P=0.500).

CONCLUSION

Regardless of nodule size, combined FNA/CNB tended to yield lower proportions of inconclusive results than CNB or FNA alone and exhibited higher performance in diagnosing malignancy. The combined FNA/CNB technique may be a more valuable diagnostic method for nodules ≤1.5 cm and nodules with a risk of malignancy than CNB and FNA alone.

Clinical and Ultrasonographic Features of Papillary Thyroid Carcinoma Located in the Isthmus

ABSTRACT

The aim of this research was to investigate the clinical and ultrasonographic features of papillary thyroid carcinoma (PTC) in the isthmus. A total of 823 patients with 823 PTCs including 133 in the isthmus and 690 in the lateral lobe were included in our study. All patients were confirmed by postoperative pathology. The clinical and ultrasonographic characteristics were retrospectively analyzed and compared. Univariate analysis and multivariate logistic regression analysis were performed. Multifactor analyses showed that PTC in the isthmus was significantly different from PTC originating from the lateral lobe in aspect ratio, microcalcification, extrathyroid extension, lymph node metastases, and lymph node density ( P < 0.05, for all). There were no significant differences in age, sex, tumor size, margin, halo, echogenicity, and homogeneity ( P > 0.05, for all). The results indicated that the sonographic appearances of PTC in the isthmus were relatively atypical; however, it had a higher incidence of extrathyroidal extension, central lymph node metastasis, and a tendency of higher lymph node density. Therefore, more careful ultrasound evaluation should be performed for these nodules.

The sonographic pattern of nodule and thyroid fine needle aspiration cytology in the evaluation of thyroid malignancy risk

Introduction: Thyroid fine-needle aspiration biopsy (TFNAB), which is basically planned according to the ultrasonographic features is of clinical importance; since it helps early diagnosis of malignancy, facilitates the selection of patients who will undergo thyroid surgery and prevents unnecessary surgical procedures. In our study, we aimed to evaluate the adequacy of TFNAB as well as the retrospective investigation of the link between the estimated malignancy risk and the descriptive features, radiologic findings and biopsy cytology of patients who underwent ultrasonography guided TFNAB.Methods: In this study, the ultrasonographic characteristics of 659 thyroid nodules belonging to 523 patients who underwent TFNAB between 2018 and 2021 were evaluated. The correlation between the risk of malignancy and demographic data, thyroid hormone levels, and ultrasonographic characteristics of nodules was examined. The diagnostic accuracy performances of European thyroid imaging reporting and data system (EU-TIRADS) classification prepared by the European Thyroid Association (ETA), the risk classification systems recommended by the American Thyroid Association (ATA) and the Society of Endocrinology and Metabolism of Turkey (TEMD) were compared with The Bethesda System for Reporting Thyroid Cytopathology (Bethesda). The adequacy of biopsy was also evaluated. The data which is obtained from the study was statistically analyzed by means of SPSS 20.0 (Statistical Package for the Social Sciences; SPSS Inc. Chicago, IL, USA) program.Results: In this study, the biopsies of 41 (6.2%) among 659 thyroid nodules appeared to be malignant. A statistically significant correlation was detected between malignancy and hypoechogenicity (p=0.011), microcalcification (p=0.005), irregular margins (p=0.028), and accompanying pathological lymph node (p=0.002). Compared to the surgical pathology results, the accuracy that was closest to that of Bethesda System (AUC: 0.778) (Area Under Curve) was found in EU-TIRADS (AUC:0.715). In the biopsies performed in our own endocrinology clinic (43.7% of the total biopsies), the ratio of non-diagnostic results was found to be 8.3%, whereas it was 29.1% in the biopsies performed in other clinics (56.3% of the total biopsies).Conclusion: It should always be kept in mind that, in the cytologic evaluation, the ultrasonographic nodule pattern recommended by the guidelines is very important in the management of patients, because cytology may show false negative and false positive results as well as unclear or non-diagnostic pathological findings. However, clinicians should also understand that classification systems may have strengths and weaknesses. Our study also emphasizes the importance of how experienced a clinic performing biopsy is as well as the role of cytopathologist in obtaining diagnostic results in biopsy.Keywords: Thyroid nodule, neoplasia, ultrasonography, biopsy fine-needle

Thyroid Nodule Margin Assessment Using ACR TI-RADS: Adding Points for Macrolobulation Impairs Performance

OBJECTIVE

We evaluated the performance of ACR TI-RADS when points for lobulated margins are applied only when the margins meet a quantified measure of margin microlobulation and not applied when nodules only demonstrate macrolobulation.

METHODS

We retrospectively reviewed ultrasound and pathology records (May 01, 2018 to July 31, 2020) to find all thyroid nodules at one institution characterized as having lobulated margins using the ACR TI-RADS lexicon and subsequently undergoing fine needle aspiration (FNA). Nodule margins were evaluated to note the presence or absence of microlobulation, quantitatively defined as a protrusion with a base <2.5 mm in length. The impact to detection of malignant nodules and avoidance of benign FNA when margin points for lobulation were added only when microlobulated was analyzed.

RESULTS

58 of 516 thyroid nodules undergoing US-guided FNA were classified as lobulated, comprising the study population. 21 (36.2%) had microlobulated margins, with 12 of the 21 (57.1%) being malignant. Comparatively, of the 37 nodules showing only macrolobulated margins without microlobulation, only 2 (5.4%) were malignant (P < .0001). For 53 nodules ≥10 mm, 15 (28.3%) benign nodules would not have met size criteria for FNA had points for margins not been applied when only showing macrolobulation, whereas all 10 malignant nodules would still have been sampled.

CONCLUSION

Adding two points to the ACR TI-RADS score for lobulated thyroid nodules should only apply when microlobulations are present.

Clinical value of molecular markers as diagnostic and prognostic tools to guide treatment of thyroid cancer

OBJECTIVE

Advances in our understanding of the molecular biology of thyroid tumours is being rapidly translated into their clinical management. This review summarizes the current use of molecular testing in thyroid tumours, focusing on their usefulness as diagnostic and prognostic tools to guide treatment with consideration of present limitations.

DESIGN

Considerations about molecular testing applications for the diagnosis and treatment of thyroid tumours are divided into four sections/roles: (1) evaluating cytologically indeterminate thyroid nodules; (2) guiding extent of surgery in indeterminate thyroid nodules; (3) completing histological characterization of thyroid tumours and (4) identifying actionable mutations in advanced progressive thyroid cancers.

RESULTS

Genomic testing can improve the presurgical malignancy risk assessment in indeterminate thyroid nodules. However, a prior in-depth analysis of institutional quality and outcomes of sonographical, cytological and histological characterization of thyroid tumours is necessary. Presently, it remains uncertain whether knowing the molecular profile of a cytologically indeterminate thyroid nodule might be advantageous to modify the extent of initial surgery. Molecular characterization of thyroid tumours can be a valuable adjunct to morphological diagnosis in some challenging cases, such as in low-risk follicular cell-derived neoplasms, or rare tumours. Finally, as selective kinase inhibitors are available, molecular testing in locally advanced/metastatic progressive thyroid cancers should also be integrated into the institutional clinical management pathway to improve outcomes and limit toxicity.

CONCLUSIONS

Molecular testing needs to be implemented into the local evidence-based clinical management thyroid nodule/cancer pathways to improve its diagnostic and prognostic value and to optimize cost-effectiveness.

[Clinical Application of the 2021 Korean Thyroid Imaging Reporting and Data System (K-TIRADS)]

In patients with thyroid nodules, ultrasonography (US) has been established as a primary diagnostic imaging method and is essential for treatment decision. The Korean Thyroid Imaging Reporting and Data System (K-TIRADS) is a pattern-based, US malignancy risk stratification system that can easily diagnose nodules during real-time ultrasound examinations. The 2021 K-TIRADS clarified the US criteria for nodule classification and revised the size thresholds for nodule biopsy, thereby reducing unnecessary biopsies for benign nodules while maintaining the appropriate sensitivity to detect malignant tumors in patients without feature of high risk thyroid cancer. Thyroid radiology practice has an important clinical role in the diagnosis and non-surgical treatment of patients with thyroid nodules, and should be performed according to standard practice guidelines for proper and effective clinical care.

Comparison of the diagnostic performance of three ultrasound thyroid nodule risk stratification systems for follicular thyroid neoplasm: K-TIRADS, ACR -TIRADS and C-TIRADS

OBJECTIVE

To explore the diagnostic performance of the currently used ultrasound-based thyroid nodule risk stratification systems (K-TIRADS, ACR -TIRADS, and C-TIRADS) in differentiating follicular thyroid adenoma (FTA) from follicular thyroid carcinoma (FTC).

METHODS

Clinical data and preoperative ultrasonographic images of 269 follicular thyroid neoplasms were retrospectively analyzed. All of them were detected by Color Doppler ultrasound instruments equipped with high-frequency liner array probes (e.g. Toshiba Apoli500 with L5-14MHZ; Philips IU22 with L5-12MHZ; GE LOGIQ E9 with L9-12MHZ and MyLab Class C with L9-14MHZ). The diagnostic performance of three TIRADS classifications for differentiating FTA from FTC was evaluated by drawing the receiver operating characteristic (ROC) curves and calculating the cut-off values.

RESULTS

Of the 269 follicular neoplasms (mean size, 3.67±1.53 cm), 209 were FTAs (mean size, 3.56±1.38 cm) and 60 were FTCs (mean size, 4.07±1.93 cm). There were significant differences in ultrasound features such as margins, calcifications, and vascularity of thyroid nodules between the FTA and FTC groups (P < 0.05). According to the ROC curve comparison analysis, the diagnostic cut-off values of K-TIRADS, ACR-TIRADS, and C-TIRADS for identifying FTA and FTC were K-TR4, ACR-TR4, and C-TR4B, respectively, and the areas under the curves were 0.676, 0.728, and 0.719, respectively. The difference between ACR-TIRADS and K-TIRADS classification was statistically significant (P = 0.0241), whereas the differences between ACR-TIRADS and C-TIRADS classification and between K-TIRADS and C-TIRADS classification were not statistically significant (P > 0.05).

CONCLUSION

The three TIRADS classifications were not conducive to distinguishing FTA from FTC. It is necessary to develop a novel malignant risk stratification system specifically for the identification of follicular thyroid neoplasms.

Orientation of the ultrasound probe to identify the taller-than-wide sign of thyroid malignancy: a registry-based study with the Thyroid Imaging Network of Korea

PURPOSE

Although the taller-than-wide (TTW) sign has been regarded as one of the most specific ultrasound (US) features of thyroid malignancy, uncertainty still exists regarding the US probe's orientation when evaluating it. This study investigated which US plane would be optimal to identify the TTW sign based on malignancy risk stratification using a registry-based imaging dataset.

METHODS

A previous study by 17 academic radiologists retrospectively analyzed the US images of 5,601 thyroid nodules (≥1 cm, 1,089 malignant and 4,512 benign) collected in the webbased registry of Thyroid Imaging Network of Korea through the collaboration of 26 centers. The present study assessed the diagnostic performance of the TTW sign itself and fine needle aspiration (FNA) indications via a comparison of four international guidelines, depending on the orientation of the US probe (criterion 1, transverse plane; criterion 2, either transverse or longitudinal plane).

RESULTS

Overall, the TTW sign was more frequent in malignant than in benign thyroid nodules (25.3% vs. 4.6%). However, the statistical differences between criteria 1 and 2 were negligible for sensitivity, specificity, and area under the curve (AUC) based on the size effect (all P<0.05, Cohen's d=0.19, 0.10, and 0.07, respectively). Moreover, the sensitivity, specificity, and AUC of the four FNA guidelines were similar between criteria 1 and 2 (all P>0.05, respectively).

CONCLUSION

A longitudinal US probe orientation provided little additional diagnostic value over the transverse orientation in detecting the TTW sign of thyroid nodules.

Risk of thyroid cancer in a lung cancer screening population of the National Lung Screening Trial according to the presence of incidental thyroid nodules detected on low-dose chest CT

PURPOSE

This study evaluated thyroid cancer risk in a lung cancer screening population according to the presence of an incidental thyroid nodule (ITN) detected on low-dose chest computed tomography (LDCT).

METHODS

Of 47,837 subjects who underwent LDCT, a lung cancer screening population according to the National Lung Screening Trial results was retrospectively enrolled. The prevalence of ITN on LDCT was calculated, and the ultrasonography (US)/fine-needle aspiration (FNA)-based risk of thyroid cancer according to the presence of ITN on LDCT was compared using the Fisher exact or Student t-test as appropriate.

RESULTS

Of the 2,329 subjects (female:male=44:2,285; mean age, 60.9±4.9 years), the prevalence of ITN on LDCT was 4.8% (111/2,329). The incidence of thyroid cancer was 0.8% (18/2,329, papillary thyroid microcarcinomas [PTMCs]) and was higher in the ITN-positive group than in the ITN-negative group (3.6% [4/111] vs. 0.6% [14/2,218], P=0.009). Among the 2,011 subjects who underwent both LDCT and thyroid US, all risks were higher (P<0.001) in the ITNpositive group than in the ITN-negative group: presence of thyroid nodule on US, 94.1% (95/101) vs. 48.6% (928/1,910); recommendation of FNA according to the American Thyroid Association guideline and Korean Thyroid Imaging Reporting and Data System guideline, 41.2% (42/101) vs. 2.4% (46/1,910) and 39.6% (40/101) vs. 1.9% (37/1,910), respectively.

CONCLUSION

Despite a higher risk of thyroid cancer in the LDCT ITN-positive group than in the ITN-negative group in a lung cancer screening population, all cancers were PTMCs. A heavy smoking history may not necessitate thorough screening US for thyroid incidentalomas.

Incorporation of a machine learning pathological diagnosis algorithm into the thyroid ultrasound imaging data improves the diagnosis risk of malignant thyroid nodules

Objective

This study aimed at establishing a new model to predict malignant thyroid nodules using machine learning algorithms.

Methods

A retrospective study was performed on 274 patients with thyroid nodules who underwent fine-needle aspiration (FNA) cytology or surgery from October 2018 to 2020 in Xianyang Central Hospital. The least absolute shrinkage and selection operator (lasso) regression analysis and logistic analysis were applied to screen and identified variables. Six machine learning algorithms, including Decision Tree (DT), Extreme Gradient Boosting (XGBoost), Gradient Boosting Machine (GBM), Naive Bayes Classifier (NBC), Random Forest (RF), and Logistic Regression (LR), were employed and compared in constructing the predictive model, coupled with preoperative clinical characteristics and ultrasound features. Internal validation was performed by using 10-fold cross-validation. The performance of the model was measured by the area under the receiver operating characteristic curve (AUC), accuracy, precision, recall, F1 score, Shapley additive explanations (SHAP) plot, feature importance, and correlation of features. The best cutoff value for risk stratification was identified by probability density function (PDF) and clinical utility curve (CUC).

Results

The malignant rate of thyroid nodules in the study cohort was 53.2%. The predictive models are constructed by age, margin, shape, echogenic foci, echogenicity, and lymph nodes. The XGBoost model was significantly superior to any one of the machine learning models, with an AUC value of 0.829. According to the PDF and CUC, we recommended that 51% probability be used as a threshold for determining the risk stratification of malignant nodules, where about 85.6% of patients with malignant nodules could be detected. Meanwhile, approximately 89.8% of unnecessary biopsy procedures would be saved. Finally, an online web risk calculator has been built to estimate the personal likelihood of malignant thyroid nodules based on the best-performing ML-ed model of XGBoost.

Conclusions

Combining clinical characteristics and features of ultrasound images, ML algorithms can achieve reliable prediction of malignant thyroid nodules. The online web risk calculator based on the XGBoost model can easily identify in real-time the probability of malignant thyroid nodules, which can assist clinicians to formulate individualized management strategies for patients.

Application of Artificial Intelligence Computer-Assisted Diagnosis Originally Developed for Thyroid Nodules to Breast Lesions on Ultrasound

As thyroid and breast cancer have several US findings in common, we applied an artificial intelligence computer-assisted diagnosis (AI-CAD) software originally developed for thyroid nodules to breast lesions on ultrasound (US) and evaluated its diagnostic performance. From January 2017 to December 2017, 1042 breast lesions (mean size 20.2 ± 11.8 mm) of 1001 patients (mean age 45.9 ± 12.9 years) who underwent US-guided core-needle biopsy were included. An AI-CAD software that was previously trained and validated with thyroid nodules using the convolutional neural network was applied to breast nodules. There were 665 benign breast lesions (63.0%) and 391 breast cancers (37.0%). The area under the receiver operating characteristic curve (AUROC) of AI-CAD to differentiate breast lesions was 0.678 (95% confidence interval: 0.649, 0.707). After fine-tuning AI-CAD with 1084 separate breast lesions, the diagnostic performance of AI-CAD markedly improved (AUC 0.841). This was significantly higher than that of radiologists when the cutoff category was BI-RADS 4a (AUC 0.621, P < 0.001), but lower when the cutoff category was BI-RADS 4b (AUC 0.908, P < 0.001). When applied to breast lesions, the diagnostic performance of an AI-CAD software that had been developed for differentiating malignant and benign thyroid nodules was not bad. However, an organ-specific approach guarantees better diagnostic performance despite the similar US features of thyroid and breast malignancies.

American Thyroid Association Guidelines and National Trends in Management of Papillary Thyroid Carcinoma

Importance

Over time, the American Thyroid Association (ATA) guidelines have increasingly promoted more limited treatments for well-differentiated thyroid cancers.

Objective

To determine whether the 2009 and 2015 ATA guidelines were associated with changes in the management of low-risk papillary thyroid carcinomas on a national scale.

Design, Setting, and Participants

This historical cohort study used the National Cancer Database. All papillary thyroid carcinomas diagnosed from 2004 to 2019 in the National Cancer Database were selected. Patients with tumors of greater than 4 cm, metastases, or clinical evidence of nodal disease were excluded. Data were analyzed from August 1, 2021, to September 1, 2022.

Main Outcomes and Measures

The primary aim was to tabulate changes in the rates of thyroid lobectomy (TL), total thyroidectomy (TT), and TT plus radioactive iodine (RAI) therapy after the 2009 and 2015 ATA guidelines. The secondary aim was to determine in which settings (eg, academic vs community) the practice patterns changed the most.

Results

A total of 194 254 patients (155 796 [80.2%] female patients; median [range] age at diagnosis, 51 [18-90] years) who underwent treatment during the study period were identified. Among patients who underwent surgery, rates of TL decreased from 15.1% to 13.7% after the 2009 guidelines but subsequently increased to 22.9% after the 2015 changes. Among patients undergoing TT, rates of adjuvant RAI decreased from 48.7% to 37.1% after 2009 and to 19.3% after the 2015 guidelines. Trends were similar for subgroups based on sex and race and ethnicity. However, academic institutions saw larger increases in TL rates (14.9% to 25.7%) than community hospitals (16.3% to 19.5%). Additionally, greater increases in TL rates were observed for tumors 1 to 2 cm (6.8% to 18.9%) and 2 to 4 cm (6.6% to 16.0%) than tumors less than 1 cm (22.8% to 29.2%).

Conclusions and Relevance

In this cohort study among patients with papillary thyroid carcinomas up to 4 cm, ATA guideline changes corresponded with increased TL and reduced adjuvant RAI. These changes were primarily seen in academic institutions, suggesting an opportunity to expand guideline-based care in the community setting.

Quantitative analysis of contrast-enhanced ultrasound combined with ultrasound in the unifocal papillary thyroid micro-carcinoma

OBJECTIVE

To evaluate diagnostic value of ultrasound (US) combined with contrast-enhanced ultrasound (CEUS) in the invasiveness of unifocal papillary thyroid micro-carcinoma (UPTMC) without capsule-invasion.

METHODS

This retrospective study included data from patients with UPTMC who received US and CEUS examinations in the Ultrasound Department of the Central Hospital of Changsha, China between June 2019 and September 2021. Univariate and multivariate logistic regression analysis were used to evaluate the risk of US and CEUS parameters for UPTMC. Diagnostic performance was estimated by ROC analysis.

RESULTS

A total of 136 cases were enrolled, including invasive UPTMC (n = 47) and non-invasive UPTMC (n = 89), which were divided into test set (n = 109) and validation set (n = 27). The occurrence of microcalcification and the ratios (R) of each time-intensity curve (TIC) of CEUS parameter were significantly higher in patients with invasive UTPMC than non-invasive UPTMC (all P < 0.05). Additionally, nodular diameter was significantly longer in the invasive group (P < 0.05). Multivariate analysis showed that microcalcification (OR = 2.917, 95% CI: 1.002-8.491, P = 0.050), R-TTP > 1 (OR = 3.376, 95%CI: 1.267-8.994, P = 0.015), R-DS > 1 (OR = 6.558, 95% CI: 2.358-18.243, P < 0.010) were independently associated with invasive UPTMC. The sensitivities of US, CEUS and their combined application were 82.1%, 46.2% and 79.5%, respectively, and their specificities were 37.1%, 88.6% and 61.4%, respectively. The combination of the two methods had the best diagnostic efficiency (AUC=0.775)compared to US (AUC = 0.596) and CEUS (AUC = 0.750).

CONCLUSION

The combination of US and CEUS might have good diagnostic value for UPTMC with capsule non-invasion.

Association of Ultrasonography With Final Histopathology in Diagnosing Thyroid Malignancy: A Single-Institute Retrospective Study

Background Thyroid nodules are well-defined regions of aberrant echogenicity within the thyroid parenchyma that are radiologically distinct from the normal thyroid gland. The most common incidental finding in imaging scans that include the neck is a thyroid nodule. Rarely are thyroid nodules cancerous, as the majority are benign. Aim The current study aims to assess the concordance between ultrasound (US) of thyroid nodules and final histopathology results to identify the different types of detected thyroid lesions. Methodology A retrospective study reviewed the medical files of all patients presenting to the Armed Forces Hospital, Southern Region, with suspected thyroid nodules from April 2018 to January 2020. Data were extracted using pre-structured proforma to avoid inconsistency. Data extracted included patient demographic, swelling laterality, size, and US and histopathological findings. Results In the present study, 47 samples had a mean age of 44.27 (SD = ±13.5) years, 85.1% were of the female gender, the majority (85.1%) had multiple nodules, 38.3% were with Thyroid Imaging Reporting and Data System (TI-RADS) TR4 US score, and the median size of the nodule on US was 3 cm with a range of 0.6 to 14 cm. The study showed that 10% of TR1 samples were lymphocytic in histopathology, 66.7% of TR3 samples were benign multinodular goiter in histopathology, and 55.6% of samples of TR4 were malignant in histopathology. Conclusions The current study showed that the malignancy rate of the examined nodules was not uncommon both by US and histopathology, where papillary carcinoma was the most detected malignancy. The study showed a satisfactory agreement rate between TI-RADS classification by US sonography and histopathological reporting, where TR4 and TR5 by the US were mainly categorized as pre-malignant/malignant lesions by histopathology.

Comparison of diagnostic accuracy and utility of artificial intelligence-optimized ACR TI-RADS and original ACR TI-RADS: a multi-center validation study based on 2061 thyroid nodules

OBJECTIVE

To determine if artificial intelligence-based modification of the Thyroid Imaging Reporting Data System (TI-RADS) would be better than the current American College of Radiology (ACR) TI-RADS for risk stratification of thyroid nodules.

METHODS

A total of 2061 thyroid nodules (in 1859 patients) sampled with fine-needle aspiration or operation were retrospectively analyzed between January 2017 and July 2020. Two radiologists blinded to the pathologic diagnosis evaluated nodule features in five ultrasound categories and assigned TI-RADS scores by both ACR TI-RADS and AI TI-RADS. Inter-rater agreement was assessed by asking another two radiologists to score a set of 100 nodules independently. The reference standard was postoperative pathological or cytopathological diagnosis according to the Bethesda system. Inter-rater agreement was determined using intraclass correlation coefficient (ICC).

RESULTS

AI TI-RADS assigned lower TI-RADS risk levels than ACR TI-RADS (p < 0.001) and had larger area under receiver operating characteristic curve (0.762 vs. 0.679, p < 0.001). The sensitivities of ACR TI-RADS and AI TI-RADS were similar (86.7% vs. 82.2%, p = 0.052), but specificity was higher with AI TI-RADS (70.2% vs. 49.2%, p < 0.001). AI TI-RADS downgraded 743 (48.63%) benign nodules, indicating that 328 (42.3% of 776 biopsied nodules) unnecessary fine-needle aspirations (FNA) could have been avoided. Inter-rater agreement was better with AI TI-RADS than with ACR TI-RADS (ICC, 0.808 vs. 0.861, p < 0.001).

CONCLUSION

AI TI-RADS can achieve meaningful reduction in the number of benign thyroid nodules recommended for biopsy and significantly improve specificity despite a slight decrease in sensitivity.

KEY POINTS

• AI TI-RADS assigned lower TI-RADS risk levels than ACR TI-RADS, showing similar sensitivity but higher specificity. • Half of the benign nodules can be downgraded of which 42.3% of biopsy nodules avoided unnecessary fine-needle aspiration (FNA). • AI TI-RADS had a better overall inter-rater agreement.

Interobserver variability in ultrasound assessment of thyroid nodules

The first diagnostic tool for thyroid disease management is ultrasound. Despite its importance, ultrasound is an extremely subjective procedure that requires a high level of performance skill. Few studies have assessed thyroid ultrasound performance and its effectiveness, particularly the variability between observers in the assessment of ultrasound images. This study evaluated the variability in ultrasound assessments and diagnoses of thyroid nodules between 2 radiologists. In this retrospective study, 75 thyroid nodules in 39 patients were reviewed by 2 experienced radiologists. The nodule composition, margin, shape, calcification, and vasculitis were determined using echogenicity. The study evaluation included these 5 assessments and the final diagnosis. Interobserver variation was determined using Cohen kappa statistics. The interobserver agreements in the interpretation of echogenicity, shape, and margin were fair (κ = 0.21-0.40), whereas there were substantial agreements for vascularity and calcification (κ = 0.62-0.78). The agreements between the observers for individual ultrasound features in this study were the highest for vascularity and the presence/absence of calcification. The interobserver reproducibility for thyroid nodule ultrasound reporting was adequate, but the diagnostic evaluation ability of the observers was inconsistent. The variability in the interpretation of sonographic features could influence the level of suspicion of thyroid malignancy. This study emphasizes the need for consistency in the training of sonographic interpretation of thyroid nodules, particularly for echogenicity, shape, and margin.

Malignancy risk stratification of thyroid nodules according to echotexture and degree of hypoechogenicity: a retrospective multicenter validation study

Various risk stratification systems show discrepancies in the ultrasound lexicon of nodule echotexture and hypoechogenicity. This study aimed to determine the malignancy risk of thyroid nodules according to their echotexture and degree of hypoechogenicity. From June to September 2015, we retrospectively evaluated 5601 thyroid nodules with final diagnoses from 26 institutions. Nodules were stratified according to the echotexture (homogeneous vs. heterogeneous) and degree of hypoechogenicity (mild, moderate, or marked). We calculated the malignancy risk according to composition and suspicious features. Heterogeneous hypoechoic nodules showed a significantly higher malignancy risk than heterogeneous isoechoic nodules (P ≤ 0.017), except in partially cystic nodules. Malignancy risks were not significantly different between homogeneous versus heterogeneous nodules in both hypoechoic (P ≥ 0.086) and iso- hyperechoic nodules (P ≥ 0.05). Heterogeneous iso-hyperechoic nodules without suspicious features showed a low malignancy risk. The malignancy risks of markedly and moderately hypoechoic nodules were not significantly different in all subgroups (P ≥ 0.48). Marked or moderately hypoechoic nodules showed a significantly higher risk than mild hypoechoic (P ≤ 0.016) nodules. The predominant echogenicity effectively stratifies the malignancy risk of nodules with heterogeneous echotexture. The degree of hypoechogenicity could be stratified as mild versus moderate to marked hypoechogenicity.