Thyroid cancer, the most common endocrine malignancy, has highly variable practice patterns. This scoping review aimed to identify quantitative and qualitative quality of care indicators (QIs) essential for providing optimal care in thyroid cancer management.

A comprehensive search across MEDLINE, EMBASE, PubMed, and Web of Science identified QIs defining structures, processes, and outcomes in five care phases: pre-diagnosis, diagnosis, treatment, post-treatment surveillance, and end-of-life care.

Of the 3,143 articles screened, 36 were included, yielding 135 unique QIs. Key diagnostic QIs were the use of a standardized ultrasound reporting system (n ​= ​4), diagnostic fine needle aspiration biopsy (FNAB) (n ​= ​3), and FNA cytology reporting with the Bethesda System (n ​= ​3). Common treatment QIs included thyroidectomy by high-volume surgeons (≥10-32 cases/year) (n ​= ​7), preoperative voice assessment for high-risk patients (n ​= ​4), and recurrent laryngeal nerve monitoring (n ​= ​3). Serum thyroglobulin (Tg) monitoring was the primary post-treatment QI for recurrence (n ​= ​2).

Developing an evidence-based QI list can identify care gaps, direct targeted interventions, promote care standardization, and improve outcomes for thyroid cancer patients.

To evaluate the efficacy of combining predictive artificial intelligence (AI) and image similarity model to risk stratify thyroid nodules, using retrospective external validation study.

Two datasets were used to determine efficacy of the AI application. One was Stanford dataset ultrasound images of 192 nodules between April 2017 and May 2018 and the second was private practice consisting of 118 thyroid nodule images between January 2018 and December 2023. The nodules had definitive diagnosis by cytology or surgical pathology. The AI application was used to predict the diagnosis and American College of Radiology Thyroid Imaging and Data System (ACR TI-RADS) score.

In the Stanford dataset, the AI application predicted malignancies with sensitivity of 1.0 and specificity of 0.55. Positive predictive value (PPV) was 0.18 and negative predictive value (NPV) was 1.0. The Area Under the Curve - Receiver Operating Characteristic was 0.78. ACR TI-RADS based clinical recommendation had a polychoric correlation of 0.67. In the private dataset, the AI application predicted malignancies with sensitivity of 0.91 and specificity of 0.95. PPV was 0.8 and NPV was 0.98. The area under the curve - receiver operating characteristic was 0.93 and accuracy was 0.94. ACR TI-RADS based score had a polychoric correlation of 0.94.

The AI application showed good performance for sensitivity and NPV between the two datasets and demonstrated potential for 61.5% reduction in the need for fine needle aspiration and strong correlation to ACR TI-RADS. However, PPV was variable between the datasets possibly from variability in image selection and prevalence of malignancy. If implemented widely and consistently among various clinical settings, this could lead to decreased patient burden associated with an invasive procedure and possibly to decreased health care spending.

The Thyroid Imaging Reporting and Data System (TI-RADS) is an essential tool for assessing thyroid nodules, primarily used by radiologists. This study aimed to compare the agreement of TI-RADS scores between sonographers and radiologists and to assess the diagnostic performance of these scores against histological findings in suspicious thyroid nodules.

In a retrospective analysis, 168 patients with suspicious thyroid nodules classified as TR3 and above by the radiologists were included. Both sonographers and radiologists independently assigned the American College of Radiologists (ACR) TI-RADS scores, which were then compared for inter-reader agreement using Cohen's Kappa statistic. The scores were also evaluated for diagnostic performance against histological results based on the Bethesda system.

The study revealed a moderate overall agreement between sonographers and radiologists in TI-RADS scoring (κ = 0.504; 95% CI: 0.409-0.599), with poor agreement noted specifically for nodule margin scores (κ = 0.102; 95% CI: -1.430-0.301). In terms of diagnostic performance against histological outcomes, sonographers' TI-RADS scores showed a sensitivity of 100% and a specificity of 44.6%, while radiologists' scores showed a sensitivity of 100% but a lower specificity of 29.3%.

The findings indicate moderate agreement in TI-RADS scoring between sonographers and radiologists, with reproducibility challenges especially in scoring nodule margins. The marginally superior diagnostic performance of sonographers' scores suggests potential efficiency benefits in involving sonographers in preliminary assessments. Future research should aim to encompass a wider range of TI-RADS categories and focus on minimizing scoring variability to enhance the system's clinical utility.

Thyroid nodules are a common incidental imaging finding and prone to overdiagnosis. Several risk stratification systems have been developed to reduce unnecessary work-up, with two of the most utilized including the American Thyroid Association 2015 (ATA2015) and the newer American College of Radiology Thyroid Imaging, Reporting and Data System (TIRADS) guidelines. The purpose of this study is to evaluate the cost-effectiveness of the ATA2015 versus the TIRADS guidelines in the management of incidental thyroid nodules.

A cost-utility analysis was conducted using decision tree modeling, evaluating adult patients with incidental thyroid nodules < 4 cm. Model inputs were populated using published literature, observational data, and expert opinion. Single-payer perspective, Canadian dollar currency, five-year time horizon, willingness to pay (WTP) threshold of $50,000, and discount rate of 1.5% per annum were utilized. Scenario, deterministic and probabilistic sensitivity analyses were performed. The primary outcome was the incremental cost-effectiveness ratio (ICER) expressed as incremental cost per quality-adjusted life year (QALY) gained.

For the base case scenario, TIRADS dominated the ATA2015 strategy by a slim margin, producing 0.005 more QALYs at $25 less cost. Results were sensitive to the malignancy rate of biopsy and the utilities of a patient with a benign nodule/subclinical malignancy or under surveillance. Probabilistic sensitivity analysis showed that TIRADS was the more cost-effective option 79.7% of the time.

The TIRADS guidelines may be the more cost-effective strategy by a small margin compared to ATA2015 in most scenarios when used to risk stratify incidental thyroid nodules.

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.

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.

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%.

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.

The advent and increased use of high-resolution ultrasonography has resulted in improved detection of thyroid nodules. Even with the use of various Thyroid Imaging-Reporting and Data System, accurate imaging diagnosis of malignant thyroid nodules has been suboptimal, which necessitated use of newer modalities like contrast-enhanced ultrasonography alone and in combination for this purpose. Although the combined use of various Thyroid Imaging-Reporting and Data System and contrast-enhanced ultrasonography has turned out to be accurate in many studies, the ideal way to integrate contrast-enhanced ultrasonography into the Thyroid Imaging-Reporting and Data System algorithm is under-investigated.

To estimate and compare the diagnostic accuracy of American College of Radiology Thyroid Imaging-Reporting and Data System and contrast-enhanced ultrasonography in differentiating benign and malignant nodules alone and in combination. To estimate the diagnostic accuracy of contrast-enhanced ultrasonography in re-categorisation of Thyroid Imaging-Reporting and Data System 3 and Thyroid Imaging-Reporting and Data System 4 thyroid nodules.

This was a prospective cohort study performed in a tertiary care university-based hospital for 3 years. Adult patients with clinical or previous sonographic diagnosis of thyroid nodules were selected. Each of the nodules were assessed using ultrasonography and categorised using American College of Radiology Thyroid Imaging-Reporting and Data System criteria. The lesion was then assessed for contrast-enhanced ultrasonography features. The final diagnosis of the nodules was made using fine needle aspiration cytology. The diagnostic accuracy in diagnosis of malignant thyroid nodules for each of the American College of Radiology Thyroid Imaging-Reporting and Data System and contrast-enhanced ultrasonography alone and in combination was assessed. The diagnostic accuracy of contrast-enhanced ultrasonography in diagnosis of malignant thyroid nodules categorised as Thyroid Imaging-Reporting and Data System 3 and Thyroid Imaging-Reporting and Data System 4 was also assessed.

American College of Radiology Thyroid Imaging-Reporting and Data System had a sensitivity, specificity, negative predictive value, positive predictive value and diagnostic accuracy of 86.6%, 54.5%, 17.4%, 97.3% and 57.7%, respectively, in diagnosis of malignant thyroid nodules. Contrast-enhanced ultrasonography had a sensitivity, specificity, negative predictive value, positive predictive value and diagnostic accuracy of 86.6%, 95.4%, 67.9%, 98.4% and 94.4%, respectively, in diagnosis of malignant thyroid nodules. Contrast-enhanced ultrasonography had sensitivity, specificity, negative predictive value, positive predictive value and diagnostic accuracy of 93.3%, 100.0%, 100.0%, 99.2% and 99.3%, respectively, in re-categorisation of Thyroid Imaging-Reporting and Data System 3 and Thyroid Imaging-Reporting and Data System 4 nodules.

Contrast-enhanced ultrasonography can play a key role in diagnosis of malignant thyroid nodules which are categorised as indeterminate on grey-scale ultrasound.

This study aimed to develop the ultrasonography (US) criteria for risk stratification of the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) 4 nodules, and to evaluate the diagnostic yield of a modified biopsy criterion in a multicenter cohort.

In total, 1,542 K-TIRADS 4 nodules (≥1 cm) were included in the study. US criteria for the subcategorization of K-TIRADS 4 nodules were developed based on high-risk US features. The diagnostic yields and false referral rates of biopsy criterion 1 (size cut-off of 1 cm), biopsy criterion 2 (size cut-off of 1.5 cm), and modified biopsy criterion 3 (size cut-off of 1 cm for K-TIRADS 4B and 1.5 cm for K-TIRADS 4A) were evaluated.

The five high-risk US features (solid composition, marked hypoechogenicity, macrocalcification, punctate echogenic foci, and irregular margin) independently increased the malignancy risk of the K-TIRADS 4 nodules (P<0.001). The K-TIRADS 4 nodules could be subcategorized into higher- and lower-risk subcategories according to the number of high-risk US features: K-TIRADS 4B (≥2 US features) and K-TIRADS 4A (≤1 US feature). The modified biopsy criterion increased the diagnostic yield by 7.8% compared with criterion 2 and reduced the false referral rate by 15.3% compared with criterion 1 (P<0.001).

The K-TIRADS 4 nodules were subcategorized as K-TIRADS 4B and K-TIRADS 4A based on high-risk US features. The modified biopsy criterion 3 showed a similar diagnostic yield and reduced false referral rate compared to criterion 1.

Thyroid nodule ultrasound-based risk stratification schemas rely on the presence of high-risk sonographic features. However, some malignant thyroid nodules have benign appearance on thyroid ultrasound. New methods for thyroid nodule risk assessment are needed.

We investigated polygenic risk score (PRS) accounting for inherited thyroid cancer risk combined with ultrasound-based analysis for improved thyroid nodule risk assessment.

The convolutional neural network classifier was trained on thyroid ultrasound still images and cine clips from 621 thyroid nodules. Phenome-wide association study (PheWAS) and PRS PheWAS were used to optimize PRS for distinguishing benign and malignant nodules. PRS was evaluated in 73 346 participants in the Colorado Center for Personalized Medicine Biobank.

When the deep learning model output was combined with thyroid cancer PRS and genetic ancestry estimates, the area under the receiver operating characteristic curve (AUROC) of the benign vs malignant thyroid nodule classifier increased from 0.83 to 0.89 (DeLong, P value = .007). The combined deep learning and genetic classifier achieved a clinically relevant sensitivity of 0.95, 95% CI [0.88-0.99], specificity of 0.63 [0.55-0.70], and positive and negative predictive values of 0.47 [0.41-0.58] and 0.97 [0.92-0.99], respectively. AUROC improvement was consistent in European ancestry-stratified analysis (0.83 and 0.87 for deep learning and deep learning combined with PRS classifiers, respectively). Elevated PRS was associated with a greater risk of thyroid cancer structural disease recurrence (ordinal logistic regression, P value = .002).

Augmenting ultrasound-based risk assessment with PRS improves diagnostic accuracy.

To examine the applicability of the "taller than wide" (ttw) criterium for risk assessment of thyroid nodules (TNs) in primary/secondary care units and the role of thyroid scintigraphy therein.

German bicenter study performed in a setting of primary/secondary care. Patient recruitment and analysis in center A was conducted in a prospective manner. In center B, patient data were retrieved from a database that was originally generated by prospective data collection. TNs were assessed by ultrasound and thyroid scans, mostly fine needle biopsy and occasionally surgery and others. In center A, only patients who presented for the first time were included. The inclusion criterion was any TN ≥ 10 mm that had at least the following two sonographic risk features: solidity and a ttw shape. In center B, consecutive patients who had at least ttw and hypofunctioning nodules ≥ 10 mm were retrieved from the above-mentioned database. The risk of malignancy was determined according to a mixed reference standard and compared with literature data.

In center A, 223 patients with 259 TNs were included into the study. For further analysis, 200 nodules with a reference standard were available. The overall malignancy rate was 2.5% (upper limit of the 95% CI: 5.1%). After the exclusion of scintigraphically hyperfunctioning nodules, the malignancy rate increased slightly to 2.8% (upper limit of the 95% CI: 5.7%). Malignant nodules exhibited sonographic risk features additional to solidity and ttw shape more often than benign ones. In addition to the exclusion of hyperfunctioning nodules, when considering only nodules without additional US risk features, i.e., exclusively solid and ttw-nodules, the malignancy rate decreased to 0.9% (upper limit 95% CI: 3.7%). In center B, from 58 patients, 58 ttw and hypofunctioning TNs on thyroid scans with a reference standard were available. Malignant nodules from center B were always solid and hypoechoic. The overall malignancy rate of hypofunctioning and ttw nodules was 21%, with the lower limit of the 95% CI (one-sided) being 12%.

In primary/secondary care units, the lowest TIRADS categories for indicating FNB, e.g., applying one out of five sonographic risk features, may not be appropriate owing to the much lower a priori malignancy risk in TNs compared to tertiary/quaternary care units. Even the combination of two sonographic risk features, "solidity" and "ttw", may only be appropriate in a limited fashion. In contrast, the preselection of TNs according to hypofunctioning findings on thyroid scans clearly warranted FNB, even when applying only one sonographic risk criterion ("ttw"). For this reason, thyroid scans in TNs may not only be indicated to rule out hyperfunctioning nodules from FNB but also to rule in hypofunctioning ones.

Thyroid nodules occur in up to 68% of people, 95% of which are benign. Of the 5% of malignant nodules, many would not result in symptoms or death, yet 600,000 FNAs are still performed annually, with a PPV of 5-7% (up to 30%). Artificial intelligence (AI) systems have the capacity to improve diagnostic accuracy and workflow efficiency when integrated into clinical decision pathways. Previous studies have evaluated AI systems against physicians, whereas we aim to compare the benefits of incorporating AI into their final diagnostic decision. This work analyzed the potential for artificial intelligence (AI)-based decision support systems to improve physician accuracy, variability, and efficiency. The decision support system (DSS) assessed was Koios DS, which provides automated sonographic nodule descriptor predictions and a direct cancer risk assessment aligned to ACR TI-RADS. The study was conducted retrospectively between (08/2020) and (10/2020). The set of cases used included 650 patients (21% male, 79% female) of age 53 ± 15. Fifteen physicians assessed each of the cases in the set, both unassisted and aided by the DSS. The order of the reading condition was randomized, and reading blocks were separated by a period of 4 weeks. The system's impact on reader accuracy was measured by comparing the area under the ROC curve (AUC), sensitivity, and specificity of readers with and without the DSS with FNA as ground truth. The impact on reader variability was evaluated using Pearson's correlation coefficient. The impact on efficiency was determined by comparing the average time per read. There was a statistically significant increase in average AUC of 0.083 [0.066, 0.099] and an increase in sensitivity and specificity of 8.4% [5.4%, 11.3%] and 14% [12.5%, 15.5%], respectively, when aided by Koios DS. The average time per case decreased by 23.6% (p = 0.00017), and the observed Pearson's correlation coefficient increased from r = 0.622 to r = 0.876 when aided by Koios DS. These results indicate that providing physicians with automated clinical decision support significantly improved diagnostic accuracy, as measured by AUC, sensitivity, and specificity, and reduced inter-reader variability and interpretation times.

To explore the diagnostic value of the TUIAS (SW_TH01/II) computer-aided diagnosis (CAD) software system for the ultrasound Thyroid Imaging Reporting and Data System (TI-RADS) features in thyroid nodules.

This retrospective study enrolled patients with thyroid nodules in Shanghai East Hospital between January 2017 and October 2021. The novel CAD software (SW_TH01/II) and three sonographers performed a qualitative analysis of the ultrasound TI-RADS features in aspect ratio, margin irregularity, margin smoothness, calcification, and echogenicity of the thyroid nodules.

A total of 225 patients were enrolled. The accuracy, sensitivity, and specificity of the CAD software in "aspect ratio" were 95.6%, 96.2%, and 95.4%, in "margin irregularity" were 90.7%, 90.5%, and 90.9%, in "margin smoothness" were 85.8%, 88.5%, and 83.0%, in "calcification" were 83.6%, 81.7%, and 82.0%, in "homogeneity" were 88.9%, 90.6%, and 82.2%, in "major echo" were 85.3%, 88.0%, and 85.4%, and in "contains very hypoechoic echo" were 92.0%, 90.0%, and 92.4%. The analysis time of the CAD software was significantly shorter than for the sonographers (2.7 ± 1.6 vs. 29.7 ± 12.7 s, P < 0.001).

The CAD system achieved high accuracy in describing thyroid nodule features. It might assist in clinical thyroid nodule analysis.

The present study aimed to evaluate the efficacy of a new two-dimensional shear wave elastography (2D-SWE) method using a Siemens ultrasound system and its combination with the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) for the differential diagnosis of benign and malignant thyroid nodules.

Conventional ultrasound images and 2D-SWE (E-whole-mean and E-stiffest-mean) were prospectively analyzed in 593 thyroid nodules from 543 patients. Nodules were divided into diameter (D) ≤10 mm and D > 10 mm groups and graded using ACR TI-RADS. The receiver operating characteristic curve was plotted using pathological findings as the gold standard. Diagnostic performance was compared among 2D-SWE, ACR TI-RADS, and their combination.

The area under the curve (AUC) for E-whole-mean was higher than that for E-stiffest-mean (0.858 vs. 0.790, P < 0.001), which indicated that it was the better 2D-SWE parameter for differentiating malignant nodules from benign nodules with an optimal cut-off point of 11.36 kPa. In the all-sizes group, the AUC for E-whole-mean was higher than that for ACR TI-RADS (0.858 vs. 0.808, P < 0.001). The combination of E-whole-mean and ACR TI-RADS resulted in a higher AUC (0.929 vs. 0.858 vs. 0.808, P < 0.001), sensitivity (87.0% vs. 80.3% vs. 85.2%), specificity (85.1% vs. 74.0% vs. 73.6%), accuracy (86.3% vs. 78.1% vs. 81.1%), positive predictive value (91.5% vs. 85.1% vs. 85.6%), and negative predictive value (78.0% vs. 67.0% vs. 72.9%) compared to E-whole-mean or ACR TI-RADS alone. The AUC for the combination of 2D-SWE and ACR TI-RADS was superior to that for E-whole-mean or ACR TI-RADS alone in both D ≤ 10 mm and D > 10 mm groups (P < 0.001).

As the better 2D-SWE parameter, E-whole-mean had a higher diagnostic power than ACR TI-RADS and enhanced the diagnostic performance of ACR TI-RADS when identifying benign and malignant thyroid nodules. The combination of E-whole-mean and ACR TI-RADS improved the diagnostic performance compared to using ACR TI-RADS alone, providing a new and reliable method for the clinical diagnosis of thyroid nodules.

The aim of this study was to compare the capacity of American Thyroid Association and Thyroid Imaging Reporting and Data System developed by the American College of Radiology in predicting malignancy risk of thyroid nodules and to verify which one is better at avoiding unnecessary fine needle aspiration.

This was a cross-sectional study with 565 thyroid nodules, followed at a tertiary care hospital, in an iodine-replete area. Those were classified as American Thyroid Association and Thyroid Imaging Reporting and Data System developed by the American College of Radiology systems and stratified according to the Bethesda classification of fine needle aspiration. The values of sensibility, specificity, positive predictive value, and negative predictive value accuracy were calculated. Also, the percentage of unnecessary biopsies was presented.

The mean age of the individuals was 58.2±13.5 [26-90] years for benign nodules and 41.7±15.6 [23-66] years for malignant nodules (p=0.002). Regarding gender, 92.6% (n=150) of the individuals with benign nodules and 85.7% (n=06) with malignant nodules were females (p=0.601). For American Thyroid Association, 90.9% of sensibility, 51.4% of specificity, 52.6% of accuracy, 10.2% of positive predictive value, and 98.9% of negative predictive value were found. For Thyroid Imaging Reporting and Data System developed by the American College of Radiology, 90.9% of sensibility, 49.7% of specificity, 52.1% of accuracy, 9.9% of positive predictive value, and 98.9% of negative predictive value were found. .Notably, 12.3% of unnecessary fine needle aspiration were found in American Thyroid Association and 44.4% were found in Thyroid Imaging Reporting and Data System developed by the American College of Radiology.

Both Thyroid Imaging Reporting and Data System developed by the American College of Radiology and American Thyroid Association are able to predict the malignancy risk of thyroid nodules. Thyroid Imaging Reporting and Data System developed by the American College of Radiology was better at avoiding unnecessary fine needle aspiration.

The performance in evaluating thyroid nodules on ultrasound varies across different risk stratification systems, leading to inconsistency and uncertainty regarding diagnostic sensitivity, specificity, and accuracy.

Comparing diagnostic performance of detecting thyroid cancer among distinct ultrasound risk stratification systems proposed in the last five years.

Systematic search was conducted on PubMed, EMBASE, and Web of Science databases to find relevant research up to December 8, 2022, whose study contents contained elucidation of diagnostic performance of any one of the above ultrasound risk stratification systems (European Thyroid Imaging Reporting and Data System[Eu-TIRADS]; American College of Radiology TIRADS [ACR TIRADS]; Chinese version of TIRADS [C-TIRADS]; Computer-aided diagnosis system based on deep learning [S-Detect]). Based on golden diagnostic standard in histopathology and cytology, single meta-analysis was performed to obtain the optimal cut-off value for each system, and then network meta-analysis was conducted on the best risk stratification category in each system.

This network meta-analysis included 88 studies with a total of 59,304 nodules. The most accurate risk category thresholds were TR5 for Eu-TIRADS, TR5 for ACR TIRADS, TR4b and above for C-TIRADS, and possible malignancy for S-Detect. At the best thresholds, sensitivity of these systems ranged from 68% to 82% and specificity ranged from 71% to 81%. It identified the highest sensitivity for C-TIRADS TR4b and the highest specificity for ACR TIRADS TR5. However, sensitivity for ACR TIRADS TR5 was the lowest. The diagnostic odds ratio (DOR) and area under curve (AUC) were ranked first in C-TIRADS.

Among four ultrasound risk stratification options, this systemic review preliminarily proved that C-TIRADS possessed favorable diagnostic performance for thyroid nodules.

https://www.crd.york.ac.uk/prospero, CRD42022382818.

The American College of Radiology Thyroid Image Reporting and Data System (ACR TI-RADS) was developed to predict malignancy risk in thyroid nodules using ultrasound features. TI-RADS was derived from a database of patients already selected for fine-needle aspiration (FNA), raising uncertainty about applicability to unselected patients.

We aimed to assess the effect of ACR TI-RADS reporting in unselected patients presenting for thyroid ultrasound in a real-world setting.

Records for all patients presenting for thyroid ultrasonography in Canterbury, New Zealand, were reviewed across two 18-month periods, prior to and after implementation of TI-RADS reporting. Patient outcomes were compared between the 2 periods. Malignancy rates were calculated for nodules 10 mm or larger with a definitive FNA or histology result.

A total of 1210 nodules were identified in 582 patients prior to implementation of TI-RADS; 1253 nodules were identified in 625 patients after implementation of TI-RADS. TI-RADS category was associated with malignancy rate (0% in TR1 and TR2, 3% in TR3, 5% in TR4, 12% in TR5; P = .02); however, 63% of nodules were graded TR3 or TR4, for which malignancy rate did not meaningfully differ from baseline risk. After implementation of TI-RADS there was a small reduction in the proportion of patients proceeding to FNA (49% vs 60%; P < .01) or surgery (14% vs 18%; P < .05), with no difference in cancer diagnoses (3% vs 4%, not significant).

TI-RADS category is associated with malignancy rate and may alter clinical decision-making in a minority of patients; however, it is nondiscriminatory in the majority of nodules. In this study of unselected patients, nodules classified as TR5 and thus considered "highly suspicious" for cancer had only a modest risk of malignancy.

Background Current guidelines recommend the use of conventional US for risk stratification and management of thyroid nodules. However, fine-needle aspiration (FNA) is often recommended in benign nodules. Purpose To compare the diagnostic performance of multimodality US (including conventional US, strain elastography, and contrast-enhanced US [CEUS]) with the American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) in the recommendation of FNA for thyroid nodules to reduce unnecessary biopsies. Materials and Methods In this prospective study, 445 consecutive participants with thyroid nodules from nine tertiary referral hospitals were recruited between October 2020 and May 2021. With univariable and multivariable logistic regression, the prediction models incorporating sonographic features, evaluated with interobserver agreement, were constructed and internally validated with bootstrap resampling technique. In addition, discrimination, calibration, and decision curve analysis were performed. Results A total of 434 thyroid nodules confirmed at pathologic analysis (259 malignant thyroid nodules) in 434 participants (mean age, 45 years ± 12 [SD]; 307 female participants) were included. Four multivariable models incorporated participant age, nodule features at US (proportion of cystic components, echogenicity, margin, shape, punctate echogenic foci), elastography features (stiffness), and CEUS features (blood volume). In recommending FNA in thyroid nodules, the highest area under the receiver operating characteristic curve (AUC) was 0.85 (95% CI: 0.81, 0.89) for the multimodality US model, and the lowest AUC was 0.63 (95% CI: 0.59, 0.68) for TI-RADS (P < .001). At the 50% risk threshold, 31% (95% CI: 26, 38) of FNA procedures could be avoided with multimodality US compared with 15% (95% CI: 12, 19) with TI-RADS (P < .001). Conclusion Multimodality US had better performance in recommending FNA to avoid unnecessary biopsies than the TI-RADS. Clinical trial registration no. NCT04574258 © RSNA, 2023 Supplemental material is available for this article.

To determine if the artificial intelligence-based Thyroid Imaging, Reporting and Data System (AI TIRADS) would perform better than the American College of Radiology (ACR) TIRADS in monitoring malignant thyroid nodules not recommended for biopsy using follow-up thresholds.

A total of 3499 thyroid nodules with surgical histopathology and ultrasound features were retrospectively reviewed and categorized using ACR TIRADS and AI TIRADS. The recommendations for biopsy and follow-up divided nodules into three groups 1) fine needle aspiration (FNA), 2) follow-up ultrasound, and 3) no further evaluation.

Of the total 1608 malignant nodules in this study, 974 malignant nodules would not be biopsied in ACR TIRADS compared with 967 in AI TIRADS. While 60.0% (584/974) of these non-biopsied malignancies could be followed-up by ultrasound in ACR TIRADS and 62.8% (607/967) in AI TIRADS. For the malignancies of no further evaluation, 97.4% (380/390) were sized <10 mm in ACR TIRADS and 93.3% (336/360) in AI TIRADS. Compared with ACR TIRADS, AI TIRADS had lower unnecessary FNA rate and missing cancer rate (41.0% vs 47.8% and 22.8% vs 27.5%, P < .05, respectively) while having higher specificity and AUC as well as lower sensitivity (65.0% vs 57.9%, 0.895 vs 0.881, and 96.1% vs 97.8%, all P < .05).

Using the follow-up thresholds, more than half of the malignancies not being biopsied were monitored by ultrasound in both ACR TIRADS and AI TIRADS, and AI TIRADS had lower missing cancer rate. More than 90% of malignancies recommended for no further evaluation were <10 mm in diameter.

Background: Sonographic evaluation is fundamental to thyroid nodule assessment. The American Thyroid Association (ATA) ultrasound risk stratification system (USRSS) is widely used, but the appearance of some nodules has been considered nonclassifiable (NC-ATA). The risk of malignancy (RoM) of NC-ATA nodules varies widely between studies, leading to uncertainty in clinical management. The aim of this study was to comprehensively evaluate the prevalence and malignancy risk of NC-ATA nodules. Methods: A systematic review was performed searching PubMed/MEDLINE and EMBASE to identify original studies of thyroid nodules classified using the ATA USRSS from 2016 to 2022 and reporting the outcome of NC-ATA nodules. Meta-analysis was conducted to obtain pooled RoM estimates and meta-regression sensitivity analyses were used to explore sources of between-study heterogeneity. Results: Of 6377 screened studies, 135 underwent full-text review, and 16 studies reporting 21,271 nodules were included. Within these, the pooled prevalence of NC-ATA nodules was 7.8% (1872 nodules; [confidence interval; CI 5.1-11.1]). The pooled RoM estimate for NC-ATA nodules was 20.3% [CI 13.0-28.7] and there was significant heterogeneity between studies (I2 = 92.8%, p < 0.001). NC-ATA nodule RoM estimates were significantly different by study type: single-center versus multicenter studies (24.8% vs. 12.3%, respectively, p = 0.031) and study design: retrospective versus prospective studies (25.1% vs. 8.5%, respectively, p = 0.003). No significant difference was observed in RoM based on inclusion of <1 cm nodules or geographic region. Meta-regression analysis showed study design and use of surgical histology for diagnostic criteria contributed significantly to differences in the reported RoM estimates. Conclusion: In this first meta-analysis comprehensively assessing the RoM of NC-ATA nodules, the malignancy risk was found to be comparable with the current ATA USRSS intermediate suspicion category. Significant heterogeneity was observed between studies and limits the interpretation of these results. In future iterations of the ATA USRSS that seek into incorporate categorization of NC-ATA nodules, these meta-analysis data may help to inform proper malignancy risk stratification. The study protocol was registered on PROSPERO, the international prospective register of systematic reviews (CRD42020182498), on July 14, 2020.

To evaluate whether the categorization methods of risk stratification systems (RSSs) is a decisive factor that influenced the diagnostic performances and unnecessary FNA rates in order to choose optimal RSS for the management of thyroid nodules.

From July 2013 to January 2019, 2667 patients with 3944 thyroid nodules had undergone pathological diagnosis after thyroidectomy and/or US-guided FNA. US categories were assigned according to the six RSSs. The diagnostic performances and unnecessary FNA rates were calculated and compared according to the US-based final assessment categories and the unified size thresholds for biopsy proposed by ACR-TIRADS, respectively.

A total of 1781 (45.2%) thyroid nodules were diagnosed as malignant after thyroidectomy or biopsy. Significantly lowest specificity and accuracy, along with the highest unnecessary FNA rates were seen in EU-TIRADS for both US categories (47.9%, 70.2%, and 39.4%, respectively, all P < 0.05) and indications for FNA (54.2%, 50.0%, and 55.4%, respectively, all P < 0.05). Diagnostic performances for US-based final assessment categories exhibited similar accuracy for AI-TIRADS, Kwak-TIRADS, C-TIRADS, and ATA guidelines (78.0%, 77.8%, 77.9%, and 76.3%, respectively, all P > 0.05), while the lowest unnecessary FNA rate was seen in C-TIRADS (30.9%) and without significant differences to that of AI-TIRADS, Kwak-TIRADS, and ATA guideline (31.5%, 31.7%, and 33.6%, respectively, all P > 0.05). Diagnostic performance for US-FNA indications showed similar accuracy for ACR-TIRADS, Kwak-TIRADS, C-TIRADS and ATA guidelines (58.0%, 59.7%, 58.7%, and 57.1%, respectively, all P > 0.05). The highest accuracy and lowest unnecessary FNA rate were seen in AI-TIRADS (61.9%, 38.6%) and without significant differences to that of Kwak-TIRADS(59.7%, 42.9%) and C-TIRADS 58.7%, 43.9%, all P > 0.05).

The different US categorization methods used by each RSS were not determinant influential factors in diagnostic performance and unnecessary FNA rate. For daily clinical practice, the score-based counting RSS was an optimal choice.

There is a limited number of studies reporting the performance of European Thyroid Imaging Reporting and Data System (EU-TIRADS) guideline in identifying thyroid nodule malignancy. We aimed to evaluate diagnostic accuracy of EU-TIRADS regardless of thyroid nodule size.

During August 2019-November 2021, subjects with thyroid nodules were prospectively included. Sonographic characteristics were recorded and scored as per EU-TIRADS guideline. Finally, fine-needle aspiration (FNA) was performed, and cytological findings were reported.

Totally, 1266 thyroid nodules from 984 subjects were assessed, of which 295 nodules were smaller than 10 mm and 971 nodules were 10 mm or larger. Among nodules <10 mm, prevalence rates of malignancy for EU-TIRADS classes 2-5 were 0.0%, 3.7%, 20.6%, and 40.9%, respectively; these rates among nodules ≥10 mm were 2.3%, 4.0%, 19.3%, and 43.2%, respectively. The accuracy values of EU-TIRADS class 5 and EU-TIRADS class 4 or 5 in diagnosis of malignancy for nodules <10 mm were 86.4% and 79.7%, respectively; these rates for nodules ≥10 mm were 83.8% and 76.3%, respectively. Hypoechogenicity, microcalcification, ill-defined and irregular margins were predictors for malignancy regardless of thyroid nodule size.

EU-TIRADS could provide an acceptable malignancy risk stratification that is helpful for better distinguishing benignity from malignancy, as well as preventing unnecessary FNA biopsies, in thyroid nodules irrespective of their size.

To compare the diagnostic performance and unnecessary ultrasound-guided fine-needle aspiration (US-FNA) biopsy rate of the 2015 American Thyroid Association (ATA), 2016 Korean Society of Thyroid Radiology (KSThR), and 2017 American College of Radiology (ACR) guidelines for patients with and without Hashimoto's thyroiditis (HT).

This retrospective study included 716 nodules from 696 consecutive patients, which were classified using the categories defined by the three guidelines: ATA, KSThR, and ACR. The malignancy risk in each category was calculated and the diagnostic performance and unnecessary fine-needle aspiration (FNA) rates of the three guidelines were compared.

In total, 426 malignant and 290 benign nodules were identified. Patients with malignant nodules had lower total thyroxine levels and higher thyroid-stimulating hormone, thyroid peroxidase antibody, and thyroglobulin antibody levels than those without malignant nodules (all P<0.01). The margin difference was significant in non-HT patients (P<0.01), but comparable in HT patients (P=0.55). The calculated malignancy risks of high and intermediate suspicion nodules in the ATA and KSThR guidelines and moderately suspicious nodules in the ACR guidelines were significantly lower in non-HT patients compared with HT patients (P<0.05). The ACR guidelines showed the lowest sensitivity, highest specificity, and lowest unnecessary FNA rates in patients with and without HT. Compared to non-HT patients, HT patients had significantly lower unnecessary FNA rates (P<0.01).

HT was associated with a higher malignancy rate of thyroid nodules with intermediate suspicion according to the ATA, KSThR, and ACR guidelines. The three guidelines, especially ACR, were likely to be more effective and could allow a greater reduction in the percentage of benign nodules biopsied in patients with HT.

The reported malignancy rate of highly suspicious thyroid nodules based on the ACR TI-RADS criteria (TI-RADS category 5 [TR5]) varies widely. The objective of our study was to determine the rate of malignancy of TR5 nodules at our institution. We also aimed to determine the predictive values of individual sonographic features, as well as the correlation of total points assigned to a nodule and rate of malignancy.

Our single-institution retrospective study evaluated 450 TR5 nodules that had cytology results available, in 399 patients over a 1-year period. Sonographic features and total TI-RADS points were determined by the interpreting radiologist. Statistical analyses included logistic regression models to find factors associated with increased odds of malignancy, and computing sensitivity, specificity, positive and negative predictive values of various individual sonographic features.

Of the 450 nodules, 95 (21.1%, 95% exact confidence interval 17.4-25.2%) were malignant. Each additional TI-RADS point increased the odds of malignancy (adjusted odds ratio 1.35, 95% confidence interval 1.13-1.60, P < .001). "Very hypoechoic" was the sonographic feature with the highest specificity and positive predictive value for malignancy (95.5 and 44.8%, respectively), while "punctate echogenic foci" had the lowest positive predictive value (20.0%).

The rate of malignancy of TR5 nodules at our institution was 21.1%, which is lower than other malignancy rates reported in the literature. The total number of points assigned on the basis of the TI-RADS criteria was positively associated with malignancy, which indicates that TR5 should be viewed as a spectrum of risk.

This study compared the malignancy risk of intermediate suspicion thyroid nodules according to the presence of suspicious ultrasonographic (US) findings.

From January 2014 to December 2014, 299 consecutive intermediate suspicion thyroid nodules in 281 patients (mean age, 50.6±12.5 years) with final diagnoses were included in this study. Two radiologists retrospectively reviewed the US findings and subcategorized the intermediate suspicion category into nodules without suspicious findings and nodules with suspicious findings, including punctate echogenic foci, nonparallel orientation, or irregular margins. The malignancy rates were compared between the two subcategory groups.

Of the 299 intermediate suspicion thyroid nodules, 230 (76.9%) were subcategorized as nodules without suspicious findings and 69 (23.1%) as nodules with suspicious findings. The total malignancy rate was 33.4% (100/299) and the malignancy rate of nodules with suspicious findings was significantly higher than that of nodules without suspicious findings (47.8% vs. 29.1%, P=0.004). In nodules with suspicious findings, the most common suspicious finding was punctate echogenic foci (48/82, 58.5%) followed by nonparallel orientation (22/82, 26.8%) and irregular margins (12/82, 14.6%). Thirteen nodules had two suspicious findings simultaneously. A linearly increasing trend in the malignancy rate was observed according to the number of suspicious US findings (P for trend=0.001).

Intermediate suspicion thyroid nodules with suspicious findings showed a higher malignancy rate than those without suspicious findings. Further management guidelines for nodules with suspicious findings should differ from guidelines for nodules without suspicious findings, even in the same US category.

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.

This study is aimed at evaluating the diagnostic efficacy and unnecessary fine-needle aspiration (FNA) rate of ultrasound-based risk stratification for thyroid nodules in the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) and the American Thyroid Association (ATA) risk stratification systems.

Children and adolescents with pathology confirmed thyroid nodules were retrospectively included in this study. A total of 217 thyroid nodules from multicenter of Union Medical College Hospital, China Japan Friendship Hospital and Civil Aviation Hospital were included, the diagnostic efficiency and unnecessary FNA rate were calculated according to ACR and ATA guidelines.

Among all thyroid nodules, 139 nodules were malignant, and 78 nodules were benign. Choosing ATA high suspicion and ACR TI-RADS TR5 as benign and malignant cut-off points, the area under the curve and sensitivity of ATA were higher than ACR (AUC: 0.887 vs 0.840, p=0.0037; sensitivity 81.3% vs 71.0%, P <0.049;specificity 96.2% vs 97.4%, p=1.000;specificity both 85.9%); choosing high/intermediate suspicion in ATA and ACR TR4/5 as benign and malignant cut-off points, the two guidelines demonstrated similar diagnostic efficacy (AUC:0.890 vs 0.897, p=0.6038, sensitivity 92.1% vs 93.5%, P =0.817;specificity both 85.9%, p=1.000). The inappropriate FNA rate of ACR guideline was relatively lower (ATA 42.9% vs ACR 27.2%, P <0.001). If ACR TI-RADS TR5 nodules less than 1.0cm were included in the FNA indication, the unnecessary biopsy rate would be further reduced to 17.9%.

This study indicated that both ATA and ACR TI-RADS risk stratification systems could provide a feasible differential diagnosis of benign and malignant thyroid nodules, while the ACR risk stratification system demonstrates a lower rate of inappropriate FNA rate. In addition, it was necessary to further study the minimum FNA threshold of thyroid nodules in Children and adolescents in order to reduce the missed biopsy rate of malignant nodules.

The American College of Radiology Thyroid Imaging Reporting and Data System for ultrasound classification of malignancy risk was developed to better triage thyroid nodules for fine-needle aspiration biopsy. To examine further, we compared thyroid cytologic classification rates in nodules before and after institutional Thyroid Imaging Reporting and Data System implementation.

Cytology diagnoses by Bethesda criteria (categories I-VI) from January 2014 to October 2021 were retrieved; observed changes in yearly category frequency were analyzed by linear regression; and pooled cohorts of pre- (2014-2018) and post-Thyroid Imaging Reporting and Data System (2019-2021) cytology call rates were compared.

Overall, 7,413 cytologic specimens were included (range/year 715-1,444). From 2014 to 2021, the proportion of benign (Bethesda category II) diagnosis per year declined stepwise from 49.7% to 19.4%, and atypia of undetermined significance/follicular lesion of undetermined significance (Bethesda category III) increased sequentially from 21.3% to 51.5%. Between 2014 and 2021, Bethesda category III diagnosis increased on average by 4.8% per year (95% confidence internal, 3.29-5.54; P < .001) and Bethesda category II results decreased on average by 4.4% per year (95% confidence interval, 6.29-3.42; P < .001). When comparing pre- and post-Thyroid Imaging Reporting and Data System, the proportion of Bethesda category II cytology results decreased (43.1% vs 21%; P = .001) while Bethesda category III (28.3% vs 47.7%; P = .002) and Bethesda category V (1.1% vs 1.7%; P = .015) results increased.

After implementation of American College of Radiology Thyroid Imaging Reporting and Data System ultrasound criteria, we observed a 2.5-fold decline in the rate of benign cytology and an increase in the proportion of atypia of undetermined significance/follicular lesion of undetermined significance results.

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.

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).

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).

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.

• 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.

Thyroid cancers are endocrine neoplasms with diverse gene expression and behavior, for which constantly evolving anatomic and functional imaging/theranostic agents have an essential role for diagnosis, staging, and treatment.

To achieve definitive diagnosis, neck ultrasound and associated risk stratification systems, notably Thyroid Imaging Reporting and Data System (TI-RADS), allow improved thyroid nodule characterization and management guidance. Radioactive iodine-131 (RAI) has long played a role in management of differentiated thyroid cancer (DTC), with recent literature emphasizing its effectiveness for intermediate-high risk cancers, exploring use of dosimetry for personalized medicine, and potential for retreatment with RAI following tumor redifferentiation. Iodine-124 positron emission tomography/computed tomography (PET/CT) has promising application for DTC staging and dosimetry. F18-fluorodeoxyglucose (FDG) PET/CT is used for staging of high risk DTC and identification of noniodine-avid disease recurrences, with metabolic uptake consistently portending poor prognosis. Poorly differentiated and anaplastic thyroid cancers are best assessed with anatomic imaging and F18-FDG PET/ CT, though recent studies show a potential theranostic role for Ga68/Lu177-prostate-specific membrane antigen. Medullary thyroid cancers are evaluated with ultrasound, CT, magnetic resonance imaging, and various positron-emitting radiotracers for PET imaging (F18-DOPA, F18-FDG, and recently Ga68-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-octreotate (DOTATATE)); the latter may enable treatment with Lu177-DOTATATE.

Multidisciplinary collaboration is essential to streamline appropriate management, given the wide array of available imaging and new therapies for metabolic and genetically complex cancers.

The Bethesda system for reporting thyroid cytopathology (TBSRTC) has attempted to standardize thyroid fine needle aspiration cytology (FNAC) reporting internationally into six diagnostic categories and help in clinical decision making. But there exists a significant variation in the reporting percentage and rates of malignancies in each category across the centres which complicates clinical decision making. To study the usefulness of TBSRTC in surgical planning of thyroid nodules and to correlate TBSRTC with final histopathology. 85 patients with thyroid nodules who underwent surgery were evaluated prospectively. Preoperatively FNAC and TBSRTC reporting was done and following surgery histopathology was correlated with cytology. Distribution of 85 patients amongst the six categories of TBSRTC was as follows: 2.35% in Category I, 68.23% II, 7.05% III, 16.47% IV, 2.35% V and 3.52% VI. In 93% (79) of patients TBSRTC correlated with histopathology whereas in 7% (6) it did not. Risk of malignancy calculated was 0% in II, 33.33% in III, 7.14% in IV and 100% in V and VI categories. Sensitivity, specificity, Positive Predictive Value and Negative Predictive Value of TBSRTC was 100% for V, VI categories, whereas it was 100%, 78%, 15% and 100% respectively for III, IV. The diagnostic accuracy in our study is 100% for Category V and VI whereas it is 79% for Category III and IV. TBSRTC proved to be a very good screening platform for triaging patients with thyroid nodules into benign and malignant groups, as it is directly related to risk of malignancy in each category. It has helped in appropriate surgical planning in 96.4% of our patients.

To identify the ultrasonographic characteristics of primary squamous cell carcinoma of the thyroid (PSCCT), and to assess the value of the 2015 American Thyroid Association (ATA) guideline and 2017 American College of Radiology (ACR) Thyroid Imaging, Reporting and Data System (TI-RADS) in the evaluation of this disease.

Eight patients with 9 PSCCTs over a 20-year study period were enrolled. Ultrasonic characteristics including nodule echogenicity, composition, shape, margin, calcification, size, vascularity, and cervical lymphadenopathy were reviewed. All nodules were then evaluated by 2017 ACR TI-RADS and 2015 ATA guidelines.

The average size of PSCCTs was 3.87 ± 1.41 cm. All PSCCTs were hypoechoic or very hypoechoic, solid nodules with intranodular vascularity. The average resistive index (RI) was 0.84 ± 0.18. Near half of PSCCTs (44.4%) demonstrated extrathyroidal extension. Taller-than-wide signs and cervical lymphadenopathy were observed in 33.3% of PSCCTs, and microcalcification was observed in 11.1% of them. All PSCCTs were classified as high suspicion patterns by 2015 ATA and recommended for fine-needle aspiration (FNA). Six PSCCTs (66.7%) were classified as grade 5 by 2017 ACR TI-RADS, while the remaining were grade 4. 88.9% of PSCCTs were recommended for FNA based on 2017 ACR TI-RADS.

PSCCT has certain ultrasonic features, including relatively large, hypoechoic, or very hypoechoic solid nodules with intranodular vascularity and extrathyroidal extension. Both 2015 ATA and 2017 ACR TI-RADS could identify PSCCT as suspicious for malignancy.

To develop an ultrasound-based machine learning classifier to diagnose benignity within indeterminate thyroid nodules (ITNs) by fine-needle aspiration, 180 patients with 194 ITNs (Bethesda classes III, IV and V) undergoing surgery over a 5-y study period were analyzed. The data set was randomly divided into training and testing data sets with 155 and 39 ITNs, respectively. All nodules were evaluated by ultrasound using the American College of Radiology Thyroid Imaging Reporting and Data System by manually scoring composition, echogenicity, shape, margin and echogenic foci. Nodule size, participant age and patient sex were recorded. A support vector machine (SVM) model with a cost-sensitive approach was developed using the aforementioned eight parameters with surgical histopathology as the reference standard. Surgical pathology determined 90 (46.4%) ITNs were malignant and 104 (53.6%) were benign. The SVM model classified 14 nodules as benign in the testing data set, of which 13 were correct (sensitivity = 93.8%, specificity = 56.5%). Considering malignancy prevalence by Bethesda group, the negative predictive values of this model for Bethesda III and IV categories were 93.9% and 93. 8%, respectively. The high negative predictive value of the SVM ultrasound-based model suggests a pathway by which surgical excision of Bethesda III and IV ITNs classified as benign may be avoided.

Clinical evidence supports the association of ultrasound features with benign or malignant thyroid nodules and serves as the basis for sonographic stratification of thyroid nodules, according to an estimated thyroid cancer risk. Contemporary guidelines recommend management strategies according to thyroid cancer risk, thyroid nodule size, and the clinical scenario. Yet, reproducible and accurate thyroid nodule risk stratification requires expertise, time, and understanding of the weight different ultrasound features have on thyroid cancer risk. The application of artificial intelligence to overcome these limitations is promising and has the potential to improve the care of patients with thyroid nodules.

To evaluate the diagnostic value of American College of Radiology (ACR) score and ACR Thyroid Imaging Report and Data System (TI-RADS) for benign nodules, medullary thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC) through comparing with Kwak TI-RADS.

Five hundred nine patients diagnosed with PTC, MTC or benign thyroid nodules were included and classified into the benign thyroid nodules group (n = 264), the PTC group (n = 189) and the MTC group (n = 56). The area under the curve (AUC) values were analyzed and the receiver operator characteristic (ROC) curves were drawn to compare the diagnostic efficiencies of ACR score, ACR TI-RADS and KWAK TI-RADS on benign thyroid nodules, MTC and PTC.

The AUC values of ACR score, ACR TI-RADS and Kwak TI-RADS for distinguishing malignant nodules from benign nodules were 0.914 (95%CI: 0.886-0.937), 0.871 (95%CI: 0.839-0.899) and 0.885 (95%CI: 0.854-0.911), respectively. In distinguishing of patients with MTC from PTC, the AUC values of ACR score, ACR TI-RADS and Kwak TI-RADS were 0.650 (95%CI: 0.565-0.734), 0.596 (95%CI: 0.527-0.664), and 0.613 (95%CI: 0.545-0.681), respectively. The AUC values of ACR score, ACR TI-RADS and Kwak TI-RADS for the discrimination of patients with MTC, PTC or benign nodules from patients without MTC, PTC or benign nodules were 0.899 (95%CI: 0.882-0.915), 0.865 (95%CI: 0.846-0.885), and 0.873 (95%CI: 0.854-0.893), respectively.

The ACR score performed the best, followed ex aequo by the ACR and Kwak TI-RADS in discriminating patients with malignant nodules from benign nodules and patients with MTC from PTC.

To compare the diagnostic performance of five different thyroid ultrasound classification systems, and determine which system is optimal for evaluating thyroid nodules and reducing the unnecessary biopsy rate.

In this prospective study, 1,010 nodules referred for biopsy during a 2-year period were classified using five classification systems: the Kwak Thyroid Imaging Reporting and Data System (Kwak TI-RADS), the European TI-RADS (EU TI-RADS, the Korean TI-RADS (K TI-RADS), the American College of Radiology TI-RADS (ACR TI-RADS), and the American Thyroid Association (ATA) classification. After fine needle aspiration biopsy, all classifications were compared for all nodules and also particularly for nodules sized 1-3 cm. Sensitivity, specificity, and interobserver agreement were evaluated for each classification system.

Of the 939 nodules (after exclusion of Bethesda 3 nodules) finally classified according to the surgical histopathology and cytology results, 73 (7.8%) were malignant and 866 nodules were benign (92.2%). The sensitivity was highest (94.5%) for the ACR TI-RADS and lowest for the Kwak TI-RADS (69%). After exclusion of small (<1 cm) and large nodules (>3 cm); while sensitivity was highest for ATA (97.8%), ACR TI-RADS was the second best classification (91.3%). There was substantial agreement among all classification systems except the Kwak TI-RADS (fair agreement).

The ACR TI-RADS was the most sensitive ultrasound risk stratification system for all nodules, while the Kwak TI-RADS was the most specific, ie, the most capable of excluding benign nodules based on the combined cytological and histopathological results. ATA and ACR-TIRADS were the most sensitive classification systems for nodules 1 to 3 cm in size. The ACR TI-RADS had higher sensitivity than the Bethesda classification system when compared according to the histopathological results.

The aim of our study was to address the potential for improvements in thyroid cancer detection in routine clinical settings using a clinical examination, the American College of Radiology Thyroid Imaging Reporting and Database System (ACR TI-RADS), and fine-needle aspiration cytology (FNAC) concurrently with molecular diagnostics. A prospective cohort study was performed on 178 patients. DNA from FNA samples was used for next-generation sequencing to identify mutations in the genes BRAF, HRAS, KRAS, NRAS, and TERT. RNA was used for real-time PCR to detect fusion genes. The strongest relevant positive predictors for malignancy were the presence of genetic mutations (p < 0.01), followed by FNAC (p < 0.01) and ACR TI-RADS (p < 0.01). Overall, FNAC, ACR TI-RADS, and genetic testing reached a sensitivity of up to 96.1% and a specificity of 88.3%, with a diagnostic odds ratio (DOR) of 183.6. Sensitivity, specificity, and DOR decreased to 75.0%, 88.9%, and 24.0, respectively, for indeterminate (Bethesda III, IV) FNAC results. FNA molecular testing has substantial potential for thyroid malignancy detection and could lead to improvements in our approaches to patients. However, clinical examination, ACR TI-RADS, and FNAC remained relevant factors.

Artificial intelligence algorithms could be used to risk-stratify thyroid nodules and may reduce the subjectivity of ultrasonography. One such algorithm is AIBx which has shown good performance. However, external validation is crucial prior to clinical implementation.

Patients harboring thyroid nodules 1-4 cm in size, undergoing thyroid surgery from 2014 to 2016 in a single institution, were included. A histological diagnosis was obtained in all cases. Medullary thyroid cancer, metastasis from other cancers, thyroid lymphomas, and purely cystic nodules were excluded. Retrospectively, transverse ultrasound images of the nodules were analyzed by AIBx, and the results were compared with histopathology and Thyroid Imaging Reporting and Data System (TIRADS), calculated by experienced physicians.

Out of 329 patients, 257 nodules from 209 individuals met the eligibility criteria. Fifty-one nodules (20%) were malignant. AIBx had a negative predictive value (NPV) of 89.2%. Sensitivity, specificity, and positive predictive values (PPV) were 78.4, 44.2, and 25.8%, respectively. Considering both TIRADS 4 and TIRADS 5 nodules as malignant lesions resulted in an NPV of 93.0%, while PPV and specificity were only 22.4 and 19.4%, respectively. By combining AIBx with TIRADS, no malignant nodules were overlooked.

When applied to ultrasound images obtained in a different setting than used for training, AIBx had comparable NPVs to TIRADS. AIBx performed even better when combined with TIRADS, thus reducing false negative assessments. These data support the concept of AIBx for thyroid nodules, and this tool may help less experienced operators by reducing the subjectivity inherent to thyroid ultrasound interpretation.

This study is aimed at evaluating the diagnostic efficacy of ultrasound-based risk stratification for thyroid nodules in the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) and the American Thyroid Association (ATA) risk stratification systems.

286 patients with thyroid cancer were included in the tumor group, with 259 nontumor cases included in the nontumor group. The ACR TI-RADS and ATA risk stratification systems assessed all thyroid nodules for malignant risks. The diagnostic effect of ACR and ATA risk stratification system for thyroid nodules was evaluated by receiver operating characteristic (ROC) analysis using postoperative pathological diagnosis as the gold standard.

The distributions and mean scores of ACR and ATA rating risk stratification were significantly different between the tumor and nontumor groups. The lesion diameter > 1 cm subgroup had higher malignant ultrasound feature rates detected and ACR and ATA scores. A significant difference was not found in the ACR and ATA scores between patients with or without Hashimoto's disease. The area under the receiver operating curve (AUC) for the ACR TI-RADS and the ATA systems was 0.891 and 0.896, respectively. The ACR had better specificity (0.90) while the ATA system had higher sensitivity (0.92), with both scenarios having almost the same overall diagnostic accuracy (0.84).

Both the ACR TI-RADS and the ATA risk stratification systems provide a clinically feasible thyroid malignant risk classification, with high thyroid nodule malignant risk diagnostic efficacy.

Ultrasonographic (US) assessment methods may affect the estimated malignancy risk of thyroid nodules. This study aimed to investigate the impact of retrospective and prospective US assessments on the estimated malignancy risk of US features, classified categories, and diagnostic performance of five risk stratification systems (RSSs) in thyroid nodules.

A total of 3685 consecutive thyroid nodules (≥1 cm) with final diagnoses (retrospective dataset, n = 2180; prospective dataset, n = 1505) were included in this study. We compared the estimated malignancy risk of US features, classified categories, and diagnostic performances of the five common RSSs between retrospective (static US images without cine clips) and prospective datasets of real-time US assessment.

There was no significant difference in the prevalence and histological type of malignant tumours between the two datasets (p ≥ 0.216). The malignancy risk of solid composition and nonparallel orientation was higher and that of microcalcification was lower in the prospective dataset than in the retrospective dataset (p < 0.001, p = 0.018, p = 0.007, respectively). The retrospective US assessment showed slightly higher malignancy risk of intermediate- or high-risk nodules according to the RSSs. Prospective US assessment showed lower specificities and higher unnecessary biopsy rates by all RSSs compared to the retrospective US assessment (p ≤ 0.006, p ≤ 0.045, respectively).

The retrospective US assessment showed higher malignancy risk of microcalcification and some classified categories by RSSs, and overestimated the specificities and underestimated the unnecessary biopsy rates by all RSSs compared to prospective US assessment.

Clinicians estimate the risk of thyroid nodules and make subsequently decision on the basis of clinical and ultrasonographic findings. Currently, there is no comprehensive diagnostic tool for predicting the malignancy rates of thyroid nodules. Our aim was to develop and validate a novel integrate diagnostic tool for predicting the malignancy probability of thyroid nodules based on clinical, B-mode, Color Doppler and elastographic ultrasonographic characteristics.

A total of 1016 nodules in 1016 patients who underwent thyroid ultrasonography and surgery from July 2021 to December 2021 were included in this retrospective study. All nodules were confirmed by pathology and randomly classified into the training and validation groups. Clinical, B-mode, Color Doppler and elastographic (CBCE) ultrasonographic characteristics of nodules were recorded. Univariate and multivariate analyses were performed to screen independent predictors associated with thyroid cancer. A multivariate model containing the extracted predictors was constructed and presented in the form of a nomogram. The validation and applicability of the CBCE nomogram was evaluated using the receiver operating characteristic (ROC) curve. Diagnostic performances were calculated to compare the CBCE nomogram with ACR-TIRADS (Thyroid Imaging Reporting Data System by American College of Radiology) and EU-TIRADS (Thyroid Imaging Reporting Data System by European Thyroid Association).

The following factors were included in the CBCE nomogram: patient gender, age, shape, margin, composition and echogenicity, calcification, vascularization distribution, vascularization degree, suspicious lymph node metastases and elastography. The area under the curve (AUC) values were 0.978 and 0.983 for the training and validation groups, respectively. Compared with ACR-TIRADS and EU-TIRADS, the CBCE nomogram showed improved accuracy (0.944) and specificity (0.913) without sacrificing sensitivity (0.963) and showed the highest AUC with an optimal cutoff value of 0.55.

The CBCE nomogram has good and high clinical practicability in predicting the malignancy probability of thyroid nodules.

Incidental thyroid nodules are commonly detected on ultrasonography (US). This has contributed to the rapidly rising incidence of low-risk papillary thyroid carcinoma over the last 20 years. The appropriate diagnosis and management of these patients is based on the risk factors related to the patients as well as the thyroid nodules. The Korean Society of Thyroid Radiology (KSThR) published consensus recommendations for US-based management of thyroid nodules in 2011 and revised them in 2016. These guidelines have been used as the standard guidelines in Korea. However, recent advances in the diagnosis and management of thyroid nodules have necessitated the revision of the original recommendations. The task force of the KSThR has revised the Korean Thyroid Imaging Reporting and Data System and recommendations for US lexicon, biopsy criteria, US criteria of extrathyroidal extension, optimal thyroid computed tomography protocol, and US follow-up of thyroid nodules before and after biopsy. The biopsy criteria were revised to reduce unnecessary biopsies for benign nodules while maintaining an appropriate sensitivity for the detection of malignant tumors in small (1-2 cm) thyroid nodules. The goal of these recommendations is to provide the optimal scientific evidence and expert opinion consensus regarding US-based diagnosis and management of thyroid nodules.