Thyroid imaging reporting and data system with MRI morphological features for thyroid nodules: diagnostic performance and unnecessary biopsy rate.

BACKGROUND: To assess MRI-based morphological features in improving the American College of Radiology Thyroid Imaging Reporting and Data System (ACR-TIRADS) for categorizing thyroid nodules. METHODS: A retrospective analysis was performed on 728 thyroid nodules (453 benign and 275 malignant) that postoperative pathology confirmed. Univariate and multivariate logistic regression analyses were used to find independent predictors of MRI morphological features in benign and malignant thyroid nodules. The improved method involved increasing the ACR-TIRADS level by one when there are independent predictors of MRI-based morphological features, whether individually or in combination, and conversely decreasing it by one. The study compared the performance of conventional ACR-TIRADS and different improved versions. RESULTS: Among the various MRI morphological features analyzed, restricted diffusion and reversed halo sign were determined to be significant independent risk factors for malignant thyroid nodules (OR = 45.1, 95% CI = 23.2-87.5, P < 0.001; OR = 38.0, 95% CI = 20.4-70.7, P < 0.001) and were subsequently included in the final assessment of performance. The areas under the receiver operating characteristic curves (AUCs) for both the conventional and four improved ACR-TIRADSs were 0.887 (95% CI: 0.861-0.909), 0.945 (95% CI: 0.926-0.961), 0.947 (95% CI: 0.928-0.962), 0.945 (95% CI: 0.926-0.961) and 0.951 (95% CI: 0.932-0.965), respectively. The unnecessary biopsy rates for the conventional and four improved ACR-TIRADSs were 62.8%, 30.0%, 27.1%, 26.8% and 29.1%, respectively, while the malignant missed diagnosis rates were 1.1%, 2.8%, 3.7%, 5.4% and 1.2%. CONCLUSIONS: MRI morphological features with ACR-TIRADS has improved diagnostic performance and reduce unnecessary biopsy rate while maintaining a low malignant missed diagnosis rate.

The diagnostic efficacy and inappropriate biopsy rate of ACR TI-RADS and ATA guidelines for thyroid nodules in children and adolescents.

Background: 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. Methods: 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. Results: 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%. Conclusion: 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 impact of thyroid imaging reporting and data system on the management of Bethesda III thyroid nodules.

Objectives: Atypia of undetermined significance (AUS) or follicular lesion of undetermined significance (FLUS) is a heterogeneous category of fine needle aspiration cytology (FNAC); the management of this condition remains controversial. The clinical significance of such patients relies on the exclusion of malignancy. In this study, we aimed to determine the validity of the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) (2017) for predicting malignancy in this specific category of patients. Methods: In this study, we analysed a cohort of patients from our previous retrospective study. This four-year retrospective cohort study included all cases undergoing surgery with a cytological diagnosis of AUS/FLUS. We enrolled 110 cases with documented final histopathological diagnoses and ultrasound examinations. Results: The study included 83 females (75.5%) and 27 males (24.5%). The overall risk of malignancy (ROM) for AUS/FLUS thyroid nodules was 47.3%. The ROMs of TI-RADS 3 (TR3), TI-RADS 4 (TR4), and TI-RADS 5 (TR5) were 43.5%, 49.4% and 40%, respectively. There was no significant association between TI-RADS and final pathological analysis. Conclusions: Repeated FNAC with initial AUS/FLUS nodules is crucial. Our findings showed that ACR TI-RADS did not contribute to the cancer risk stratification of AUS/FLUS nodules. A large prospective multi-institutional study is now required to determine the validity of ACR TI-RADS and whether other adjunct clinical, cytological, molecular, or biochemical tools could facilitate the management of patients with these heterogeneous nodules.

Clinical and ultrasonographic features in cancer risk stratification of indeterminate thyroid nodules.

OBJECTIVES: To estimate the risk of malignancy in indeterminate thyroid nodules and to determine whether certain clinical or radiological parameters can predict the risk of malignancy. METHODS: This retrospective study enrolled all adult patients (age ≥14 years) with a cytological diagnosis of atypia/follicular lesion of undetermined significance and follicular neoplasm/suspicious for a follicular neoplasm between January 2014 and January 2020. Fifty patients with surgically treated primary thyroid nodules, documented final histological diagnosis, and ultrasound examination records were included. Thyroid nodules were evaluated radiologically using Thyroid Imaging Reporting and Data System introduced by the American College of Radiology (2017). RESULTS: Forty-two (84.0%) female and 8 (16.0%) male patients were enrolled in the study. The malignancy risks were 44.8% for Bethesda III and 28.6% for Bethesda IV. The malignancy risks for the Thyroid Imaging Reporting and Data System categories were 33.3% (TR2), 39.1% (TR3), 35.3% (TR4), and 50% (TR5). No significant associations were observed between age, gender, Bethesda category, and Thyroid Imaging Reporting and Data System and the risk of malignancy. CONCLUSION: None of the clinical or radiological characteristics evaluated in this study contributed to the cancer risk stratification of thyroid nodules with indeterminate cytology. A prospective multicenter study is needed to better understand cytologically indeterminate thyroid nodules.

Effect of training on resident inter-reader agreement with American College of Radiology Thyroid Imaging Reporting and Data System.

BACKGROUND: The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) was introduced to standardize the ultrasound characterization of thyroid nodules. Studies have shown that ACR-TIRADS reduces unnecessary biopsies and improves consistency of imaging recommendations. Despite its widespread adoption, there are few studies to date assessing the inter-reader agreement amongst radiology trainees with limited ultrasound experience. We hypothesize that in PGY-4 radiology residents with no prior exposure to ACR TI-RADS, a statistically significant improvement in inter-reader reliability can be achieved with a one hour training session. AIM: To evaluate the inter-reader agreement of radiology residents in using ACR TI-RADS before and after training. METHODS: A single center retrospective cohort study evaluating 50 thyroid nodules in 40 patients of varying TI-RADS levels was performed. Reference standard TI-RADS scores were established through a consensus panel of three fellowship-trained staff radiologists with between 1 and 14 years of clinical experience each. Three PGY-4 radiology residents (trainees) were selected as blinded readers for this study. Each trainee had between 4 to 5 mo of designated ultrasound training. No trainee had received specialized TI-RADS training prior to this study. Each of the readers independently reviewed the 50 testing cases and assigned a TI-RADS score to each case before and after TI-RADS training performed 6 wk apart. Fleiss kappa was used to measure the pooled inter-reader agreement. The relative diagnostic performance of readers, pre- and post-training, when compared against the reference standard. RESULTS: There were 33 females and 7 males with a mean age of 56.6 ± 13.6 years. The mean nodule size was 19 ± 14 mm (range from 5 to 63 mm). A statistically significant superior inter-reader agreement was found on the post-training assessment compared to the pre-training assessment for the following variables: 1. "Shape" (k of 0.09 [slight] pre-training vs 0.67 [substantial] post-training, P < 0.001), 2. "Echogenic foci" (k of 0.28 [fair] pre-training vs 0.45 [moderate] post-training, P = 0.004), 3. 'TI-RADS level' (k of 0.14 [slight] pre-training vs 0.36 [fair] post-training, P < 0.001) and 4. 'Recommendations' (k of 0.36 [fair] pre-training vs 0.50 [moderate] post-training, P = 0.02). No significant differences between the pre- and post-training assessments were found for the variables 'composition', 'echogenicity' and 'margins'. There was a general trend towards improved pooled sensitivity with TI-RADS levels 1 to 4 for the post-training assessment while the pooled specificity was relatively high (76.6%-96.8%) for all TI-RADS level. CONCLUSION: Statistically significant improvement in inter-reader agreement in the assigning TI-RADS level and recommendations after training is observed. Our study supports the use of dedicated ACR TI-RADS training in radiology residents.

Evaluation of ACR TI-RADS cytologically indeterminate thyroid nodules and molecular profiles: a single-institutional experience.

INTRODUCTION: The American College of Radiology (ACR) Thyroid Imaging Reporting and Data Systems (TI-RADS) was developed to standardize thyroid ultrasound reports and predict the likelihood of malignancy. In our study, we aimed to correlate indeterminate thyroid fine needle aspiration cytology cases with preceding ultrasound (US) ACR TI-RADS scores and concurrent molecular testing results to examine how well the use of the ACR TI-RADS in our institution predicted which patients with indeterminate cytology might harbor molecular alterations. MATERIALS AND METHODS: We performed a retrospective review of thyroid nodules. Patients with US reports that included TI-RADS scores, fine needle aspiration specimens with indeterminate cytology (Bethesda class III-V), and molecular testing results were included. RESULTS: A total of 46 indeterminate cytology cases had had preceding US reports with TI-RADS scores and molecular testing (Bethesda class III, n = 37; Bethesda class IV, n = 6; Bethesda class V, n = 3). Most of the indeterminate cases had had a TI-RADS score of TR4 (31 of 46; 67.39%) or TR5 (9 of 46; 19.57%). RAS mutations were the most common alteration (n = 12). Of the 46 cases, 22 (47.85%) showed no alterations. Ten cases proceeded to surgery, of which seven displayed malignancies. CONCLUSIONS: Molecular testing in cytologically indeterminate thyroid nodules provided valuable information for TR4 and TR5 lesions; however, the TR2 and TR3 lesions often had no molecular alterations. These findings highlight the potential value of including US imaging features when assessing the significance of indeterminate cytology findings.

Do ACR TI-RADS scores demonstrate unique thyroid molecular profiles?

PURPOSE: The present study aimed to examine the molecular profiles of cytologically indeterminate thyroid nodules stratified by American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) categories and to determine whether certain ultrasonographic features display particular molecular alterations. METHODS: A retrospective review was conducted of cases from January 1, 2016 to April 1, 2018. Cases with in-house ultrasonography, fine-needle aspiration Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) diagnoses, molecular testing, and surgery were included. All cases were diagnosed as TBSRTC indeterminate categories. The ultrasound studies were retrospectively reviewed and assigned TI-RADS scores (TR1-TR5) by board-certified radiologists. The final diagnoses were determined based on the surgical resection pathology. Binary logistic regression analysis was used to study whether demographic characteristics, TI-RADS levels, and TBSRTC diagnoses were associated with ThyroSeq molecular results. RESULTS: Eighty-one cases met the inclusion criteria. RAS mutations were the most common alteration across all TI-RADS categories (TR2 2/2; TR3 10/19, TR4 13/44, and TR5 8/16), and did not stratify with any particular TI-RADS category. Only TR4 and TR5 categories displayed more aggressive mutations such as BRAFV600E and TERT. ThyroSeq results were positively correlated with thyroid malignancy when non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was categorized in the malignant category (odds ratio [OR], 6.859; P<0.01), but not when NIFTP was removed from the malignancy category. Echogenicity scores were found to be negatively correlated with ThyroSeq results in thyroid nodules (OR, 0.162; P<0.01). CONCLUSION: Higher-risk molecular alterations tended to stratify with the higher TI-RADS categories.

Comparative analysis of C-TIRADS and ACR-TIRADS in the diagnostic efficiency of thyroid nodules / 中华健康管理学杂志

Objective:To investigate the diagnostic efficiency of the 2020 Chinese Thyroid Imaging Reporting and Data System (C-TIRADS) and the 2017 American College of Radiology Thyroid Imaging Reporting and Data System (ACR-TIRADS) in the diagnosis of benign and malignant thyroid nodules.Methods:A retrospective analysis of the two-dimensional ultrasound image results of 324 thyroid nodules in 289 patients with thyroid nodules and thyroid nodules were performed in the physical examination of the Health Management Department of the Guangdong Second Provincial General Hospital from January 2018 to January 2019. A superficial professional doctor with a senior professional title simultaneously uses the C-TIRADS and ACR-TIRADS methods to evaluate the above nodules. The results are all pathologically referenced for the χ2 test and the receiver operating characteristic curve is drawn. Results:The sensitivity of C-TIRADS in diagnosing benign and malignant thyroid nodules was 81.90%, specificity was 97.72%, accuracy was 92.59%, negative predictive value was 91.85%, positive predictive value was 84.51%; ACR-TIRADS diagnosis The sensitivity of benign and malignant thyroid nodules was 59.05%, specificity was 99.54%, accuracy was 86.42%, negative predictive value was 83.52%, and positive predictive value was 98.41%. The area under the ROC curve was 0.958 and 0.935( Z=2.31 P=0.021). Conclusion:C-TIRADS classification based on counting method is better than ACR-TIRADS classification based on sub-method in the diagnosis of thyroid nodules. It has better efficacy and is more suitable for the current status of diagnosis and treatment of thyroid nodules in China.

The Diagnostic Value of the American College of Radiology Thyroid Imaging Reporting and Data System Classification and Shear-Wave Elastography for the Differentiation of Thyroid Nodules.

This study aimed to determine the diagnostic accuracy of the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) classification and shear-wave elastography (SWE) for the diagnosis of benign and malignant thyroid nodules. This retrospective study enrolled 141 patients (18-84 y of age) undergoing thyroidectomy between January 2015 and August 2020. All statistical analysis was based on pathologic results of patients. The cut-off value was found as category 4 for ACR TI-RADS classification and 5 m/s for shear-wave velocity (Vs) by the receiver operator characteristic curve analysis (area under the curve [AUC] = 0.684, p = 0.020 and AUC = 0.715, p = 0.005, respectively). SWE has higher diagnostic accuracy than the ACR TI-RADS classification system and can improve thyroid nodule discrimination in all sizes of the nodules. Also, the diagnostic performance decreases when the nodule diameter increases.

Reducing Unnecessary Biopsy of American College of Radiology Thyroid Imaging Reporting and Data System Category 4 Nodules.

OBJECTIVES: To assess the effectiveness of strain elastography (SE), Virtual Touch tissue imaging and quantification (VTIQ; Siemens Medical Solutions, Mountain View, CA) and their combination (SE + VTIQ) in distinguishing benign from malignant American College of Radiology Thyroid Imaging Reporting and Data System category 4 nodules (TR4) to reduce unnecessary biopsy. METHODS: In this retrospective study, 985 thyroid nodules from 920 patients were initially enrolled and examined with conventional ultrasound, SE, and VTIQ. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of SE, VTIQ, and SE + VTIQ were calculated respectively. An area under the receiver operating characteristic curve analysis was applied to evaluate the diagnostic efficiency of SE, VTIQ, and SE + VTIQ in the differentiation of benign and malignant TR4 nodules. RESULTS: A total of 864 patients with 922 TR4 nodules were enrolled ultimately, as 63 thyroid nodules from 56 patients were excluded because they did not meet the inclusion criteria of this study. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of SE, VTIQ, and SE + VTIQ were 72.4% versus 86.3% versus 82.1%, 77.7% versus 80.5% versus 83.5%, 70.6% versus 76.1% versus 80.2%, 73.4% versus 76.3% versus 83.5%, and 75.5% versus 79.7% versus 82.8%, respectively. The areas under the receiver operating characteristic curve for the diagnosis of TR4 nodules by SE, VTIQ, and SE + VTIQ were 0.751, 0.817, and 0.844. CONCLUSIONS: In spite of a slight decrease in the sensitivity, the application of combining SE and VTIQ techniques can improve the specificity and accuracy of TR4 nodule diagnosis, which can help reduce unnecessary biopsies of TR4 nodules.

Comparison of different ultrasound classification systems of thyroid nodules for identifying malignant potential: a cross-sectional study

OBJECTIVE: In our organization, it has been necessary in our organization to calculate the risk categories according to the American Thyroid Association (ATA), the American Association of Clinical Endocrinologists/American College of Endocrinology/Associazione Medici Endocrinologi (AACE/ACE/AME), and the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TIRADS) classification systems for each patient, from the year 2019; these are also required to be registered in the database. This creates a barrier to medical collaboration in everyday radiological practice because using multiple rating systems can be confusing for both readers and patients. For the change in routine practice, this study aimed to compare diagnostic parameters of the ATA, AACE/ACE/AME, and ACR TIRADS classification systems for the detection of suspicious thyroid nodule(s) considering the results of fine-needle aspiration cytopathology as the reference standard. METHODS: Data on ultrasound characteristics (2,000 nodules) and fine-needle aspiration cytopathology (39 nodules) were included in the analysis. The decision making of fine-needle aspiration biopsies was evaluated from the ultrasound characteristics as per the ATA, AACE/ACE/AME, and ACR TIRADS classification systems. RESULTS: The ATA, AACE/ACE/AME, and ACR TIRADS recommended 26, 32, and 37 nodules for fine-needle aspiration biopsies, respectively. Considering the results of fine-needle aspiration cytopathology as the reference standard, the ATA, AACE/ACE/AME, and ACR TIRADS classification systems had 0.993, 0.996, and 0.998 sensitivity, respectively. The accuracies were 0.641, 0.795, and 0.923, respectively. CONCLUSION: The ACR TIRADS classification system is less invasive and can identify suspicious nodules more accurately than that of ATA and AACE/ACE/AME.

BRAFV600E mutation combined with American College of Radiology thyroid imaging report and data system significantly changes surgical resection rate and risk of malignancy in thyroid cytopathology practice.

BACKGROUND: Ultrasonography patterns and molecular testing may assist in stratifying the malignancy risk of indeterminate cytology diagnosis. The purpose of this study was to assess the value of fine needle aspiration (FNA) cytology in combination with American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) and BRAFV600E mutation in differentiating high-risk thyroid nodules. METHODS: From February 2010 to February 2014, 2,643 consecutive thyroid nodules from 2,399 patients (688 men and 1,711 women; mean age, 44.3±12.5 years) who underwent preoperative FNA biopsies were enrolled. The Jiangsu Institute of Nuclear Medicine has adopted TI-RADS stratification and BRAFV600E mutation analysis as a routine procedure to assist in evaluating FNA cytopathology since January 2016. From February 2017 to July 2018, 1,905 thyroid nodules of 1,837 patients (501 men and 1,336 women, 49.5±12.8 years) who underwent preoperative ultrasound-guided FNA biopsies with BRAFV600E mutation analysis and ACR TI-RADS grading data available were enrolled for comparison in this study. RESULTS: The cancer risk in nodules with BRAFV600E mutation was 99.7% (905/908) according to the histological findings. The risk of malignancy (ROM) was found to increase with advancing ACR TI-RADS category. High-risk ultrasound features (TI-RADS 5) did show a good performance in predicting malignancy (98.1%). The combination of TI-RADS 5 and BRAFV600E mutation reached the best diagnostic efficiency [sensitivity 97.7%, specificity 94.8%, positive predictive value (PPV) 99.6%]. It is apparent that after the implementation of ACR TI-RADS and the BRAFV600E mutation analysis, the resection rates (RRs) of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) I and III categories showed significant decreases (39.1% vs. 21.6% and 36.1% vs. 16.7%, respectively). In contrast, the risks of malignancy of TBSRTC I and III categories indicated substantial increases (41.5% vs. 80.0% and 34.6% vs. 50.0%, respectively). The ROM of thyroid nodules with nondiagnostic (ND, I) category showed the most significant increase of 41.5% to 80.0%. CONCLUSIONS: ACR TI-RADS, together with BRAFV600E mutation and cytological diagnoses, can assist in improving the prediction of malignancy of thyroid nodules, especially in the TBSRTC I and III categories.

Improving Malignancy Prediction in AUS/FLUS Pediatric Thyroid Nodules with the Aid of Ultrasound.

INTRODUCTION: The standard workup of thyroid nodules concerning for malignancy includes fine-needle aspiration (FNA). In 2015, the American Thyroid Association (ATA) guidelines for the management of pediatric thyroid nodules recommended that all nodules with a Bethesda III cytology undergo surgical resection. OBJECTIVES: To correlate a Bethesda III cytology with histologic and clinical outcomes to determine the relevance of the ATA recommendations, and to evaluate whether Thyroid Imaging Reporting and Data System (TI-RADS) scoring could identify Bethesda III nodules at a lower risk of malignancy. METHODS: A retrospective chart review of patients who had undergone thyroid nodule FNA from 2008 to 2018 was performed. Malignancy rates were determined for each Bethesda category. The reference standard was histopathology or 2-year follow-up of imaging outcomes for nonoperative cases. Ultrasound exams of Bethesda III nodules were reviewed and TI-RADS scores assigned. RESULTS: A total of 143 FNA samples from 128 patients were identified. The mean age was 14.9 years (range 7-22). Twenty-two (15%) of the FNA samples were Bethesda III; the malignancy rate was 38%. A TI-RADS score was assigned in 20 of the 22 Bethesda III nodules. ROC analysis found an optimal cut-off for malignancy prediction of ≥7 points (risk category TR5). The negative predictive value was 85.7% (95% CI 35.9-99.6) and the positive predictive value was 83.3% (95% CI 57.2-98.2). CONCLUSION: Although, at baseline, thyroid nodules with a Bethesda III classification carry a moderate risk of malignancy in the pediatric population, TI-RADS scoring can identify nodules with a lower risk within this group. If validated by larger studies, this can inform decision making and reduce unneeded surgery.

Does a higher American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) score forecast an increased risk of malignancy? A correlation study of ACR TI-RADS with FNA cytology in the evaluation of thyroid nodules.

BACKGROUND: Ultrasound has become the initial approach to evaluating thyroid nodules, facilitating the distinction between benign and malignant nodules based on composition, echogenicity, nodule border or margin, shape, the presence of calcifications, and nodule dimensions. The American College of Radiology (ACR) recommended the Thyroid Imaging Reporting and Data System (TI-RADS) as a classification system to standardize thyroid ultrasound reports and to predict the probability of malignancy in thyroid nodules using a scoring system (TR1-TR5) based on multiple ultrasound characteristics and nodule size. Fine-needle aspiration (FNA) is recommended as the next step for nodules that warrant further workup. The authors assessed the accuracy of the ACR TI-RADS based on the corresponding FNA cytology results (Bethesda system diagnoses I-VI). METHODS: ACR TI-RADS ultrasound reports and corresponding FNA cytology diagnoses from January 1, 2018 to August 30, 2018 were evaluated. RESULTS: From January 1, 2018 to August 30, 2018, 2306 thyroid ultrasound-guided FNAs were performed at our institution. Of 2306 cases, 361 had ACR TI-RADS reports available. The majority of FNAs were TR4 (180; 49.9%) or TR3 (108; 29.9%). No TR2 or TR3 nodules were associated with Bethesda category V or VI diagnoses. The majority of TR4 nodules (142 of 180; 78.9%) and TR5 nodules (42 of 65; 64.6%) exhibited benign (Bethesda category II) cytology. Fourteen TR5 cases (21.5%) had malignant (Bethesda category VI) cytology. CONCLUSIONS: Although there were no TR2 or TR3 malignant (Bethesda category VI) diagnoses, and there were only a few malignancies in the TR4 and TR5 categories, the current results reassert the notion that the ACR TI-RADS scoring system shows at least some correlation between benign or malignant cytology diagnoses, as illustrated by the greater number of malignant cases in the higher ACR TI-RADS categories.

Inter-observer Variability in the American College of Radiology Thyroid Imaging Reporting and Data System: In-Depth Analysis and Areas for Improvement.

The American College of Radiology (ACR) introduced a new standardized system for management of thyroid nodules, the Thyroid Imaging Reporting and Data System (TI-RADS). The purpose of this retrospective study is to evaluate the inter-observer variability in applying TI-RADS in clinical practice without prior dedicated training. We evaluated a total of 180 nodules constituting all consecutive thyroid aspirations performed in the radiology department between January 1, 2014 and June 30, 2014, with exclusion of histologically inadequate samples. Four radiologists, blinded to each other's evaluation and to final pathology results, evaluated all of the nodules based on the TI-RADS lexicon. TI-RADS score and management recommendations were then deduced from the inputted features. Statistical analysis was performed to determine inter-observer agreement among all readers, as well as between each two readers, in all TI-RADS sonographic features and for recommended management per TI-RADS score with multi-user Cohen's κ (Light's κ) and percentage agreement using R. There was fair-to-moderate inter-observer agreement in nodule composition (two-reader κ range: 0.327-0.533) and presence of calcifications (κ range: 0.229-0.527), but poor-to-fair agreement in echogenicity (κ range: 0.141-0.355), shape (κ range: 0.0729-0.513) and margins (κ range: 0.176-0.283). There was fair inter-observer agreement regarding management recommendations (κ range: 0.242-0.359).