The other thing that matters in the deathloops story is that the world is already in an age of war. These publications erroneously add weight to the belief that TIRADS is a proven and superior model for the investigation of thyroid nodules. Only a small percentage of thyroid nodules are cancerous. Thyroid Nodule Characterization: How to Assess the Malignancy Risk. The actual number of inconclusive FNA results in the real-world validation set has not been established (because that study has not been done), but the typical rate is 30% (by this we mean nondiagnostic [ie, insufficient cells], or indeterminate [ie, atypia of undetermined significance (AUS)/follicular lesion of undetermined significance (FLUS)/follicular neoplasm/suspicious for follicular neoplasm [Bethesda I, III, IV]). However, many patients undergoing a PET scan will have another malignancy. 1 Most thyroid nodules are detected incidentally when imaging is performed for another indication. The difference was statistically significant (P<0.05). In which, divided into groups such as: Malignant 3.3%; malignancy 9.2%; malignant 44.4 - 72.4%, malignant. The financial costs and surgical morbidity in this group must be taken into account when considering the cost/benefit repercussions of a test that includes US imaging for thyroid cancer. This data set was a subset of data obtained for a previous study and there are no clear details of the inclusion and exclusion criteria, including criteria for FNA. The optimal investigation and management of the 84% of the population harboring the remaining 50% of cancer remains unresolved. Whereas using TIRADS as a rule-in cancer test would be the finding that a nodule is TR5, with a sufficiently high chance of cancer that further investigations are required, compared with being TR1-4. 'Returning to TI-RADS' may assist with triage of indeterminate thyroid Therefore, the rates of cancer in each ACR TIRADS category in the data set where they used four US characteristics can no longer be assumed to be the case using the 5 US characteristics plus the introduction of size cutoffs. Thyroid nodules are lumps that can develop on the thyroid gland. Castellana M, Castellana C, Treglia G, Giorgino F, Giovanella L, Russ G, Trimboli P. Oxford University Press is a department of the University of Oxford. Depending on the constellation or number of suspicious ultrasound features, a fine-needle biopsy is . The most common reason for our diagnosis is the thyroid nodule, a growth that often develops on the thyroid, the organ that controls our metabolism. These cutoffs are somewhat arbitrary, with conflicting data as to what degree, if any, size is a discriminatory factor. Thyroid imaging reporting and data system for US features of nodules: a step in establishing better stratification of cancer risk. Clinical Application of C-TIRADS Category and Contrast-Enhanced Ultrasound in Differential Diagnosis of Solid Thyroid Nodules Measuring 1 cm. Your email address will not be published. Until TIRADS is subjected to a true validation study, we do not feel that a clinician can currently accurately predict what a TIRADS classification actually means, nor what the most appropriate management thereafter should be. Authors TIRADS 4: suspicious nodules (5-80% malignancy rate). These final validation sets must fairly represent the population upon which the test is intended to be applied because the prevalence of the condition in the test population will critically influence the test performance, particularly the positive predictive value (PPV) and negative predictive value (NPV). As it turns out, its also very accurate and detailed. Whilst the details of the design of the final validation study can be debated, the need for a well-designed validation study to determine the test characteristics in the real-world setting is a basic requirement of any new test. Write for us: What are investigative articles. Thyroid imaging reporting and data system (TI-RADS) A key factor is the low pretest probability of important thyroid cancer but a higher chance of finding thyroid cancers that are very unlikely to cause ill health during a persons lifetime. But the test that really lets you see a nodule up close is a CT scan. 2022 Jun 30;12:840819. doi: 10.3389/fonc.2022.840819. This approach likely performs better than randomly selecting 1 in 10 nodules for FNA, but we intentionally made assumptions that would favor the performance of ACR TIRADS to illustrate that if a poor clinical comparator cannot clearly be beaten, then the clinical value that such new systems bring is correspondingly poor. Mao S, Zhao LP, Li XH, Sun YF, Su H, Zhang Y, Li KL, Fan DC, Zhang MY, Sun ZG, Wang SC. Ultrasonographic scoring systems such as the Thyroid Imaging Reporting and Data System (TIRADS) are helpful in differentiating between benign and malignant thyroid nodules by offering a risk stratification model. Many studies have not found a clear size/malignancy correlation, and where it has been found, the magnitude of the effect is modest. To illustrate the effect of the size cutoffs we have given 2 examples, 1 where the size cutoffs are not discriminatory and the cancer rate is the same above and below the size cutoff, and the second example where the cancer risk of the nodule doubles once the size goes above the cutoff. Reference article, Radiopaedia.org (Accessed on 05 Mar 2023) https://doi.org/10.53347/rID-21448. The site is secure. The summary of test performance of random selection, ACR TIRADS as a rule-out test, ACR TIRADS as a rule-in test, and ACR TIRADS applied across all TIRADS categories are detailed in Table 2, and the full data, definitions, and calculations are given elsewhere [25]. Value of Contrast-Enhanced Ultrasound in Adjusting the Classification of Chinese-TIRADS 4 Nodules. High Risk Thyroid Nodule Discrimination and Management by Modified TI no financial relationships to ineligible companies to disclose. In ACR TI-RADS, points in five feature categories are summed to determine a risk level from TR1 to TR5 . We examined the data set upon which ACR-TIRADS was developed, and applied TR1 or TR2 as a rule-out test, TR5 as a rule-in test, or applied ACR-TIRADS across all nodule categories. The frequency of different Bethesda categories in each size range . Cao H, Fan Q, Zhuo S, Qi T, Sun H, Rong X, Xiao X, Zhang W, Zhu L, Wang L. J Ultrasound Med. HHS Vulnerability Disclosure, Help Full data including 95% confidence intervals are given elsewhere [25]. Outlook. The process of establishing of CEUS-TIRADS model. Diagnostic approach to and treatment of thyroid nodules. We realize that such factors may increase an individuals pretest probability of cancer and clinical decision-making would change accordingly (eg, proceeding directly to FNA), but we here ascribe no additional diagnostic value to avoid overestimating the performance of the clinical comparator. Bookshelf For TIRADS to add clinical value, it would have to clearly outperform the comparator (random selection), particularly because we have made some assumptions that favor TIRADS performance. A subdivision into 4a (malignancy between 5 and 10%) and 4b (malignancy between 10 and 80%) was optional. Unable to load your collection due to an error, Unable to load your delegates due to an error. Differentiation of Thyroid Nodules (C-TIRADS 4) by Combining Contrast-Enhanced Ultrasound Diagnosis Model With Chinese Thyroid Imaging Reporting and Data System Front Oncol. Endocrinol. Bethesda, MD 20894, Web Policies K-TIRADS category was assigned to the thyroid nodules. Lancet (2014) 384(9957): 1848:184858. To further enhance the performance of TIRADS, we presume that patients present with only 1 TR category of thyroid nodules. Performance of Contrast-Enhanced Ultrasound in Thyroid Nodules: Review of Current State and Future Perspectives. If one assumes that in the real world, 25% of the patients have a TR1 or TR2 nodule, applying TIRADS changes the pretest 5% probability of cancer to a posttest risk of 1%, so the absolute risk reduction is 4%. doi: 10.12659/MSM.936368. The findings that ACR TIRADS has methodological concerns, is not yet truly validated, often performs no better than random selection, and drives significant costs and potential harm, are very unsettling but result from a rational and scientific assessment of the foundational basis of the ACR TIRADS system. They are found . Performing FNA on TR5 nodules is a relatively effective way of finding thyroid cancers. Because we have a lot of people who have been put in a position where they dont have the proper education to be able to learn what were going through, we have to take this time and go through it as normal. The CEUS-TIRADS category was 4c. Before Sometimes a physician may refer you to a specialist (doctor) at a clinic that specializes in thyroid cancer. This study has many limitations. However, given that TR1 and TR2 make up only 25% of the nodules, then to find 25 nodules that are TR1 or TR2, you would need to do 100 scans. The gender bias (92% female) and cancer prevalence (10%) of the data set suggests it may not accurately reflect the intended test population. TI-RADS 2: Benign nodules. 2021 Oct 30;13(21):5469. doi: 10.3390/cancers13215469. The authors suggested, as with BI-RADS, that biopsy candidates were those nodules categorized as TI-RADS category 4 or 5, meaning demonstrating at least one suspicious sonographic feature. Department of Endocrinology, Christchurch Hospital. Second, the proportion of patients in the different ACR TIRADS (TR) categories may, or may not, reflect the real-world population (Table 1). Advances in knowledge: The study suggests TIRADS and thyroid nodule size as sensitive predictors of malignancy. Bessey LJ, Lai NB, Coorough NE, Chen H, Sippel RS. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide, This PDF is available to Subscribers Only. This causes the nodules to shrink and signs and symptoms of hyperthyroidism to subside, usually within two to three months. Tirads classification in ultrasound evaluation of thyroid nodules This site needs JavaScript to work properly. Objective: To determine whether the size of thyroid nodules in ACR-TIRADS ultrasound categories 3 and 4 is correlated with the Bethesda cytopathology classification. Haugen BR, Alexander EK, Bible KC, et al. Based on the methodology used to acquire the data set, the gender bias, and cancer rate in the data set, it is unlikely to be a fair reflection of the population upon which the test is intended to be applied, and so cannot be considered a true validation set. Such validation data sets need to be unbiased. 19 (11): 1257-64. Until a well-designed validation study is completed, the performance of TIRADS in the real world is unknown. The arrival time, enhancement degree, enhancement homogeneity, enhancement pattern, enhancement ring, and wash-out time were analyzed in CEUS for all of the nodules. Summary Test Performance of Random Selection of 1 in 10 Nodules for FNA, Compared with ACR-TIRADS. The health benefit from this is debatable and the financial costs significant. Lin JD, Chao TC, Huang BY, Chen ST, Chang HY, Hsueh C. Bongiovanni M, Crippa S, Baloch Z, et al. Based on the 2017 ACR TIRADS classification, the doctor will continue to specify whether the patient needs a biopsy of thyroid cells or not: Thyroid nodule size > 2.5cm: Indication for cytology biopsy. If a patient presented with symptoms (eg, concerns about a palpable nodule) and/or was not happy accepting a 5% pretest probability of thyroid cancer, then further investigations could be offered, noting that US cannot reliably rule in or rule out thyroid cancer for the majority of patients, and that doing any testing comes with unintended risks. The diagnostic schedule of CEUS could get better diagnostic performance than US in the differentiation of thyroid nodules. (2017) Radiology. The ACR TIRADS management flowchart also does not take into account these clinical factors. Using TIRADS as a rule-out cancer test would be the finding that a nodule is TR1 or TR2 and hence has a low risk of cancer, compared with being TR3-5. In view of their critical role in thyroid nodule management, more improved TI-RADSs have emerged. We chose a 1 in 10 FNA rate to reflect that roughly 5% of thyroid nodules are palpable and so would likely go forward for FNA, and we considered that a similar number would be selected for FNA based on clinical grounds such as other risk factors or the patient wishes. TIRADS Management Guidelines in the Investigation of Thyroid Nodules; Illustrating the Concerns, Costs, and Performance TIRADS Management Guidelines in the Investigation of Thyroid Nodules; Illustrating the Concerns, Costs, and Performance J Endocr Soc. doi: 10.1210/jendso/bvaa031. Tests and procedures used to diagnose thyroid cancer include: Physical exam. They will want to know what to do with your nodule and what tests to take. A prospective validation study that determines the true performance of TIRADS in the real-world is needed. We assessed a hypothetical clinical comparator where 1 in 10 nodules are randomly selected for fine needle aspiration (FNA), assuming a pretest probability of clinically important thyroid cancer of 5%. The Value of Chinese Thyroid Imaging Report and Data System Combined With Contrast-Enhanced Ultrasound Scoring in Differential Diagnosis of Benign and Malignant Thyroid Nodules. Refer to separate articles for the latest systems supported by various professional societies: A TI-RADS was first proposed by Horvath et al. . The https:// ensures that you are connecting to the Risk Stratification of Thyroid Nodules Using the Thyroid Imaging These patients are not further considered in the ACR TIRADS guidelines. Learn how t. EU-TIRADS 1 category refers to a US examination where no thyroid nodule is found; there is no need for FNAB. Federal government websites often end in .gov or .mil. 2009;94 (5): 1748-51. This allows patients with a TR1 or TR2 nodule to be reassured that they have a low risk of thyroid cancer, rather than a mixture of nodules (not just TR1 or TR2) not being able to be reassured. Thyroid surgery, Microvascular reconstruction, Neck surgery, Reconstructive surgery, Facial reconstruction, Parathyroid. Thyroid nodules with TIRADS 4 and 5 and diameter lower than 12 mm, are highly suspicious for malignancy and should be considered as indications for fine needle aspiration biopsy. Cheng H, Zhuo SS, Rong X, Qi TY, Sun HG, Xiao X, Zhang W, Cao HY, Zhu LH, Wang L. Int J Endocrinol. 2021 Dec 7;101(45):3748-3753. doi: 10.3760/cma.j.cn112137-20210401-00799. FOIA If your doctor is not sure what to do with your nodule, lets say its just a very small, non-cancerous, nodule, you may need to go to an endocrinologist. Ultrasound classification of thyroid nodules: does size matter? It is important to validate this classification in different centres. Applying ACR-TIRADS across all nodule categories did not perform well, with sensitivity and specificity between 60% and 80% and overall accuracy worse than random selection (65% vs 85%). For example, a previous meta-analysis of more than 25,000 FNAs showed 33% were in these groups [17]. Thyroid nodules - Doctors and departments - Mayo Clinic The first time Tirads 3 after cytology is benign, but you do not say how many mm and after 3 months of re-examination, it was . These appear to share the same basic flaw as the ACR-TIRADS, in that the data sets of nodules used for their development is not likely to represent the population upon which it is intended for use, at least with regard to pretest probability of malignancy (eg, malignancy rate 12% for Korean TIRADS [26]; 18% and 31% for EU TIRADS categories 4 and 5 [27, 28]). The ROC curves of C-TIRADS, CEUS, and CEUS-TIRADS of 100 nodules in the validation cohort. TR5 in the data set made up 16% of nodules, in which one-half of the thyroid cancers (183/343) were found. We refer to ACR-TIRADS where data or comments are specifically related to ACR TIRADS and use the term TIRADS either for brevity or when comments may be applicable to other TIRADS systems. Accessibility All of the C-TIRADS 4 nodules were re-graded by CEUS-TIRADS. The vast majority of nodules followed-up would be benign (>97%), and so the majority of FNAs triggered by US follow-up would either be benign, indeterminate, or false positive, resulting in more potential for harm (16 unnecessary operations for every 100 FNAs). This equates to 2-3 cancers if one assumes a thyroid cancer prevalence of 5% in the real world. Any additional test has to perform exceptionally well to surpass this clinicians 95% negative predictive performance, without generating false positive results and consequential harm. Results: doi: 10.1111/j.1754-9485.2009.02060.x The equation was as follows: z = -2.862 + 0.581X1- 0.481X2- 1.435X3+ 1.178X4+ 1.405X5+ 0.700X6+ 0.460X7+ 0.648X8- 1.715X9+ 0.463X10+ 1.964X11+ 1.739X12. This is likely an underestimate of the number of scans needed, given that not all nodules that are TR1 or TR2 will have purely TR1 or TR2 nodules on their scan. Perhaps surprisingly, the performance ACR-TIRADS may often be no better than random selection. Cavallo A, Johnson DN, White MG, et al. Second, we then apply TIRADS across all 5 nodule categories to give an idea how TIRADS is likely to perform overall. Using TR5 as a rule-in test was similar to random selection (specificity 89% vs 90%). Your email address will not be published. Most nodules and swellings are not cancerous. Epub 2021 Oct 28. Data Set Used for Development of ACR TIRADS [16] and Used for This Paper The possible cancer rate column is a crude, unvalidated estimate, calculated by proportionately reducing the cancer rates by 10.3%: 5% to reflect the likely difference in the cancer rate in the data set used (10.3%) and in the population presenting with a thyroid nodule (5%). PMC The more FNAs done in the TR3 and TR4 groups, the more indeterminate FNAs and the more financial costs and unnecessary operations. 2022 Jan 6;2022:5623919. doi: 10.1155/2022/5623919. Doctors use radioactive iodine to treat hyperthyroidism. Among the 228 C-TIRADS 4 nodules, 69 were determined as C-TIRADS 4a, 114 were C-TIRADS 4b, and 45 were C-TIRADS 4c. The other one-half of the cancers that are missed by only doing FNA of TR5 nodules will mainly be in the TR3 and TR4 groups (that make up 60% of the population), and these groups will have a 3% to 8% chance of cancer, depending upon whether the population prevalence of thyroid cancer in those being tested is 5% or 10%. Keywords: The flow chart of the study. Friedrich-Rust M, Meyer G, Dauth N et-al. to propose a simpler TI-RADS in 2011 2. Conclusions: In 2013, Russ et al. Using TR1 and TR2 as a rule-out test had excellent sensitivity (97%), but for every additional person that ACR-TIRADS correctly reassures, this requires >100 ultrasound scans, resulting in 6 unnecessary operations and significant financial cost. Diagnosis and Management of Small Thyroid Nodules: A Comparative Study with Six Guidelines for Thyroid Nodules. It has been retrospectively applied to thyroidectomy specimens, which is clearly not representative of the patient presenting with a thyroid nodule [34-36], and has even been used on the same data set used for TIRADS development, clearly introducing obvious bias [32, 37]. For the calculations, we assume an approximate size distribution where one-third of TR3 nodules are25 mm and half of TR4 nodules are15 mm. Tom James Cawood, Georgia Rose Mackay, Penny Jane Hunt, Donal OShea, Stephen Skehan, Yi Ma, TIRADS Management Guidelines in the Investigation of Thyroid Nodules; Illustrating the Concerns, Costs, and Performance, Journal of the Endocrine Society, Volume 4, Issue 4, April 2020, bvaa031, https://doi.org/10.1210/jendso/bvaa031. Putting aside any potential methodological concerns with ACR TIRADS, it may be helpful to illustrate how TIRADS might work if one assumed that the data set used was a fair approximation to the real-world population. A meta-analysis, This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs licence (, Mitoguardin2 is Associated with Hyperandrogenism and Regulates Steroidogenesis in Human Ovarian Granulosa Cells, Factors Associated with Diabetes Distress among Patients with Poorly Controlled Type 2 Diabetes, Serum adiponectin and leptin is not related to skeletal muscle morphology and function in young women, Association Between Metabolic Syndrome Inflammatory Biomarkers and COVID-19 Severity, Long-term outcome of body composition, ectopic lipid and insulin resistance changes with surgical treatment of acromegaly, Volume 7, Issue 4, April 2023 (In Progress), The Journal of Clinical Endocrinology & Metabolism, https://www.uptodate.com/contents/diagnostic-approach-to-and-treatment-of-thyroid-nodules, https://doi.org/10.6084/m9.figshare.11640168.v, http://creativecommons.org/licenses/by-nc-nd/4.0/, Receive exclusive offers and updates from Oxford Academic, 1 in 10 nodules having FNA, assuming pretest probability of cancer of 5%, Negative test being TR1 or TR2; positive test meaning TR3, TR4, or TR5, Positive test meaning TR5; negative test meaning TR1-4, Positive test meaning TR5, TR4 above size cutoff and TR3 above size cutoff; negative test meaning TR1, TR2, TR3 Below Size Cutoff or TR4 below size cutoff, Positive Test Meaning TR5, TR4 Above Size Cutoff and TR3 Above Size Cutoff; negative test meaning TR1, TR2, TR3 below size threshold or TR4 below size cutoff. In a patient with normal life expectancy, a biopsy should be performed for nodules >1cm regardless of the ACR TI-RADS risk category. A minority of these nodules are cancers. doi: 10.1089/jayao.2019.0098 If it performs well enough, then the test is applied to a training set of data to better establish performance characteristics. Here at the University of Florida, we are currently recruiting endocrinologists to work with us to help people with thyroid nodules. At the time the article was created Praveen Jha had no recorded disclosures. This assumption is obviously not valid and favors TIRADS management guidelines, but we believe it is helpful for clarity and illustrative purposes. In: Thyroid 26.1 (2016), pp. These figures cannot be known for any population until a real-world validation study has been performed on that population. However, there are ethical issues with this, as well as the problem of overdiagnosis of small clinically inconsequential thyroid cancer. The detection rate of thyroid cancer has increased steeply with widespread utilization of ultrasound (US) and frequent incidental detection of thyroid nodules with other imaging modalities such as computed tomography, magnetic resonance imaging, and, more recently, positron emission tomography-computed tomography, yet the mortality from thyroid cancer has remained static [10, 11]. published a simplified TI-RADS that was prospectively validated 5. All of the C-TIRADS 4 nodules were re-graded by CEUS-TIRADS. The Thyroid Imaging Reporting and Data System (TI-RADS) of the American College of Radiology (ACR) was designed in 2017 with the intent to decrease biopsies of benign nodules and improve overall . The more important test metric for diagnosing a disease is the specificity, where a positive test helps rule-in the disease. Current thyroid cancer trends in the United States, Association between screening and the thyroid cancer epidemic in South Korea: evidence from a nationwide study, 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: the American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer, Thyroid ultrasound and the increase in diagnosis of low-risk thyroid cancer, Korean Society of Thyroid Radiology (KSThR) and Korean Society of Radiology, Ultrasonography diagnosis and imaging-based management of thyroid nodules: revised Korean Society of Thyroid Radiology Consensus Statement and Recommendations, European Thyroid Association Guidelines for Ultrasound Malignancy Risk Stratification of Thyroid Nodules in Adults: the EU-TIRADS, Multiinstitutional analysis of thyroid nodule risk stratification using the American College of Radiology Thyroid Imaging Reporting and Data System, The Bethesda System for reporting thyroid cytopathology: a meta-analysis, The role of repeat fine needle aspiration in managing indeterminate thyroid nodules, The indeterminate thyroid fine-needle aspiration: experience from an academic center using terminology similar to that proposed in the 2007 National Cancer Institute Thyroid Fine Needle Aspiration State of the Science Conference. -, Fresilli D, David E, Pacini P, Del Gaudio G, Dolcetti V, Lucarelli GT, et al. Clinicians should be using all available data to arrive at an educated estimate of each patients pretest probability of having clinically significant thyroid cancer and use their clinical judgment to help advise each patient of their best options. The performance of any diagnostic test in this group has to be truly exceptional to outperform random selection and accurately rule in or rule out thyroid cancer in the TR3 or TR4 groups. Given that a proportion of thyroid cancers are clinically inconsequential, the challenge is finding a test that can effectively rule-in or rule-out important thyroid cancer (ie, those cancers that will go on to cause morbidity or mortality). The challenge of appropriately balancing the risks of missing an important cancer versus the chance of causing harm and incurring significant costs from overinvestigation is major. The results were compared with histology findings. TI-RADS 1: normal thyroid gland TI-RADS 2: benign nodule TI-RADS 3: highly probable benign nodule TI-RADS 4a: low suspicion for malignancy TI-RADS 4b: high suspicion for malignancy TI-RADS 5: malignant nodule with more than two criteria of high suspicion Imaging features TI-RADS 2 category Constantly benign patterns include simple cyst A robust validation study is required before the performance and cost-benefit outcomes of any of the TIRADS systems can be known. The authors stated that TI-RADS 4 and 5 nodules must be biopsied. ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. Chinese thyroid imaging reporting and data system(C-TIRADS); contrast-enhanced ultrasound (CEUS); differentiation; thyroid nodules; ultrasound (US). 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. The system has fair interobserver agreement 4. That particular test is covered by insurance and is relatively cheap. Zhang B, Tian J, Pei S, Chen Y, He X, Dong Y, Zhang L, Mo X, Huang W, Cong S, Zhang S. Wildman-Tobriner B, Buda M, Hoang JK, Middleton WD, Thayer D, Short RG, Tessler FN, Mazurowski MA. Furthermore, we are presuming other clinical factors (ie, palpability, size, number, symptoms, age, gender, prior radiation exposure, family history) add no diagnostic value above random selection. Interobserver Agreement of Thyroid Imaging Reporting and Data System (TIRADS) and Strain Elastography for the Assessment of Thyroid Nodules. The category definitions were similar to BI-RADS, based on the risk of malignancy depending on the presence of suspicious ultrasound features: The following features were considered suspicious: The study included only nodules 1 cm in greatest dimension. Keywords: For a rule-out test, sensitivity is the more important test metric. Diagnostic approach to and treatment of thyroid nodules We have also estimated the likely costs associated with using the ACR TIRADS guidelines, though for simplicity have not included the costs of molecular testing for indeterminate nodules (which is not readily available in the New Zealand public health system) nor any US follow-up and associated costs. Thyroid nodules - Diagnosis and treatment - Mayo Clinic Search for other works by this author on: University of Otago, Christchurch School of Medicine, Department of Endocrinology, St Vincents University Hospital, Department of Radiology, St Vincents University Hospital, Dublin 4 and University College Dublin, Biostatistician, Department of Medical & Womens Business Management, Canterbury District Health Board, Thyroid incidentalomas: management approaches to nonpalpable nodules discovered incidentally on thyroid imaging, The prevalence of thyroid nodules and an analysis of related lifestyle factors in Beijing communities, Prevalence of differentiated thyroid cancer in autopsy studies over six decades: a meta-analysis, Occult papillary carcinoma of the thyroid. Thyroid nodules are common, affecting around one-half of the population and become increasingly common with advancing age [1, 2].