{"product_id":"a-patients-guide-to-the-acr-ti-rads-how-doctors-decide-which-thyroid-nodules-need-biopsy","title":"A Patient's Guide to the ACR TI-RADS: How Doctors Decide Which Thyroid Nodules Need Biopsy","description":"\u003cp\u003eThyroid nodules are extremely common findings on neck ultrasound, yet most are benign and do not require biopsy. The American College of Radiology (ACR) has developed the Thyroid Imaging, Reporting and Data System (TI-RADS) — a standardized scoring system that helps doctors determine which nodules should be biopsied, which should be monitored with follow-up ultrasound, and which can be safely left alone. Based on five categories of ultrasound features, the system assigns points that place each nodule into a risk level from TR1 (benign) to TR5 (highly suspicious), with specific size thresholds guiding whether a fine-needle aspiration (FNA) or follow-up scan is recommended. The goal is to catch clinically significant thyroid cancers while dramatically reducing unnecessary biopsies of benign nodules.\u003c\/p\u003e\n\n\u003ch1\u003eA Patient's Guide to the ACR TI-RADS: How Doctors Decide Which Thyroid Nodules Need Biopsy\u003c\/h1\u003e\n\n\u003ch2\u003eTable of Contents\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"#ddn-key-points\"\u003eKey Points\u003c\/a\u003e\u003c\/li\u003e\n\n  \u003cli\u003e\u003ca href=\"#introduction\"\u003eIntroduction: Thyroid Nodules and the Challenge of Overdiagnosis\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#rationale\"\u003eWhy Was the ACR TI-RADS Developed?\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#overview\"\u003eHow the ACR TI-RADS Scoring System Works\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#differences\"\u003eHow ACR TI-RADS Differs From Other Risk-Stratification Systems\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#features\"\u003eThe Five Feature Categories in Detail\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#benign\"\u003eAdditional Benign Appearances\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#microcarcinomas\"\u003ePapillary Thyroid Microcarcinomas: The Special Case of Tiny Cancers\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#reporting\"\u003eReporting Considerations: Measurement, Growth, and Follow-Up\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#implications\"\u003eWhat This Means for Patients\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#limitations\"\u003eStudy Limitations\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#recommendations\"\u003eRecommendations for Patients\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#ddn-faq\"\u003eFrequently Asked Questions\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#source\"\u003eSource Information\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c!-- ddn:keypoints:start --\u003e\n\u003ch2 id=\"ddn-key-points\"\u003eKey Points\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eThyroid nodules are found in up to 68% of adults on high-resolution ultrasound, but most are benign.\u003c\/li\u003e\n\u003cli\u003eACR TI-RADS assigns points from five ultrasound features to classify nodules as TR1 through TR5, guiding biopsy decisions.\u003c\/li\u003e\n\u003cli\u003eBiopsy thresholds vary by risk level: 2.5 cm for TR3, 1.5 cm for TR4, and 1 cm for TR5 nodules.\u003c\/li\u003e\n\u003cli\u003eRoutine biopsy is not recommended for nodules smaller than 1 cm, though 5–9 mm TR5 nodules may be biopsied after shared decision making.\u003c\/li\u003e\n\u003cli\u003eSignificant nodule growth is defined as a 20% increase in at least two dimensions with a 2 mm minimum, or a 50% volume increase.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- ddn:keypoints:end --\u003e\n\n\n\u003ch2 id=\"introduction\"\u003eIntroduction: Thyroid Nodules and the Challenge of Overdiagnosis\u003c\/h2\u003e\n\n\u003cp\u003eThyroid nodules are growths that develop within the thyroid gland, a butterfly-shaped organ located in the front of the neck that regulates metabolism. These nodules are extraordinarily common — according to research cited in the white paper, high-resolution ultrasound detects them in \u003cstrong\u003eup to 68% of adults\u003c\/strong\u003e. That means more than two out of every three people may have at least one thyroid nodule.\u003c\/p\u003e\n\n\u003cp\u003eThe standard test used to evaluate a nodule is fine-needle aspiration (FNA), a procedure in which a thin needle is inserted into the nodule to collect cells for microscopic examination. FNA is considered the most effective and practical test available to determine whether a nodule is malignant (cancerous) or may require surgery for a definitive diagnosis.\u003c\/p\u003e\n\n\u003cp\u003eHere is the critical problem: \u003cstrong\u003emost thyroid nodules are benign\u003c\/strong\u003e. Furthermore, even malignant nodules — particularly those smaller than 1 centimeter — frequently exhibit what doctors call indolent or nonaggressive behavior, meaning they grow slowly, if at all, and are unlikely to cause harm. Because of this, not every detected nodule requires FNA or surgery.\u003c\/p\u003e\n\n\u003cp\u003eThe issue of overdiagnosis is substantial. In South Korea, screening thyroid ultrasound in asymptomatic patients led to a rapid increase in the reported incidence of papillary thyroid cancer — yet mortality from the disease remained extremely low. In the United States, overdiagnosis of thyroid cancer — defined in the paper as \"diagnosis of thyroid tumors that would not, if left alone, result in symptoms or death\" — accounted for \u003cstrong\u003e70% to 80% of thyroid cancer cases in women and 45% of cases in men\u003c\/strong\u003e between 2003 and 2007.\u003c\/p\u003e\n\n\u003cp\u003eThis disconnect between detection and actual harm prompted the ACR to develop a reliable, noninvasive method to identify which nodules warrant FNA based on a reasonable likelihood of biologically significant malignancy — cancers that actually threaten a patient's health or life.\u003c\/p\u003e\n\n\u003ch2 id=\"rationale\"\u003eWhy Was the ACR TI-RADS Developed?\u003c\/h2\u003e\n\n\u003cp\u003eSince 2009, many professional societies and research groups have proposed various ultrasound-based risk-stratification systems to guide practitioners in recommending FNA. Some of these were named TI-RADS because they were modeled on the ACR's BI-RADS system, which has been widely adopted in breast imaging. Others, such as the American Thyroid Association (ATA), took a different, pattern-oriented approach — grouping nodules into patterns rather than assigning individual feature scores — but with the same underlying goal.\u003c\/p\u003e\n\n\u003cp\u003eThe sheer number of systems, combined with their complexity and lack of agreement between them, limited adoption in the ultrasound community. This inspired the ACR to develop a unified classification system that would be:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFounded on the standardized ultrasound terms defined in the ACR's previously published lexicon (a common vocabulary for describing ultrasound findings)\u003c\/li\u003e\n  \u003cli\u003eEasy to apply across a wide range of ultrasound practices, from academic medical centers to community hospitals\u003c\/li\u003e\n  \u003cli\u003eAble to classify \u003cem\u003eall\u003c\/em\u003e thyroid nodules — not just those that fit into predetermined patterns\u003c\/li\u003e\n  \u003cli\u003eEvidence-based to the greatest extent possible\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eIn 2012, the ACR convened committees with three missions: (1) to provide recommendations for reporting incidental thyroid nodules, (2) to develop a set of standard terms (lexicon) for ultrasound reporting, and (3) to propose a TI-RADS based on that lexicon. The first two efforts were published in 2015. This white paper presents the committee's final risk-stratification system.\u003c\/p\u003e\n\n\u003cp\u003eThe recommendations were developed through conference calls, e-mail discussions, and online surveys. They represent the \u003cstrong\u003econsensus opinion of the ACR TI-RADS Committee\u003c\/strong\u003e, based on a review of the published literature, analysis of data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program, evaluation of existing risk classification systems, and expert opinion.\u003c\/p\u003e\n\n\u003cp\u003eImportantly, the authors stress that these recommendations are intended as guidance, not as strict standards. Practitioners must apply their own professional judgment to each individual case, and the decision to perform FNA should account for the referring physician's preferences and the patient's specific risk factors for thyroid cancer, anxiety, other medical conditions (comorbidities), life expectancy, and other relevant considerations.\u003c\/p\u003e\n\n\u003ch2 id=\"overview\"\u003eHow the ACR TI-RADS Scoring System Works\u003c\/h2\u003e\n\n\u003cp\u003eThe ACR TI-RADS categorizes ultrasound features as benign, minimally suspicious, moderately suspicious, or highly suspicious for malignancy. Points are assigned for each feature, with more suspicious features receiving more points. The system is built around five categories of ultrasound findings:\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eComposition\u003c\/strong\u003e (what the nodule is made of — fluid, solid tissue, or a mix)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEchogenicity\u003c\/strong\u003e (how bright or dark the nodule appears compared to surrounding thyroid tissue)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eShape\u003c\/strong\u003e (whether the nodule is wider than tall, or taller than wide)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMargin\u003c\/strong\u003e (the character of the nodule's edge or border)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEchogenic foci\u003c\/strong\u003e (bright spots inside the nodule, including calcifications)\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003eFor the first four categories, the reader selects \u003cem\u003eone\u003c\/em\u003e feature; for the fifth category (echogenic foci), the reader selects \u003cem\u003eall\u003c\/em\u003e features that apply. The points from all categories are added together to determine the nodule's TI-RADS level, which ranges from \u003cstrong\u003eTR1 (benign)\u003c\/strong\u003e to \u003cstrong\u003eTR5 (high suspicion of malignancy)\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eThe scoring works as follows:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e0 points\u003c\/strong\u003e = TR1 (Benign) — No FNA recommended\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e2 points\u003c\/strong\u003e = TR2 (Not Suspicious) — No FNA recommended\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e3 points\u003c\/strong\u003e = TR3 (Mildly Suspicious) — FNA if nodule is 2.5 cm or larger; follow-up ultrasound if 1.5 cm or larger\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e4 to 6 points\u003c\/strong\u003e = TR4 (Moderately Suspicious) — FNA if nodule is 1.5 cm or larger; follow-up ultrasound if 1 cm or larger\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e7 or more points\u003c\/strong\u003e = TR5 (Highly Suspicious) — FNA if nodule is 1 cm or larger; follow-up ultrasound if 0.5 cm or larger\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eOne important detail: although it is possible for a nodule to receive zero points and be classified as TR1, all other nodules receive at least two points. This is because a nodule that has a mixed cystic and solid composition (one point) will also receive at least one additional point for the echogenicity of its solid component.\u003c\/p\u003e\n\n\u003cp\u003eThe committee deliberately chose not to incorporate sonoelastography — a technique that measures tissue stiffness — into the ACR TI-RADS, noting that while it is a promising technology, it is not available in many ultrasound laboratories.\u003c\/p\u003e\n\n\u003cp\u003eThe size thresholds for biopsy were designed to balance the benefit of identifying clinically important cancers against the risk and cost of subjecting patients with benign nodules or indolent (slow-growing, harmless) cancers to unnecessary biopsy and treatment. The follow-up ultrasound recommendations substantially reduce the possibility that significant malignancies will go undetected over time, and they align with an increasing trend toward active surveillance (\"watchful waiting\") for low-risk thyroid cancer.\u003c\/p\u003e\n\n\u003ch2 id=\"differences\"\u003eHow ACR TI-RADS Differs From Other Risk-Stratification Systems\u003c\/h2\u003e\n\n\u003cp\u003eSeveral design choices distinguish the ACR TI-RADS from other proposed systems.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eStructure.\u003c\/strong\u003e To keep the system easy to understand and apply, the ACR TI-RADS does not include subcategories, nor does it include a TR0 category to indicate a normal thyroid gland (a category that appears in some other systems). It is also designed to be implemented as templates in voice recognition reporting systems or computerized decision support tools.\u003c\/p\u003e\n\n\u003cp\u003eThe committee decided against the pattern-based approach used by the American Thyroid Association. This decision was influenced by a study by Yoon and colleagues, which showed that the ATA guidelines were \u003cstrong\u003eunable to classify 3.4% of 1,293 nodules\u003c\/strong\u003e — and of those unclassifiable nodules, \u003cstrong\u003e18.2% were malignant\u003c\/strong\u003e. The study only included nodules that underwent FNA or surgery, so the researchers note that an even greater percentage of nodules would likely have been unclassifiable if all nodules — including those that were not biopsied — had been included. This is because it is not practical to create patterns that account for every possible combination of features.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eSize thresholds for FNA.\u003c\/strong\u003e The ACR TI-RADS is consistent with most other guidelines in recommending FNA for highly suspicious nodules that are 1 cm or larger. However, the thresholds for mildly suspicious and moderately suspicious nodules — 2.5 cm and 1.5 cm, respectively — are \u003cstrong\u003ehigher than the cutoffs advocated by the ATA and the Korean Society of Thyroid Radiology\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eWhy the higher thresholds? In a 2005 publication cited by both organizations, Machens and colleagues contended that the cumulative risk for distant metastases from papillary and follicular thyroid cancer rose at a threshold of 2 cm — the point at which they advocated biopsy.\u003c\/p\u003e\n\n\u003cp\u003eHowever, the ACR committee's review of the Machens graphs suggested a gradual, slight increase that actually began at a larger size. More importantly, the Machens analysis was based on tumor size measured in surgically removed specimens (pathology), not on ultrasound dimensions. Subsequent research has demonstrated a significant lack of concordance between sonographic and pathologic sizing, with ultrasound tending to produce larger measurements.\u003c\/p\u003e\n\n\u003cp\u003eOne striking example: in a study by Bachar and colleagues of \u003cstrong\u003e205 papillary carcinomas that measured 1.5 cm or smaller\u003c\/strong\u003e, the mean diameter on ultrasound was \u003cstrong\u003e2.65 ± 1.07 cm\u003c\/strong\u003e, compared with \u003cstrong\u003e1.97 ± 1.17 cm\u003c\/strong\u003e on pathology. The committee's higher size cutoffs reflect this discrepancy — in other words, ultrasound measurement may overestimate a nodule's true size, so a threshold that appears conservative on ultrasound is actually less conservative in reality.\u003c\/p\u003e\n\n\u003cp\u003eFurther guiding the committee's choices was an analysis of a database of \u003cstrong\u003emore than 3,000 proven thyroid nodules\u003c\/strong\u003e created for a study sponsored by the Society of Radiologists in Ultrasound. Partial analysis showed cancer risk levels of:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNo more than 2%\u003c\/strong\u003e for TR1 and TR2 nodules\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e5%\u003c\/strong\u003e for TR3 nodules\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e5% to 20%\u003c\/strong\u003e for TR4 nodules\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAt least 20%\u003c\/strong\u003e for TR5 nodules\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe committee also reviewed published and newly performed SEER data analyses showing a slight increase in distant metastases at \u003cstrong\u003e2.5 cm\u003c\/strong\u003e, as well as slight increments in 10-year relative survival and thyroid-cancer-specific mortality at \u003cstrong\u003e3 cm\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003ch2 id=\"features\"\u003eThe Five Feature Categories in Detail\u003c\/h2\u003e\n\n\u003cp\u003eEach of the five ultrasound categories contains specific features, each with a point value. Understanding these features helps patients grasp \u003cem\u003ewhy\u003c\/em\u003e their nodule received a particular TR level. The categories below reflect the detailed definitions in the ACR lexicon.\u003c\/p\u003e\n\n\u003ch3\u003eComposition (Choose 1)\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCystic or almost completely cystic\u003c\/strong\u003e — 0 points. Nodules that are largely or entirely fluid-filled are almost universally benign, so they receive no points.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSpongiform\u003c\/strong\u003e — 0 points. A spongiform nodule is composed predominantly (more than 50%) of small cystic spaces. This appearance is highly correlated with benign cytology, regardless of the nodule's relative echogenicity or other features. Notably, nodules should \u003cem\u003enot\u003c\/em\u003e be called spongiform just because they have a few scattered cystic components in an otherwise solid nodule. Also, spongiform nodules should not receive additional points for other features, and small echogenic foci sometimes seen within them probably represent the back walls of minute cysts — these are not suspicious in this context.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMixed cystic and solid\u003c\/strong\u003e — 1 point. This category combines two lexicon features: predominantly solid and predominantly cystic. The appearance of the solid component is more important than the overall nodule size or the proportion of solid versus cystic material in determining whether biopsy is warranted. Solid material that is eccentric (off-center) and forms an acute angle with the nodule's wall is suspicious, as is solid material with moderately or highly suspicious characteristics, such as decreased echogenicity, lobulation, and punctate echogenic foci.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSolid or almost completely solid\u003c\/strong\u003e — 2 points. Nodules that are mostly or entirely solid tissue receive the highest composition score.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe original paper notes that although color Doppler ultrasound has not been shown to reliably discriminate between benign and malignant nodules, the presence of blood flow in solid components can help distinguish actual solid tissue from echogenic debris or hemorrhage. Inconsequential debris may be identified by its layering or by motion elicited when the patient changes position.\u003c\/p\u003e\n\n\u003ch3\u003eEchogenicity (Choose 1)\u003c\/h3\u003e\n\n\u003cp\u003eEchogenicity refers to how the nodule reflects ultrasound waves compared with adjacent thyroid tissue — essentially, how bright or dark it appears on the screen.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAnechoic\u003c\/strong\u003e — 0 points. This means the nodule appears completely black (no internal echoes), which applies to cystic or almost completely cystic nodules. This zero-point feature was added specifically so that cystic nodules would not be awarded three points for appearing very hypoechoic.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHyperechoic or isoechoic\u003c\/strong\u003e — 1 point. The nodule appears brighter than (hyperechoic) or the same as (isoechoic) the surrounding thyroid tissue.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHypoechoic\u003c\/strong\u003e — 2 points. The nodule appears darker than the adjacent thyroid parenchyma.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eVery hypoechoic\u003c\/strong\u003e — 3 points. The nodule appears darker even than the strap muscles of the neck, which serve as the comparison standard for this feature. This is usually evident on visual inspection. If echogenicity cannot be determined (for example, because of calcifications that block the view), one point is assigned.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eShape (Choose 1)\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eWider-than-tall\u003c\/strong\u003e — 0 points. \u003cstrong\u003eTaller-than-wide\u003c\/strong\u003e — 3 points.\u003c\/p\u003e\n\n\u003cp\u003eA taller-than-wide shape is an insensitive but highly specific indicator of malignancy. This feature is evaluated in the axial (transverse) plane by comparing the height (\"tallness\") of the nodule — measured parallel to the ultrasound beam — with its width, measured perpendicular to the beam. In practice, a taller-than-wide configuration is usually evident on visual inspection and rarely requires formal measurements.\u003c\/p\u003e\n\n\u003ch3\u003eMargin (Choose 1)\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSmooth\u003c\/strong\u003e — 0 points. A well-defined, smooth border.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIll-defined\u003c\/strong\u003e — 0 points. The margin cannot be clearly delineated. This category was included so that reporting templates would not be left empty if a nodule is not well defined. If the margin cannot be determined for any reason, zero points should be assigned.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLobulated or irregular\u003c\/strong\u003e — 2 points. This refers to a spiculated or jagged edge, with or without protrusions into the surrounding thyroid tissue. It may be difficult to recognize this finding if the nodule is ill defined, embedded in a heterogeneous (uneven-textured) gland, or abuts multiple other nodules.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eExtrathyroidal extension (ETE)\u003c\/strong\u003e — 3 points. This means the nodule extends beyond the thyroid border. The paper clarifies that the term \"border\" is used because the thyroid gland lacks a true fibrous capsule. Extensive ETE — characterized by frank invasion of adjacent soft tissue and\/or vascular structures — is a highly reliable sign of malignancy and is an unfavorable prognostic sign. Minimal ETE may be suspected when there is border abutment, contour bulging, or loss of the echogenic thyroid border on ultrasound.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe authors caution that agreement among pathologists for identifying minimal ETE is poor, and its clinical significance is controversial. They therefore advise practitioners to exercise caution when reporting minimal ETE, particularly for otherwise benign-appearing nodules.\u003c\/p\u003e\n\n\u003cp\u003eThe ACR TI-RADS also deliberately omits the \"halo\" sign — a dark rim sometimes seen around nodules — noting that its presence is neither discriminatory nor mutually exclusive with other margin types.\u003c\/p\u003e\n\n\u003ch3\u003eEchogenic Foci (Choose All That Apply)\u003c\/h3\u003e\n\n\u003cp\u003eThis category — the only one in which multiple features can be selected — describes bright spots (hyperechoic foci) seen inside a nodule. Different types of foci carry very different implications.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNone or large comet-tail artifacts\u003c\/strong\u003e — 0 points. Large comet-tail artifacts are V-shaped echoes deeper than 1 mm that trail behind echogenic foci. They are associated with colloid (a gelatinous substance produced by thyroid cells) and are strongly indicative of benignity when found within the cystic components of thyroid nodules.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMacrocalcifications\u003c\/strong\u003e — 1 point. These are coarse echogenic foci accompanied by acoustic shadowing (a dark area behind the calcification caused by sound wave blockage). Evidence in the literature regarding their association with increased malignancy risk is mixed, especially in nodules lacking other malignant features. Given published data showing a weakly positive relationship with malignancy, macrocalcifications receive one point — with the understanding that the risk is increased if the nodule also contains moderately or highly suspicious features that warrant additional points.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePeripheral (rim) calcifications\u003c\/strong\u003e — 2 points. These lie along all or part of the nodule's margin. Their correlation with malignancy in the literature is variable. However, because some publications suggest that peripheral calcifications are more strongly associated with malignancy than macrocalcifications, they are awarded two points. Some authors have called attention to interrupted peripheral calcifications with protruding soft tissue as suspicious for malignancy, but with low specificity. In the ACR TI-RADS, this appearance qualifies as a lobulated margin, which adds another two points to the nodule's total.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePunctate echogenic foci\u003c\/strong\u003e — 3 points. These are smaller than macrocalcifications and do not produce acoustic shadowing. In the solid components of thyroid nodules, they may correspond to the psammomatous calcifications associated with papillary cancers and are therefore considered highly suspicious — particularly when combined with other suspicious features. This category also includes echogenic foci associated with small comet-tail artifacts in solid components, distinguishing them from the large comet-tail artifacts described earlier that indicate benign colloid.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWhen calcifications cause strong acoustic shadowing that prevents assessment of internal characteristics — particularly echogenicity and composition — the paper advises assuming the nodule is solid and assigning two points for composition and one point for echogenicity.\u003c\/p\u003e\n\n\u003ch2 id=\"benign\"\u003eAdditional Benign Appearances\u003c\/h2\u003e\n\n\u003cp\u003eSeveral ultrasound findings have been described as characteristic of benign nodules with a high degree of reliability, even though they were not formally incorporated into the ACR TI-RADS chart due to their relative scarcity. These include:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eThe \u003cstrong\u003e\"white knight\"\u003c\/strong\u003e appearance — a uniformly hyperechoic (very bright) nodule\u003c\/li\u003e\n  \u003cli\u003eThe \u003cstrong\u003e\"giraffe hide\"\u003c\/strong\u003e pattern — a variegated appearance with hyperechoic areas separated by hypoechoic bands, reminiscent of a giraffe's coat\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eBoth of these patterns occur in the setting of Hashimoto's thyroiditis, an autoimmune condition that causes chronic inflammation of the thyroid gland.\u003c\/p\u003e\n\n\u003ch2 id=\"microcarcinomas\"\u003ePapillary Thyroid Microcarcinomas: The Special Case of Tiny Cancers\u003c\/h2\u003e\n\n\u003cp\u003eThe ACR TI-RADS is consistent with other guidelines in recommending \u003cstrong\u003eagainst routine biopsy of nodules smaller than 1 cm, even if they are highly suspicious\u003c\/strong\u003e. However, the committee acknowledges an important exception: because some thyroid specialists advocate active surveillance, ablation, or lobectomy for papillary microcarcinomas (papillary thyroid cancers smaller than 1 cm), biopsy of \u003cstrong\u003e5- to 9-mm TR5 nodules\u003c\/strong\u003e (highly suspicious nodules) may be appropriate under certain circumstances.\u003c\/p\u003e\n\n\u003cp\u003eThe determination to perform FNA on these tiny, highly suspicious nodules should involve \u003cstrong\u003eshared decision making\u003c\/strong\u003e between the referring physician and the patient. Key considerations include:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eWhether the nodule can be measured reproducibly on follow-up studies (so that growth can be reliably tracked)\u003c\/li\u003e\n  \u003cli\u003eWhether the nodule is located in a critical area near the edge of the thyroid — nodules that abut the trachea (windpipe) or sit adjacent to the tracheoesophageal groove (the location of the recurrent laryngeal nerve, which controls the vocal cords) may complicate surgery if they grow\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor TR5 nodules in these critical submarginal locations, the report should specifically note their proximity to these structures.\u003c\/p\u003e\n\n\u003ch2 id=\"reporting\"\u003eReporting Considerations: Measurement, Growth, and Follow-Up\u003c\/h2\u003e\n\n\u003ch3\u003eMeasurement and Documentation\u003c\/h3\u003e\n\n\u003cp\u003eAccurate sizing of thyroid nodules is critical, because the maximum dimension determines whether a nodule should be biopsied or followed. Although some variability between different readers is inevitable, consistent technique improves measurement accuracy and reproducibility.\u003c\/p\u003e\n\n\u003cp\u003eNodules should be measured in \u003cstrong\u003ethree axes\u003c\/strong\u003e:\u003c\/p\u003e\n\u003col\u003e\n  \u003cli\u003eThe maximum dimension on an axial (cross-sectional) image\u003c\/li\u003e\n  \u003cli\u003eThe maximum dimension perpendicular to the first measurement on the same image\u003c\/li\u003e\n  \u003cli\u003eThe maximum longitudinal dimension on a sagittal (side-view) image\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003eFor obliquely oriented nodules, these measurements may differ from the dimensions used to determine a taller-than-wide shape, but this discrepancy should rarely present a problem in practice. Measurements should include the nodule's halo, if present. Practitioners may use linear dimensions to calculate nodule volume, a calculation available on many ultrasound machines.\u003c\/p\u003e\n\n\u003ch3\u003eDefining Significant Growth\u003c\/h3\u003e\n\n\u003cp\u003eWhen a nodule is followed with serial ultrasounds, doctors need a clear definition of what constitutes meaningful growth that would change management. In the ACR TI-RADS, \u003cstrong\u003esignificant enlargement\u003c\/strong\u003e is defined as:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eAn increase of \u003cstrong\u003e20% or more\u003c\/strong\u003e in at least two nodule dimensions, \u003cstrong\u003ewith a minimal increase of 2 mm\u003c\/strong\u003e, or\u003c\/li\u003e\n  \u003cli\u003eA \u003cstrong\u003e50% or greater increase in volume\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThese criteria align with those adopted by other professional societies. The paper stresses that enlargement may not be apparent if the current sonogram is compared only with the immediately preceding one — it is important to also review measurements from earlier scans, if available, to appreciate the full trajectory of growth.\u003c\/p\u003e\n\n\u003ch3\u003eTiming of Follow-Up Sonograms\u003c\/h3\u003e\n\n\u003cp\u003eThere is little consensus in the literature regarding the optimal spacing of follow-up sonograms for nodules that do not meet size criteria for FNA, because growth rates do not reliably distinguish benign from malignant nodules. The committee believes that scanning intervals of \u003cstrong\u003eless than 1 year are not warranted\u003c\/strong\u003e, except for proven cancers under active surveillance, which may require more frequent follow-up at the discretion of the referring physician.\u003c\/p\u003e\n\n\u003ch2 id=\"implications\"\u003eWhat This Means for Patients\u003c\/h2\u003e\n\n\u003cp\u003eFor patients, the practical significance of the ACR TI-RADS is substantial. Historically, many patients with incidental thyroid nodules — nodules discovered by chance when imaging the neck for other reasons — were referred for FNA, only to find that the vast majority were benign. This creates unnecessary anxiety, discomfort, expense, and potential complications from the biopsy procedure itself.\u003c\/p\u003e\n\n\u003cp\u003eUnder the ACR TI-RADS framework, a patient with a small, low-suspicion nodule may be spared biopsy entirely and instead offered a simple follow-up ultrasound in one to two years. A patient with a highly suspicious nodule measuring 1 cm or more will still be recommended for FNA, but with a clearer understanding of the risk level that prompted the recommendation.\u003c\/p\u003e\n\n\u003cp\u003eThe risk stratification is transparent: patients can see whether their nodule falls into a category with a cancer risk of approximately 2% or less (TR1\/TR2), about 5% (TR3), 5% to 20% (TR4), or at least 20% (TR5). This evidence-based transparency supports informed, shared decision making between patients and their care teams.\u003c\/p\u003e\n\n\u003ch2 id=\"limitations\"\u003eStudy Limitations\u003c\/h2\u003e\n\n\u003cp\u003eIt is important to recognize what this white paper does — and does not — provide. The ACR TI-RADS recommendations are based on the published literature, SEER data analyses, evaluation of existing risk classification systems, and expert opinion. However, the authors explicitly state that the proposals represent the \u003cstrong\u003econsensus opinion of the ACR TI-RADS Committee\u003c\/strong\u003e and are intended as guidance for practitioners, \u003cstrong\u003enot as standards of care\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eSeveral specific limitations were acknowledged:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eThe committee was unable to fully validate the partial analysis of the Society of Radiologists in Ultrasound database at the time of publication, though the risk levels cited (2% for TR1\/TR2, 5% for TR3, 5-20% for TR4, ≥20% for TR5) were drawn from it.\u003c\/li\u003e\n  \u003cli\u003eSonoelastography, a promising technique for assessing tissue stiffness, was not incorporated due to limited availability.\u003c\/li\u003e\n  \u003cli\u003eAgreement among pathologists for identifying minimal extrathyroidal extension is poor, which complicates the interpretation of this feature.\u003c\/li\u003e\n  \u003cli\u003eThe optimal spacing of follow-up ultrasounds remains uncertain, as growth rates do not reliably distinguish benign from malignant nodules.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003ePerhaps most importantly, the authors emphasize that interpreting and referring physicians remain legally and professionally responsible for applying their professional judgment to every case — the ACR TI-RADS is a decision-support tool, not a substitute for individualized medical care.\u003c\/p\u003e\n\n\u003ch2 id=\"recommendations\"\u003eRecommendations for Patients\u003c\/h2\u003e\n\n\u003cp\u003eFor patients who have been told they have a thyroid nodule, or who have just received an ACR TI-RADS score, the following points are worth discussing with your doctor:\u003c\/p\u003e\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNot all nodules need biopsy.\u003c\/strong\u003e If your nodule is scored as TR1 or TR2, no FNA is recommended. If it is TR3, TR4, or TR5, biopsy may or may not be recommended depending on the nodule's size in centimeters.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eKnow your nodule's size and score.\u003c\/strong\u003e These two numbers drive the entire management plan. Ask your radiologist or referring physician for both.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFollow-up imaging matters.\u003c\/strong\u003e Even when immediate biopsy is not needed, your doctor may recommend a follow-up ultrasound in one year or more. Growth criteria — a 20% increase in at least two dimensions with a minimum 2 mm change, or a 50% volume increase — help determine whether intervention is later needed. Ask your practice whether they will compare your scan with all prior studies, not just the most recent one.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eContext is key.\u003c\/strong\u003e The decision to biopsy a small but highly suspicious nodule (TR5, 5-9 mm) should involve shared decision making. Factors such as nodule location near critical structures, your overall health, life expectancy, and anxiety level should all be part of the conversation.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eConsider the bigger picture.\u003c\/strong\u003e Overdiagnosis of thyroid cancer is a recognized problem — many small or low-risk cancers would never cause symptoms or death if left alone. The ACR TI-RADS was specifically designed to reduce unnecessary biopsies while still catching clinically significant cancers.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003eIf you have questions about your thyroid nodule, ask your doctor to explain your nodule's composition, echogenicity, shape, margin, and echogenic foci — the five categories described in this article. Understanding how your nodule was scored can help you feel more confident about the recommended next step, whether that is biopsy, surveillance, or neither.\u003c\/p\u003e\n\n\u003c!-- ddn:faq:start --\u003e\n\u003ch2 id=\"ddn-faq\"\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eWhat is the ACR TI-RADS?\u003c\/h3\u003e\n\u003cp\u003eIt is a standardized scoring system for thyroid nodules seen on ultrasound. Doctors assign points based on five ultrasound features: composition, echogenicity, shape, margin, and echogenic foci. The total score places the nodule into a risk level from TR1 (benign) to TR5 (highly suspicious), which guides whether biopsy, follow-up ultrasound, or no further action is recommended.\u003c\/p\u003e\n\u003ch3\u003eWhat does my TI-RADS score mean?\u003c\/h3\u003e\n\u003cp\u003eTR1 and TR2 mean a cancer risk of about 2% or less, and no biopsy is recommended. TR3 means roughly 5% risk. TR4 means 5% to 20% risk. TR5 means at least 20% risk. Your score alone does not decide biopsy; the nodule's size in centimeters is also considered.\u003c\/p\u003e\n\u003ch3\u003eWill I need a biopsy of my thyroid nodule?\u003c\/h3\u003e\n\u003cp\u003eIt depends on your nodule's TI-RADS level and size. TR3 nodules need biopsy only if 2.5 cm or larger. TR4 nodules need biopsy if 1.5 cm or larger. TR5 nodules need biopsy if 1 cm or larger. TR1 and TR2 nodules do not need biopsy. Smaller nodules may instead have follow-up ultrasound.\u003c\/p\u003e\n\u003ch3\u003eMy nodule is small but highly suspicious (TR5). Should I get a biopsy?\u003c\/h3\u003e\n\u003cp\u003eGuidelines generally do not recommend routine biopsy of nodules smaller than 1 cm, even if highly suspicious. However, for TR5 nodules that are 5 to 9 mm, biopsy may be considered in certain situations, especially if the nodule is near the windpipe or vocal-cord nerve. This decision should involve shared decision making with your doctor.\u003c\/p\u003e\n\u003ch3\u003eWhat counts as significant growth of a thyroid nodule on follow-up?\u003c\/h3\u003e\n\u003cp\u003eSignificant enlargement is defined as an increase of 20% or more in at least two nodule dimensions, with a minimal increase of 2 mm, or a 50% or greater increase in volume. Doctors also recommend comparing with earlier scans, not just the most recent one, to appreciate the full growth pattern.\u003c\/p\u003e\n\u003ch3\u003eWhy are the size limits for biopsy set higher than in some other guidelines?\u003c\/h3\u003e\n\u003cp\u003eUltrasound tends to overestimate nodule size compared with surgical pathology measurements. For example, in one study of 205 papillary carcinomas that were 1.5 cm or smaller, the average diameter on ultrasound was 2.65 cm, but only 1.97 cm on pathology. Higher size cutoffs help avoid unnecessary biopsies.\u003c\/p\u003e\n\u003ch3\u003eWhat is thyroid cancer overdiagnosis?\u003c\/h3\u003e\n\u003cp\u003eOverdiagnosis means diagnosing thyroid tumors that would not, if left alone, cause symptoms or death. In the United States between 2003 and 2007, overdiagnosis accounted for 70% to 80% of thyroid cancer cases in women and 45% in men. Many small cancers grow slowly and would never become harmful.\u003c\/p\u003e\n\u003c!-- ddn:faq:end --\u003e\n\n\u003ch2 id=\"source\"\u003eSource Information\u003c\/h2\u003e\n\n\u003cp\u003eThis patient-friendly article is based on peer-reviewed research.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eOriginal article title:\u003c\/strong\u003e ACR Thyroid Imaging, Reporting and Data System (TI-RADS)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors:\u003c\/strong\u003e Franklin N. Tessler, MD, CM; William D. Middleton, MD; Edward G. Grant, MD; Jenny K. Hoang, MBBS; Lincoln L. Berland, MD; Sharlene A. Teefey, MD; John J. Cronan, MD; Michael D. Beland, MD; Terry S. Desser, MD; Mary C. Frates, MD; Lynwood W. Hammers, DO; Ulrike M. Hamper, MD; Jill E. Langer, MD; Carl C. Reading, MD; Leslie M. Scoutt, MD; A. Thomas Stavros, MD\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003ePublication:\u003c\/strong\u003e Journal of the American College of Radiology, Volume 14, Issue 5, Pages 587-595 (May 2017). Copyright © 2017 American College of Radiology.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDOI:\u003c\/strong\u003e 10.1016\/j.jacr.2017.01.046\u003c\/p\u003e","brand":"DiagnosticDetectives.Com","offers":[{"title":"Default Title","offer_id":47415300128924,"sku":null,"price":0.0,"currency_code":"CHF","in_stock":true}],"url":"https:\/\/diagnosticdetectives.ch\/fr\/products\/a-patients-guide-to-the-acr-ti-rads-how-doctors-decide-which-thyroid-nodules-need-biopsy","provider":"DiagnosticDetectives.Com","version":"1.0","type":"link"}