Radiology Reports for Incidental Thyroid Nodules on CT and MRI: High Variability across Subspecialties

BACKGROUND AND PURPOSE:Variability in radiologists'' reporting styles and recommendations for incidental thyroid nodules can lead to confusion among clinicians and may contribute to inconsistent patient care. Our aim was to describe reporting practices of radiologists for incidental thyroid nodules seen on CT and MR imaging and to determine factors that influence reporting styles.MATERIALS AND METHODS:This is a retrospective study of patients with incidental thyroid nodules reported on CT and MR imaging between January and December 2011, identified by text search for “thyroid nodule” in all CT and MR imaging reports. The studies included CT and MR imaging scans of the neck, spine, and chest. Radiology reports were divided into those that mentioned the incidental thyroid nodules only in the “Findings” section versus those that reported the incidental thyroid nodules in the “Impression” section as well, because this latter reporting style gives more emphasis to the finding. Univariate and multivariate analyses were performed to identify radiologist, patient, and nodule characteristics that influenced reporting styles.RESULTS:Three hundred seventy-five patients met the criterion of having incidental thyroid nodules. One hundred thirty-eight (37%) patients had incidental thyroid nodules reported in the “Impression” section. On multivariate analysis, only radiologists'' divisions and nodule size were associated with reporting in “Impression.” Chest radiologists and neuroradiologists were more likely to report incidental thyroid nodules in the “Impression” section than their abdominal imaging colleagues, and larger incidental thyroid nodules were more likely to be reported in “Impression” (P ≤ .03). Seventy-three percent of patients with incidental thyroid nodules of ≥20 mm were reported in the “Impression” section, but higher variability in reporting was seen for incidental thyroid nodules measuring 10–14 mm and 15–19 mm, which were reported in “Impression” for 61% and 50% of patients, respectively.CONCLUSIONS:Reporting practices for incidental thyroid nodules detected on CT and MR imaging are predominantly influenced by nodule size and the radiologist''s subspecialty. Reporting was highly variable for nodules measuring 10–19 mm; this finding can be partially attributed to different reporting styles among radiology subspecialty divisions. The variability demonstrated in this study further underscores the need to develop CT and MR imaging practice guidelines with the goal of standardizing reporting of incidental thyroid nodules and thereby potentially improving the consistency and quality of patient care.

Incidental thyroid nodules (ITNs) are a common radiologic finding, seen in 1 in 6 patients undergoing CT and MR imaging examinations of the neck.^1,2 Unlike nodules seen on sonography, there are no reliable signs of malignancy and no well-accepted guidelines for reporting ITNs detected on CT and MR imaging. Consequently, the current practice of reporting thyroid nodules on CT and MR imaging by radiologists is highly variable.³ Some radiologists may report all ITNs because there is a chance that an ITN could be malignant. Other radiologists may not report any ITNs because thyroid cancers in ITNs are relatively uncommon⁴ and small thyroid cancers often have an indolent course.^5,6 In particular, reporting an ITN in the “Impression” section of a radiology report provides more emphasis of the finding and may increase the chance of further work-up.Different recommendations for patients with the same nodule characteristics and clinical history are problematic because they can lead to variation in practice patterns, potential variation in the quality of patient care, and anxiety for patients, and they can potentially increase health care costs from the performance of more imaging studies, biopsies, and diagnostic surgeries.^2,7–9 Although some incidental cancers may be diagnosed and treated at an earlier stage, >50% of patients with ITNs that have surgery will ultimately be diagnosed with benign disease.^10,11The variation in reporting styles for ITNs seen on CT and MR imaging has been measured in a recent study, which surveyed radiologists on how they reported different scenarios varying in nodule size and patient history.³ The study demonstrated high variability of ITN reporting, with an overall mean agreement in reporting style of 53% and lower rates of agreement for smaller nodules. A limitation of a survey, however, is that it may not accurately reflect what a radiologist actually does in practice. Another study evaluated reporting practices for ITNs based on radiology reports for cervical spine CT.¹² The authors found that recommendations for ITNs are made inconsistently and the type of management recommended is variable. However, variability in reporting may have been underestimated in their study because it was limited to CT reports issued only by emergency radiologists and did not encompass the reporting practices of abdominal, chest, and neuroimaging radiologists. In addition, the authors did not differentiate between ITNs reported in the “Impression” section of the report versus only the “Findings” section. To fully examine variability in reporting of ITNs, a study should evaluate the reporting style, encompass all radiology subspecialties, and include all CT and MR imaging studies that may lead to detection of ITNs.The purpose of this study was to describe the reporting practices of radiologists for ITNs seen on CT and MR imaging and to determine the factors associated with reporting ITNs in the “Impression” section of the radiology report. We hypothesized that reporting styles would be influenced not only by nodule and patient characteristics but also by radiologist-specific factors, such as subspecialty training and years of experience. Understanding factors associated with variation in reporting practices among radiologists may help to standardize practice patterns, and demonstration of highly variable practices would support the need for guidelines for reporting ITNs seen on CT and MR imaging.     

Thyroid Nodules Detected on CT: A Retrospective Audit Study and Analysis of Differences in Reporting Practices Across Radiology Subspecialties

Thyroid nodules (TNs) are common incidental findings  on imaging and TN reporting practices are variable among radiologists, leading to unnecessary or inadequate investigations. We aimed to document current literature adherence for TN reporting practices on thoracic CTs and assess the variability in TN reporting across radiology subspecialties. This is a 2-parts retrospective study. First part was an audit study including all adult patients with thoracic CTs in January 2020. Patients with prior thyroidectomy and/or lack of TN were excluded. A local committee was created for literature review and elaboration of a local TN management algorithm. The algorithm was shared with the thoracic radiology team. Imaging and medical records were reviewed and adequate adherence was assessed in the pre- and post-intervention cohorts. Second part included all adult patients who underwent neck or cervical spine CT imaging in the same timeframe and with same inclusion/exclusion criteria as the pre-intervention thoracic cohort. In the pre-intervention cohort 802 participants were screened and 137 patients included. TNs were reported in “body” and “conclusion” of the report in 51% and 7% of the time respectively. Thyroid US was recommended in 10% of the patients and inadequately recommended 3% of the time. Overall adequate adherence was 86%. In the post-intervention cohort 962 participants were screened and 167 patients included. Thyroid US was recommended in 7% of the patients and no inadequate US recommendation was made. Overall adequate adherence in the post-intervention cohort was 93%, increased by 7% (P= 0.039). The musculoskeletal and neuroradiology cohorts reported more TNs in “conclusion” (P= 0.013 and P< 0.0001) and recommended more thyroid US (P = 0.033 and P= 0.0018) compared to the preintervention thoracic cohort. No significant difference in overall adequate adherence between subspecialties (P= 0.48 and P= 0.51). Improvement in adequate TN reporting on thoracic CT by 7% while reducing inadequate thyroid US recommendations from 3% to none. Significant reporting trends were also noted across radiology subspecialties.     

Managing Incidental Thyroid Nodules Detected on Imaging: White Paper of the ACR Incidental Thyroid Findings Committee

The incidental thyroid nodule (ITN) is one of the most common incidental findings on imaging studies that include the neck. An ITN is defined as a nodule not previously detected or suspected clinically, but identified by an imaging study. The workup of ITNs has led to increased costs from additional procedures, and in some cases, to increased risk to the patient because physicians are naturally concerned about the risk of malignancy and a delayed cancer diagnosis. However, the majority of ITNs are benign, and small, incidental thyroid malignancies typically have indolent behavior. The ACR formed the Incidental Thyroid Findings Committee to derive a practical approach to managing ITNs on CT, MRI, nuclear medicine, and ultrasound studies. This white paper describes consensus recommendations representing this committee’s review of the literature and their practice experience.     

甲状腺结节的CT及MRI诊断进展

甲状腺结节是指甲状腺内单发或多发结节性病变,是一种常见的甲状腺疾病,普通人群的发生率约为10%.大多数甲状腺结节无临床症状,由患者偶然或在体检时发现.甲状腺结节分为良性及恶性结节,只有不到5%的为甲状腺癌.影像学检查是甲状腺结节术前诊断、分期及预后评价的主要方法.本文将着重对甲状腺结节的CT及MRI诊断进展逐一阐述,以提高对甲状腺结节影像诊断的认识水平,减少不必要的穿刺活检.     

甲状腺结节良恶性与MRI表现特征的相关性研究

目的 研究甲状腺结节MRI的特征表现及其与病理类型的相关性.方法 回顾性分析72例甲状腺结节患者术前的MRI表现特征与术后病理结果的关系,并行统计学检验.结果 72例共计有结节192个,包括147个良性结节和45个恶性结节.良恶性结节的MRI表现在数目、形态(x2=95.02)、“包膜”(x2 =73.51)、囊变(x2=67.96)、实性部分强化特点(x2=77.41)及淋巴结肿大方面差异具有显著统计学意义(P＜0.05),而在有无出血和/或钙化方面差异无统计学意义(x2=0.028,P=0.867).结论 结节MRI表现为单发、形态不规则、囊变少及实性部分强化不均可提示恶性诊断;无明确边界或瘤周有“包膜”样低信号影但不连续是恶性结节的特征性表现;甲状腺周围脂肪间隙是否清晰,邻近组织器官是否受侵,是否有颈部淋巴结转移和/或远处转移是鉴别良恶性结节的主要征象.     

高频超声对甲状腺早期结节的诊断价值

目的:通过高频超声对甲状腺微小结节的影像分析确定其临床诊断价值及意义。材料和方法:应用高频探头对182例健康体检者中发现的67例甲状腺低回声结节的检查分析,并与同位素扫描对照。结果:高频超声能够发现甲状腺内小于0.5cm的微小结节,并可区分为液性的还是实性的,其发现病变的敏感性100％,明显优于核素扫描。结论:高频超声可作为甲状腺普查的首选方法。高度重视微小结节的检出,有助于提高超声诊断和鉴别诊断水平。     

甲状腺癌的CT和MRI诊断

评价ＣＴ和ＭＲＩ对甲状腺癌的诊断价值。材料和方法：回顾分析临床、病理证实的５０例甲状腺癌：３８例进行ＣＴ扫描,２８例作ＭＲＩ检查,其中１６例兼作ＣＴ和ＭＲＩ检查。结果：肿瘤内出血６例（１２％）、相邻结构受侵１１例（２２％）、颈部淋巴结转移１５例（３０％）、甲状腺内囊变２６例（５２％）和钙化２４例（４８％）,对甲状腺的定性诊断有重要价值。ＣＴ对甲状腺癌内钙化的发现明显优于ＭＲＩ,对肿瘤侵犯相邻结构的显示与ＭＲＩ相仿。ＭＲＩ对肿瘤内囊变,出血和颈部淋巴结转移的发现优于ＣＴ。结论：在甲状腺癌的定性诊断上,ＭＲＩ优于ＣＴ,但若能将两者相结合,能更准确地作出甲状腺癌的诊断。     

Extraspinal Incidental Findings on Routine MRI of Lumbar Spine: Prevalence and Reporting Rates in 1278 Patients

ObjectiveThe aim of the present study was to determine the prevalence and reporting rate of incidental findings (IF) in adult outpatients undergoing lumbar magnetic resonance imaging (MRI).ResultsA total of 253 IFs were found in 241 patients (18.8% of 1278). Among these, clinically significant IFs (n = 34) included: 2 renal masses (0.15%), 2 aortic aneurysms (0.15%), 2 cases of hydronephrosis (0.15%), 11 adrenal masses (0.86%), 7 lymphadenopathies (0.55%), 6 cases of endometrial or cervical thickening (0.47%), 1 liver hemangioma (0.08%), 1 pelvic fluid (0.08%) and 2 ovarian dermoid cysts (0.15%). Overall, 28% (71/253) of IFs were included in the clinical reports, while clinically significant findings were reported in 41% (14/34) of cases.ConclusionExtraspinal IFs are commonly detected during a routine lumbar MRI, and many of these findings are not clinically significant. However, IFs including clinically important findings are occasionally omitted from formal radiological reports.     

2021 Korean Thyroid Imaging Reporting and Data System and Imaging-Based Management of Thyroid Nodules: Korean Society of Thyroid Radiology Consensus Statement and Recommendations

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