RPS 2108 - A journey through thyroid imaging

Author Block: L. Sollmann, M. Eveslage, M. Danzer, M. Schäfers, B. Heitplatz, D. Hescheler, B. Riemann, B. Noto; Münster/DE
Purpose: Thyroid nodules are a highly prevalent, predominantly benign finding, yet their accurate evaluation remains challenging. While ultrasound and TIRADS are now widely accepted as standard in evaluation, the utility of thyroid scintigraphy in euthyroid patients remains debated. Previous studies have investigated the diagnostic potential of TIRADS or radionuclide scanning in isolation, but an integrated approach has not been explored so far. This study aimed to evaluate if pertechnetate scintigraphy enhances the diagnostic value of TIRADS in a multimodal framework.
Methods or Background: The diagnostic capabilities of ACR-TIRADS, EU-TIRADS, pertechnetate scintigraphy, and multimodal models were retrospectively analyzed for 322 nodules (231 benign, 91 malignant) in 208 euthyroid patients undergoing thyroidectomy. Statistical analysis employed generalized estimating equations.
Results or Findings: Thyroid scintigraphy demonstrated an AUC of 0.6 (95%CI:0.55-0.66), ACR-TIRADS of 0.84 (95%CI:0.79-0.89) and EU-TIRADS of 0.78
(95%CI: 0.72-0.83). Integrating thyroid scintigraphy with ACR-TIRADS enhanced diagnostic accuracy, yielding an AUC of 0.86 (p=0.039). Similarly, combining thyroid scintigraphy with EU-TIRADS resulted in an AUC of 0.80 (p =0.008), surpassing the individual TIRADS performances. Furthermore, the integration of thyroid scintigraphy adjusted the malignancy probability among TIRADS categories. Iso- or hyperfunctioning nodules in ACR-TIRADS TR4 and hypofunctioning nodules in TR3 exhibited comparable probabilities of malignancy. Similarly, iso- or hyperfunctioning nodules in EU-TIRADS 4 showed similar malignancy probabilities to hypofunctional nodules in EU-TIRADS 3, indicating the potential for more refined risk stratification.
Conclusion: This study demonstrates enhanced diagnostic performance achieved by integrating thyroid scintigraphy with ACR—and EU-TIRADS for classifying thyroid nodules in euthyroid patients. Such a multimodal approach could improve risk stratification and management decisions, particularly in complex scenarios like multinodular goiter. Further research is warranted to validate these findings and explore their clinical implications.
Limitations: Retrospective design
Funding for this study: The Medical Faculty, University of Münster, Germany supported B.N. as a clinician scientist.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The study protocol was approved by the ethics committee of the University of Munster and performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments.

Author Block: A. Borlea, D. I. Stoian; Timisoara/RO
Purpose: To evaluate the use of Subtraction Ultrasound Microangiography (SUMA) in the quantitative assessment of microvascularity patterns in diffuse thyroid diseases and to compare these findings with normal thyroid tissue.
Methods or Background: Conventional color Doppler ultrasound is limited by its subjective nature in assessing thyroid vascularity. SUMA provides a quantitative approach through color pixel percentage (CPP) measurement. A cohort of 220 subjects was studied, including 90 with autoimmune thyroiditis, 20 with Graves' disease, and 110 normal controls. SUMA was used to quantify CPP, and results were analyzed to identify differences between the groups. The relationship between TSH levels and CPP was also explored.
Results or Findings: Significant differences in CPP were observed across the groups. Normal controls (euthyroid) demonstrated a median CPP of 26% (IQR 18-37%), Graves' disease patients with clinical and subclinical hyperthyroidism had a median CPP of 75% (IQR 55-82%), and those with untreated hypothyroid Hashimoto thyroiditis (hypothyroid) had a median CPP of 63% (IQR 49-75%). A U-shaped relationship was found between TSH levels and CPP, indicating alterations in vascularity in both hypo- and hyperthyroid states.
Conclusion: SUMA allows for a more objective and quantitative assessment of thyroid microvascularity, revealing distinct differences between normal, autoimmune thyroiditis, and Graves' disease tissues. The technique may improve diagnostic accuracy compared to conventional Doppler ultrasound.
Limitations: Further studies are needed to validate SUMA’s diagnostic potential, including its reproducibility across different ultrasound systems and settings, as well as its sensitivity in detecting disease progression or treatment response.
Funding for this study: The study received no external funding
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Victor BAbes University of Medicine and Pharmacy

Author Block: Y. Li, Y. Luo, M. Zhang; Beijing/CN
Purpose: The purpose of this study was to compare the clinical outcomes of microwave ablation versus thyroidectomy for patients with solitary nodular retrosternal goiter (RSG).
Methods or Background: This retrospective study evaluated 243 patients with solitary nodular RSG treated with MWA (M group, n=111) or thyroidectomy (T group, n=132). Complications, thyroid function, and treatment variables, including procedure time, estimated blood loss, hospitalization, and cost, were compared. The volume, volume reduction rate, symptoms, and cosmetic score were also evaluated in the W group.
Results or Findings: The rate of overall complications, transient RLN injury and hypothyroidism was 35.6%, 9.1%, and 10.6% in the T group, respectively, but these complications were 7.2%, 2,7%, and 0 in the M group (all P<.05). Patients in the M group had a significantly shorter procedure time (median, 6.48 versus 95.0 minutes, P<.0001), less estimated blood loss (0 versus 50 ml, P<.0001), and lower cost (US ＄1541.25 versus ＄2839.40, P<.0001) than those treated by thyroidectomy. After MWA, the VRR was 76.31% and 89.37% at the 12 months and last follow-up time, respectively. Of all the nodules treated by MWA, 50 (45%) received additional ablation. The symptom and cosmetic scores were both significantly reduced at the last follow-up.
Conclusion: MWA is an effective and safe treatment for solitary nodular RSG. Moreover, MWA is associated with a faster recovery, fewer complications, and superior esthetic results relative to thyroidectomy and it may be a potential alternative to surgery in selected patients, especially for those who are ineligible or unwilling to receive surgical treatment.
Limitations: This study was carried out in a single center, and multicenter studies are warranted.
Funding for this study: This study recieved no funding.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Ethical approval was obtained from the Institutional Ethics Committee of the Chinese PLA General Hospital.

Author Block: Y-H. Chen¹, P-L. Chiang¹, Y-H. Chang², C-K. Chou², W-C. Lin¹; ¹Kaohsiung/TW, ²Kaohsiung City/TW
Purpose: Radiofrequency ablation (RFA) has gained recognition as a highly effective treatment for benign thyroid nodules. While thyroid function alterations have been observed during post-RFA follow-up, this study specifically focuses on the potential link between changes in thyroid function and volume reduction ratio of treated nodules. Additionally, it seeks to evaluate whether fluctuations in thyroid function at mid-term follow-up can serve as early indicators for the development of long-term hypothyroidism following RFA.
Methods or Background: In this retrospective study, 50 euthyroid individuals (mean age = 47.0 years; 43 females, 7 males) with a total of 72 benign thyroid nodules (median volume = 4.61 mL) undergoing RFA were evaluated. Comprehensive assessments, including clinical examinations, ultrasound imaging, and blood tests, were conducted at specific intervals (pre-RFA, and at 6 months, 12 months, and annually post-RFA).
Results or Findings: The mean follow-up period was 22.3 months. Both medium-term and long-term follow-ups revealed significant reductions in T3 levels (p<0.001, p=0.005) and elevations in TSH levels (p<0.001, p<0.001) compared to baseline measurements. A negative correlation was found between medium-term T3 levels and long-term volume reduction ratio (r=-0.332, p=0.005). Furthermore, patients with lower T3 levels during medium-term follow-up demonstrated a significantly higher long-term volume reduction ratio compared to those with higher T3 levels (0.92 vs. 0.77, p=0.017).
Conclusion: Following radiofrequency ablation, notable unexpected alterations in thyroid function were observed, without meeting the criteria of hypothyroidism. Additionally, a lower mid-term T3 level may be indicative of a better volume reduction ratio during long-term follow-up.
Limitations: The study is limited by biases associated with its retrospective design and a lack of short-term data within a six-month period. To address these limitations, further prospective studies with increased focus on short-term data are necessary.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study received approval from the institutional review board under the reference number 202200189B0.

Author Block: E. Tobcu, E. Karavaş, G. Taşova Yılmaz, Z. Tobcu; Balıkesir/TR
Purpose: To evaluate the performances of three internationally recognized thyroid imaging reporting and data systems (TIRADS) for risk stratification of malignancy in comparison to one another.
Methods or Background: A total of 225 thyroid nodules with definitive FNAB cytology or histopathological diagnoses were included in the study. Various ultrasound (US) features were classified into categories based on three TIRADS editions. The guidelines were assessed regarding sensitivity, specificity, predictive values, and diagnostic accuracy to compare diagnostic value.
Results or Findings: American College of Radiology (ACR)-TIRADS demonstrated the best diagnostic accuracy (63.1%), the highest specificity (58.7%), and positive predictive value (36.3%) among three different TIRADS systems. Korean (K)-TIRADS exhibited the highest sensitivity (94.2%), negative predictive value (96.1%), and the most favorable negative likelihood ratio (0.13). The European (EU)-TIRADS had a sensitivity of 90.4%, specificity of 48.6%, and diagnostic accuracy of 58.2%, ranking between the other two guidelines across most parameters.
Conclusion: The rigorous use of the guidelines established by each of the three TIRADS systems would have markedly reduced the number of FNABs performed. The comparison of the three guidelines in our study indicated that they are effective screening methods for identifying malignant thyroid nodules. Among them, K-TIRADS showed the most effective diagnostic performance in sensitivity, while ACR-TIRADS yielded the best specificity.
Limitations: The main limitation of our study was its single-center design. Another limitation of our study was the lack of histopathological diagnoses for all nodules. All nodules with malignant cytological results underwent surgery that enables us to reach histopathological diagnoses, but only two nodules with benign cytology underwent surgery due to the clinician's discretion and the patient's preference. Cytology results were used as a reference standard diagnosis in the remaining nodules.
Funding for this study: No funding
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The study was performed in accordance with the ethical guidelines of the Helsinki Declaration and approved by the local ethics review committee (2024-3).

Author Block: C. Di Bella¹, E. David², C. Solito¹, V. Dolcetti¹, P. Pacini¹, G. Del Gaudio¹, M. Renda¹, C. Catalano¹, V. Cantisani¹; ¹Rome/IT, ²Catania/IT
Purpose: To evaluate the diagnostic performance of CAD compared with TI-RADS systems and to compare the performance of TI-RADS when used by operators with different levels of experience.
Methods or Background: Three operators with different levels of experience evaluated 484 thyroid nodules and the diagnostic accuracy of three risk stratification systems (ACR-, EU-, K-TIRADS) and CAD software (S-Detect) in characterizing the nodules.
Nodules were characterized and stratified by using the three TIRADS systems; then S-detect software was applied and the data were compared with each other and with the gold standard (citology).
Results or Findings: The sensitivity of the human operator measurement and the negative predictive value (NPV) is 100%, for all three types of TIRADS. The positive predictive value (PPV) is 50%. The specificity is 78.4% (EU), 85.7% (ACR), 89% (K); this implies a certain proportion of "false positives", especially in the use of the tirads EU.
The sensitivity of the measurement of s-detect alone is 66.7%, for all TRAIDS. This estimate implies a low certainty of the negative result. The NPV is 96.2% (ACR, K) and 96.3% (EU). The PPV is 50% (ACR-K) and 66.7% (EU). The specificity is higher than the sensitivity: 92.7% (ACR - K) and 96.3% (EU).
Conclusion: S-DETECT combined with EU-TIRADS has similar results as S-DETECT with ACR- and K- TIRADS in terms of sensitivity, specificity and NPV. However, it has a slightly better PPV, suggesting greater accuracy in correctly diagnosing positive cases than the ACR- and K-classification systems. S-Detect cannot yet be considered a substitute for the human operator but is a valuable tool for characterizing thyroid nodules, when integrated with radiologist evaluation and for support tool for less experienced operators and in doubtful cases
Limitations: Reduced patient sample. Ultrasound's operator dependence
Funding for this study: None
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Ethics committee "Sapienza"

Author Block: D. I. Stoian, A. Borlea; Timisoara/RO
Purpose: To evaluate the diagnostic accuracy of Shear Wave Elastography (SWE) in differentiating benign from malignant nodules in patients with chronic autoimmune thyroiditis.
Methods or Background: SWE has been widely studied in assessing thyroid nodules, but the background of thyroid lymphocitic infiltration and fibrosis may impact diagnostic performance. This study enrolled 130 subjects aged 18-84 years with a previous diagnosis of autoimmune thyroiditis and thyroid nodules. SWE measurements were performed on both thyroid parenchyma and nodules, assessing elasticity indices (EIs), including mean and maximum values, and the nodule-to-thyroid (N/T) ratio. Conventional ultrasound risk assessment using TIRADS was also evaluated. The relationship between elasticity indices and biochemical parameters and thyroid volume was examined.
Results or Findings: There were no statistically significant differences in thyroid function or autoimmunity parameters between benign and malignant nodules. Significant differences were found in TIRADS scores (p < 0.0001), mean nodule EI (p < 0.0001), and N/T shear wave ratio (p < 0.0001). The mean nodule EI (47.2 kPa for malignant vs. 18.1 kPa for benign nodules) had the highest diagnostic performance, significantly outperforming both the maximum EI (p = 0.0360) and the N/T ratio (p = 0.0130). The mean nodule EI also demonstrated superior diagnostic accuracy compared to TIRADS (p = 0.0025).
Conclusion: SWE demonstrates high diagnostic accuracy in evaluating nodules also in context of autoimmune thyroiditis. The mean nodule EI is the most reliable elastographic parameter, outperforming other elasticity indices and TIRADS in distinguishing malignant from benign nodules.
Limitations: This study did not include a control group of nodules without autoimmune thyroiditis, limiting comparisons of SWE performance in different thyroid backgrounds. Further studies are needed to assess reproducibility across other clinical settings.
Funding for this study: There was no funding for the study
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The studies involving humans were approved by The Ethics Committee of the Victor Babes University of Medicine and Pharmacy. The studies were conducted in accordance with the local legislation and institutional requirements. The participants provided their written informed consent to participate in this study.

Author Block: E. Tobcu, E. Karavaş, Z. Tobcu, G. Taşova Yılmaz; Balıkesir/TR
Purpose: The purpose of this study is to ascertain the rate of malignancy in nodules that are <10 mm in diameter in the TR-4 and TR-5 categories, as defined by the American College of Radiology Thyroid Imaging and Reporting Data System (ACR-TIRADS) 2017 whitepaper.
Methods or Background: Assessment of thyroid nodules was conducted in accordance with the 2017 whitepaper of the ACR. The fine-needle aspiration biopsy (FNAB) procedure was performed under the guidance of ultrasound. Lesions designated as Bethesda group 3, 4, 5, and 6 were classified as "non-benign group," while nodules defined as Bethesda group 2 were classified as "benign group.”. All patients underwent surgery, except for those with benign cytology.
Results or Findings: A total of 60 nodules were included in the study. Based on cytological analysis, 12 of the 15 nodules classified in the TR-4 category were determined to be benign thyroid nodules, while 3 nodules were classified as "suspicious for malignancy" (Bethesda-V) (%20) after cytological assessment. In the assessment of 45 TR-5 nodules, 30 were identified as non-benign (66.6%), while the remaining 15 were classified as benign thyroid nodules after cytological evaluation.
Conclusion: Our investigation demonstrated that <10mm thyroid nodules classified in categories TR-4 and TR-5, according to ACR-TIRADS 2017 guideline, have a malignancy rate of 55%. We think that FNAB should be performed prior to the decision of active surveillance, in order to determine the PMTCs that exhibit aggressive cytologic features and to identify those with benign cytology to avoid an unnecessary active surveillance process.
Limitations: The research was conducted with a small number of patients and was completed at a single center. Second, we did not exclude patients with thyroiditis that may have an impact on the accuracy of FNAB.
Funding for this study: The authors state that this study has not received any funding
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This prospective study was approved by the institutional review board of our in¬stitution (decision number: 2024/3-40), and any requirement of informed consent was waived.

Author Block: L. L. Ye¹, X. Zheng¹, Y. Liao²; ¹Dongguan/CN, ²Guangzhou/CN
Purpose: To assess the diagnostic value of the arterial enhancement fraction (AEF) derived from dual-layer spectral detector CT scans in detecting lymph node metastasis in papillary thyroid carcinoma (PTC).
Methods or Background: Preoperative spectral CT images of 58 lymph nodes from 25 PTC patients (7 males, 18 females; aged 28-74) confirmed by surgery and pathology were analyzed. All patients underwent lymph node dissection. Lymph nodes were classified into metastatic (N = 24) and non-metastatic (N = 34) groups based on pathology. AEF (defined as iodine concentration in the arterial phase / iodine concentration in the venous phase) was measured. The Mann-Whitney U test was used to compare AEF between groups. ROC analysis evaluated AEF's predictive performance for lymph node metastasis.
Results or Findings: AEF was significantly higher in metastatic lymph nodes than in non-metastatic ones (p<0.05). In terms of differentiating lymph node metastasis, the AUC of AEF is 0.737 (95%CI 0.582-0.891), with an accuracy of 0.810, a sensitivity of 0.583, and a specificity of 0.971.
Conclusion: AEF from dual-layer spectral detector CT demonstrates significant differences between metastatic and non-metastatic lymph nodes in PTC and has diagnostic potential for identifying metastatic lymph nodes, providing a basis for precise preoperative treatment planning.
Limitations: Not applicable
Funding for this study: Not applicable
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Not applicable

Author Block: X. Li, Y. Yue, J. Ren; Beijing/CN
Purpose: To explore the diagnostic efficacy of histogram parameters of IVIM in differentiating benign and malignant thyroid nodules.
Methods or Background: A total of 51 patients with thyroid nodules were retrospectively included from March 2017 to September 2022, including the benign group 24 cases and malignant group 27 cases . All results were confirmed by surgical pathology. multiple b-value small field diffusion weighted images were collected to generate true diffusion coefficient(D), pseudo diffusion coefficient(D*), and perfusion fraction(f) images. At the same time, an apparent diffusion coefficient(ADC) image with a b-value of 990s/mm2 was generated. Manually outline the volume of interest(VOI) of the entire lesion. Using a self-designed program in Matlab, calculate the histogram parameters of the D, D *, and f at VOI, and calculate the mean ADC at VOI. Compare the intergroup differences between IVIM histogram parameters and ADC mean. Using multiple logistic regression, further select the optimal parameters and establish a multi parameter joint model and verify and compare the diagnostic performance of different models.
Results or Findings: The statistically significant differences between benign and malignant thyroid nodules are as follows(P<0.05): gender, ADC mean, 5th, 15th, 85th, and 95th percentile, mean, skewness, and root mean square difference in the D-plot, 5th and 15th percentile percentile, mean, skewness, and coefficient of variation in the D * plot. The AUC values for skewness, 15th percentile, and root mean square difference of the D-plot combined with gender were 0.94, with a sensitivity of 88.46% and a specificity of 90.91%. The AUC value of the mean ADC combined with gender is 0.86, with a sensitivity of 77.78% and a specificity of 87.50%.
Conclusion: Histogram parameters of IVIM has good diagnostic value in distinguishing benign and malignant thyroid nodules.
Limitations: Not applicable.
Funding for this study: Not applicable.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: This is a retrospective study.

Author Block: Y. Zhang; Shanghai/CN
Purpose: This study aimed to establish a new risk stratification system for FTN and new methods for non-invasive and practical preoperative evaluation of thyroid follicular tumors to reduce missed diagnoses and unnecessary biopsies.
Methods or Background: 535 FTNs of 535 patients from four hospitals were included in this retrospective study. All the nodules were randomly divided into test and validation groups. FTN-TIRADS was established based on the results of univariate analysis and logistic regression of ultrasonography features in the test group. Each nodule was evaluated and classified by existing risk stratification systems (EU-RSS, ATA-RSS, ACR-TIRADS, Chinese TIRADS [C-TIRADS]) and FTN-TIRADS. The diagnostic value of FTN-TIRADS in the validation group was verified and compared with the test group and the other four risk stratification systems. The unnecessary rates of fine needle aspiration (FNA) of FTN-TIRADS and the other four risk stratification systems were compared, too.
Results or Findings: Test group and validation group included 370 patients and 165 patients. The following features were independent risk factors and included in FTN-TIRADS: nodule composition, echogenicity, calcifications, halo sign, and indistinct boundary with thyroid capsule. The AUC of FTN-TIRADS was 0.855, statistically higher than EU-RSS, ATA-RSS, ACR-TIRADS, and C-TIRADS (0.759, 0.759, 0.753, 0.677, respectively). The FTN-TIRADS of the validation group had a similar diagnostic performance. The unnecessary FNA rate of the FTN-TIRADS was 26.0%, which was significantly lower than that of EU-RSS (79.9%), ATA-RSS (92.5%), ACR-TIRADS (55.8%) and C-TIRADS (62.2%).
Conclusion: FTN-TIRADS achieved better differential diagnosis of FTN than current risk stratification systems and significantly reduced the rate of unnecessary FNA.
Limitations: The study was performed retrospectively; a more conclusive validation could be achieved using a prospective design that better captured the diverse characteristics of actual clinical cases.
Funding for this study: This work was supported by the National Natural Science Foundation of China (Grants No. 81927801, 81725008, 81772849, 82171942, and 82371971)
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The institutional review board of the university-affiliated hospital approved this retrospective study (approval number 22K82)