RPS 308 - Thyroid and parathyroid imaging

Author Block: J. Bosschee; Eindhoven/NL
Purpose: To identify ultrasonographic features in ACR TIRADS 3 and 4 thyroid nodules to predict malignant potential.
Methods or Background: Thyroid carcinoma incidence in the Netherlands has increased from 372 new cases in 2000 to 904 in 2023, primarily due to population aging and improved imaging techniques. Fortunately the overall prognosis is relatively favorable with a 30 year survival rate of 95%. The inevitable accompanying increase of thyroid ultrasound and ultrasound guided fine needle aspirations (FNA) may result in overdiagnosis and unnecessary patient burden. The revised Dutch thyroid cancer guidelines aim to reduce this overdiagnosis with clinical and radiological recommendations. However, recommendations regarding ACR TIRADS 3 and 4 nodules remain ambiguous, with clinical management relying on expert consensus.

Thyroid ultrasound and FNA results of patients presented to the Catharina hospital in Eindhoven (Netherlands) from 2019-2022 were retrospectively analyzed. All pathological specimens were assigned a Besthesda score and a pathological diagnosis. Predictive ultrasonographic features regarding malignant potential were investigated.
Results or Findings: A total of 341 FNA were analyzed of which 101 (30%) were TIRADS 3 nodules and 124 (36%) were TIRADS 4 nodules. Pathology results were available for 96 TIRADS 3 and 116 TIRADS 4 nodules. A total of 29 (30%) TIRADS 3 noduli scored a Bethesda score 3 or higher and five (5%) turned out to be malignant. 55 (47%) TIRADS 4 noduli scored a Bethesda 3 or higher and 17 (15%) were malignant.
Conclusion: This study will further investigate the predictive ultrasonographic features of TIRADS 3 and 4 nodules that turn out to be thyroid carcinoma. Our goal is to aid radiologists in deciding on ultrasound follow-up and/ or FNA in order to prevent overdiagnosis and consequently unnecessary patient burden and health care costs.
Limitations: Retrospective study.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information:

Author Block: D. I. Stoian, M. Latia, A. Borlea; Timisoara/RO
Purpose: PURPOSE
To evaluate whether elastography improves diagnostic performance beyond TIRADS in papillary (PTC), follicular (FTC), and medullary (MTC) thyroid cancers, particularly where ultrasound-based stratification underperforms.
Methods or Background: METHODS
We retrospectively analyzed 452 thyroid cancers over 10 years. Subgroups included 29 PTC with 65 benign controls, 32 FTC with 65 Bethesda IV controls, and 20 MTC without controls. All nodules underwent B-mode ultrasound, TIRADS categorization, and strain (SE) and/or shear wave elastography (SWE). Stiffness was integrated as an additional risk factor and compared with TIRADS alone.
Results or Findings: RESULTS
In PTC, 31 nodules were intermediate- and 16 high-risk by TIRADS. Elastography upgraded 8 nodules using SWE and 14 using SE. Diagnostic accuracy improved, with AUC increasing from 0.764 (B-mode) to 0.886 (TIRADS+SWE) and 0.861 (TIRADS+SE). In FTC, only 13/32 nodules (40.6%) were identified as high-risk by TIRADS, versus 27/32 (84.4%) when stiffness was added. In MTC, TIRADS flagged ~60% as high-risk; on SE, 75% scored ES 3–4 (mean ES 3.2), and SWE with a 30.5 kPa cut-off correctly identified 87.5% of malignancies.
DISCUSSION
Elastography significantly enhances TIRADS across histologies. Across subtypes, most nodules were stiff, contradicting the traditional view that FTC and MTC are “soft” cancers. While B-mode alone often misses FTC and MTC, stiffness integration markedly improves cancer detection and supports surgical decision-making.
Conclusion: CONCLUSION
Stiffness is not a stand-alone criterion but consistently augments TIRADS. Elastography should be incorporated into routine assessment of intermediate and high-risk thyroid nodules.
Limitations: LIMITATIONS
Retrospective design, sample sizes, monocentric study.
Funding for this study: No funding
Has your study been approved by an ethics committee? Not applicable
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: J. Yu¹, Y. Chen¹, Z. Song¹, X. Zhang², D. Zhang¹, X. Liu³; ¹Chongqing/CN, ²Chengdu/CN, ³Guangzhou/CN
Purpose: To evaluate the predictive value of dual-layer spectral computed tomography (DSCT)-derived arterial enhancement fraction (AEF) in diagnosing thyroid microcarcinomas.
Methods or Background: A total of 321 pathologically confirmed thyroid micronodules (131 benign, 190 malignant) underwent preoperative DSCT. Quantitative parameters, including normalized iodine concentration (NIC), normalized effective atomic number (NZeff), and the slope of the spectral Hounsfield unit curve (λHU(40–100)), were assessed. Both single-energy CT-derived AEF (AEFS) and DSCT-derived AEF (AEFD) were calculated. Conventional features like microcalcifications were also analyzed. Correlation between AEFD and AEFS was determined using Spearman’s correlation coefficient. Diagnostic performance was evaluated by calculating the area under the curve (AUC) using receiver operating characteristic (ROC) analysis.
Results or Findings: Malignant nodules showed significantly lower AEFD and AEFS than benign nodules (p < 0.001). Arterial phase spectral parameters differed significantly between groups (p < 0.001), unlike venous phase parameters. Multivariate analysis identified λHU(40–100) as an independent predictor of malignancy (OR: 0.600, p = 0.002). AEFD and AEFS were strongly correlated (r = 0.710, p < 0.001). AEFD demonstrated superior diagnostic performance (AUC: 0.794; sensitivity: 70.5%; specificity: 81.7%; accuracy: 75.1%) compared to AEFS, APλHU(40–100), and calcification. Clinically, using AEFD reduced the unnecessary biopsy rate to 18.3%, preventing 107 procedures.
Conclusion: AEFD correlates strongly with AEFS and shows favorable diagnostic efficacy for thyroid micronodules, significantly reducing unnecessary biopsies and optimizing patient management.
Limitations: Study limitations include its retrospective, single-center design and the need to validate AEFD for other histological subtypes. Future work should automate ROI placement and integrate molecular biomarkers.
Funding for this study: The study was funded by the Post-Doctoral Science Foundation of Chongqing, China (No. CSTB2022NSCQ-BHX0737), the Medical Research Program of the Combination of Chongqing National Health Commission and Chongqing Science and Technology Bureau, China (No. 2024MSXM094), and the Medical Research Youth Program, a joint initiative of the Chongqing National Health Commission and the Chongqing Science and Technology Bureau, China (No. 2024QNXM047).
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: his retrospective study was approved by the Medical Ethics Committee of Chongqing General Hospital with a waiver of informed consent.

Author Block: T. Charkhalashvili; Kutaisi/GE
Purpose: According to Global Cancer Observatory (GLOBOCAN 2024), thyroid cancer is among 10 most frequent cancers worldwide. It's most common subtype - PTC spreads to the regional lymph nodes in 20-50% of cases. Accurate preoperative ultrasound (US) evaluation is crucial, as the detection and precise localisation of metastatic nodes directly influence the extent of surgical dissection and better patient outcome. Purpose of this abstract is to highlighting diagnostic criteria, scanning technique and practical tips for mapping LNs and easy communication with surgeons.
Methods or Background: Patients, previously diagnosed with PTC by Thyroid FNA, are scanned with high frequency ultrasound transducer (12-15MHz) prior to surgery in supine position, extending head cranially, with pillow under shoulders, for maximal identity whit surgical position. All the cervical levels are scanned step-by-step on right and left sides. Nodes are assessed for suspicious features: rounded morphology, absence of fatty hilum, microcalcifications, cystic changes and atypical vascularity. LNs are labeled on the neck with marker, as well as on the schematic template for patient history.
Results or Findings: Systematic scanning prevented missed nodes, while structured reporting improved preoperative planning. In our series of standardised Ultrasound mapping of cervical lymph nodes we have high detection rates(80-92%) of regional metastatic LN, and better communications with colleagues.
Conclusion: A standardised systematic ultrasound protocol for cervical lymph node assessment in PTC increases detection rate, accurate cevical level mapping and effective communication with surgeons. Adoption of such protocols improves preoperative planning and contributes to optimised patient outcomes.
Limitations: Small or deeply located nodes may be difficult to visualise, especially in obese patients or those with short necks. Reactive or inflammatory LNs may mimic metastases, lowering specificity, also, early metastases or micrometastases are not be detectable by US.
Funding for this study: N/A
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information:

Author Block: C. Peter, T. Denecke, H-J. Meyer; Leipzig/DE
Purpose: To systematically review clinical and radiological characteristics of thyroid metastases from non-thyroid primary tumors.
Methods or Background: Metastases to the thyroid gland from non-thyroid malignancies are rare but clinically relevant. Reported frequencies vary. Prior reviews mainly addressed clinical and histopathological aspects, while analyses of radiological features remain limited.
We conducted a systematic PubMed search (2010–2025) according to PRISMA guidelines. Eligible studies included case reports, case series and observational studies on histologically confirmed thyroid metastases from non-thyroid primaries with radiological data (ultrasound, CT, or MRI). Studies on primary thyroid malignancies or non-human data were excluded. Extracted data included demographics, primary tumor, interval between primary diagnosis and thyroid metastasis, clinical presentation, and imaging findings
Results or Findings: A total of 215 studies, including 1,006 patients, with mean age of 61.7 years were identified. The most common primary tumors metastasizing to the thyroid are lung cancer, breast cancer and renal cell cancer. Most metastasis are identified metachronous after the initial tumor diagnosis. Most cases present as a painless neck mass and as a unilateral manifestation. On ultrasound, most lesions were hypoechogenic with a blurred border. On CT, metastases were predominantly hypodense. On MRI, lesions were typically intermediate on T2-weighted images and iso- to hyperintense on T1-weighted images. A misdiagnosis is common in up to 31% of cases.
Conclusion: Metastases to the thyroid gland are rare but should be considered in the differential diagnosis of thyroid lesions, especially in patients with a history of malignancy. This systematic review provides an overview of clinical and radiological features, which may aid in diagnosis and differentiation from primary thyroid tumors.
Limitations: Heterogeneity of included studies, small case numbers of case reports with potential publication bias, incomplete radiological data, restricting generalizability to broader clinical practice
Funding for this study: None
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information:

Author Block: P. Pacini, M. Renda, C. Catalano, V. Dolcetti, C. Solito, F. Raponi, G. Bonito, G. Maglia, V. Cantisani; Rome/IT
Purpose: To compare the diagnostic performance of ACR-TIRADS, assessed by an experienced radiologist, with that of the S-Detect system in the evaluation of thyroid nodules, and to validate both methods against the cytological gold standard, fine-needle aspiration cytology (FNAC).
Methods or Background: This prospective study included 120 patients (35–75 years) with thyroid nodules or lesions detected clinically or on routine neck ultrasound at Umberto I Hospital, Rome. Thyroid nodules are a common finding, with a prevalence exceeding 50% in women and in individuals >60 years. While FNAC remains the diagnostic gold standard, it carries significant financial costs for healthcare systems and psychological stress for patients. Recent efforts have focused on improving ultrasound-based diagnostic accuracy to reduce unnecessary FNAC procedures.
Results or Findings: ACR-TIRADS demonstrated a sensitivity of >97% and specificity of 92%. S-Detect achieved a sensitivity of 94% and specificity of 90%. When compared with FNAC, ACR-TIRADS showed a sensitivity of 94% and S-Detect 91%, confirming strong diagnostic performance for both tools.
Conclusion: ACR-TIRADS demonstrated excellent agreement with FNAC and remains a reliable tool in thyroid nodule characterization. S-Detect also showed high diagnostic accuracy, supporting its role as a complementary, cost-effective aid in clinical practice.
Limitations: A sample size that needs to be expanded
Funding for this study: No
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Roma sapienza universit?

Author Block: A. Borlea, S. Bunceanu, D. I. Stoian; Timisoara/RO
Purpose: To evaluate the diagnostic performance of quantitative contrast-enhanced ultrasound (CEUS) parameters in differentiating benign from malignant thyroid nodules.
Methods or Background: Thirty thyroid nodules with histopathologic confirmation (15 benign, 15 malignant: 12 papillary, 2 follicular, 1 medullary) underwent CEUS. Quantitative time–intensity curve (TIC) analysis included: Arrival Time (AT), Rise Time (RT), Time to Peak (TTP), Fall Time or Wash-out Time (FT), Mean Transit Time (mTT), Peak Intensity (PKI), Area Under Curve (AUC), Wash-in AUC (WiAUC), Wash-out AUC (WoAUC), Ascending Slope (AS), Descending Slope (DS), Slope Ratio (SR), and mean TIC.
Results or Findings: Malignant nodules showed significantly shorter AT (12.3 ± 3.5 vs. 16.7 ± 4.2 s, p=0.01), faster RT (7.1 ± 2.2 vs. 9.8 ± 2.6 s, p=0.02), and earlier TTP (19.4 ± 4.6 vs. 26.5 ± 5.3 s, p<0.01). FT was prolonged (31.2 ± 8.4 vs. 22.5 ± 6.7 s, p=0.02), yielding longer mTT (38.3 ± 9.2 vs. 32.3 ± 7.1 s, p=0.04). PKI was higher in malignant nodules (28.6 ± 5.7 vs. 21.4 ± 4.9 a.u., p=0.01). Perfusion integrals were increased: AUC 1520 vs. 980 a.u.*s (p=0.01), WiAUC 650 vs. 410 (p=0.02), WoAUC 870 vs. 570 (p=0.03). Slopes were steeper in malignancy: AS 2.3 vs. 1.6 a.u./s (p=0.03), DS 2.1 vs. 1.3 (p=0.04), with higher SR (0.91 vs. 0.78). ROC analysis showed AUC 0.86 for TTP and 0.88 for PKI; combining PKI+TTP achieved 0.92 sensitivity and 0.88 specificity.
Conclusion: Malignant thyroid nodules present rapid wash-in, higher peak enhancement, and delayed wash-out. Quantitative CEUS parameters, particularly TTP and PKI, significantly improve diagnostic accuracy and may complement TIRADS and elastography in risk stratification.
Limitations: Small, single-center cohort; larger studies needed for threshold validation.
Funding for this study: No funding
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: UMFT Victor Babes Ethics Committee

Author Block: F. Zengin, M. M. Geres, A. Gemalmaz, A. Özel; Istanbul/TR
Purpose: This study aimed to evaluate the diagnostic performance of 4D-CT in patients with PHPT, focusing on preoperative localization of abnormal parathyroid glands, comparing enhancement patterns with those described in the literature, and determining overall diagnostic efficacy.
Methods or Background: This retrospective study included 215 parathyroid lesions from 194 PHPT patients who underwent 4D-CT and surgery. An experienced radiologist, blinded to surgical and pathological findings, assessed the scans for lesion detection, size, polar vessel presence, and enhancement characteristics. HU values of lesions and normal thyroid tissue were measured in pre-contrast, arterial, and venous phases.
Results or Findings: 4D-CT localized 90.7% of lesions. Sensitivity, PPV, and accuracy were higher in single-gland cases (94%, 97.5%, 92%) than multiglandular ones (82.3%, 87.5%, 73.7%). Most lesions showed Bahl Type B enhancement (74.4%), but all mislocalizations occurred in this group, suggesting limited specificity. Parathyroid lesions had lower pre-contrast HU than thyroid tissue; however, the <58 HU threshold was only supportive (AUC ≈ 0.72). Arterial enhancement rose by 321.9%, and venous washout reached 42.0%. Absolute (61.3%) and relative (46.5%) washout ratios were strong differentiators. Larger lesions (>11 mm) were associated with polar vessels (p < 0.001). Lesion size correlated with arterial HU, washout, PTH, and calcium. Ectopic lesions (4.2%) had fewer polar vessels (p = 0.010). The study proposes a novel pattern-based approach incorporating arterial HU ratio and washout rates, suggesting their combination may improve preoperative localization.
Conclusion: 4D-CT is highly effective for preoperative localization in PHPT. Dynamic contrast parameters, particularly arterial enhancement and washout, improve accuracy beyond classical classifications and may further benefit from radiomics integration.
Limitations: The single-center design and the limited number of rare enhancement patterns, non-localized lesions, and multiglandular cases underscore the need for further multicenter studies to validate these findings.
Funding for this study: This research received no specific grant from any funding agency.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: University of Health Sciences Şişli Hamidiye Etfal Training and Research Hospital Clinical Research Ethics Committee-4802

Author Block: B. G. ÜRKMEZ, A. Gürsoy Çoruh, M. Kul, S. N. Yılmazer, M. K. Gökcan, Ç. Uzun; Ankara/TR
Purpose: To investigate the association between radiological findings of parathyroid adenomas (PA) on 4 dimensional computed tomography (4D-CT) and biochemical parameters, as well as the impact of polar vessel presence on these relationship.
Methods or Background: This retrospective study included patients who underwent 4D-CT imaging for parathyroid adenoma between 2015 and 2025, with the diagnosis confirmed histopathologically. PV presence was evaluated in consensus by two observers. Densities of PA were measured in pre-contrast, arterial, and venous phases using the largest region of interest excluding cystic/calcified areas. Volume was calculated as 0.523 × long axis × short axis × craniocaudal length. Enhancement indices (‘wash-in’, ‘wash-out’, and ‘retained’) were calculated. Serum parathyroid hormone (PTH), calcium (Ca), and creatinine levels were recorded. Correlations between imaging and biochemical findings were analyzed; Differences according to PV presence were assessed using the t-test/Mann–Whitney U test.
Results or Findings: A total of 84 patients (mean age: 56.42 ± 15.04 years) were included, comprising 45 PV-positive (PV+) and 39 PV-negative (PV−). PV+ patients had higher PTH (p=0.044), higher arterial phase density (p=0.020), and significantly greater wash-in and wash-out values (p=0.010 and p=0.033, respectively). PA volume correlated positively with PTH (r=0.300, p=0.006) and Ca (r=0.432, p=0.014). Pre-contrast density correlated negatively with PTH (r=−0.248, p=0.023). No other significant correlations between densities and biochemical parameters were observed.
Conclusion: The presence of a polar vessel is associated with higher arterial enhancement, greater wash-in/wash-out, and elevated PTH levels, supporting its diagnostic role in 4D-CT evaluation of PA. Larger adenoma volume correlates with higher biochemical activity, suggesting a contribution to hypercalcemia through increased PTH secretion. PV assessment should be considered an important imaging finding in the diagnostic work-up.
Limitations: Retrospective design, moderate sample size, and lack of fine-needle aspiration PTH measurements.
Funding for this study: No funding was provided for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: