Philipp Seifert

Background: Accurate thyroid volume determination is essential for treatment planning. This feasibility study evaluated the accuracy of a novel tomographic ultrasound (tUS) approach compared to 2D ultrasound, using contrast-enhanced computed tomography (ceCT) as reference standard. Methods: In this prospective, single-center study, 50 patients undergoing neck ceCT were enrolled. Thyroid volume was measured by 2D ultrasound (ellipsoid model), automatedvolume (tUS uncorrected), physician-corrected volume (tUS corrected) and ceCT. Linear regression for proportional bias, log-transformed Bland–Altman analysis, clinical error metrics and correction duration were evaluated. Results: 2D ultrasound showed significant proportional bias (slope=-0.215, p<0.0001) and systematic underestimation (mean difference -6.0mL; geometric mean ratio 0.76). Corrected tUS eliminated proportional bias (p=0.0557) and reduced bias (mean difference +0.8mL; geometric mean ratio 1.04). Corrected tUS achieved lower MAE (4.42mL vs. 6.53mL) and MAPE (19.4% vs. 25.4%) than 2D ultrasound, placing 60.0% vs. 34.0% of cases within ±20% error limits. In enlarged glands (n=19), corrected tUS maintained superior accuracy (MAE 5.82mL, MAPE 12.4%) versus 2D ultrasound (MAE 11.35mL, MAPE 26.5%). Physician correction averaged 2:51minutes, independent of thyroid volume (r=-0.081, p=0.5784). Conclusions: In this feasibility study, physician-corrected tUS reduced the size-dependent systematic underestimation observed with 2D ultrasound and yielded volumes closer to ceCT, particularly in enlarged glands, within a clinically feasible workflow. Because the best-performing method required manual expert correction and the limits of agreement with ceCT exceeded the predefined clinical threshold, corrected tUS should be regarded as a promising semi-automated approach that requires further validation, including interobserver assessment, before it can be considered interchangeable with ceCT.

Background/Objectives: To assess the agreement between an artificial intelligence (AI)-based decision support system (DS System), applied in real time directly on the ultrasound console, and an expert panel for ACR TI-RADS classification of thyroid nodules (TNs) in a region with a history of iodine deficiency and a consequently high prevalence of TNs. Methods: A single-center prospective study including 118 consecutive patients (with 276 TNs) referred for thyroid ultrasound between March and May 2024. DS System ultrasound features, ACR TI-RADS classifications (TR1–TR5) and management recommendations were recorded per TN, with and without the ‘AI-Adapter’ (AI-based modification of the TI-RADS score), and compared to the consensus assessment of a TI-RADS expert panel (paired tests of marginal homogeneity, Cohen’s unweighted and weighted κ; all analyses adjusted for clustering of TNs within patients). Results: No malignancy was identified during 24-month follow-up (composite reference standard; cytology or histology in six TNs). The DS System could be applied to all TNs without technical failure. Marginal distributions differed between the expert panel and the DS System for all ultrasound feature categories except echogenicity (p = 0.23). Interrater agreement ranged from poor (“lobulated or irregular”, κ = −0.08) to substantial (“cystic or almost completely cystic”, κ = 0.62), most frequently slight to fair. TI-RADS classifications showed slight agreement with (κ = 0.04; linear-weighted κ = 0.14) and without AI-Adapter (κ = 0.13; linear-weighted κ = 0.21). The AI-Adapter changed the ACR TI-RADS score by −1.01 ± 1.04 points. Management recommendations showed fair agreement with (κ = 0.23) and without the AI-Adapter (κ = 0.39). Although the number of TR5 ratings was similar (expert panel: 27; DS System: 26 without and 30 with the AI-Adapter), only seven and eight of the 27 TR5 TNs of the expert panel, respectively, were also rated TR5 by the DS System. Conclusions: Real-time application of the DS System on the ultrasound console was technically feasible, but agreement with an expert panel was low. As all TNs were benign, diagnostic accuracy and clinical safety could not be assessed. Validation in cohorts including malignant TNs is required before the DS System can be considered a substitute for expert assessment in regions with a high prevalence of TNs.

Conventional ultrasound phantoms typically lack anatomical surface geometry and procedural access constraints, limiting the transferability of acquired skills to clinical practice. The objective of the present work was to develop and describe such a platform for ultrasound-guided thyroid nodule puncture training, including its construction and initial ultrasound appearance. We present a modular, body-mimicking ultrasound phantom platform comprising three components: an anatomically shaped epoxy composite chassis cast from a healthy volunteer and covering the cervical and upper thoracic region, interchangeable gelatin-based inserts representing thyroid (including puncture target lesions) and surrounding tissue structures, and an integrated dual-camera optical feedback system for real-time and post-procedural needle trajectory visualization. Two chassis configurations reflecting different chin and shoulder positions allow deliberate modulation of procedural difficulty. Insert composition can be varied to simulate tissues of differing echogenicity and density, including liquid-filled targets. Under appropriate storage and disinfection conditions, inserts remained usable for up to four weeks in qualitative observation. The optical feedback system supports self-directed learning and structured debriefing. In combination with magnet-based ultrasound needle guidance technology, the platform is intended to support a longitudinal, competency-based training concept with quantifiable performance metrics, enabling systematic documentation of individual learning curves. The presented system is designed to more closely replicate the anatomical and procedural complexity of clinical ultrasound-guided interventions than conventional phantoms and represents a flexible simulation platform for interventional ultrasound education.

Preclinical imaging has recently been expanded through the use of ostrich embryos as an alternative in vivo model. In ovo experiments represent a promising substitute for conventional rodent-based animal testing. For artifact-free dynamic nuclear medicine imaging, reliable immobilization of embryos is essential. Although previous studies have demonstrated the feasibility of isoflurane anesthesia, the kinetics and uptake mechanisms of isoflurane in ostrich embryos remain insufficiently characterized. The aim of this study was to characterize gas exchange dynamics in ostrich eggs and to quantify isoflurane uptake using two complementary approaches: indirect consumption measurements in a closed system and direct quantification by serial blood sampling. Fourteen ostrich eggs, including seven fertilized and seven unfertilized specimens, were analyzed at developmental stages up to day 37 of incubation. Gas exchange was assessed in a sealed container using a clinical anesthesia gas monitoring system to measure oxygen consumption and carbon dioxide excretion. Isoflurane uptake was evaluated during exposure to concentrations of 2%, 4%, or 6%. In a separate experimental series, serial blood samples were collected during and after exposure to the same concentrations to determine systemic uptake. Fertilized embryos showed progressive increases in metabolic activity, with a maximal oxygen consumption and carbon dioxide excretion of 116 mL/h/kg and 93 mL/h/kg on day 37. Indirect measurements demonstrated isoflurane uptake rates of up to 1.1 mL/min at 6%, with proportionally lower values at 4% and 2%. Blood analyses confirmed systemic absorption, peak concentrations of 160 µg/mL, and detectable residual levels for up to 120 min after exposure. These findings refine in ovo imaging.

Transarterial radioembolization generally results in low radiation exposure for medical staff; ¹⁶⁶ Ho-poly-L-lactic acid microspheres led to the highest body doses, while ⁹⁰ Y-resin microspheres generated the highest hand doses, with interventional radiologists receiving the highest overall doses.

Background/Objectives: The increasing use of radiopharmaceuticals in clinical practice has raised concerns regarding potential radiation exposure for healthcare personnel handling biological samples from treated patients. The objective of this study was to assess the radioactivity levels in clinically necessary blood samples taken from patients treated with radioactive iodine-131 (I-131) or lutetium-177 (Lu-177) in a real-world setting. Methods: Prospective, tertiary care single-center study. Blood samples, at the clinically necessary time points, from 220 consecutive targeted radionuclide therapies (TRTs) used to treat 151 distinct patients between October 2021 and January 2025 were included. The influences of the eGFR and the time interval between tracer administration and blood sampling on radioactivity concentration were investigated by linear regression models. The applied amount of radioactivity was excluded as a confounder by adjusting all cases to 1 GBq. Statistical programming language R was utilized and p < 0.05 was considered significant. Results: The mean age of the patients was 62 years and 52% were male. Mean radioactivity concentrations of 6 vs. 60 kBq/mL were measured at 52 vs. 13 h after application of 1.9 vs. 6.7 GBq I-131 vs. Lu-177, respectively. Better renal function and later blood sampling were both associated with lower radioactivity concentration in blood samples (each p < 0.001). Total radioactivity levels in all samples were well below the upper limits for the disposal of biological samples (1 MBq for I-131 and 10 MBq for Lu-177). Conclusions: There was only a low exposure risk for nuclear medicine personnel and laboratory staff. These findings emphasize that handling blood samples from patients treated with I-131 and Lu-177 in clinical routine is minimal.

Background/Objectives: Autonomously functioning thyroid nodules (AFTNs) are most frequently diagnosed as benign. However, they show high ratings in ultrasound (US) risk stratification systems (RSSs) that utilize the current clinical standard methodology of conventional static image capture (SIC) documentation. The objective of this study was to evaluate the RSS ratings and respective fine needle cytology (FNC) recommendations of cine loop (CL) video sequences in comparison to SIC. Methods: 407 patients with 424 AFTNs were enrolled in this unicentric, retrospective study between 11/2015 and 11/2023. Recorded US CL and SIC were analyzed lesion-wise and compared regarding US features, Kwak and ACR TIRADS, ACR FNC recommendations, as well as assessment difficulties and artifacts. Statistical analyses were conducted using the Chi² test and Spearman’s correlation coefficient in SPSS software. p-values < 0.05 were considered significant. Results: Strong to very strong correlations were observed for all US features, RSS ratings, and ACR FNC recommendations (Spearman’s correlation: each p < 0.001), comparing CL and SIC. For >60% of the AFTNs, ACR FNC recommendation was given. Kwak TIRADS were more consistent with the benign nature of AFTNs than the ACR ratings. CL captured significantly more “echogenic foci” than SIC (Chi²: p < 0.001). Artifacts (poor image quality, acoustic shadowing, sagittal incompletely displayed AFTN) were significantly more common on CL, affecting ~40% of AFTNs, compared to ~15% on SIC (Chi²: each p < 0.05). Weak correlation was observed for assessment confidence between CL and SIC, with SIC outperforming CL (Spearman’s correlation: each p < 0.001). Conclusions: A strong correlation was identified between CL and SIC in terms of RSS ratings and ACR FNC recommendations. Kwak is a superior representative of the benign character of AFTNs than ACR. However, CL provided more detailed information while being associated with decreased observer confidence and more artifacts. Specific operator training and technical improvements, including AI implementation, could improve image quality in future.

Background/Objectives: Static image captures (SICs) are the prevailing methodology for documenting thyroid nodules (TNs) on ultrasound examinations. Ultrasound cine-loop (CL) video sequences of the thyroid enable the storage and review of the entire organ in PACS, analogous to sectional imaging modalities such as CT or MRI. Expanding on SIC, the collection of more extensive datasets is possible, with the potential to enhance diagnostic performance. However, there is an absence of reliable data concerning this process. Methods: This retrospective, tertiary care, single-center study included all patients with cytologically and histopathologically diagnosed TNs from 01/16 to 12/23. A standardized CL protocol was routinely acquired in addition to conventional SIC. The diagnostic performance of ACR and Kwak TIRADS was examined for both CL and SIC in a PACS. Advantages, challenges, and limitations of CL were analyzed. Conclusions: In total, 189 patients with 329 TNs (78% females, aged 54 ± 15 years; 76% diagnosed via surgery; 14% malignant) were included. On SIC, 58 TNs (18%) were not identified (all benign). When comparing CL with SIC, a strong correlation was observed for nearly all ultrasound features (echogenicity, composition, margin, and foci; each p < 0.001) and both TIRADSs (each p < 0.001). The diagnostic accuracy of CL was slightly superior, with maximum values of 85% for ACR and 87% for Kwak TIRADS, respectively. Rating confidence and image quality exhibited superiority on SIC (each p < 0.001). The occurrence of image artifacts was more prevalent in CL (p < 0.001). The integration of cine loops into thyroid ultrasound was found to be a seamless process, thereby enhancing the risk stratification of nodules. Image quality impairments manifested more frequently in cine loops, while static image captures demonstrated higher levels of assessment confidence.