In ovo studies are a valuable option in preclinical research, but imaging studies are severely limited by the costs of dedicated equipment needed for small-sized eggs. We sought to verify the feasibility of using larger, ostrich, eggs () for imaging on the PET/CT scanners used for routine clinical investigations. Ostrich eggs were incubated until shortly before hatching, prepared for intravitelline venous injection of contrast medium or radiotracer, and imaged using native CT, contrast-enhanced CT, and PET/CT. Any technical adaptations that were needed to improve the outcome were noted. Of the 34 eggs initially incubated, 12 became fully available for imaging of embryonal development. In ovo imaging with conventional PET/CT not only was feasible but also provided images of good quality, including on dynamic PET imaging. In ovo imaging with ostrich eggs and routine clinical scanners may allow broader application of this field of preclinical research, obviating costly dedicated equipment and reducing the number of animals needed for classic animal research. Further experiments are warranted to refine this novel approach, especially to reduce motion artifacts and improve monitoring of viability.

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In-ovo imaging using ostrich eggs has been described as a potential alternative to common animal testing. The main advantage is its independence from small animal imaging devices as ostrich eggs provide good image quality on regular CT, MRI, or PET used in examinations of humans. However, embryonal motion during dynamic imaging studies produce artifacts. The aims of this study were (1) to explore the feasibility of biomagnetism to detect cardiac signals and embryonal motion and to use these findings (2) to investigate the effect of isoflurane anesthesia on ostrich embryos. A standard magnetoencephalography developed for brain studies was used to detect embryonal signals of ostrich eggs on developmental day 34. Signals were instantly shown on a screen and data were also postprocessed. For assessing the effects of anesthesia, nine ostrich eggs were investigated using isoflurane 6% for 90 min. Biomagnetic signals were recorded simultaneously. A control group consisting of eight different ostrich eggs was also investigated. Cardiac signals similar to electrocardiography were observed in all eggs. Postprocessing revealed frequent motion of embryos without anesthesia. The exposure to isoflurane led to a significant decrease in motion signals in 9/9 ostrich embryos after 8 min. Motion was significantly reduced in the isoflurane group versus control group. There were no isoflurane-related deaths. This study shows that biomagnetism is feasible to detect cardiac signals and motion of ostrich embryos in-ovo. Application of isoflurane is safe and leads to a rapid decrease in embryonal motion, which is an important prerequisite for the implementation of in-ovo imaging using ostrich eggs.

Aims: Thyroid volume has to be measured in goiters prior to radioiodine treatment to calculate the needed amount of radioactivity. Modern clinical equipment for ultrasonography shows the trend to smaller probes, so that larger goiters do not fit any longer into the probe’s field of view. This study evaluated the feasibility and accuracy of stitching procedures applied to thyroid volumetric analysis performed using three-dimensional ultrasound (3D-US).Material and methods: Ad hoc thyroid phantoms of different shapes (regular, nodular, thickened isthmus) and volumes (ranging between 50 and 400 mL) were developed. In 15 such phantoms the left and right lobes were separately scanned, and the 3D-US datasets were then assembled (stitched) using predefined landmarks and dedicated software. Volumetric analysis was then assessed via a conventional ellipsoid model (em) and manual tracing (mt). The correlation of measured and reference volumes was determined using Pearson’s correlation coefficients and Bland and Altman limits of agreement.Results: The results showed a high level of agreement (with correlation coefficients ranging from 0.974 to 0.999) for all shapes and volumes tested, including the largest volume of 400 mL. The mt method, although more time consuming, proved superior to the em.Conclusions: Stitching-mediated thyroid volumetric analysis is accurate, and its clinical performance should be investigated in future studies

Aim To investigate the value of I-124 positron emission tomography (PET) / ultrasound (US) fusion imaging in comparison to conventional diagnostics (CD) of Thyroid nodules (TN) by multiple observers. Methods Digital patient case files (PCF) of patients that received CD and I-124-PET/US in clinical routine were prepared containing cine-loops of the examinations. All physicians with nuclear medicine specialty from Germany, Austria, and Switzerland were invited to participate. 106 acquired observers completed 7.2 ± 1.8 (median: 8, range: 4–14) randomly assigned PCF (CD only or CD+PET/US). They assessed the TN function, stated their confidence in functional assessment, and suggested a treatment course for each TN. Results 68 PCF of 34 patients comprising 66 TN ≥ 1 cm (= 1.94 TN/patient) were created. A total of 748 (11.2/TN), and 751 ratings (11.4/TN) were recorded for CD only, and CD+PET/US, respectively. The functional assessment revealed more hyper- or hypofunctioning (524 vs. 320, p < 0.0001) and less indifferent or not rateable (209 vs. 428, p < 0.0001) TN in CD+PET/US vs. CD only. The observers’ confidence in functional assessment was superior in CD+PET/US (p < 0.0001). Furthermore, the ratings were carried out more homogeneous in CD+PET/US (p < 0.0001). Fewer suggestion of follow up (p < 0.0001), and more (p < 0.0001) suggestion of invasive treatments (fine-needle aspiration & surgery) was observed in CD+PET/US. Radioiodine therapy was more often (p = 0.0036), and thyroid medication less often (p = 0.0167) advised in CD+PET/US. Conclusion Functional assessment of equivocal TN shows frequent failures in CD, underestimating the incidence of hyper- and hypofunctioning lesions. Confidence in functional assessment significantly increases with additional PET/US. This influences the proposed treatment course.