Objectives: Anthropomorphic phantoms offer a promising solution to minimize animal testing, enable medical training, and support the efficient development of medical devices. The adjustable mechanical, biochemical, and imaging properties of the polyvinyl alcohol cryogel (PVA-C) make it an appropriate phantom material for mimicking soft tissues. Conventional manufacturing (CM) of aqueous solutions requires constant stirring, using a heated water bath, and monitoring. Methods: To explore potential improvements in the dissolution of PVA crystals in water, a microwave-based manufacturing method (MWM) was employed. Samples created using CM and MWM (n = 14 each) were compared. Because PVA-C is a multifunctional phantom material (e.g., in magnetic resonance imaging (MRI)), its MRI properties (T1/T2 relaxation times) and elasticity were determined. Results: T1 relaxation times did not significantly differ between the two methods (p = 0.3577), whereas T2 and elasticity for the MWM were significantly higher than those for the CM (p < 0.001). The MWM reduced the production time by 11% and decreased active user involvement by 93%. Conclusions: The MWM offers a promising, easily implementable, and time-efficient method for manufacturing PVA-C-based phantoms. Nevertheless, manufacturing-related microstructural properties and sample molding require further study.

Anthropomorphic CT phantoms are essential training tools for interventional radiology. Given the high technical demands and stringent safety requirements in this field, realistic CT phantoms are vital simulation tools that support effective hands-on training, procedural planning, and risk mitigation. However, commercially available phantom geometries are limited in their scope. This study investigates the use of polyvinyl alcohol (PVA) to fabricate customizable training phantoms. PVA, a non-toxic material, can be processed into PVA cryogels (PVA-C) with tissue-like mechanical properties. We modified PVA-C (10 wt.% PVA) by incorporating various additives to adjust X-ray attenuation and achieve Hounsfield units (HUs) similar to different soft tissues. HU values were measured at X-ray tube voltages of 70, 120, and 150 kV. The inclusion of barium sulfate (e.g., U = 120 kV; 0.1–2 wt.%: 33.29 ± 5.45–323.72 ± 12.64 HU) and iohexol (e.g., U = 120 kV; 0.1–2 wt.%: 26.05 ± 4.74–161.99 ± 5.69 HU) significantly increased HU values. Iohexol produced more homogeneous HU distributions than barium sulfate and cellulose derivatives, with the latter having air gaps and inconsistencies. The tested formulations encompassed a wide range of soft tissue densities, with HU values varying significantly across the energy range (p < 0.001). While cellulose derivatives showed variable HU modulation, their primary role appears to be in modifying phantom texture and morphology rather than precise attenuation control. In conclusion, PVA-C demonstrates strong potential for use in interventional radiology training phantoms. Further studies may enhance phantom realism by replicating tissue textures, for example, through the incorporation of cellulose-based substances.

Background: Radionuclide therapy, such as with iodine‐131 or lutetium‐177–labeled substances, is used to treat thyroid cancer and neuroendocrine tumors. Due to the incorporated radioactivity, patients must remain hospitalized until radiation levels are deemed safe, according to national regulations. This is particularly problematic for patients who require hemodialysis (HD). While contamination of dialysis waste after radionuclide therapy is generally well recognized, a critical gap remains regarding its duration and extent. This poses risks for patient management and outpatient staff. Purpose: This study aims to demonstrate the problems with classifying residual waste and provides arguments for appropriate regulation. It evaluates if the radioactivity of the dialysate and residuals at discharge, based on whole‐body measurements, complies with relevant limits. If not, the waste is classified as radioactive and treated accordingly. Methods: We studied four patients treated by radionuclide therapy who required dialysis: three received [ ¹³¹ I]I for thyroid disease and one [ ¹⁷⁷ Lu]Lu‐DOTATATE for neuroendocrine neoplasia. Dialysis was performed in the nuclear medicine ward, and patients were discharged once the local dose rate limits were met. Subsequent dialysis sessions were conducted in a radiation protection area until the activity concentration in the dialysate dropped below the specific limit. Results: Patient 1 ([ ¹³¹ I]I, thyroid cancer) showed the highest extraction rate and was discharged after 9 days, requiring nine additional dialysis sessions over 21 days. Patients 2 and 3 ([ ¹³¹ I]I, benign thyroid disease) were discharged after 8 and 4 days, with dialysis continued for 31 and 18 days under supervision, respectively. Patient 4 ([ ¹⁷⁷ Lu]Lu‐DOTATATE) lost 4.9% of the total body radioactivity per dialysis session and was discharged after 9 days; supervised dialysis continued for 17 days. Conclusions: This study highlights the need for refined monitoring and the limitations of standard discharge strategies for patients requiring dialysis during radionuclide therapy. Even if dose limits are met, dialysate and residuals may still require regulated handling and storage.

Dose optimization in computed tomography (CT) is crucial, especially in CT fluoroscopy (fluoro-CT) used for real-time navigation, affecting both patient and operator safety. This study evaluated the impact of spectral X-ray filtering using a tin filter (Sn filter), and a method called partial-angle computed tomography (PACT), which involves segmentally switching off the X-ray tube current at the ambient dose rate ${\dot{H}}^{*}(10)$ at the interventional radiologist’s (IR) position. Measurements were taken at two body regions (upper body: head/neck; lower body: lower legs/feet) using a 120 kV X-ray tube voltage, 3 × 5.0 mm CT collimation, 0.5 s rotation speed, and X-ray tube currents of 43 Eff.mAs (without Sn filter) and 165 Eff.mAs (with Sn filter). The study found significant dose reductions in both body regions when using the Sn filter and PACT together. For instance, in the upper body region, the combination protocol reduced ${\dot{H}}^{*}(10)$ from 11.8 µSv/s to 6.1 µSv/s (p < 0.0001) compared to the protocol without using these features. Around 8% of the reduction (about 0.5 µSv/s) is attributed to the Sn filter (p = 0.0005). This approach demonstrates that using the Sn filter along with PACT effectively minimizes radiation exposure for the IR, particularly protecting areas like the head/neck, which can only be insufficiently covered by (standard) radiation protection material.

Holding a remote keyless entry fob near the head provides a practical opportunity to investigate configuration-dependent changes in operating range. This pilot study examined five head-contact configurations in nine adults using a factory 433.92 MHz fob and its vehicle. Complementary assessments included an anatomically shaped skull phantom and 7 T magnetic resonance imaging (MRI). Operating thresholds were determined using a staircase procedure. The submental configuration yielded positive gains in all nine participants and the largest mean and median gains: 11.11 m and 12 m, respectively. The within-subject analysis identified an overall difference among configurations in eight complete cases (Friedman ${\chi }^2\left(4\right)=23.24$; Monte Carlo $p<0.00001$ based on 200,000 permutations; Kendall’s $W=0.73$). In the phantom series, each condition with distilled water yielded a higher gain than the condition with air at the same location, although gains did not increase consistently across fill levels. These observations identify promising configurations for further investigation. MRI characterized anatomical variation to inform future studies, with no significant associations after correction for multiple comparisons. Each condition was assessed once, and placement was evaluated with fob orientation and hand/body geometry. Building on these observations, repeated measurements with independent control of these factors will help establish repeatability and clarify the electromagnetic contributions.