Human Phantom Research Articles

ICRP pregnant-female mesh-type reference computational phantoms part 1: development of fetal phantoms.

The International Commission on Radiological Protection (ICRP) decided to develop pregnant-female reference computational phantoms, including the maternal and fetal phantoms, through its 2007 general recommendations. Acknowledging the advantages of the mesh geometry, the ICRP decided to develop the pregnant-female mesh-type reference computational phantoms (MRCPs) for 8-, 10-, 15-, 20-, 25-, 30-, 35-, and 38-week fetal ages directly in the mesh format. As part of this process, the present study developed the mesh-type fetal phantoms. The reference blood-inclusive organ masses, elemental compositions, and densities were established based on various scientific literatures. Then, the phantoms were developed in accordance with the established reference dataset while reflecting the anatomical features of the developing fetus, such as fetal-age-specific anthropometric parameters, bone ossification, and contents formation time. The phantoms were developed in the tetrahedral-mesh format and can be implemented in the general-purpose Monte Carlo codes (i.e., Geant4, PHITS, MCNP6, and EGSnrc) without the necessity of the voxelization process. To explore the dosimetric impact of the developed phantoms, photon specific absorbed fractions (SAFs) were computed for energies between 10-2 to 101 MeV for the fetal liver and spleen as source regions and self-irradiation and cross-irradiation to the fetal brain, lungs, and urinary bladder wall as target regions. The SAFs showed the fetal-age-dependent dose trends (i.e., SAF decreases with increasing fetal age) due to organ masses increases via fetal growth. The mesh-type fetal phantoms, as part of the ICRP pregnant-female MRCPs, will be used to calculate reference dose coefficients for fetal members of the public for both the current and future ICRP general recommendations.

Towards accurate dose assessment for emergency industrial radiography source retrieval operations: A preliminary study of 4D Monte Carlo dose calculations

The exposure devices utilizing high-activity gamma radiation sources for industrial radiography frequently encounter issues such as stuck or disconnected sources, posing a substantial risk of radiation exposure to the workers executing emergency source retrieval operations, emphasizing the importance of accurate dose assessment. In the present study, the radiation dose to the main worker during the process of source retrieval was calculated and compared for five emergency source retrieval procedures to retrieve stuck or disconnected sources, using 4D Monte Carlo dose calculation and a mesh-type reference computational phantom. For a stuck source, the dose values of the two source retrieval procedures (i.e., repair and cut methods) were found to be relatively small, which indicates that the worker might select either method based on personal preference or situational convenience. Conversely, for a disconnected source, the dose values of the three source retrieval procedures (i.e., fishing, connect/push, and hot stick methods) were much larger and show significant differences. Notably, the fishing method was associated with the lowest dose, whereas the hot stick method resulted in significantly higher doses, differences being as large as ∼5 times. These results underscore the fishing method as a preferable option, particularly over the hot stick method.

Design and optimization of flexible DGS-based microstrip antenna for wearable devices in the Sub-6 GHz range using the nelder-mead simplex algorithm

This study introduces a Nelder-Mead Simplex Algorithm based low-profile, flexible, and wearable defected ground structure (DGS)-loaded deformed microstrip antenna for Sub-6 GHz 5 G applications. It is fabricated on a low-loss 20 mil Rogers RT/Duroid 5880 substrate and the antenna demonstrates robust performance with reflection coefficient magnitude (|S11|) of –22.34 dB with peak gain of about 5.57 dBi at resonant frequency (fr) of 2.185 GHz. Comprehensive key performance metrics such as |S11|, far-field gain patterns, and specific absorption rate (SAR) of the proposed antenna is demonstrated. The SAR for 1 g and 10 g tissues at various separation distances are analyzed and presented by utilizing human multilayer phantom model with antenna. Additionally, the lowest SAR is measured to be 0.0959 W/kg for 1 g of tissue and 0.0755 W/kg for 10 g of tissue when the antenna is placed 0.291λ0 away from the model. The study also explores the proposed antenna performance under various bending conditions for the conformability analysis and in different on-body scenarios, with placement on the hand, leg, and chest. The measured |S11| values, particularly strong on the chest, underscore the antenna effectiveness for wearable technology.

Estimation and analysis of S values for 131I using paediatric mesh type reference computational phantoms

This study examines the effect of paediatric mesh-type reference computational phantoms on organSvalues resulting from radioiodine (131I) intake. Using Geant4, we estimated131ISvalues for 30 radiosensitive target tissues due to emission from the thyroid (Target ← Thyroid) in these phantoms. Our results show thatSvalues differ between male and female phantoms of the same age andSvalues also decrease as phantom age increases. The male-to-femaleSvalue ratio typically varies within 10%, with larger differences observed for the esophagus, extra-thoracic regions, muscles, bladder, and sex organs. On average,Svalues for mesh phantoms are approximately 17% higher than those for voxel phantoms, with larger discrepancies for organs remodelled separately in mesh phantoms. The study provides organSvalues for the paediatric population due to131I exposure from the thyroid, based on the reference mesh-type computational phantoms, enhancing organ dose estimation in emergency situations and during radioiodine treatment.

Calculation of dose conversion coefficients for radiation workers in various postures

The present study investigates the impact of various body postures on dose assessment. Existing radiation protection systems that assume a standing posture are generally valid in most situations; however, they may not be effective in assessing the dose received by individuals in specific conditions such as radiation accidents. To address this, we used the Geant4 simulation code and mesh-type reference computational phantoms (MRCPs) to model and calculate the dose conversion coefficients (DCCs) for 19 representative working postures. These representative postures were developed by referencing existing industrial posture categories, combining movements of arms, torso, and legs. The exposure geometries considered in the present study include generalized parallel beams such as anterior-posterior (AP), posterior-anterior (PA), left-lateral (LLAT), and right-lateral (RLAT), and isotropic exposures from all sides (rotational (ROT) and isotropic (ISO)), along with semi-isotropic forms of ground and ceiling contamination ranging from 30 cm to 50 m in radius. The results demonstrate that the dose ratios between a personal dosimeter and whole-body (i.e. DCCs) are significantly influenced by the body posture and the exposure geometry. Particularly, exposures involving significant body shielding, such as ground and ceiling contamination and PA direction exposures, were mainly affected by the degree of torso bending. For instance, a DCC of 2.3 was recorded for a posture with approximately 45 degrees of torso bending under PA exposure. Additionally, in a ground contamination scenario having a 1 m radius beam, DCCs ranged from 0.8 to 2.5 depending on the degree of torso bending, and in a 2 m radius ceiling contamination scenario, DCCs of 1.2–1.7 were observed in postures with 90 degrees of torso bending. These findings emphasize the importance of posture-specific dose assessments in various contamination scenarios.

Study on the Effect of Adipose Tissue on Neutron Dose Evaluation for the Human Body Using Voxel Phantoms with Different Weight

Abstract When human body is irradiated by neutrons, the adipose content has a significant impact on the neutron dose and induced 24Na activity. To investigate the effect of human adipose content on the conversion coefficients from 24Na activity to neutron dose, five male adult reference computational phantoms with weights ranging from 73.5 kg to 136.5 kg were used. The Monte Carlo N-particle (MCNP) code was used to calculate the neutron absorbed dose and the yield of induced 24Na in the phantoms irradiated by 252Cf neutrons and monoenergetic neutrons. The results showed that the difference in the conversion coefficients from 24Na activity to neutron absorbed dose among the five phantoms irradiated by 252Cf neutrons with anterior posterior (AP) geometry was ≤23.30%, and this difference was attributed mainly to the neutron absorbed dose, which increases with increasing adipose content. Considering the self-absorption of gamma rays in the human body, the counts of 24Na characteristic gamma rays measured directly by the radiation detector outside of the body have no significant trend varying with adipose content, and the difference in the conversion coefficients from the measured counts to neutron dose among the five phantoms irradiated by 252Cf neutrons with AP geometry was ≤5.25%.

Development of age-specific population-based paediatric computational phantoms for image-based data mining and other radiotherapy applications

Objective.Computational anatomical models have many applications in paediatric radiotherapy. Age-specific computational anatomical models were historically developed to represent average and/or healthy individuals, where cancer patients may present with anatomical variations caused by the disease and/or treatment effects. We developed RT-PAL, a library of computational age-specific voxelized anatomical models tailored to represent the paediatric radiotherapy population.Approach.Data from patients undergoing craniospinal irradiation (CSI) were used (n = 74, median age 7.3y, range: 1-17y). The RT-PAL phantoms were generated using groupwise deformable image registration to spatially normalize and average a sub-set of twenty clinical CTs and contours (n = 74, median age 7.7y, range: 3-14 y). To assess their anatomical and age-dependency plausibility, the RT-PAL models were compared against clinical cancer patient data and two healthy population based libraries of phantoms: the International Commission on Radiological Protection (ICRP) pediatric reference computational phantoms (n = 8, median age 7.5y, range: 1-15y) and a range of 4D paediatric extended cardiac torso (XCAT) phantoms (n = 75, median age 9.1y, range: 1-18y). For each dataset, nineteen organs were segmented on all age models to determine their volume. Each set was evaluated through a linear fit of organ volume with age, where comparisons were made relative to the linear fit of the clinical data.Main Results.Overall good anatomical plausibility was found for the RT-PAL phantoms. The age-dependency reported was comparable to both the clinical data and other phantoms, demonstrating their efficacy as a library of age-specific phantoms. Larger discrepancies with the clinical, ICRP and XCAT organ data were attributable to differences in organ filling, segmentation strategy and age distribution of the datasets, limitations of RT-PAL generation methodology, and/or possible anatomical differences between healthy and cancer populations.Significance.The RT-PAL models showed potential in representing the paediatric radiotherapy cohort, who are most likely to benefit from dedicated, age-specific anatomical phantoms.

Attempt to re-estimate organ doses of victims in non-homogeneous exposure accident by means of the state-of-the-art Mesh-type Reference Computational Phantom-a case study of an IR-192 source accident.

An attempt was made to estimate organ doses of a victim in a high-dose non-homogeneous exposure accident caused by a sealed 192Ir gamma-ray source. The Gilan accident was selected as a case study. Organ doses including testis, red bone marrow and so on were properly estimated by applying the Monte Carlo calculation with the state-of-the-art adult male Mesh type Reference Computational Phantom. By introducing a complicated exposure scenario, the dose distribution on the right chest of the victim in the Gilan accident could be reproduced to a certain extent.

A modular, human body-mimicking phantom with active thermoregulation capabilities for validation and verification of convective hyperthermia devices

Objectives This study aims to design and fabricate a modular phantom for hyperthermia applications, addressing interpatient variability in thermal regulation mechanisms like sweating rate, metabolic heat production, and blood redistribution. Materials & methods The phantom can be constructed in various weights and dimensions by connecting identical units. Each unit consists of an agar-based block, an ethyl cellulose-based top layer, a heat source, deep and superficial water circulation, and a sweating mechanism. Agar and ethyl cellulose gels mimic the thermal properties of human tissues and fat respectively. The blocks are wrapped in PVC foil to prevent water evaporation. A heating wire, coiled around an embedded aluminum tubing simulates metabolic heat production. A superficial water circulation mimics skin capillaries. A water pump ensures a steady flow rate throughout the tubing system. Sweat production is simulated using a water pump and perforated tubing. A programmed controller maintains core temperature in a normal operating mode and simulates an anesthetized patient in anesthesia mode. Results Temperature uniformity and regulation were assessed under varying environmental conditions. The phantom effectively regulated its core temperature at 37.0 °C +/- 0.7 °C with an ambient temperature ranging between 21 °C and 30 °C. Activating the water circulation reduced the maximum temperature gradient within the phantom from 4.70 °C to 1.92 °C. Conclusion The versatile phantom successfully models heat exchange processes. Its thermal properties, dimensions, and heat exchange rates can be tuned to mimic different patient models. These are promising results as an effective tool for hyperthermia device validation and verification, representing human physiological responses.

Feasibility of Measuring Magnetic Resonance Elastography-derived Stiffness in Human Thoracic Aorta and Aortic Dissection Phantoms

Type-B aortic dissection (TBAD) represents a serious medical emergency with up to a 50% associated 5-year mortality caused by thoracic aorta, dissection-associated aneurysmal (DAA) degeneration, and rupture. Unfortunately, conventional size related diagnostic methods cannot distinguish high-risk DAAs that benefit from surgical intervention from stable DAAs. Our goal is to use DAA stiffness measured with magnetic resonance elastography (MRE) as a biomarker to distinguish high-risk DAAs from stable DAAs. This is a feasibility study using MRE to 1) fabricate human-like geometries TBAD phantoms with different stiffnesses. 2) measure stiffness in TBAD phantoms with rheometry and 3) demonstrate the first successful application of MRE to the thoracic aorta of a human volunteer. Aortic dissection phantoms with heterogenous wall stiffness demonstrated the correlation between MRE-derived stiffness and rheometric measured stiffness. A pilot scan was performed in a healthy volunteer to test the technique's feasibility in the thoracic aorta.

Dose coefficients of mesh-type reference Korean phantoms (MRKPs) for idealized external exposure geometries of photons and electrons

The present study produced Korean-specific dose coefficients for idealized external exposures to photons and electrons by performing Monte Carlo dose calculations with mesh-type reference Korean phantoms (MRKPs). The Korean dose coefficients were then compared with those previously calculated using the mesh-type reference computational phantoms (MRCPs) of the International Commission on Radiological Protection (ICRP). For photons, excellent agreements in the organ/tissue dose coefficients between the Korean and ICRP phantoms were observed for the most energies except for the low energies (<0.1 MeV), in which significant differences were observed. For example, the colon dose coefficient of the female MRKP was ∼1780 times lower at 0.02 MeV for LLAT. For electrons, while excellent agreements were observed at the energies > ∼30 MeV, significant differences were observed in the lower energy region, especially from 0.3 to 20 MeV. For example, the gonad dose coefficient of the male MRKP was ∼57 times lower at 1.5 MeV for PA. When comparing the effective dose coefficients, the differences were generally small, i.e., generally less than 20 %, for both photons and electrons, although some exposure cases showed notable differences (e.g., 32 % at 0.03-MeV photon and 61 % at 10-MeV electron for PA).

Brain Tumor Detection and Size Estimation using Microwave Imaging

This project focuses on developing an antenna that utilising microwave imaging technology for visualising, detecting, and estimating the size of human tumors using simulation approach. A rectangular microstrip patch antenna is chosen for its advantages of low cost, convenience, efficiency, and compactness, offering a non-ionised alternative. To meet the antenna specifications, rectangular slots are incorporated into the design. The antenna performs effectively at 7.5 GHz, exhibiting a return loss of -24.20383 dB, well below the -10 dB threshold. Placing the antenna 15 mm away from the human brain model results in a specific absorption rate (SAR) value of 0.2 W/kg for 10g, indicating its safety for brain imaging. By scanning a human head phantom with and without a tumor, the antenna captures reflected signals from different locations, enabling the generation of tumour images. A 10-mm-radius tumor is introduced to the phantom, and the unique reflected signal serves as an indicator for tumor detection, using the signal without a tumor as a reference. MATLAB software is employed for image processing, allowing the generation of tumour images and the estimation of tumor size. The simulation results demonstrate 63% accuracy in tumor size estimation. In conclusion, the antenna proves to be a safe and effective brain imaging system for tumor detection.

Investigation of Radiation Exposure of Medical Staff During Lateral Fluoroscopy for Posterior Spinal Fusion Surgery.

Background/Objectives: In spinal surgery, it is especially crucial to insert implants in the correct location. Intraoperative fluoroscopy is often necessary to safely perform spinal surgery because of serious complications that can occur if the screw deviates. However, the use of intraoperative fluoroscopy comes at the cost of radiation exposure to the surgeons and operating room staff. Therefore, it is desirable for spinal surgeons to understand the characteristics of radiation in order to minimize patient and medical staff exposure. This study aimed to create an aerial radiation dose distribution map for lateral fluoroscopy, a commonly used technique for posterior spinal fusion. Methods: A human body-equivalent phantom was placed in a prone position on the Jackson Table. The measurement method used was a lateral fluoroscopic evaluation, assuming posterior spinal fusion. Measurements were taken at three levels: 80 (gonadal), 100 (thoracoabdominal), and 150 cm (lens and thyroid). Results: The highest radiation doses were received by primary surgeons. The scrub nurse was the next most exposed. Conclusions: We developed an aerial dose distribution map for lateral fluoroscopy in posterior spinal fusion. Radiation exposure was the highest among primary surgeons.

Automated, Reproducible, and Reconfigurable Human Head Phantom for Experimental Testing of Microwave Systems for Stroke Classification

ABSTRACTMicrowave systems for prehospital stroke classification are currently being developed. In the future, these systems should enable rapid recognition of the type of stroke, shorten the time to start treatment, and thus significantly improve the prognosis of patients. In this study, we realized a realistic and reconfigurable 3D human head phantom for the development, testing, and validation of these newly developed diagnostic methods. The phantom enables automated and reproducible measurements for different positions of the stroke model. The stroke model itself is also interchangeable, so measurements can be made for different types, sizes, and shapes of strokes. Furthermore, an extensive series of measurements was performed at a frequency of 1 GHz, and an SVM classification algorithm was deployed, which successfully identified ischemic stroke in 80% of the corresponding measured data. If similar classification accuracy could be achieved in patients, it would lead to a dramatic reduction in the consequences of strokes.

How does the position of the pelvis and femur influence the selection of prosthesis size during 2D preoperative planning for total hip arthroplasty?

PurposeTotal Hip Arthroplasty (THA) is the primary treatment for hip diseases today. Nevertheless, total hip arthroplasty has its challenges, and one of these challenges is the potential for incorrect execution of the preoperative planning process. Such errors can lead to complications such as loosening and instability of the prosthesis and leg length discrepancy. In this study, we used human phantoms to investigate the influence of pelvic and femoral factors on prosthesis size selection in the preoperative planning of total hip arthroplasty and to provide a reference standard for clinical imaging in preoperative planning of total hip arthroplasty.MethodsIn this experiment, we utilised a custom-made experimental device that enabled us to manipulate the movement of the pelvis and femur in various directions. The device also incorporated sensors to control the angle of movement. By obtaining X-rays from different positions and angles, we were able to determine the size of the prosthesis based on the 2D preoperative planning generated by the mediCAD software.ResultsWhen the pelvis was in a nonneutral position, the size of the acetabular cup varied within a range of three sizes. Similarly, when the femur was in a nonneutral position, the size of the femoral stem varied within a range of two sizes. The movement of the pelvis and femur in the coronal plane, relative to the neutral position, did not impact the selection of the prosthesis size. However, the motion of the pelvis and femur in the sagittal and transverse planes had a notable effect.ConclusionThe selection of the prosthesis size for preoperative planning can be significantly influenced by specific positions of the pelvis and femur. It is crucial for the radiographer to ensure that the pelvis and femur maintain a standard neutral position, particularly in the sagittal and transverse planes, during the image acquisition process.

Photon-counting computed tomography versus energy-integrating computed tomography for detection of small liver lesions: comparison using a virtual framework imaging.

Photon-counting computed tomography (PCCT) has the potential to provide superior image quality to energy-integrating CT (EICT). We objectively compare PCCT to EICT for liver lesion detection. Fifty anthropomorphic, computational phantoms with inserted liver lesions were generated. Contrast-enhanced scans of each phantom were simulated at the portal venous phase. The acquisitions were done using DukeSim, a validated CT simulation platform. Scans were simulated at two dose levels ( 1.5 to 6.0mGy) modeling PCCT (NAEOTOM Alpha, Siemens, Erlangen, Germany) and EICT (SOMATOM Flash, Siemens). Images were reconstructed with varying levels of kernel sharpness (soft, medium, sharp). To provide a quantitative estimate of image quality, the modulation transfer function (MTF), frequency at 50% of the MTF ( ), noise magnitude, contrast-to-noise ratio (CNR, per lesion), and detectability index ( , per lesion) were measured. Across all studied conditions, the best detection performance, measured by , was for PCCT images with the highest dose level and softest kernel. With soft kernel reconstruction, PCCT demonstrated improved lesion CNR and compared with EICT, with a mean increase in CNR of 35.0% ( ) and 21% ( ) and a mean increase in of 41.0% ( ) and 23.3% ( ) for the 1.5 and 6.0mGy acquisitions, respectively. The improvements were greatest for larger phantoms, low-contrast lesions, and low-dose scans. PCCT demonstrated objective improvement in liver lesion detection and image quality metrics compared with EICT. These advances may lead to earlier and more accurate liver lesion detection, thus improving patient care.

Monte Carlo simulation study of the effect of thyroid shielding on radiation dose in dental cone beam CT in an adult male phantom.

In this paper, the effect of thyroid collars on radiation dose during dental cone-beam computed tomography (CBCT) was evaluated using Monte Carlo simulations and to calculate the effective dose underestimated for the actual CBCT examination due to accounting only for the head and neck. Three thyroid collar models that covered the surface of the phantom were established according to the International Commission on Radiological Protection (ICRP) adult-male mesh-type reference computational phantoms, and a Particle and Heavy Ion Transport code System was used to calculate the equivalent and effective doses of ICRP phantom when different thyroid shielding protocols were used in NewTom VGi evo CBCT, considering one medium (12×8cm) and one small (8×5cm) fields of view (FOVs), and two centre positions were used for each FOV. In four CBCT scanning scenarios, thyroid shielding reduced the equivalent dose for many tissues. The results indicate that the portion of the thyroid collar that wraps around the neck has the main role in reducing the effective dose during dental CBCT examinations, and the higher the axial level of the top of the shielding, the better the effectiveness of the shielding. In this study, the underestimation of the effective dose due to considering only the head and neck was 3.1%-8.1%, and the underestimation was more pronounced in larger FOVs.

Comparing organ and effective dose of various CT localizer acquisition strategies: A Monte Carlo study.

CT examinations commonly start with the acquisition of one or two localizer radiographs (2D localizers). Recently, a manufacturer introduced the option to perform a heavily filtrated low-dose helical scan as a localizer acquisition. To compare the dose of one or two 2D localizer acquisitions to the dose of a 3D localizer acquisition, one cannot simply compare the CTDIs of the different acquisition techniques, because of the use of different geometries and spectra. To compare the organ and effective dose for various CT localizer acquisition techniques. A Geant4-based Monte Carlo simulation, replicating a clinical wide-area CT scanner was developed and validated. Various localizer acquisition strategies were simulated: Anterior-posterior (AP) alone, PA alone, combined AP+lateral (LAT), and PA+LAT 2D localizers, and an Ag-filtered 3D localizer acquisition. Validation was performed by measuring and simulating CTDI100 in both the periphery and the center of a CTDI phantom. The software was subsequently used to estimate organ and effective doses for localizers for chest, abdomen+pelvis, and the combined chest, abdomen, and pelvis exams. As representations of patients, eight ICRP computational phantoms (adult, 15-, 10-, and 5-year, both male and female) and five female and five male XCAT phantoms with various BMIs were used. The dose of the various strategies was compared to the current clinically-implemented AP+LAT localizers. CTDI100-measurements and simulations within the CTDI-phantom differs by a maximum of 8.1% and by an average of 0.9%. For chest, the average effective doses for AP, PA, AP+LAT, and the 3D localizer are 0.10, 0.07, 0.32, and 0.22 mSv, respectively. The organ dose to the breast varies the most across the various localizer strategies and is, on average, 0.17, 0.03, 0.44, and 0.33 mGy, in the same order. For abdomen, the average effective doses are 0.11, 0.07, 0.36, and 0.25 mSv for the AP, PA, AP+LAT and the 3D localizer, respectively. The organ dose to the stomach varies the most across the various localizers and is on average 0.14, 0.08, 0.58, and 0.30 mGy, in the same order. The PA-only localizer results in the lowest organ dose to the most radiosensitive organs and the lowest effective dose. For the chest exam, compared to AP+LAT, the PA+LAT results in a 7±2% effective dose reduction (mean±standard deviation), while the 3D localizer results in a 21±3% effective dose reduction. Using AP or PA only would result in 69±2% and 76±2% reduction, respectively. For the abdomen exam, also compared to AP+LAT, PA+LAT results in 6±2% effective dose reduction, while the 3D localizer results in a 20±5% reduction. Using AP or PA only would result in 69±5% and 76±4% reduction, respectively. Using a PA localizer results in a lower or equivalent organ dose in the most radiosensitive organs, and a lower effective dose compared to an AP localizer for both chest and abdomen+pelvis exams. Compared to a two-localizer strategy, the 3D localizer results in a lower effective dose in both the chest and abdomen+pelvis region.

A 3D wideband electromagnetic horn antenna applicator for biomedical applications

Abstract This paper proposes a new, compact, wideband 3D horn antenna for biomedical wireless applications such as cancer and tumor detection. In order to achieve the best penetration level, the antenna has been built and tuned to work in the low frequency range of 0.48–1.24 GHz, which can exhibit a high-resolution detection result. The proposed applicator is a double ridge horn antenna (DRHA). The layout and operation of the key needed components to assemble a wideband hyperthermia system are provided in this study. We assume a cylindrical human tissue phantom with wideband dispersive tissue properties, and simulation results are given. The resulting field maps are displayed in several planes to illustrate the energy localization process. The findings indicate that, in contrast to traditional narrowband systems, wideband operation may improve energy localization in deep tumor locations while eliminating hot spots. The suggested antenna was built and measured to verify the result.

SYRMEP beamline: state of the art, upgrades and future prospects

SYRMEP is the hard X-ray imaging beamline of Elettra synchrotron offering X-ray full-field techniques, micro-computed tomography (microCT) and phase-contrast modality in the energy range 10–40 keV. The beamline operates in a multidisciplinary research context spanning from biomedical applications to botany, from zoology to food technology and cultural heritage, from materials engineering to geology and earth science. Thanks to the flexibility of SYRMEP setup, in situ experiments can be performed as well, novel imaging methods can be developed and implemented in a synergical manner with interested users and collaborators. SYRMEP peculiar wide beam together with the long sample-to-detector distance enables multiscale phase-contrast studies with optimized contrast and spatial resolution on rather large specimens, such as human lung phantoms. This is particularly relevant in view of future clinical lung imaging foreseen in the framework of Elettra 2.0 program. Here, the current beamline features and recent upgrades are illustrated, an overview of the imaging methods routinely offered to SYRMEP users’ community is presented, and the outlook for the new beamline SYRMEP-Life Science (SYRMEP-LS) is reported.