Radiation risk from medical imaging

Effects of rotation and scanning spatial resolution on gafchromic film response in high energy photon beam

One of the main parameters which can affect the precision of the gafchromic film dosimetry results is scanning procedure of irradiated films. The effects of film scanning resolution as well as film orientation inside the flat-bed scanner on the final gafchromic film response have been evaluated in the current study. Gafchromic EBT2 films were used in the current study. The films were cut into 2 × 1 cm2 and irradiated by different dose levels of 0-600 cGy using 6 MV clinical photon beam produced by an ELEKTA compact linear accelerator. To evaluate the effect of scanning spatial resolution on film response, irradiated films were scanned with different dpi values of 50, 72, 200, and 300. Accordingly, relevant signal to noise ratios (SNR) were measured. Furthermore, films were scanned at different angles of 0-, 30-, 60-, and 90-degrees respect to the scan direction and corresponding dose-response curves were acquired and compared to assess the effect of film orientation inside the scanner bed. The results showed that both parameters have a measurable impact on the film response. The SNR decreased by increasing the dpi value (e.g. SNR reduces about 50 % with changing dpi from 50 to 300). Film rotation inside the scanner bed can also considerably affect the film dose-response curve so that the film rotation from zero to 90° can change the film response by 59 % at the maximum level. Based on the results, it can be concluded that lower scanning dpi values (lower than 100) can improve the film response SNR and precision of the developed film dosimetry system. Furthermore, any film rotation during the film readout inside the scanner bed should be avoided, because it can considerably change the film response and relevant dosimetry data.

Assessment of the Effects of Ionizing Radiation on Biologic Drugs: mAb Product Quality and Risk Evaluation for Global Shipping Logistics

PURPOSE

It is critical to ensure that drug product quality is not negatively impacted after transportation and shipping so that the product remains safe and effective. The traditional shipping validation and product quality assessments focus on factors such as temperature, vibration, shock, agitation, light exposure, and potential contamination. At the same time, due to the complexity of biologics modalities including cell therapy products, the increasing prevalence of non-intrusive inspection (NII) technologies employing ionizing radiation such as X-ray and Gamma rays at security screening at border points has prompted an evaluation of their impact on biologics.

METHODS

In this study, the effect of X-ray radiation on monoclonal antibody (mAb)-related biologic drug substance and drug products was investigated by subjecting them to worst-case scenario radiation levels, approximately 200 times higher than the recommended dose, within commonly deployed shipping packaging and primary container. Subsequently, product quality attributes, including visible particles, sub-visible particles, purity, and charge variants, were assessed.

RESULTS

The results revealed no significant changes in the exposed samples compared to controls, indicating that the mAb-related biologics maintained their product quality despite exposure to heightened X-ray radiation.

CONCLUSIONS

These findings provide valuable assurance regarding the stability and safety of mAb-related biologics when subjected to X-ray radiation during transportation and security screenings. Our goal is that this work will stimulate further discussion and guidance from drug sponsors and health authorities to evaluate ionizing radiation impact on current biologics and others new modalities to ensure drug and patient safety.

Deciphering microbial and metabolic influences in gastrointestinal diseases-unveiling their roles in gastric cancer, colorectal cancer, and inflammatory bowel disease

INTRODUCTION

Gastrointestinal disorders (GIDs) affect nearly 40% of the global population, with gut microbiome-metabolome interactions playing a crucial role in gastric cancer (GC), colorectal cancer (CRC), and inflammatory bowel disease (IBD). This study aims to investigate how microbial and metabolic alterations contribute to disease development and assess whether biomarkers identified in one disease could potentially be used to predict another, highlighting cross-disease applicability.

METHODS

Microbiome and metabolome datasets from Erawijantari et al. (GC: n = 42, Healthy: n = 54), Franzosa et al. (IBD: n = 164, Healthy: n = 56), and Yachida et al. (CRC: n = 150, Healthy: n = 127) were subjected to three machine learning algorithms, eXtreme gradient boosting (XGBoost), Random Forest, and Least Absolute Shrinkage and Selection Operator (LASSO). Feature selection identified microbial and metabolite biomarkers unique to each disease and shared across conditions. A microbial community (MICOM) model simulated gut microbial growth and metabolite fluxes, revealing metabolic differences between healthy and diseased states. Finally, network analysis uncovered metabolite clusters associated with disease traits.

RESULTS

Combined machine learning models demonstrated strong predictive performance, with Random Forest achieving the highest Area Under the Curve(AUC) scores for GC(0.94[0.83-1.00]), CRC (0.75[0.62-0.86]), and IBD (0.93[0.86-0.98]). These models were then employed for cross-disease analysis, revealing that models trained on GC data successfully predicted IBD biomarkers, while CRC models predicted GC biomarkers with optimal performance scores.

CONCLUSION

These findings emphasize the potential of microbial and metabolic profiling in cross-disease characterization particularly for GIDs, advancing biomarker discovery for improved diagnostics and targeted therapies.

Intra- and inter-rater reliability of anterior and posterior drawer tests for the assessment of people with shoulder instability

BackgroundThe well-known drawer tests to assess glenohumeral laxity and instability have shown appropriate reliability, although analysed mainly in healthy subjects.ObjectiveTo evaluate the intra- and inter-rater reliability of anterior and posterior drawer tests in subjects with symptoms of shoulder instability.DesignClinometric study of intra- and inter-rater reliability of drawer tests was carried out following COSMIN recommendations and GRRAS checklist.SettingCentres with equipped facilities for assessments.ParticipantsThere were 105 participants (69 male/36 female) aged 18 to 60 years with instability symptoms in at least one shoulder. Each participant underwent bilateral assessments. The sample consists of 210 shoulders, unstable and healthy.InterventionAnterior and posterior drawer tests.Main measuresHumeral translations were assessed using drawer tests and graded with Hawkins scale, modified Hawkins and dichotomising (positive/negative). Two sessions were performed (seven to fourteen-day washout period): Each patient was evaluated by two examiners in the first session and by one of them in the second. Weighted Kappa analysed the reliability.ResultsThe intra-rater reliability of the anterior and posterior drawer tests was excellent (weighted Kappa = 1) with the Hawkins scale. Inter-rater reliability was good for the anterior drawer: weighted Kappa = 0.76 (95%confidence interval: 0.67-0.85) with the Hawkins scale, weighted Kappa = 0.78 (95%confidence interval: 0.69-0.87) with modified Hawkins, and weighted Kappa = 0.80 (95%confidence interval: 0.71-0.89) dichotomising; and for the posterior drawer: weighted Kappa = 0.62 (95%confidence interval: 0.52-0.72), weighted Kappa = 0.67 (95%confidence interval: 0.57-0.78), and weighted Kappa = 0.70 (95%confidence interval: 0.59-0.80), respectively.ConclusionDrawer tests demonstrated excellent intra-rater and good inter-rater reliability in subjects with symptoms of shoulder instability.

Guidance for chest-CT in children and adults with cystic fibrosis: A European perspective

The European Cystic Fibrosis Society-Clinical Trials Network (ECFS-CTN) herein proposes guidance for the use of chest CT-scans for the regular monitoring of lung disease in CF. Statements were completed in a 3-step process: the questions were identified via an anonymous online survey, followed by a comprehensive literature search, and a final Delphi process. The guidance recommends the use of ultra-low dose CT scans (effective radiation dose, 0.08 mSv; equivalent to 2 to 4 chest X-rays), tracking of patients' cumulative radiation and effective communication strategies using "de-medicalized" information for shared decision making. Chest CT scans (with lung volume monitoring) are not recommended systematically in both children and adults. Ultimate responsibility for justifying a chest CT scan lies with the individual professionals directly involved, the final decision being influenced by indications, costs, expertise, available material, resources and/or the patient's values, as well as possible impact on treatment modalities.

Radiation in the Bronchoscopy Suite: One Center's Experience With Navigational Bronchoscopy and a Review of the Literature

BACKGROUND

This study aimed to quantify radiation doses during navigational bronchoscopy procedures, comparing them with reported cohorts and evaluating the LungVision (Body Vision Medical Inc.) system's efficacy in dose reduction.

METHODS

This retrospective observational study included 52 consecutive navigational bronchoscopy cases, categorized into 4 imaging groups based on the C-arm: Cios Spin (Siemens Healthineers), or OEC 9900 (GE HealthCare); and the 3D tomographic imaging algorithm: Cios Spin's onboard imaging, or LungVision's AI-driven imaging. Patient and lesion data, outcomes, and radiation indices were collected. Existing literature on 3D image guidance for bronchoscopic lung nodules was reviewed to compare reported radiation doses.

RESULTS

Combining LungVision with Cios Spin significantly reduced radiation dose in all cases compared with using Cios Spin alone: Cumulative air kerma (Ka,r) reduced from 238.7 to 119.1 mGy (P=0.03), and air kerma-area product (KAP) decreased from 28.19 to 15.09 Gy·cm2 (P=0.03). For biopsy cases, LungVision led to notable dose reductions: Ka,r of 279 to 129.1 mGy, and KAP of 30.70 to 16.27 Gy·cm2. LungVision notably reduced radiation indices in 7 paired spins, isolating the 3D imaging algorithm as the sole variable with the same Cios Spin C-arm. A literature review provides additional context on radiation for bronchoscopic biopsies.

CONCLUSION

Following the "as low as reasonably achievable" (ALARA) principle minimizes ionizing radiation exposure, benefiting patients and operators. Physicians should compare baseline radiation levels with the literature and adopt dose-reduction techniques. LungVision's lower dose indices render it effective for real-time 3D imaging during navigational bronchoscopy while reducing radiation dose.

Development of a personalized parametric finite element model of the knee: Evaluation of geometric variables affecting osteoarthritis progression

Background

Osteoarthritis is a degenerative condition that impacts synovial joints, particularly the knee joint. Researchers regard Finite Element Analysis as a promising technique for managing knee osteoarthritis. However, these models often depend on input geometry from one or more individuals, feature complex interfaces, and require a significant amount of time, which makes them unsuitable for clinical use and reduces their reliability.

Purpose

This study aims to assess the effectiveness of the personalized parametric model technique in predicting the knee joint's mechanical response, taking into account anatomical variables that influence osteoarthritis.

Methods

A 3D model of the knee was created from CT images of a patient with knee osteoarthritis. Lateral, anterior, and posterior knee radiographs were obtained from twenty-six subjects to customize the geometric parameters of the developed parametric model. The knee geometry was parameterized using Ansys software. The models used six parameters to represent the articular surface of the tibial plateau, its slope, and variables attached to the medial and lateral femoral condyles. Parametric FE models were created individually by applying the ground reaction force diagram to each model.

Results

Mean maximum von Mises stress was higher in the OA group than in the control group. Simulations of the patients in the OA group indicated that the mean von Mises stress at the articular surfaces diminished with an increase in tibial plateau tilt. Also, individual geometry-specific models exhibited varying responses, thereby confirming the significance of taking personalized geometry into account.

Conclusion

Personalized models can be used to simulate mechanical responses and specifically evaluate the effect of the tibial plateau tilt. This work presented an innovative method for creating individualized finite element models of osteoarthritic knees, which can be used as a practical and effective tool in clinical environments.

Quantum-Dot Ceramic Composites for Oxidative Stress Mitigation under Broad-Spectrum Radiation Exposure

Nanomaterials offer a promising approach to mitigating radiation-induced oxidative stress by scavenging reactive oxygen species (ROS). However, developing a nanomaterial that provides protection across a wide range of radiation conditions is challenging due to the photoelectric effects linked to the atomic number (Z) of the materials. Quantum dots (QDs) in a composite system, owing to their small size and when used at low concentrations, minimize photoelectric effects and secondary electron generation. In this study, cerium oxide (CeO2) QDs were combined with low-Z yttrium oxide (Y2O3) to create a nanocomposite (NC) (henceforth CeO2 QDs-Y2O3) that exploits the synergistic effects of both materials, providing protection across a broader spectrum of radiation. CeO2 QDs-Y2O3 demonstrated superior ROS scavenging than individual CeO2 and Y2O3 under nonradiative conditions, particularly for hydroxyl radicals (•OH) and hydrogen peroxide (H2O2), two primary ROS generated under radiation. This improved performance, due to increased oxygen vacancies and a higher Ce3+/Ce4+ ratio, indicates that these properties could help protect cells from oxidative stress during radiation exposure. Radioprotection analysis using the linear-quadratic (LQ) model revealed that the NC provided effective protection at both 150 kVp and 10 MV radiation energies. At 150 kVp, the obtained protection enhancement ratio (PER) values at 10% cell survival for CeO2 QDs-Y2O3, Y2O3, and CeO2 were 1.07, 1.16, and 0.89, respectively, suggesting that the radioprotection afforded by Y2O3 in the NC outweighed the radiosensitization of the encrusted CeO2 QDs. Additionally, despite the higher PER of Y2O3, the NC displayed increased biocompatibility toward the human keratinocyte HaCaT cell line in the absence of radiation compared to Y2O3. At 10 MV, where photoelectric effects are minimal, the NC outperformed both individual components, yielding a PER of 1.28, or a 28% dose enhancement compared to 12% for Y2O3 alone and 19% for CeO2. This study highlights the potential of CeO2 QDs-Y2O3 as a broad-spectrum radioprotective agent, offering enhanced biocompatibility and effective protection against radiation-induced oxidative stress across broad-ranging radiation conditions.

Diagnostic Performance of Advanced Tomosynthesis in Patients with Metal Devices in the Affected Knee: A Case Report

Simple radiography is the most frequently and widely available technology to examine bone pathologies. Computed tomography (CT) can evaluate pathologies more accurately in multiple planes and three dimensions; however, radiation exposure is much higher than with simple radiography. In addition, diagnostic ability is decreased for both technologies when metal devices are present. Tomosynthesis is a radiographic technology used to evaluate tissues quasi-three-dimensionally with less radiation exposure. Tomosynthesis technology was recently upgraded to reduce the effects of metal artifacts. This case report compares examination time, medical expense, image resolution, and radiation exposure for upgraded tomosynthesis, simple radiography, CT, and standard tomosynthesis in three patients with metal devices in the affected knees. Examination times were similar for the imaging technologies. Diagnostic performance was better for upgraded tomosynthesis than for simple radiography and standard tomosynthesis, and similar to that for CT. Moreover, radiation exposure and expense were higher for tomosynthesis than for simple radiography but lower than for CT. These findings suggest that upgraded tomosynthesis is the best method for evaluating bone pathology when metal devices are present and radiation exposure must be limited.

Radiation Dose Savings Associated with Personalized CT Scan Range in 18F-NaF Bone PET/CT

A disadvantage of 18F-NaF PET/CT compared with other types of bone scintigraphy is the additional radiation dose from the standard whole-body CT scan for lesion localization and characterization (L/C). This study investigated whether the L/C CT region can be personalized to reduce CT radiation dose, according to uptake in the PET images. Methods: Attenuation-corrected 18F-NaF PET images were reviewed for the clinically required L/C CT range by 1 medical observer and 1 technologist observer in 25 patients with breast cancer scanned before neoadjuvant chemotherapy. For each patient, effective doses were estimated for whole-body L/C CT, personalized L/C CT, and whole-body CT for attenuation correction only. Dose savings for the personalized method incorporating both whole-body CT for attenuation correction and personalized L/C CT were expressed relative to standard whole-body L/C CT. The clinical impact of the personalized method was determined by evaluating whether lesions clinically requiring coverage had been missed from the L/C CT region. Results: Potential dose savings of 43%-54% were estimated for the personalized CT method, according to the observers. From the 25 patients reviewed, the medical observer did not miss any clinically significant lesions from the L/C CT region, whereas the technologist observer missed 2 clinically significant lesions of 61 suggestive lesions identified by medical observer follow-up. Conclusion: Mean CT dose could be reduced by around half in this patient group with personalized CT. Future work should further evaluate whether this method can be implemented in clinical practice without compromising clinical image evaluation.

Knowledge and perceptions of ionising radiation among Croatian general practitioners: is there cause for concern?

Recent data suggest that general practitioners (GPs) are insufficiently familiar with health risks associated with ionising radiation and radiation doses. The aim of our cross-sectional study was therefore to see if this holds true for Croatian GPs. To do that, we distributed a questionnaire about ionising radiation and doses used in various radiological procedures by email or by handing it out to participants at a national GP conference. We received responses from 120 participating GPs. Most were women (83.1 %), and the mean participant age was 44.2 years (range 26-65) with mean practice of 17.1 years (range 1-40). Most participants (97 %) believed patients should be informed about the procedures they were referred to. All respondents knew that radiological procedures irradiate the patient's body, but not everyone agreed that they could be harmful. Less than half (47 %) thought that exposure to a single irradiation dose was enough to increase cancer risk. Most participants (89.2 %) identified X-ray scans as the largest irradiation source, whereas three GPs replied that computed tomography (CT) and conventional X-ray procedures did not involve radiation. Some respondents did not know if ultrasound involved ionising radiation. Although most GPs were women, only 21.7 % correctly identified the radiation dose in mammography. Our findings confirm inadequate GPs' knowledge of radiation exposures and call for better training programmes as part of continuing professional development.

Advancing Exposure Index in Radiology for Optimized Imaging, Accuracy, and Future Innovations

Exposure index (EI) is a critical parameter in digital radiography, providing a quantitative measure of the radiation dose received by the detector. This review examines the significance of EI, methods for its determination, influencing factors, and clinical implications. Additionally, it explores challenges in standardization efforts and the role of emerging technologies, particularly artificial intelligence (AI), in optimizing exposure management. A comprehensive review of literature published over the last two decades was conducted using databases such as PubMed, ScienceDirect, and Google Scholar. Studies addressing EI measurement, clinical applications, and advancements in exposure monitoring technology were analyzed. Guidelines from the International Electrotechnical Commission (IEC), the American Association of Physicists in Medicine (AAPM), and the European Federation of Organizations for Medical Physics (EFOMP) were also reviewed to assess standardization efforts and best practices. Findings highlight the importance of EI in radiation dose optimization and quality control. Despite standardization initiatives, variations persist across manufacturers and imaging systems due to factors such as patient characteristics, beam energy, detector sensitivity, and post-processing algorithms. Artificial intelligence-driven exposure monitoring systems have shown promise in enhancing EI accuracy and enabling real-time dose adjustments. Artificial intelligence technologies have the potential to revolutionize EI utilization by enabling automated exposure optimization, real-time monitoring, and predictive analytics. Future efforts should focus on refining AI algorithms, ensuring cross-platform standardization, and enhancing radiographer training to fully integrate AI into EI-based radiation safety protocols.

Serum microRNA-146a-5p and microRNA-221-3p as potential clinical biomarkers for papillary thyroid carcinoma

PURPOSE

Papillary thyroid carcinoma (PTC) is the most common malignant thyroid neoplasm, accounting for approximately 85% of all follicular cell-derived thyroid nodules. This study aimed to assess the diagnostic potential of circulating microRNA-146a-5p and microRNA-221-3p as biomarkers for PTC and their usefulness in monitoring disease progression during patient follow-up.

METHODS

An observational study was conducted on two cohorts of PTC patients and healthy controls (HCs) using digital PCR. We collected patients' clinical, biochemical, and imaging data during the post-surgery surveillance. We analyzed the levels of circulating miRNAs in serum samples of patients before surgery and during the follow-up, including those with indeterminate/biochemical incomplete response (IndR/BIR) and residual thyroid tissues (Thy Residue).

RESULTS

Both miR-146a-5p and miR-221-3p were confirmed as effective biomarkers for PTC diagnosis. They enabled differentiation between pre-surgery PTC patients and HCs with an area under the curve (AUC) of 92% and 87.3%, respectively, using a threshold level of 768,545 copies/uL for miR-146a-5p and 389,331 copies/uL for miR-221-3p. It was found that miRNA fold change levels, rather than absolute levels, can be useful during patient follow-up. In particular, we found that a fold change of 2 for miR-146a-5p and 2.2 for miR-221-3p can identify a progressive disease, regardless of the presence of TgAbs or remnant thyroid.

CONCLUSION

MiRNA-146a-5p and miRNA-221-3p, particularly the former, could be valuable diagnostic biomarkers for PTCs. They also seem to be effective in monitoring disease progression during patient follow-up by evaluating their fold change, even when thyroglobulin is uninformative.

CAR/CSTR Practice Guideline on CT Screening for Lung Cancer

Lung cancer is the second-most diagnosed cancer and the leading cause of cancer-related death in Canada. The updated CAR/CSTR Practice Guideline on CT Screening for Lung Cancer reflects advancements in evidence since the 2016 guideline, including findings from the NELSON trial and preliminary data from multiple provincial lung cancer screening programs, and aims to support Canadian diagnostic imaging departments in implementing organized lung cancer screening programs. The guideline emphasizes screening with the use of low-dose CT (LDCT) to reduce lung cancer mortality in appropriately selected individuals with increased risk of lung cancer, using eligibility criteria based on risk prediction models such as the PLCOm2012. It outlines training requirements for radiologists, standardized CT and reporting protocols, quality assurance measures, and the integration of AI tools for nodule risk stratification. The document also highlights emerging areas for investigation, including the potential for biennial screening and equitable access to programs across Canada.

Computed Tomography Doses Calculation: Do We Really Need a New Dose Assessment Tool?

Background/Objectives: The increasing use of computed tomography (CT) scans significantly contributes to population exposure to ionizing radiation. Traditional dose metrics, such as dose-length product (DLP) and effective dose (ED), lack precision in reflecting individual radiation exposure. This study introduces a novel parameters such as size-specific effective dose (EDss) and the size-specific dose-length product (DLPss), to improve patient-specific dose estimation. The aim of this study is to enhance dose calculation accuracy, optimize CT protocols, and guide the development of next-generation CT technologies. Methods: A retrospective analysis of 247 abdominal and pelvic CT scans (113 women, 134 men) was conducted. Anthropometric parameters, including body mass index (BMI), cross-sectional dimensions, and dose indices, were measured. EDss and DLPss were calculated using size-specific correction factors, and statistical correlations between these parameters were assessed. Results: The mean BMI was 25.92 ± 5.34. DLPss values ranged from 261.63 to 1217.70 mGy·cm (mean: 627.83 ± 145.32) and were roughly 21% higher than traditional DLP values, with men showing slightly higher mean values than women. EDss values ranged from 6.65 to 15.45 mSv (mean: 9.42 ± 2.18 mSv), approximately 22% higher than traditional ED values, demonstrating improved individualization. Significant correlations were observed between BMI and effective diameter (r = 0.78), with stronger correlations in men (r = 0.85). The mean CTDIvol was 11.37 ± 3.50 mGy, and SSDE averaged 13.91 ± 2.39 mGy. Scan length reductions were observed in 53.8% of cases, with statistically significant differences by gender. Conclusions: EDss and DLPss offer improved accuracy in radiation dose estimation, addressing the limitations of traditional methods. Their adoption into clinical protocols, supported by AI-driven automation, could optimize diagnostic safety and significantly reduce radiation risk for patients. Further multicenter studies and technological advancements are recommended to validate these metrics and facilitate their integration into daily practice.

The Impact of Videofluoroscopic Pulse Rate on Duration and Kinematic Measures in Infants and Adults with Feeding and Swallowing Disorders

This investigation assessed the impact of temporal resolution during a videofluoroscopic evaluation of swallowing (VFSS) on measures of duration and kinematics. Thirty adult and ten infant swallow studies, all acquired at 30 frames and 30 pulses per second, were obtained from a New Mexico hospital. All swallow studies were altered to simulate 15 and 5 pulses per second. Duration measures included pharyngeal response time, duration of upper esophageal sphincter (UES) opening, velopharyngeal closure duration and total swallow duration. Kinematic measures were assessed in adults only and included peak hyoid position and extent of UES opening during the swallow. Analysis of outcome measures was performed and compared across the three temporal resolutions (30, 15, and 5 pulses per second). For data points where normative values are available, we evaluated the impact of temporal resolution on clinical determination (i.e., did a change in pulse rate alter the clinical classification). Kinematic and duration measures were altered with changes in pulse rate and these changes increased as temporal resolution decreased. For outcome measures where normative values are available, accuracy of clinical determination decreased with decreased pulse rate. Temporal resolution impacts duration and kinematic measures. However, the direction of these changes is unpredictable, indicating sensitivity and specificity are both affected. Without a predictable impact, the use of lower pulse rates may alter clinical impressions and treatment recommendations yielding inappropriate treatment goals and treatment duration.

Assessment of scattered and leakage radiation from ultra-portable X-ray systems in chest imaging: An independent study

Ultraportable (UP) X-ray devices are ideal to use in community-based settings, particularly for chest X-ray (CXR) screening of tuberculosis (TB). Unfortunately, there is insufficient guidance on the radiation safety of these devices. This study aims to determine the radiation dose by UP X-ray devices to both the public and radiographers compared to international dose limits. Radiation dose measurements were performed with four UP X-ray devices that met international criteria, utilizing a clinically representative CXR set-up made with a thorax phantom. Scatter and leakage radiation dose were measured at various positions surrounding the phantom and X-ray tube, respectively. These measurements were used to calculate yearly radiation doses for different scenarios based on the median of all UP X-ray devices. From the yearly scatter doses, the minimum distances from the phantom needed to stay below the international public dose limit (1 mSv/year) were calculated. This distance was longest in the direction back towards the X-ray tube and shortest to the left/right sides of the phantom, e.g., 4.5 m and 2.5 m resp. when performing 50 exams/day, at 90 kV, 2.5 mAs and source skin distance (SSD) 1 m. Additional calculations including leakage radiation were conducted at a typical radiographer position (i.e., behind the X-ray tube), with a correction factor for wearing a lead apron. At 2 m behind the X-ray tube, a radiographer wearing a lead apron could perform 106 exams/day at 2.5 mAs and 29 exams/day at 10 mAs (90 kV, SSD 1 m), while keeping his/her radiation dose below the public dose limit (1 mSv/year) and well below the radiographer dose limit (20 mSv/year). In most CXR screening scenarios, the radiation dose of UP X-ray devices can be kept below 1 mSv/year by employing basic radiation safety rules on time, distance and shielding and using appropriate CXR exposure parameters.

Differential Diagnosis of Urinary Cancers by Surface-Enhanced Raman Spectroscopy and Machine Learning

Bladder, kidney, and prostate cancers are prevalent urinary cancers, and developing efficient detection methods is of significance for the early diagnosis of them. However, noninvasive and sensitive detection of urinary cancers still challenges traditional techniques. In this study, we developed a SERS-based method to analyze serum samples from patients with urinary cancers. Rapid, label-free, and highly sensitive detection of human sera is achieved by cleaning and aggregating silver nanoparticles. Furthermore, a long short-term memory deep learning algorithm is used to distinguish serum spectra, and the performance of the model is evaluated by comparing the accuracy, sensitivity, specificity, and receiver operating characteristic curves. Taking advantage of SERS and machine learning in sensitivity and data processing, the three urinary cancers are clearly classified. This is the first attempt to exploit the SERS-machine learning strategy to discriminate multiple urinary cancers with clinical serum samples, and our results showed the potential application of this method in the early diagnosis and screening of cancers.

Radiographers' perspective of patient safety at ultrasound units in radiology departments

INTRODUCTION

The radiology department plays an important role in healthcare settings, facilitating diagnoses using different imaging modalities, including ultrasound. However, this high-tech environment can pose various risks to patients. In this study, we aimed to describe the risk of patient safety incidents, and factors associated with the prevention of risks related to ultrasound examinations and the diagnostic work, from the perspective of Swedish radiographers.

METHODS

We conducted a qualitative study, based on the written answers to three open-ended questions addressed to Swedish radiographers in ultrasound units of radiology departments, between March 2022 and May 2023. Data from the responses were analyzed using content analysis.

RESULTS

A total of 22 radiographers participated in this study. The described risks were categorized into two groups: risk of tissue damage; and risk of missed, delayed, or incorrect diagnoses. Participants stated that patient safety relied on good organizational conditions-such as having enough time for ultrasound examinations and the diagnostic work, together with adequate technical equipment and new ultrasound devices not older than 5 years. As risk-prevention factors, the radiographers recommended ensuring adequate individual competence-for example, through recurrent mandatory education in ultrasound physics and safety performed by the hospital physicist, and by implementing a certificate with an identified level of expertise at every level of the ultrasound examination.

CONCLUSIONS

Within ultrasound units in Sweden, collaborative individual, organizational, and technical factors are important for reducing the risks of tissue damage and of missed, delayed, or incorrect diagnoses.

IMPLICATIONS FOR PRACTICE

In ultrasound diagnostics, risk-preventing factors include the use of adequate technical equipment and ultrasound devices not older than 5 years, sufficient time for ultrasound examinations and diagnostic work, thoroughly education in all ultrasound methods and recurrent mandatory education in ultrasound physics performed by hospital physicists.

Use of optical techniques to evaluate the ionizing radiation effects on biological specimens

Radiation induces various changes in biological specimens; however, the evaluation of these changes is usually complicated and can be achieved only through investment in time and labor. Optical methods reduce the cost of such evaluations as they require less pretreatment of the sample, are adaptable to high-throughput screening and are easy to automate. Optical methods are also advantageous, owing to their real-time and onsite evaluation capabilities. Here, we discuss three optical technologies to evaluate the effects of radiation on biological samples: single-molecule tracking microscopy to evaluate the changes in the physical properties of DNA, Raman spectral microscopy for dosimetry using human hair and second-harmonic generation microscopy to evaluate the effect of radiation on the differentiation of stem cells. These technologies can also be combined for more detailed information and are applicable to other biological samples. Although optical methods are not commonly used to evaluate the effects of radiation, advances in this technology may facilitate the easy and rapid assessment of radiation effects on biological samples.

Assessing Therapeutic Nanoparticle Accumulation in Tumors Using Nanobubble-Based Contrast-Enhanced Ultrasound Imaging

This study explores the challenges associated with nanoparticle-based drug delivery to the tumor parenchyma, focusing on the widely utilized enhanced permeability and retention effect (EPR). While EPR has been a key strategy, its inconsistent clinical success lacks clear mechanistic understanding and is hindered by limited tools for studying relevant phenomena. This work introduces an approach that employs multiparametric dynamic contrast-enhanced ultrasound (CEUS) with a nanoscale contrast agent for noninvasive, real-time examination of tumor microenvironment characteristics. We demonstrate that CEUS imaging can: (1) evaluate tumor microenvironment features, (2) be used to help predict the distribution of doxorubicin-loaded liposomes in the tumor parenchyma, and (3) be used to predict nanotherapeutic efficacy. CEUS using nanobubbles (NBs) was carried out in two tumor types of high (LS174T) and low (U87) vascular permeability. LS174T tumors consistently showed significantly different time intensity curve (TIC) parameters, including area under the rising curve (AUCR, 2.7×) and time to peak intensity (TTP, 1.9×) compared to U87 tumors. Crucially, a recently developed decorrelation time (DT) parameter specific to NB CEUS dynamics successfully predicted the distribution of doxorubicin-loaded liposomes within the tumor parenchyma (r = 0.86 ± 0.13). AUCR, TTP, and DT were used to correlate imaging findings to nanotherapeutic response with 100% accuracy in SKOV-3 tumors. These findings suggest that NB-CEUS parameters can effectively discern tumor vascular permeability, serving as a biomarker for identifying tumor characteristics and predicting the responsiveness to nanoparticle-based therapies. The observed differences between LS174T and U87 tumors and the accurate prediction of nanotherapeutic efficacy in SKOV-3 tumors indicate the potential utility of this method in predicting treatment efficacy and evaluating EPR in diseases characterized by pathologically permeable vasculature. Ultimately, this research contributes valuable insights into refining drug delivery strategies and assessing the broader applicability of EPR-based approaches.

Radiation exposure and safety in low-dose CT-guided glycerol rhizotomy for trigeminal Neuralgia outside the operating room

BACKGROUND

Percutaneous rhizotomy of the Gasserian ganglion is a well-established intervention for patients suffering from refractory trigeminal pain, not amenable to pharmacological management or microvascular decompression. Traditionally conducted under fluoroscopic guidance using Hartel's technique, this study investigates a modified approach employing low-dose CT guidance to achieve maximal procedural precision and safety with the emphasis on minimizing radiation exposure.

METHODS

A retrospective analysis of patients undergoing percutaneous rhizotomy of the Gasserian ganglion at our institution was undertaken. Procedures were divided into fluoroscopy and CT-guided foramen ovale (FO) cannulation cohorts. Radiation doses were assessed, excluding cases with incomplete data. The study included 32 procedures in the fluoroscopy group and 30 in the CT group.

RESULTS

In the CT-guided group, the median effective dose was 0.21 mSv. The median number of CT scans per procedure was 4.5, and the median procedure time was 15 min. Successful FO cannulation was achieved in all 30 procedures (100%). In the fluoroscopy group, the median effective dose was 0.022 mSv, and the median procedure time was 15 min. Cannulation of FO was successful in 31 of 32 procedures (96.9%). The only complications in the CT-guided group were three minor cheek hematomas. Immediate pain relief in the CT-guided group was reported in 25 of 30 procedures (83.3%), 22 of 30 (73.3%) provided relief at one month, and 10 of 18 (55.6%) procedures resulting in pain relief at one month continued to provide relief after two years.

CONCLUSION

Low-dose CT-guided percutaneous rhizotomy conducted in the radiology suite carries negligible radiation exposure for patients and eliminates it for personnel. This method is fast, simple, precise, and carries a very low risk of complications.

Overuse of CT for Minor Head Trauma Patients: A Retrospective Analysis from Poland and Lithuania Trauma Centres

Background and Objectives: Head trauma is one of many conditions that trauma centres deal with daily. This study aimed to analyse the utilisation of head CT scans for patients with minor head trauma in two major hospitals in Lithuania and Poland. Materials and Methods: We conducted a retrospective, descriptive study of CT utilisation in minor head trauma patients presenting to the Level 1 trauma centre Hospital of the Lithuanian University of Health Sciences Kaunas Clinics (HLUHS KC) and Jan Biziel University Hospital in Bydgoszcz emergency departments (EDs), during the study period from 01 February to 30 April 2023. Results: During the study period, 1048 patients visited the HLUHS KC emergency department (ED) due to head trauma, and 388 patients visited the Jan Biziel University Hospital. Overall, 611 patients were included in the study. Most of the patients (92%) who suffered minimal trauma were younger than 65 years old. Eighty-two per cent of the patients older than 65 years old arrived at the ED after suffering a fall. Almost all the patients who were using antiplatelets (93%) or anticoagulants (91%) had CT scans. Non-emergency medicine (EM) physicians were more likely to order head CT scans than EM physicians (170 (83%) vs. 249 (62%), p < 0.001). There were 33 (5%) CT scans with traumatic features, and 8 (1%) of these were categorised as clinically significant. Patients who suffered clinically significant head trauma were more likely to be on anticoagulants and older than 65 when compared to normal/insignificant CT findings: 3 (38%) vs. 25 (6%), p < 0.001; and 6 (75%) vs. 146 (36%), p < 0.021. Conclusions: A significant number of head CT scans performed were not necessary according to existing head CT guidelines and risk calculators. However, even in minor head traumas, clinically significant head injuries may occur.

A novel microfluidic chip for on-site radiation risk evaluation

This paper proposes a microfluidic chip for on-site radiation risk evaluation using immunofluorescence staining for the DNA double-strand break (DSB) marker phosphorylated histone, H2AX (γ-H2AX). The proposed microfluidic chip separates lymphocytes, the cells of the DNA DSB evaluation target, from whole blood based on their size and traps them in the trap structure. The subsequent DNA DSB evaluation, γ-H2AX assay, can be performed on a chip, which saves space and simplifies the complicated operation of the assay, which conventionally requires a large experimental space. Therefore, this chip will enable the biological effect evaluation of radiation exposure to be completed on-site. Bead experiments with samples containing 10 μm and 27 μm diameter beads showed that the proposed chip introduced the sample into the flow channel only by centrifugal force and passively separated the two types of beads by the structure in the flow channel. In addition, bead experiments showed that isolated 10 μm diameter beads were trapped in more than 95% of the 1000 lymphocyte trap structures (LTSs). The feasibility of the proposed method for on-site radiation risk evaluation was demonstrated through cell-based experiments by performing the γ-H2AX assay in human lymphoblastoid TK6 cells. The experiment shows that LTSs in the flow channel are capable of trapping TK6 cells, and γ-H2AX foci which are markers of DNA DSBs are observed in the TK6 cells on the chip. Thus, the results suggest that the proposed microfluidic chip simplifies the γ-H2AX assay protocol and provides a novel method to perform the assay on-site, which is conventionally impracticable.

Monte Carlo methods for medical imaging research

In radiation-based medical imaging research, computational modeling methods are used to design and validate imaging systems and post-processing algorithms. Monte Carlo methods are widely used for the computational modeling as they can model the systems accurately and intuitively by sampling interactions between particles and imaging subject with known probability distributions. This article reviews the physics behind Monte Carlo methods, their applications in medical imaging, and available MC codes for medical imaging research. Additionally, potential research areas related to Monte Carlo for medical imaging are discussed.

Enhancing the X-ray Sensitivity of Cs2AgBiBr6 Double Perovskite Single Crystals through Cation Engineering

Owing to their outstanding optoelectronic properties, halide perovskite (HP) materials have been employed in a wide range of applications, including solar cells, light-emitting devices, and X-ray detectors. Among them, lead-free double HPs are characterized by enhanced stability and reduced toxicity compared with lead-based alternatives. Cs2AgBiBr6, in particular, has emerged as a promising candidate for direct X-ray detection. The detection sensitivity, on the other hand, cannot yet compete with that of lead-containing perovskites. Developing schemes to improve X-ray detection efficiency is critical for reducing radiation exposure in medical imaging applications. Here, we investigate the potential of controlled doping and cation substitution with either lanthanides or small organic cations to improve the X-ray detection performance of Cs2AgBiBr6. Our findings reveal that by growing the perovskite in a slightly Bi-poor and Eu-rich environment, the X-ray sensitivity significantly increases 7-fold (from 17 to 120 μC Gyair -1 cm-2) and simultaneously improves the phototo-dark current ratio (from 2.5 to 29). Additionally, Cs-site substitution with imidazolium remarkably enhances the sensitivity over 10-fold (180 μC Gyair -1 cm-2), and ammonium enhances the phototo-dark current ratio to 37. Terahertz photoconductivity measurements reveal a positive correlation between enhanced X-ray sensitivity and improved charge transport properties (e.g., increased scattering time and, thus, carrier mobility) by doping. This study outlines straightforward strategies for boosting X-ray detection and fundamental photoconductivity in lead-free double HP, with potential implications for broader optoelectronic applications.

Space-Confined Growth for Thickness-Controlled Cs3Bi2I9 Perovskite Single Crystal Wafers for X-Ray Detectors

The Cs3Bi2I9 single crystal, as an all-inorganic non-lead perovskite, offers advantages such as stability and environmental friendliness. Its superior photoelectric properties, attributed to the absence of grain boundary influence, make it an outstanding X-ray detection material compared to polycrystals. In addition to material properties, X-ray detector performance is affected by the thickness of the absorption layer. Addressing this, a space-confined method is proposed. The temperature field is determined through finite element simulation, effectively guiding the design of the space-confined method. Through this innovative method, a series of thickness-controlled perovskite single crystal wafers (PSCWs) are successfully prepared. Corresponding X-ray detectors are then prepared, and the impact of single crystal thickness on device performance is investigated. With an increase in single crystal thickness, a rise followed by a decline in device sensitivity is observed, reaching an optimal value at 0.7 mm thickness at 40V mm-1 with a device performance of 11313.6µC Gy-1 cm-2. This space-confined method enables the direct growth of high-quality perovskite single crystals with specified thickness, eliminating the need for slicing or etching.

Factors affecting radiation dose, radiation exposure time and procedural time in arterial embolization for active hemorrhage

PURPOSE

To evaluate patient and procedure-related factors contributing to the radiation dose, cumulative fluoroscopy time (CFT), and procedural time (PT) of Arterial Embolization (AE) for suspected active bleeding.

METHODS

Data on patients who underwent AE for suspected bleeding was retrospectively gathered between January 2019 and April 2022. Data collected included the dependent variables consisting of dose-area product (DAP), CFT, PT, and independent variables consisting of demographic, bleeding-specific, and procedure-specific parameters. All statistical computations were performed in SPSS statistics. The alpha value was set at 0.05.

RESULTS

Data from a total of 148 AE were collected with an average patient's age of 61.06 ± 21.57 years. Higher DAP was independently associated with male sex (p < 0.002), age ranges between 46 and 65 years (p = 0.019) and > 66 years (p = 0.027), BMI above 30 (p = 0.016), attending with less than 10 years of experience (p = 0.01), and bleeding in the abdomen and pelvis (p = 0.027). Longer CFT was independently associated with attending with less than 10 years of experience (p < 0.001), having 2 (p = 0.004) or > 3 (p = 0.005) foci of bleed, and age between 46 and 65 years (p = 0.007) and ≥ 66 years (p = 0.017). Longer PT was independently associated with attending with less than 10 years of experience (p < 0.001) and having 2 (p = 0.014) or > 3 (p = 0.005) foci of bleed.

CONCLUSION

The interventionist experience influenced radiation dose, CFT and PT. Dose was also affected by patients' sex, age, BMI, as well as bleeding location. CFT was also affected by patients' age, and both CFT and PT were also affected by the number of bleeding foci. These findings highlight the multifaceted factors that affect radiation dose and procedural time, emphasizing the importance of interventionist expertise, patient's age, sex, BMI, location and number of bleeds.

Additive value of invasive haemodynamic assessment for predicting post-operative outcomes after Fontan

Routine pre-Fontan cardiac catheterization remains standard practice at most centres. However, with advances in non-invasive risk assessment, an invasive haemodynamic assessment may not be necessary for all patients.Using retrospective data from patients undergoing Fontan palliation at our institution, we developed a multivariable model to predict the likelihood of a composite adverse post-operative outcome including prolonged length of stay ≥ 30 days, hospital readmission within 6 months, and death and/or transplant within 6 months. Our baseline model included non-invasive risk factors obtained from clinical history and echocardiogram. We then incrementally incorporated invasive haemodynamic data to determine if these variables improved risk prediction.Our baseline model correctly predicted favourable versus adverse post-Fontan outcomes in 118/174 (68%) patients. Covariates associated with adverse outcomes included the presence of a systemic right ventricle (adjusted adds ratio [aOR] 2.9; 95% CI 1.4, 5.8; p = 0.004), earlier surgical era (aOR 3.1 for era 1 vs 2; 95% CI 1.5, 6.5; p = 0.002), and performance of concomitant surgical procedures at the time of Fontan surgery (aOR 2.5; 95% CI 1.1, 5.0; p = 0.026). Incremental addition of invasively acquired haemodynamic data did not improve model performance or percentage of outcomes predicted.Invasively acquired haemodynamic data does not add substantially to non-invasive risk stratification in the majority of patients. Pre-Fontan catheterization may still be beneficial for angiographic evaluation of anatomy, for therapeutic intervention, and in select patients with equivocal risk stratification.

Exploring Patient Preferences for Information About CT Radiation Exposure: Bridging the Gap Between Patient Preference and Physician Practice

Background

CT scan utilizes ionizing radiation poses a danger to the patient's health. Thus, telling the patient about ionizing radiation would be critical in promoting shared decision-making and improving patient-doctor communication. However, few studies have examined this topic broadly.

Objective

The study was conducted to identify the frequency of physicians informing patients about the radiation risk before ordering a CT scan, as well as to examine the association between patients' demographic characteristics and their awareness of the radiation risks associated with CT scans.

Methods

A cross-sectional study was conducted among 387 patients who had undergone CT scans at a tertiary hospital in Riyadh, Saudi Arabia. Data were collected via phone interviews using a structured questionnaire. Chi-squared tests were employed to assess associations between patients' demographic characteristics and their awareness of CT scan radiation risks.

Results

When examining knowledge, 58% of patients knew that CT involves harmful radiation. This knowledge was significantly associated with higher education level and previous experience with CT scans. Regarding doctors' practice of providing information to patients about the scan, 344 (88.9%) patients indicated that their doctor had explained to them why they needed the scan. Only 28 (7.2%) patients stated that their doctor had mentioned the amount of radiation, and 74 (19.1%) patients indicated that doctors mentioned the risks associated with the radiation of the scan. Almost all patients (96.9%) preferred to be told about why they needed a CT scan.

Conclusion

The vast majority of patients who underwent CT scans did not receive enough information about the harm of the scans. However, most of them preferred to know about this harm.

Low-Dose Radiation Induces Alterations in Fatty Acid and Tyrosine Metabolism in the Mouse Hippocampus: Insights from Integrated Multiomics

In recent years, there has been a drastic surge in neurological disorders with sporadic cases contributing more than ever to their cause. Radiation exposure through diagnostic or therapeutic routes often results in neurological injuries that may lead to neurodegenerative pathogenesis. However, the underlying mechanisms regulating the neurological impact of exposure to near-low doses of ionizing radiation are not known. In particular, the neurological changes caused by metabolomic reprogramming have not yet been elucidated. Hence, in the present study, C57BL/6 mice were exposed to a single whole-body X-ray dose of 0.5 Gy, and 14 days post-treatment, the hippocampus was subjected to metabolomic analysis. The hippocampus of the irradiated animals showed significant alterations in 15 metabolites, which aligned with altered tyrosine, phenylalanine, and alpha-linolenic acid metabolism and the biosynthesis of unsaturated fatty acids. Furthermore, a multiomics interaction network comprising metabolomics and RNA sequencing data analysis provided insights into gene-metabolite interactions. Tyrosine metabolism was revealed to be the most altered, which was demonstrated by the interaction of several crucial genes and metabolites. The present study revealed the regulation of low-dose radiation-induced neurotoxicity at the metabolomic level and its implications for the pathogenesis of neurological disorders. The present study also provides novel insights into metabolomic pathways altered following near-low-dose IR exposure and its link with neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease.

Micro computed tomography analysis of barley during the first 24 hours of germination

BACKGROUND

Grains make up a large proportion of both human and animal diets. With threats to food production, such as climate change, growing sustainable and successful crops is essential to food security in the future. Germination is one of the most important stages in a plant's lifecycle and is key to the success of the resulting plant as the grain undergoes morphological changes and the development of specific organs. Micro-computed tomography is a non-destructive imaging technique based on the differing x-ray attenuations of materials which we have applied for the accurate analysis of grain morphology during the germination phase.

RESULTS

Micro Computed Tomography conditions and parameters were tested to establish an optimal protocol for the 3-dimensional analysis of barley grains. When comparing optimal scanning conditions, it was established that no filter, 0.4 degrees rotation step, 5 average frames, and 2016 × 1344 camera binning is optimal for imaging germinating grains. It was determined that the optimal protocol for scanning during the germination timeline was to scan individual grains at 0 h after imbibition (HAI) and then the same grain again at set time points (1, 3, 6, 24 HAI) to avoid any negative effects from X-ray radiation or disruption to growing conditions.

CONCLUSION

Here we sought to develop a method for the accurate analysis of grain morphology without the negative effects of possible radiation exposure. Several factors have been considered, such as the scanning conditions, reconstruction, and possible effects of X-ray radiation on the growth rate of the grains. The parameters chosen in this study give effective and reliable results for the 3-dimensional analysis of macro structures within barley grains while causing minimal disruption to grain development.

Radiation shielding calculation for interventional radiology: An updated workload survey using a dose monitoring software

Shielding design is an essential aspect of radiation protection. It is necessary to ensure that barriers safeguard workers, patients, the general public, and the environment from the harmful radiation emitted by X-ray machines. The National Council on Radiation Protection and Measurements (NCRP) 147 method is widely accepted within the radiation protection experts' (RPEs) community for structural shielding design for medical X-ray imaging facilities. However, these indications are based on data collected in 1996. In recent years, interventional radiology procedures have seen significant developments. Therefore, it is important to evaluate whether updating the data on workload in the different specialities is necessary. We extracted all interventional radiology exposure data parameters from three angiographs from two vendors using dose monitoring software for 3066 procedures and 214,697 individual exposures. The workload distribution as a function of the kVp for five interventional rooms was calculated by summing all exposures and then normalising them by the number of patients. Analysing this data, we obtained new transmission curves through lead, concrete and gypsum wallboard, finding the parameters (α, β, and γ) in the Archer equation for the secondary radiation. Finally, our aim was to share an example of shielding calculations for haemodynamics and neuroangiography rooms to illustrate the impact of updated transmission data.

Second-generation piperazine derivatives as promising radiation countermeasures

The increasing threat of nuclear incidents and the widespread use of ionizing radiation (IR) in medical treatments underscore the urgent need for effective radiation countermeasures. Despite the availability of compounds such as amifostine, their clinical utility is significantly limited by adverse side effects and logistical challenges in administration. This study focuses on the synthesis and evaluation of novel piperazine derivatives as potential radioprotective agents, with the aim of overcoming the limitations associated with current countermeasures. We designed, synthesized, and evaluated a series of 1-(2-hydroxyethyl)piperazine derivatives. The compounds were assessed for cytotoxicity across a panel of human cell lines, and for their radioprotective effects in the MOLT-4 lymphoblastic leukemia cell line and in peripheral blood mononuclear cells (PBMCs) exposed to gamma radiation. The radioprotective efficacy was further quantified using the dicentric chromosome assay (DCA) to measure DNA damage mitigation. Among the synthesized derivatives, compound 6 demonstrated the most significant radioprotective effects in vitro, with minimal cytotoxicity across the tested cell lines. Compound 3 also showed notable efficacy, particularly in reducing dicentric chromosomes, thus indicating its potential to mitigate DNA damage from IR. Both compounds exhibited superior safety profiles and effectiveness compared to amifostine, suggesting their potential as more viable radioprotective agents. This study highlights the development of novel piperazine derivatives with promising radioprotective properties. Compound 6 emerged as the leading candidate, offering an optimal balance between efficacy and safety, with compound 3 also displaying significant potential. These findings support the further development and clinical evaluation of these compounds as safer, and more effective radiation countermeasures.

Case report: Possible role of low-dose PEM for avoiding unneeded procedures associated with false-positive or equivocal breast MRI results

Contrast-enhanced breast magnetic resonance imaging (MRI) is currently recommended as a screening tool for high-risk women and has been advocated for women with radiologically dense breast tissue. While breast MRI is acknowledged for its high sensitivity (with an exception for lower-grade ductal carcinoma in situ (DCIS) where emerging techniques like diffusion-weighted imaging offer improvement), its limitations include sensitivity to hormonal changes and a relatively high false-positive rate, potentially leading to overdiagnosis, increased imaging uncertainty, and unnecessary biopsies. These factors can exacerbate patient anxiety and impose additional costs. Molecular imaging with breast-targeted Positron Emission Tomography (PET) has shown the capability to detect malignancy independent of breast density and hormonal changes. Furthermore, breast-targeted PET has shown higher specificity when compared with MRI. However, traditional PET technology is associated with high radiation dose, which can limit its widespread use particularly in repeated studies or for undiagnosed patients. In this case report, we present a clinical application of low-dose breast imaging utilizing a breast-targeted PET camera (Radialis PET imager, Radialis Inc). The case involves a 33-year-old female patient who had multiple enhanced lesions detected on breast MRI after surgical removal of a malignant phyllodes tumor from the right breast. A benign core biopsy was obtained from the largest lesion seen in the left breast. One month after the MRI, 18F-fluorodeoxyglucose (18F-FDG) PET imaging session was performed using the Radialis PET Imager. Although the Radialis PET Imager has proven high count sensitivity and the capability to detect breast lesions with low metabolic activity (at a dose similar to mammography), no areas of increased 18F-FDG uptake were visualized in this particular case. The patient underwent a right-sided nipple-sparing mastectomy and left-sided lumpectomy, with bilateral reconstruction. The excised left breast tissue was completely benign, as suggested by both core biopsy and the PET results. The case presented highlights a promising clinical application of low-dose breast-targeted PET imaging to mitigate the uncertainty associated with MRI while keeping radiation doses within the safe range typically used in X-ray mammography.

Clinical value of low-dose three-dimensional reconstruction by multi-slice spiral computed tomography and by traditional X-ray in the diagnosis of distal radius epiphyseal injury in children

OBJECTIVE

To compare the clinical value of multi-slice spiral computed tomography (MSCT) low-dose three-dimensional reconstruction and traditional X-ray in the auxiliary diagnosis of distal radius epiphyseal injury in children.

METHODS

A retrospective analysis was performed on 105 children with distal radius bone scale injury (classified by Salter-Harris classification) admitted from March 2020 to June 2022. All children underwent MSCT three-dimensional reconstruction examination and traditional X-ray examination. The detection rate of epiphyseal injury of the distal radius was compared, along with the resolution, sensitivity and specificity. The image clarity and display degree of bone structure were analyzed. The radiation dose-related indicators and the time required for diagnosis were compared.

RESULTS

The detection rate and diagnostic accuracy of MSCT (100%, 92.38%) was significantly higher than that of X-ray (76.19%, 64.76%). In terms of radiation dose index, the volume dose index CTDI of MSCT ranged from 1-5 mGy while the X-ray group ranged from 5-10 mGy. The dose length product (DLP) value of the MSCT group was lower than in the X-ray group (20-100 mGy·cm vs. 50-150 mGy·cm). The diagnostic scan time for MSCT was shorter than that of conventional X-ray. The acceptance rate with MSCT was 99%, significantly higher than that with conventional X-ray (85%).

CONCLUSIONS

Low-dose three-dimensional reconstruction of MSCT in the diagnosis of epiphyseal injury of distal radius in children shows significant advantages over traditional CT in the detection rate, diagnostic accuracy, postoperative reduction quality evaluation, and radiation dose.

Cosmic Ionizing Radiation: A DNA Damaging Agent That May Underly Excess Cancer in Flight Crews

In the United States, the Federal Aviation Administration has officially classified flight crews (FC) consisting of commercial pilots, cabin crew, or flight attendants as "radiation workers" since 1994 due to the potential for cosmic ionizing radiation (CIR) exposure at cruising altitudes originating from solar activity and galactic sources. Several epidemiological studies have documented elevated incidence and mortality for several cancers in FC, but it has not yet been possible to establish whether this is attributable to CIR. CIR and its constituents are known to cause a myriad of DNA lesions, which can lead to carcinogenesis unless DNA repair mechanisms remove them. But critical knowledge gaps exist with regard to the dosimetry of CIR, the role of other genotoxic exposures among FC, and whether possible biological mechanisms underlying higher cancer rates observed in FC exist. This review summarizes our understanding of the role of DNA damage and repair responses relevant to exposure to CIR in FC. We aimed to stimulate new research directions and provide information that will be useful for guiding regulatory, public health, and medical decision-making to protect and mitigate the risks for those who travel by air.

Mixed shift rotations, sleep, burnout and well-being in professions similar to radiographers: A systematic review

INTRODUCTION

Delivering 24 h healthcare requires rotational shift work from doctors and the medical imaging team, while contributing to safe and timely care of patients. Additional service pressure and staff shortfall leads to workload pressures, adjusted shift patterns and risk of burnout. Evidence should be sought to the effects of this work on staff.

METHODS

This systematic review followed PRISMA reporting guidelines, using a convergent mixed methods approach according to Guidance from Joanna Briggs International. Quantitative trends and results were qualified in order to thematically analyse in conjunction with qualitative data and discussed together in context. Following initial searching, returned articles were screened by title and abstract. A team of 3 reviewers undertook blinded critical appraisal of those suitable, with quality assurance from a 4th team member. Papers passing a threshold of 75% on JBI appraisal tools were accepted for synthesis. Data extraction of appropriate articles retrieved was undertaken in parallel.

RESULTS

Following screening and critical appraisal, 13 studies were returned focusing exclusively on Non Consultant Doctors. No studies investigated diagnostic radiographers. 85% (n = 11) reported negative association between shift work and the three themes of sleep/fatigue, burnout and wellbeing: including after the introduction of shift pattern control or adjusted shift patterns. The remainder showed no change, or any improvement nullified by countermeasures to maintain service delivery.

CONCLUSION

Current working practices and shift plans in the target population showed detrimental effects on the participants - this can be suggested that Diagnostic Radiographers may suffer fatigue, burnout and poor mental health from stretched shift working patterns.

IMPLICATIONS FOR PRACTICE

Further study into the effects of shift work on Diagnostic Radiographers and other allied health professionals is indicated - relating to the above themes in the context of errors and patient safety. Additional research into Non Consultant Doctors, shift work effects and the context of wider service delivery required; with suitable interventions and education to maximise understanding of legal working practices, monitoring and self-management of symptoms.

Testicular seminoma presenting as a large conglomerate mass in abdomen

Testicular seminoma commonly occurs in young men aged between 15 and 45 years old. Those with testicular cancer may present with a lump or swelling in the testicle. If treated and managed early, patients can expect a greater than 95% success rate. However, advanced stages of testicular seminoma can lead to eventual metastasis. We present a 45-year-old male patient with a prior history of testicular seminoma who was admitted to the emergency department with abdominal distension and acute abdominal pain. The CT identified a rather sizable abdominal mass and the biopsy confirmed metastatic testicular seminoma. Lymphoma was considered as the other differential diagnosis. Abdominal metastasis is rare in patients with testicular seminoma and usually leads to a poor survival outcome. Our patient did not attend follow-up appointments postorchidectomy, likely resulting in abdominal metastasis of testicular seminoma. This demonstrates the importance of ongoing surveillance of seminoma patients, and the challenges associated with differentiating large abdominal conglomerate mass in the CT scan. This patient is currently on active chemotherapy with bleomycin, cisplatin, and etoposide.

Low-Dose Ionizing Radiation Exposure on Human Male Gametes: Damage or Benefit

With the improvement of medical devices for diagnosis and radiotherapy, concerns about the effects of low doses of ionizing radiation are also growing. There is no consensus among scientists on whether they might have beneficial effects on humans in certain cases or pose more risks, making the exposure unreasonable. While the damaging consequences of high-dose radiation have been known since the discovery of radioactivity, low-dose effects present a much bigger investigative challenge. They are highly specific and include radio-adaptive responses, bystander effects, and genomic instability. Current data regarding the consequences of exposure to low-dose radiation on the quality of male gametes and fertility potential are contradictory. The reports suggest two directions: indirect impact on male gametes-through spermatogenesis-or direct effects at low doses on already mature spermatozoa. Although mature gametes are used for observation in both models, they are fundamentally different, leading to varied results. Due to their unique physiological characteristics, in certain cases, exposure of spermatozoa to low-dose ionizing radiation could have positive effects. Despite the findings indicating no beneficial effects of low-dose exposure on male fertility, it is essential to research its impact on mature spermatozoa, as well.

Diversity in Lacrimal Pathway Morphology Among Patients with Congenital Nasolacrimal Duct Obstruction

Purpose

This prospective observational study aimed to explore the diversity in lacrimal pathway morphology among patients with congenital nasolacrimal duct obstruction (CNLDO) by examining dacryocystography (DCG) images.

Patients and Methods

The study included 64 patients who underwent DCG before undergoing general anesthesia probing for unilateral CNLDO. Several parameters were measured from the lateral view of the DCG images: (1) the lacrimal sac (LS) and the nasolacrimal duct (NLD) angle, (2) the angle formed by the superior orbital rim (SOR), LS, and the NLD, (3) LS length, and (4) bony NLD length. Additionally, frontal views of the DCG images were utilized to measure (5) LS-NLD angle and (6) LS angle concerning the midline.

Results

The average age of the patients was 34.3 months. The mean ± standard deviation of the measurements of the above parameters was (1) -1.2° ± 16.5° (range: -44.6° ± 46.6°), (2) -5.0° ± 10.3° (range: -24.0° ± 19.0°), (3) 10.2 ± 2.4 mm (range: 6.5-16.0 mm), (4) 8.0 ± 2.5 mm (range: 3.1-14.8 mm), (5) 15.6° ± 11.2° (range: -16.8° ± 41.0°), and (6) 15.1 ± 5.2° (range: 3.3°-29.8°). All parameters, except for parameter (3), conformed to a normal distribution.

Conclusion

This study provides valuable anthropometric data derived from DCG images, highlighting the substantial variability in lacrimal pathway morphology among patients with CNLDO. Furthermore, anatomical constraints made probing with a straight metal bougie anatomically infeasible in 25.0% of the patients included in this study.

HEAL: High-Frequency Enhanced and Attention-Guided Learning Network for Sparse-View CT Reconstruction

X-ray computed tomography (CT) imaging technology has become an indispensable diagnostic tool in clinical examination. However, it poses a risk of ionizing radiation, making the reduction of radiation dose one of the current research hotspots in CT imaging. Sparse-view imaging, as one of the main methods for reducing radiation dose, has made significant progress in recent years. In particular, sparse-view reconstruction methods based on deep learning have shown promising results. Nevertheless, efficiently recovering image details under ultra-sparse conditions remains a challenge. To address this challenge, this paper proposes a high-frequency enhanced and attention-guided learning Network (HEAL). HEAL includes three optimization strategies to achieve detail enhancement: Firstly, we introduce a dual-domain progressive enhancement module, which leverages fidelity constraints within each domain and consistency constraints across domains to effectively narrow the solution space. Secondly, we incorporate both channel and spatial attention mechanisms to improve the network's feature-scaling process. Finally, we propose a high-frequency component enhancement regularization term that integrates residual learning with direction-weighted total variation, utilizing directional cues to effectively distinguish between noise and textures. The HEAL network is trained, validated and tested under different ultra-sparse configurations of 60 views and 30 views, demonstrating its advantages in reconstruction accuracy and detail enhancement.

Editorial Commentary: Both 3-Dimensional Magnetic Resonance Imaging and Computed Tomography Are Valuable for Determination of Glenoid and Humeral Bone Loss in Patients With On- and Off-Track Shoulder Instability

Improving the modalities for advanced glenohumeral joint imaging has been an important area to address in the field of orthopaedic surgery. The current gold standard for imaging glenoid and humeral bone loss in patients with shoulder instability, 3-dimensional (3D) computed tomography (CT), provides high-quality 3D images of bones but comes with a cost of extra time, additional imaging because of the need for an additional magnetic resonance imaging (MRI) scan, and exposure to radiation. Three-dimensional MRI is a promising solution that can produce high-contrast images depicting both bony structures and soft tissues. Multiple 3D MRI sequences have been studied, with the FRACTURE (fast field echo resembling a CT using restricted echo-spacing) sequence showing high comparability of bony measurements to 3D CT scans, as well as the ability for widespread clinical use. Recent research has shown minimal differences in 3D CT and 3D MRI and has confirmed that 3D imaging does provide clinically relevant data for determination of on- and off-track instability. Finally, the gold standard for determination of bone loss is the measurement of deficiencies in the surface area of the glenoid using the best-fit circle with a diameter line measurement. This is most practical for day-to-day clinical use.

ICRP PUBLICATION 157. ETHICS IN RADIOLOGICAL PROTECTION FOR MEDICAL DIAGNOSIS AND TREATMENT

Publication 138 defines the ethical foundations of the ICRP System of Radiological Protection based on core values (beneficence and non-maleficence, dignity, justice, and prudence) and procedural values (accountability, transparency, and inclusiveness). The purpose of the present publication is to propose a practical application of values for medical radiological protection professions. As medicine has a long history and strong culture of ethics, this publication starts by identifying the shared values, and defines a common language between biomedical ethics and radiological protection. The core values are very similar, with the autonomy of biomedical ethics, which can be seen as a corollary of dignity, and the precautionary principle, which can be understood as the implementation of prudence. In recent years, medical education and training has emphasised the values of solidarity, honesty, and, above all, empathy. All these values are defined and interpreted in the specific context of the use of ionising radiation in medicine. For those more familiar with radiological protection, the ethical implications of their actions are described. Conversely, for those who already have a good background in ethics, this publication highlights the specificities of ionising radiation that also deserve consideration.In order to emphasise the coherence between the values involved in biomedical ethics and those involved in radiological protection, this publication proposes to combine them: dignity and autonomy; beneficence and non-maleficence; prudence and precaution; justice and solidarity; transparency, accountability, and honesty; and inclusiveness and empathy. This allows a structured review of practical situations from an ethical perspective. For the sake of both example and education, this publication proposes 21 realistic scenarios (11 in imaging procedures and 10 in radiation therapies). Sensitising questions are provided to stimulate reflection and discussion. The ultimate goal is to be able to use ethical values in clinical imaging and therapy situations. Required education and training in ethics is essential for medical radiological workers throughout their career span. An example of a framework of knowledge, skills, and competencies is proposed. In order to assist the reader in a theoretically complex subject, key messages are distributed throughout the text as fixed points that can be easily understood. Although primarily aimed at medical radiological protection professionals, this publication is also intended for authorities, patients, and the public.© 2024 ICRP. Published by SAGE.

Radiation Dose Optimization in Radiology: A Comprehensive Review of Safeguarding Patients and Preserving Image Fidelity

Radiation dose optimization in radiology is a critical aspect of modern healthcare, aimed at balancing the necessity of diagnostic imaging with the imperative of patient safety. This comprehensive review explores the fundamental principles, techniques, and considerations in optimizing radiation dose to safeguard patients while preserving image fidelity. Beginning with acknowledging the inherent risks associated with medical radiation exposure, the review highlights strategies such as the As Low as Reasonably Achievable (ALARA) principle, technological advancements, and quality assurance measures to minimize radiation dose without compromising diagnostic accuracy. Regulatory guidelines and the importance of patient education and informed consent are also discussed. Through a synthesis of current knowledge and emerging trends, the review underscores the pivotal role of radiation dose optimization in radiology practice. Furthermore, it emphasizes the need for ongoing research and collaboration to advance dose reduction strategies, establish standards for radiation safety, and explore personalized dose optimization approaches. By prioritizing radiation dose optimization, healthcare providers can ensure the highest standards of patient care while minimizing potential risks associated with medical radiation exposure.

Advances in Imaging (Intraop Cone-Beam Computed Tomography, Synthetic Computed Tomography, Bone Scan, Low-Dose Protocols)

Spine surgery has seen a rapid advance in the refinement and development of 3-dimensional and nuclear imaging modalities in recent years. Cone-beam CT has proven to be a valuable tool for improving the accuracy of pedicle screw placement. The use of synthetic CT and low-dose CT have also emerged as modalities which allow for little to no radiation while streamlining imaging workflows. Bone scans also serve to provide functional information about bone metabolism in both the preoperative and postoperative monitoring phases.

Liquid Biopsy Response Evaluation Criteria in Solid Tumors (LB-RECIST)

Current evaluation of treatment response in solid tumors depends on dynamic changes in tumor diameters as measured by imaging. However, these changes can only be detected when there are enough macroscopic changes in tumor volume, which limits the usability of radiological response criteria in evaluating earlier stages of disease response and necessitates much time to lapse for gross changes to be notable. One promising approach is to incorporate dynamic changes in circulating tumor DNA (ctDNA), which occur early in the course of therapy and can predict tumor responses weeks before gross size changes manifest. However, several issues need to be addressed before recommending the implementation of ctDNA response criteria in daily clinical practice such as clinical, biological, and regulatory challenges and, most importantly, the need to standardize/harmonize detection methods and ways to define ctDNA response and/or progression for precision oncology. Herein, we review the use of liquid biopsy (LB) to evaluate response in solid tumors and propose a plan toward standardization of LB-RECIST.

Crescent Antennas as Sensors: Case of Sensing Brain Pathology

Microstrip crescent antennas offer compactness, conformability, low profile, high sensitivity, multi-band operability, cost-effectiveness and ease of fabrication in contrast to bulky, rigid horn, helical and Vivaldi antennas. This work presents crescent sensors for monitoring brain pathology associated with stroke and atrophy. Single- and multi-element crescent sensors are designed and validated by software simulations. The fabricated sensors are integrated with glasses and experimentally evaluated using a realistic brain phantom. The performance of the sensors is compared in terms of peak gain, directivity, radiation performance, flexibility and detection capability. The crescent sensors can detect the pathologies through the monitoring of backscattered electromagnetic signals that are triggered by dielectric variations in the affected tissues. The proposed sensors can effectively detect stroke and brain atrophy targets with a volume of 25 mm3 and 56 mm3, respectively. The safety of the sensors is examined through the evaluation of Specific Absorption Rate (peak SAR < 1.25 W/Kg, 100 mW), temperature increase within brain tissues (max: 0.155 °C, min: 0.115 °C) and electric field analysis. The results suggest that the crescent sensors can provide a flexible, portable and non-invasive solution to monitor degenerative brain pathology.

Rising use of diagnostic imaging in Australia: An analysis of Medicare-funded radiology services between 2000 and 2021

INTRODUCTION

The use of diagnostic imaging services is increasing worldwide. This has important impacts on healthcare resource allocation and potential risks to the population. This study aimed to quantify trends in medical imaging in Australia over the past two decades.

METHODS

Data were extracted from the Australian Medicare Benefits Schedule (MBS) between 2000 and 2021. Simple linear regression analyses were performed to assess changes in absolute utilisation and utilisation rate per 100,000 population of total imaging services as well as by each imaging modality. Logistic regression analysis was performed to assess changes in total imaging services as a proportion of total Medicare services over time. Chi-squared test was used to assess for change in modality composition of imaging services.

RESULTS

There were 436,255,500 imaging studies performed between 2000 and 2021. The absolute utilisation of total imaging services increased annually by an average of 864,404 (95% CI: 808,235-920,573, p < 0.001). For each consecutive year, the proportion of total Medicare services attributed to total imaging services increased by 0.01% (95% CI: 0.01-0.01, p < 0.01). There was also a statistically significant increase in the utilisation rates of imaging services per 100,000 population for each imaging modality. The number of imaging services per radiologist increased on average by 74 (95% CI: 26-122, p < 0.05) annually.

CONCLUSION

The utilisation of diagnostic imaging services has increased in Australia between 2000 and 2021, outpacing the population growth, total healthcare services, and the radiologist workforce.