Use of medical imaging continues to increase, making the largest contribution to the exposure of populations from artificial sources of radiation worldwide. The principle of optimisation of protection is that \'the likelihood of incurring exposures, the number of people exposed, and the magnitude of their individual doses should all be kept as low as reasonably achievable (ALARA), taking into account economic and societal factors\'. Optimisation for medical imaging involves more than ALARA - it requires keeping individual patient exposures to the minimum necessary to achieve the required medical objectives. In other words, the type, number, and quality of images must be adequate to obtain the information needed for diagnosis or intervention. Dose reductions for imaging or x-ray-image-guided procedures should not be used if they degrade image quality to the point where the images are inadequate for the clinical purpose. The move to digital imaging has provided versatile acquisition, post-processing, and presentation options, and enabled wide and often immediate availability of image information. However, because images are adjusted for optimal viewing, the appearance may not give any indication if the dose is higher than necessary. Nevertheless, digital images provide opportunities for further optimisation, and allow the application of artificial intelligence methods.Optimisation of radiological protection for digital radiology (radiography, fluoroscopy, and computed tomography) involves selection and installation of equipment, design and construction of facilities, choice of optimal equipment settings, day-to-day methods of operation, quality control programmes, and ensuring that all personnel receive proper initial and career-long training. The radiation dose levels that patients receive also have implications for doses to staff. As new imaging equipment incorporates more options to improve performance, it becomes more complex and less easily understood, so operators have to be given more extensive training. Ongoing monitoring, review, and analysis of performance is required that feeds back into the improvement and development of imaging protocols. Several different aspects relating to optimisation of protection that need to be developed are set out in this publication. The first is collaboration between radiologists/other radiological medical practitioners, radiographers/medical radiation technologists, and medical physicists, each of whom have key skills that can only contribute to the process effectively when individuals work together as a core team. The second is appropriate methodology and technology, with the knowledge and expertise required to use each effectively. The third relates to organisational processes which ensure that required tasks, such as equipment performance tests, patient dose surveys, and review of protocols, are carried out. There is wide variation in equipment, funding, and expertise around the world, and the majority of facilities do not have all the tools, professional teams, and expertise to fully embrace all the possibilities for optimisation. Therefore, this publication sets out broad levels for aspects of optimisation that different facilities might achieve, and through which they can progress incrementally: Level D - preliminary; Level C - basic; Level B - intermediate; and Level A - advanced. Guidance from professional societies can be invaluable in helping users to evaluate systems and aid in adoption of best practice. Examples of systems and activities that should be in place to achieve the different levels are set out. Imaging facilities can then evaluate the arrangements they already have, and use this publication to guide decisions about the next actions to be taken in optimising their imaging services.

BACKGROUND: Pregnancy and trauma are complex situations with significant implications for maternal and fetal health. Physical and psychological trauma during pregnancy can lead to pre-term labor, abruptio-placenta, and fetal injury or death. Management of trauma is challenging due to physiological and anatomical changes, which can affect fracture management and the risk of radiation exposure. A multidisciplinary approach is beneficial for patient care. This study aimed to determine the impact of orthopaedic trauma on pregnancy and its outcome, and influence of pregnancy on fracture management.
METHODS: A retrospective-study was conducted at a Level-1 trauma-care-center, focusing on 54 pregnant women who sustained trauma between January 2015 and December 2022. The study included patients with closed or open fractures, but excluded those without fractures. Forty-two patients were available with minimum 1 year follow-up. Data was collected from hospital records and PACS, including demographic details, emergency care, and laboratory parameters. Changes made in protocol in fracture management due to pregnancy (primary definitive fixation vs staged management), and impact of trauma on pregnancy outcome; mode-of-delivery, maternal and fetal loss were evaluated.
RESULTS: The mean age was 30-years (range: 21-43years). Road-traffic-collision was most-common mode-of-injury (66.7 %). 38.1 % were in the first-trimester, 35.7 % in second, and 26.2 % in third-trimester. Eight patients had polytrauma, seven had multiple-injuries, and 27 had isolated-injuries. The maternal-mortality-rate was 0.45 %. Three polytraumatized patients ended up with intrauterine death, two polytrauma patients underwent elective abortion, one patient presented with spontaneous-abortion, and fetal loss was 14.3 % (6-of-42). Out of 42 patients, 10 had open-injuries and 32 had closed-injuries. Nine patients underwent LSCS(lower-segment-caesarean-section), six of them were planned for elective-LSCS due to injury and associated fractures (two patients with pelvic injuries, two neck femur fracture patients, one open distal femur fracture, and one ankle fracture dislocation).
CONCLUSIONS: Orthopaedic trauma during pregnancy can significantly affect pregnancy outcomes and is associated with a notably higher risk of fetal loss. An elective-caesarean-section is recommended for patients with polytrauma, pelvic-injuries, and those who are immobilized for longer-duration. During the third-trimester and in polytraumatized patients, external-fixator-application for lower-limb-injuries is a safe strategy, and definitive fixation could be performed post-delivery.

Although coil embolization is commonly perceived as a minimally invasive procedure, the associated radiation exposure cannot be disregarded. To date, no specific study has investigated radiation exposure during coil embolization. This study aimed to investigate the potential of lowering the pulse rate to decrease radiation exposure during coil embolization while maintaining patient safety. Radiation data and clinical features of 70 patients who underwent coil embolization between 2015 and 2020 were retrospectively analyzed. Since July 2017, the pulse rate was regulated from 7.5 to 4 frames per second (f/s). Statistical analyses were performed to examine the correlation between pulse rate and radiation exposure. Out of the 70 procedures, 30 were performed at the standard pulse rate (7.5 f/s), and 40 were performed at the lower pulse rate (4 f/s). In the lower-pulse-rate group, the absorbed dose to the patient (AK) was 2580.7 (±217) mGy, whereas in the standard-pulse-rate group, it was 4760 (±411.1). Both the dose-area product (DAP) and AK were substantially reduced in the low pulse rate group (p = 0.000002). There was a significant correlation between DAP and AK and pulse rate (p = 0.004, p = 0.0017, respectively). Moreover, there was no significant correlation between pulse rate and perioperative complications. Our findings suggest that using a lower pulse rate (4 f/s) can effectively reduce radiation exposure during coil embolization for cerebral aneurysms while ensuring patient safety.

Electromagnetic tracking of endovascular instruments has the potential to substantially decrease radiation exposure of patients and personnel. In this study, we evaluated the in vivo accuracy of a vessel-based method to register preoperative computed tomography angiography (CTA) images to physical coordinates using an electromagnetically tracked guidewire. Centerlines of the aortoiliac arteries were extracted from preoperative CTA acquired from five swine. Intravascular positions were obtained from an electromagnetically tracked guidewire. An iterative-closest-point algorithm registered the position data to the preoperative image centerlines. To evaluate the registration accuracy, a guidewire was placed inside the superior mesenteric, left and right renal arteries under fluoroscopic guidance. Position data was acquired with electromagnetic tracking as the guidewire was pulled into the aorta. The resulting measured positions were compared to the corresponding ostia manually identified in the CTA images after applying the registration. The three-dimensional (3D) Euclidean distances were calculated between each corresponding ostial point, and the root mean square (RMS) was calculated for each registration. The median 3D RMS for all registrations was 4.82 mm, with an interquartile range of 3.53-6.14 mm. A vessel-based registration of CTA images to vascular anatomy is possible with acceptable accuracy and encourages further clinical testing. RELEVANCE STATEMENT: This study shows that the centerline algorithm can be used to register preoperative CTA images to vascular anatomy, with the potential to further reduce ionizing radiation exposure during vascular procedures. KEY POINTS: Preoperative images can be used to guide the procedure without ionizing intraoperative imaging. Preoperative imaging can be the only imaging modality used for guidance of vascular procedures. No need to use external fiducial markers to register/match images and spatial anatomy. Acceptable accuracy can be achieved for navigation in a preclinical setting.

Spine radiographs in the standing position are the recommended standard for diagnosing idiopathic scoliosis. Though the deformity exists in 3D, its diagnosis is currently carried out with the help of 2D radiographs due to the unavailability of an efficient, low-cost 3D alternative. Computed tomography (CT) and magnetic resonance imaging (MRI) are not suitable in this case, as they are obtained in the supine position. Research on 3D modelling of scoliotic spine began with multiplanar radiographs and later moved on to biplanar radiographs and finally a single radiograph. Nonetheless, modern advances in diagnostic imaging have the potential to preserve image quality and decrease radiation exposure. They include the DIERS formetric scanner system, the EOS imaging system, and ultrasonography. This review article briefly explains the technology behind each of these methods. They are compared with the standard imaging techniques. The DIERS system and ultrasonography are radiation free but have limitations with respect to the quality of the 3D model obtained. There is a need for 3D imaging technology with less or zero radiation exposure and that can produce a quality 3D model for diseases like adolescent idiopathic scoliosis. Accurate 3D models are crucial in clinical practice for diagnosis, planning surgery, patient follow-up examinations, biomechanical applications, and computer-assisted surgery.

There are currently no available FDA-cleared biodosimetry tools for rapid and accurate assessment of absorbed radiation dose following a radiation/nuclear incident. Previously we developed a protein biomarker-based FAST-DOSE bioassay system for biodosimetry. The aim of this study was to integrate an ELISA platform with two high-performing FAST-DOSE biomarkers, BAX and DDB2, and to construct machine learning models that employ a multiparametric biomarker strategy for enhancing the accuracy of exposure classification and radiation dose prediction. The bioassay showed 97.92% and 96% accuracy in classifying samples in human and non-human primate (NHP) blood samples exposed ex vivo to 0-5 Gy X-rays, respectively up to 48 h after exposure, and an adequate correlation between reconstructed and actual dose in the human samples (R2 = 0.79, RMSE = 0.80 Gy, and MAE = 0.63 Gy) and NHP (R2 = 0.80, RMSE = 0.78 Gy, and MAE = 0.61 Gy). Biomarker measurements in vivo from four NHPs exposed to a single 2.5 Gy total body dose showed a persistent upregulation in blood samples collected on days 2 and 5 after irradiation. The data indicates that using a combined approach of targeted proteins can increase bioassay sensitivity and provide a more accurate dose prediction.

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UNASSIGNED: Radiation induced lymphopenia (RIL) deteriorate survival and diminishes the benefit of immune checkpoint inhibitors in combined treatment of lung cancer. Given the inconsistent data across various studies on the predictors of RIL, we aim to methodically elucidate these predictors and formulate a practical guide for clinicians.
UNASSIGNED: We conducted observational cohort study in four tertiary cancer centers. Patients with non-small cell lung cancer and small cell lung cancer, without lymphopenia grade >1, who underwent standalone radiotherapy (RT) in minimum 15 fractions were eligible. Dose-volume parameters of structures and clinical factors were comprehensively analyzed using various predictors selection methods and statistical models (Linear Regressors, Elastic Net, Bayesian Regressors, Huber Regression, regression based on k-nearest neighbors, Gaussian Process Regressor, Decision Tree Regressor, Random Forest Regressor, eXtreme Gradient Boosting, Automated Machine Learning) and were ranked to predict lymphocytes count nadir (alc_nadir).
UNASSIGNED: Two hundred thirty eight patients (stage I-3.4%, II-17.6%, III-75.2%, IV-3.8%) who underwent RT to median dose of 60 Gy were analyzed. Median alc_nadir was 0.68K/mm3. The 60 feature sets were evaluated in 600 models (RMSE 0.27-0.41K/mm³). The most important features were baseline lymphocyte count (alc_1), mean lung_dose, lung v05, lung v10, heart v05 and effective dose to immune cells (edic). In patients with alc_1 ≤ 2.005K/mm3, median alc_nadir predictions were 0.54K/mm3 for lung_v05p > 51.8% and 0.76K/mm3 for lung_v05p ≤ 51.8%. Lymphopenia was rare in patients with alc_1 > 2.005K/mm3.
UNASSIGNED: RIL was most severe in patients with low early lymphocyte counts, primarily triggered by low RT doses in the heart and lungs.

The Western Australian mining industry is a global supplier of critical minerals, including lithium and rare earths. The lithology of these minerals is associated with elevated concentrations of naturally occurring radionuclides (NORs). An increase in the number of mines producing the minerals has witnessed a commensurate increase in the number of workers potentially exposed to the radiation from NORs. The regulatory framework in Western Australia underwent significant change in March 2022. Mining operations whose workers are likely to receive doses greater than one mSvy-1 are referenced as relevant mines and are required to submit an annual report of worker doses to the mining regulator. This research provides an overview of the new legislative framework and updates the information in Ralph and Cattani (2022) to include data derived from annual radiation doses reported by relevant mines in the period spanning 2020-21 to 2022-23. In 2022-23, 38 mining operations were identified as relevant mines, an increase of sixteen from 2020-21. The mean effective dose (ED) reported in the three-year period was 1.0 mSv, and the maximum ED was 4.9 mSv. The collective effective dose of the mine worker population reached an historical maximum of 2,339 man.mSv in 2022-23. Inhalation of long-lived alpha emitting radionuclides in dust remains the most significant contributor to worker doses. Inhalation of radon-22, radon-220 and their short-lived progeny, once considered as a negligible contributor to worker doses, is the second most significant exposure pathway. A declining trend in the number of samples collected per worker is highlighted as requiring remediation to provide confidence in the reported dose estimates. The transition to the new legislative framework for radiation protection in mines has been supported by the publication of guidance materials which have been widely endorsed by the industry. .

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