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The goal of this article is to document early attitudes to X-rays in scientific culture in the city of Buenos Aires. Using various types of periodical sources, the text explores the different reactions to the novelty among different actors in the literary world. Newspapers and weekly magazines for the general public quickly broadcast the discovery, stressing its marvelous or prodigious nature. Meanwhile, physicians in the city took contrasting positions, ranging from mistrust to enthusiasm. Lastly, spiritualists in the city wrote numerous texts about the innovation, and reinterpreted it in accordance with their strategies for self-legitimation.

Background: To evaluate the performance of the extended modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) incorporating information from anteroposterior (AP) lumbar radiographs as compared to the conventional mSASSS in detection of radiographic spinal progression in patients with axial spondyloarthritis (axSpA) METHODS: A total of 210 patients with axSpA, 115 with radiographic axSpA (r-axSpA), and 95 with non-radiographic axSpA (nr-axSpA), from the GErman SPondyloarthritis Inception Cohort (GESPIC), were included in the analysis based on the availability of spinal radiographs (cervical spine lateral, lumbar spine lateral, and AP views), at baseline and year 2. Two trained readers independently scored lateral cervical and lumbar spine images according to the mSASSS system (0-3 per vertebral corner, 0-72 in total). In addition, all vertebral corners of vertebral bodies visible on lumbar AP radiographs (lower T12 to upper S1) were assessed according to the same scoring system that resulted in a total range for the extended mSASSS from 0 to 144. Reliability and sensitivity to detect radiographic spinal progression of the extended mSASSS as compared to the conventional mSASSS were evaluated., Results: The reliability of conventional and extended scores was excellent with intraclass correlation coefficients (ICCs) of 0.926 and 0.927 at baseline and 0.920 and 0.933 at year 2, respectively. The mean ± SD score for mSASSS and extended mSASSS at baseline were 4.25 ± 8.32 and 8.59 ± 17.96, respectively. The change score between baseline and year 2 was 0.73 ± 2.34 and 1.19 ± 3.73 for mSASSS and extended mSASSS, respectively. With the extended mSASSS, new syndesmophytes after 2 years were detected in 4 additional patients, new syndesmophytes or growth of existing syndesmophytes in 5 additional patients, and progression by ≥ 2 points in the total score in 14 additional patients meaning a 25%, 28%, and 46% increase in the proportion of patients with progression according to the respective definition as compared to the conventional score., Conclusions: Incorporation of lumbar AP radiographs in the assessment of structural damage in the spine resulted into detection of additional patients with radiographic spinal progression not captured by the conventional mSASSS score.

Background: The Commission of the European Communities has published guidelines to be used as a gold standard for quality assessment of diagnostic radiographic images. Image quality and radiation dose must be monitored and optimally balanced for diagnostic purposes on patients. The objective of the current study was to assess intra- and inter-observer reproducibility in less experienced observers using the proposed European Guidelines on Quality Criteria for Diagnostic Radiographic Images in a quality assessment of lumbar spine radiographs in primary chiropractic practice in Denmark., Methods: Two observers initially evaluated lumbar spine radiographs randomly selected from fifty chiropractic clinics, all connected to the national PACS server (KirPACS) in Denmark. All evaluations were performed twice by both observers using a four-week interval and for compliance with the European Quality Criteria for Diagnostic Radiographic Images. Inter- and intra-observer reproducibility was calculated using kappa statistics. In the interpretation of the kappa coefficient, the standards for strength of agreement reported by Landis and Koch were followed., Results: The strength of the inter-observer agreement of general image quality at baseline ranged from moderate agreement ( k = 0.47) to substantial agreement ( k = 0.68). After four weeks, the inter-observer agreement still ranged from moderate agreement ( k = 0.59) to substantial agreement ( k = 0.71), but with increased agreement for both kappa coefficients. In relation to intra-observer agreement of general image quality, the strength for observer A ranged from moderate ( k = 0.58) to substantial ( k = 0.72) and the strength for observer B overall was substantial ( k = 0.63-0.75)., Conclusion: The European Guidelines on Quality Criteria for Diagnostic Radiographic Images are considered a gold-standard and used in a method for quality assurance within the Danish chiropractic profession. The inter-rater and intra-rater agreements in this study, using the CEC-criteria, were found mostly acceptable. With appropriate attention to clear understanding of the individual criteria and sufficient training, this method is found to be reliable, even using less experienced observers, to carry out Diagnostic Radiographic Image Quality-assurance in primary care settings., Competing Interests: Information on authors qualifications and affiliations is found on the first page of this article.Not applicable. This study was done in conjunction with quality assurance procedures required by Danish law [6] and all personal data were blinded for the observers. Only documentation of image quality was performed, with no possible correlation to patients. The procedures are mandatory and has no consequences for diagnoses and treatment of patients.Not applicable.The authors declare that they have no competing interests.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Background: Postnatal evaluation of prenatally identified congenital lung malformations (CLMs) often includes a chest x-ray (CXR) and neonatal intensive care unit (NICU) admission for observation. With current efforts aimed at prioritizing value and resource utilization, we sought to assess the utility of this practice in infants with known CLMs. We hypothesized that CXR and NICU admission are overused and could be deferred in the majority of cases., Methods: Clinical and radiographic data for infants with CLM from 2007 to 2016 were reviewed with IRB approval. Regression models were developed for respiratory support (RS), symptoms within 30 days of discharge (Sx30), and abnormal CXR. Predictors included initial symptoms (IS), birth weight (BW), gestational age (GA), cyst-volume-ratio (CVR) and abnormal CXR. Odds ratios (ORs) and ROC curves were generated for significant predictors (p < 0.05)., Results: Fifty-eight infants were identified. Eight were excluded because birth or surgery occurred outside of our institution. Another four were excluded for requiring immediate surgery, leaving forty-six for full analysis. All infants underwent initial CXR and NICU admission, and 22 (47.8%) had an abnormal CXR. Higher CVR (OR = 6.69, p = 0.024) and lower BW (OR = 0.27, p = 0.028) both increased the odds of an abnormal CXR. Applying optimal ROC cutoffs for CVR and BW would have safely eliminated 21 of 46 CXRs, increasing CXR sensitivity from 48% to 68%. For RS and Sx30, no variable, including abnormal CXR, significantly predicted outcomes. Twenty-seven infants (59%) had a NICU stay of <24 h and only three patients (6.8%) developed Sx30., Conclusions: Both CXR and NICU admission appear to be overused in infants with CLM. CXR result did not predict need for respiratory support or symptoms following discharge, and thus may not aid in the initial evaluation or in the prediction of future care needs. Using CVR and birth weight can guide CXR use and optimize its sensitivity. Need for NICU admission could not be predicted, but a majority of infants spent <24 h in the NICU without intervention, suggesting that NICU admission was likely not needed for all infants in this setting., Level of Evidence: Study of diagnostic test, Level II evidence., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: X-ray grating interferometry (XGI) provides substantially increased contrast over conventional absorption-based imaging methods and therefore shows great potential for future biomedical applications. In this work, we propose a single-shot phase retrieval method for synchrotron-based high-energy x-ray grating interferometry. Contrary to existing retrieval methods, the presented novel approach enables direct retrieval of the object's phase map quantitatively from a single projection image, thus significantly simplifying the experimental procedure and reducing data acquisition times., Methods: The phase retrieval method is analytically derived, based on the phase-attenuation duality of soft tissues when being imaged with high-energy x rays. The sensitivity of the retrieved phase map, quantified by the standard deviation, is evaluated as a function of the photon number. Numerical experiments are performed to validate the proposed method and provide some quantitative insight., Results: The numerical results show that the method can provide high-quality phase images, where the well-known streak artifacts are significantly suppressed. Moreover, the retrieved phase maps confirm that the method is highly stable with respect to statistical noise., Conclusions: Thanks to simplified experimental procedure and reduced acquisition time and dose deposition to the sample, we believe that this new method can find its potential in biomedical imaging and in vivo studies. Future work will focus on the adaptation of the method to polychromatic x ray from tube source and to computed tomography., (© 2019 American Association of Physicists in Medicine.)

Background: The alignment of a prosthesis affects the way load is transferred to the stump through the socket; this is critically important for its comfort and function. The aim of the study was to assess the value of radiopaque materials in evaluation of stump-socket fit in people with below-knee amputation., Material and Methods: Thirty-two amputees (skin breakdown group) had cutaneous lesions in the stump, and another 26 amputees (control group) had no lesion in the stump after training with their prosthesis. Metallic markers were attached to weight-bearing points in the internal socket. X-rays were taken in the antero-posterior and lateral projections., Results: In the antero-posterior view, the weight-bearing points of the stump did not correspond to the metallic markers placed over the patellar tendon and the tibial tuberosity points in the socket in 78.1% of the 32 amputees in the skin breakdown group. This malalignment was present in 42.3% of the 26 amputees in the control group (Pearson Chi-Square, p&lt;0.007). In the lateral view, in 65.6% of the 32, the weight-bearing points of the stump did not correspond to the metallic markers placed over the patellar tendon and the tibial tuberosity points in the socket. This malalignment was noted in 23.1% of the 26 patients in the other group (Pearson Chi-Square, p&lt;0.002)., Conclusions: 1. The conflict between the prosthesis and residual limb is the cause of skin disruption at different sites of the stump and can be successfully treated by prosthetic socket modification. 2. Efforts should be made to systematically identify any discrepancies between the stump and the soc-ket. 3. Correct adaptation of the prosthesis to the weight-bearing points of the stump will offer clinicians the possibility of quantification and visualization of this interaction using simple radiographic techniques.

Purpose: In previous work, a theoretical model of the point spread function (PSF) for oblique x-ray incidence in amorphous selenium (a-Se) detectors was proposed. The purpose of this paper is to develop a complementary model that includes two additional features. First, the incidence angle and the directionality of ray incidence are calculated at each position, assuming a divergent x-ray beam geometry. This approach allows the non-stationarity of the PSF to be modeled. Second, this paper develops a framework that is applicable to a digital system, unlike previous work which did not model the presence of a thin-film transistor (TFT) array., Methods: At each point on the detector, the incidence angle and the ray incidence direction are determined using ray tracing. Based on these calculations, an existing model for the PSF of the x-ray converter (Med Phys. 1995;22:365-374) is generalized to a non-stationary model. The PSF is convolved with the product of two rectangle functions, which model the sampling of the TFT array. The rectangle functions match the detector element (del) size in two dimensions., Results: It is shown that the PSF can be calculated in closed form. This solution is used to simulate a digital mammography (DM) system at two x-ray energies (20 and 40 keV). Based on the divergence of the x-ray beam, the direction of ray incidence varies with position. Along this direction, the PSF is broader than the reference rect function matching the del size. The broadening is more pronounced with increasing obliquity. At high energy, the PSF deviates more strongly from the reference rect function, indicating that there is more blurring. In addition, the PSF is calculated along the polar angle perpendicular to the ray incidence direction. For this polar angle, the shape of the PSF is dependent upon whether the ray incidence direction is parallel with the sides of the detector. If the ray incidence direction is parallel with either dimension, the PSF is a perfect rectangle function, matching the del size. However, if the ray incidence direction is at an oblique angle relative to the sides of the detector, the PSF is not rectangular. These results illustrate the non-stationarity of the PSF., Conclusions: This paper demonstrates that an existing model of the PSF of a-Se detectors can be generalized to include the effects of non-stationarity and digitization. The PSF is determined in closed form. This solution offers the advantage of shorter computation time relative to approaches that use numerical methods. This model is a tool for simulating a-Se detectors in future work, such as in virtual clinical trials with computational phantoms., (© 2018 American Association of Physicists in Medicine.)

Background: In the treatment of early onset scoliosis (EOS), there has been a trend to use magnetically controlled growing rods (MCGR) in order to reduce the number of surgeries. To confirm the amount of lengthening, spine radiographs were required. Recently, ultrasound (US) has been added to monitor lengthening of MCGR to avoid radiation exposure. Our aim was to determine whether US is as accurate as plain radiography (x-ray) in determining the amount of length achieved at individual MCGR lengthening episodes., Methods: Retrospective study; inclusion criteria: EOS cases with dual MCGR with minimum 12 months follow-up. Intended lengthening IL (mm), lengthening on US (mm) and x-ray (mm) were documented from medical records for both right and left rods. Primary (no surgery before MCGR) and conversion (other types of instrumentation were replaced with MCGR) cases were reviewed separately. P-values determined with analysis of variance., Results: Sixteen cases with 100 lengthening episodes met the inclusion criteria. Eleven were primary MCGR cases with 67 episodes. Mean follow-up was 19±5 months. Significant differences were found between IL (3.4±1 mm), US (2.7±1.9 mm), and x-ray (4.1±2.2 mm) (P<0.001). The difference between IL and x-ray was minimal, but statistically significant (P=0.046). US showed statistically lower values than both IL (P=0.001) and x-ray (P<0.001). The mean ratio of x-ray/IL, US/IL, and US/x-ray were 1.1, 0.75, and 0.84, respectively. Five conversion cases had 33 episodes. Mean follow-up was 21±2 months. Significant differences were found between IL (3.4±0.8 mm), US (1.3±0.8 mm), and x-ray (1.7±0.9 mm) (P<0.001) but there was no significant difference between US and x-ray (P=0.283). IL was significantly higher than both US (P< 0.001) and x-ray (P<0.001). The mean ratio of x-ray/IL, US/IL, and US/x-ray were 0.64, 0.41, and 1.1, respectively., Conclusions: US can provide confirmatory information of noninvasive lengthening of MCGR. However, US tended to underestimate the achieved length as measured by x-ray in primary cases. Conversion cases demonstrate better concordance between US and x-ray but in these cases less overall length was achieved at each lengthening episode., Level of Evidence: Level III.

Purpose: One limitation of experimental techniques for quantifying resolution and noise in detectors is that the measurement is made in a region-of-interest (ROI). With theoretical modeling, these properties can be measured at a point, allowing for quantification of spatial anisotropy. This paper calculates nonstationary transfer functions for amorphous selenium (a-Se) detectors in breast imaging. We use this model to demonstrate the performance advantage of a "next-generation" tomosynthesis (NGT) system, which is capable of x-ray source motion with more degrees of freedom than a clinical tomosynthesis system., Methods: Using Swank's formulation, the optical transfer function (OTF) and presampled noise power spectra (NPS) are determined based on the point spread function derived in Part 1. The modulation transfer function (MTF) is found from the normalized modulus of the OTF. To take into account the presence of digitization, the presampled NPS is convolved with a two-dimensional comb function, for which the period along each direction is the reciprocal of the detector element size. The detective quantum efficiency (DQE) is then determined from combined knowledge of the OTF and NPS., Results: First, the model is used to demonstrate the loss of image quality due to oblique x-ray incidence. The MTF is calculated along various polar angles, corresponding to different orientations of the input frequency. The MTF is independent of the incidence angle if the polar angle is perpendicular to the ray incidence direction. However, along other polar angles, oblique incidence results in MTF degradation at high frequencies. The MTF degradation is most substantial along the ray incidence direction. Unlike the MTF, the normalized NPS (NNPS) is independent of the incidence angle. To measure the relative signal-to-noise, the DQE is also calculated. Oblique incidence yields high-frequency DQE degradation, which is more pronounced than the MTF degradation. This arises because the DQE is proportionate with the square of the MTF. Ultimately, this model is used to evaluate how the image quality varies over the detector area. For various projection images, we calculate the variation in the incidence angle over this area. With the NGT system, the source can be positioned in such a way that this variation is minimized, and hence the DQE exhibits less anisotropy. To achieve this improvement in the image quality, the source needs to have a component of motion in the posteroanterior (PA) direction, which is perpendicular to the conventional direction of source motion in tomosynthesis., Conclusions: In a-Se detectors, the DQE at high frequencies is degraded due to oblique incidence. The DQE degradation is more pronounced than the MTF degradation. This model is used to quantify the spatial variation in DQE over the detector area. The use of PA source motion is a strategy for minimizing this variation and thus improving the image quality., (© 2018 American Association of Physicists in Medicine.)

Purpose: Two phase gratings in an X-ray grating interferometers can solve several technical challenges for clinical use of X-ray phase contrast. In this work, we adapt and evaluate this setup design to clinical X-ray sources and detectors in a simulation study., Methods: For a given set of gratings, we optimize the remaining parameter space of a dual-phase grating setup using a numerical wave front simulation. The simulation results are validated with experimentally obtained visibility measurements on a setup with a microfocus tube and a clinical X-ray detector. We then confirm by simulation that the Lau condition for the [Formula: see text] grating also holds for two phase gratings. Furthermore, we use a [Formula: see text] grating with a fixed period to search for periods of matching phase grating configurations., Results: Simulated and experimental visibilities agree very well. We show that the Lau condition for a dual-phase grating setup requires the interference patterns of the first phase grating to constructively overlay at the second phase grating. Furthermore, a total of three setup variants for given [Formula: see text] periods were designed with the simulation, resulting in visibilities between 4.5 and 9.1%., Conclusion: Dual-phase gratings can be used and optimized for a medical X-ray source and detector. The obtained visibilities are somewhat lower than for other Talbot-Lau interferometers and are a tradeoff between setup length and spatial resolution (or additional phase stepping, respectively). However, these disadvantage appears minor compared to the overall better photon statistics, and the fact that dual-phase grating setups can be expected to scale to higher X-ray energies.

This work aims to assess the efficacy of current x-ray quality assurance (QA) testing regimes on tube and generator systems for general radiographic usage in the UK. 1393 sets of QA results data from nine UK medical physics departments were collected and analysed. Test failure rates ranged from 0% to 39% and were used to assess the likelihood of the test finding a fault. The magnitude of the recorded faults were used to assess the severity of the failure with due consideration to its impact on image quality and patient dose. The severity and likelihood of the faults were used along with a risk matrix to assess the efficacy of each test. Eleven tests were graded 'orange' (indicating an effective test that should be continued), four tests were graded 'yellow' (indicating a less effective test that may be continued with a lower frequency considered) and four tests were graded green (indicating a low efficacy test that could be removed from test regimes).

In radiography with focused grid, it is important to agree the X-ray center on the grid center. Actually, radiography is often put the off-center alignment which disagrees the X-ray center to the grid center. This misalignment decreases radiographic contrast because of cutoff the primary X-rays. The grid-tilt technique which makes the grid tilt corresponding to the misalignment of the X-ray center and the grid center was investigated. Using solid state dosimeter and 10 cm water phantom, transited dose of focused grids (focal distance 120 cm, grid ratio 6:1 and 8:1) were measured at off-center. The transited dose at 6 cm off-center by conventional manner was lower 20% (6:1) and 30% (8:1) to center's one. While by grid-tilt technique, the transited dose at off-center was same to the center's one. Axial radiography of hip joint was applied by this technique.

The use of routine spinal X-rays within chiropractic has a contentious history. Elements of the profession advocate for the need for routine spinal X-rays to improve patient management, whereas other chiropractors advocate using spinal X-rays only when endorsed by current imaging guidelines. This review aims to summarise the current evidence for the use of spinal X-ray in chiropractic practice, with consideration of the related risks and benefits. Current evidence supports the use of spinal X-rays only in the diagnosis of trauma and spondyloarthropathy, and in the assessment of progressive spinal structural deformities such as adolescent idiopathic scoliosis. MRI is indicated to diagnose serious pathology such as cancer or infection, and to assess the need for surgical management in radiculopathy and spinal stenosis. Strong evidence demonstrates risks of imaging such as excessive radiation exposure, overdiagnosis, subsequent low-value investigation and treatment procedures, and increased costs. In most cases the potential benefits from routine imaging, including spinal X-rays, do not outweigh the potential harms. The use of spinal X-rays should not be routinely performed in chiropractic practice, and should be guided by clinical guidelines and clinician judgement., Competing Interests: Not applicableNot applicableSDF is Deputy Editor-in-Chief of Chiropractic and Manual Therapies. He played no part in the assignment of this manuscript to Associate Editors or peer reviewers, and was blinded in the online editorial system for this manuscript from submission to final decision. Otherwise, the authors declare that they have no competing interests.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

X-ray and optical technologies are the two central pillars for human imaging and therapy. The strengths of x-rays are deep tissue penetration, effective cytotoxicity, and the ability to image with robust projection and computed-tomography methods. The major limitations of x-ray use are the lack of molecular specificity and the carcinogenic risk. In comparison, optical interactions with tissue are strongly scatter dominated, leading to limited tissue penetration, making imaging and therapy largely restricted to superficial or endoscopically directed tissues. However, optical photon energies are comparable with molecular energy levels, thereby providing the strength of intrinsic molecular specificity. Additionally, optical technologies are highly advanced and diversified, being ubiquitously used throughout medicine as the single largest technology sector. Both have dominant spatial localization value, achieved with optical surface scanning or x-ray internal visualization, where one often is used with the other. Therapeutic delivery can also be enhanced by their synergy, where radio-optical and optical-radio interactions can inform about dose or amplify the clinical therapeutic value. An emerging trend is the integration of nanoparticles to serve as molecular intermediates or energy transducers for imaging and therapy, requiring careful design for the interaction either by scintillation or Cherenkov light, and the nanoscale design is impacted by the choices of optical interaction mechanism. The enhancement of optical molecular sensing or sensitization of tissue using x-rays as the energy source is an important emerging field combining x-ray tissue penetration in radiation oncology with the molecular specificity and packaging of optical probes or molecular localization. The ways in which x-rays can enable optical procedures, or optics can enable x-ray procedures, provide a range of new opportunities in both diagnostic and therapeutic medicine. Taken together, these two technologies form the basis for the vast majority of diagnostics and therapeutics in use in clinical medicine., ((2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).)

Talbot-Lau x-ray imaging provides additionally to the conventional attenuation image, two further images: the differential phase-contrast image which is especially sensitive to differences in refractive properties and the dark-field image which is showing the x-ray scattering properties of the object. Thus, in the dark-field image sub-pixeled object information can be observed. As it has been shown in recent studies, this is of special interest for lung imaging. Changes in the alveoli structure, which are in the size of one detector pixel, can be seen in the dark-field images. A fast acquisition process is crucial to avoid motion artifacts due to heartbeat and breathing of the patient. Using moiré imaging the images can be acquired with a single-shot exposure. Nevertheless, the spatial resolution is reduced compared to the phase-stepping acquisition. We evaluate the results of both imaging techniques towards their feasibility in clinical routine. Furthermore, we analyse the influence of artificial linear object movement on the image quality, in order to simulate the heartbeat of a patient.

Hard x-ray lenses are useful elements in x-ray microscopy and in creating focused illumination for analytical applications such as x-ray fluorescence imaging. Recently, polymer compound refractive lenses for focused illumination in the soft x-ray regime (< 10 keV) have been created with nano-printing. However, there are no such lenses yet for hard x-rays, particularly of short focal lengths for benchtop microscopy. We report the first instance of a nano-printed lens for hard x-ray microscopy, and evaluate its imaging performance. The lens consists of a spherically focusing compound refractive lens designed for 22 keV photon energy, with a tightly packed structure to provide a short total length of 1.8 mm and a focal length of 21.5 mm. The resulting lens technology was found to enable benchtop microscopy at 74x magnification and 1.1 μm de-magnified image pixel size at the object plane. It was used to image and evaluate the focal spots of tungsten-anode micro-focus x-ray sources. The overall system resolution with broadband illumination from a tungsten-anode x-ray tube at 30 kV and 10 mm focal distance was measured to be 2.30±0.22 μm., Competing Interests: The authors have declared that no competing interests exist.

Background and Objective: Several studies have evaluated the reproducibility of the Cobb angle for measuring the degree of scoliotic deformities from X-ray spine images, and proposed different geometric models for describing the spinal curvature. The ellipse was shown to be an adequate geometric form, but was not yet applied for the identification and quantification of scoliotic curvatures. The purpose of this study is therefore to propose and validate a novel computerized methodology for the detection of elliptical patterns from X-ray images to evaluate the extent of the underlying scoliotic deformity., Methods: For anteroposterior each X-ray spine image, the spine curve is first reconstructed from vertebral centroids. The ellipse that best fits to the obtained spine curve is the found within a least square and genetic algorithm optimization framework. The geometric parameters of the resulting best fit ellipse are finally used to define an index that quantifies the spinal curvature., Results: The proposed methodology was validated on three synthetic images and then successfully applied to 20 clinical anteroposterior X-ray spine images of patients with a different degree of scoliotic deformity, with the resulting maximal relative error of 3% for the synthetic images and an overall error of 0.5 ± 0.4 mm (mean ± standard deviation) for the clinical cases., Conclusions: The results indicate that the proposed computerized methodology is able to reliably reproduce scoliotic curvatures using the geometric parameters of the underlying ellipses. In comparison to conventional approaches, the proposed methodology potentially produces less errors, requires a relatively low observer interaction, takes into account all vertebrae within the observed scoliotic deformity, and allows for both qualitative and quantitative evaluations that may complement the diagnosis, study and treatment of scoliosis., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Imaging in side bending, supine, traction, fulcrum, and push prone are examples of methods used to evaluate the curve reduction of scoliotic spine. However, being able to determine spine curve flexibility from MRI would eliminate the need of additional X-ray radiation related to radiograph acquisition in side-bending., Purpose/hypothesis: To find specific texture features of lumbar postural muscles on MRI that can distinguish flexible from rigid lumbar scoliotic curves. We hypothesized that the changes occurring in postural muscles with scoliosis can be seen with MRI., Study Type: Retrospective study case control., Population: With Institutional Review Board approval and informed consent, 15 adolescents with idiopathic scoliosis and scheduled for surgery were involved., Field Strength/sequence: T 1 -weighted MR images were performed on a 1.5T system using a spin echo sequence in the axial direction., Assessment: The spinal erector, quadratus lumborum and psoas major muscles were analyzed using textural features., Statistical Tests: Principal component analysis (PCA) and agglomerative hierarchical clustering (AHC) were used to classify the lumbar postural muscles and calculate performance metrics. The lumbar flexibility index, measured from suspension tests, was used as ground truth measurement., Results: The five discriminant features (out of 34 tested features) obtained from PCA were able to keep over 90% of the variability of the dataset. The right and left spinal erector and the left psoas major had the highest performance metrics to classify the spinal curve flexibility, with an accuracy over 0.80, a sensitivity over 0.82, a specificity over 0.68, and a Matthews correlation coefficient over 0.57., Data Conclusion: This study analyzed MRI using texture information of muscle to distinguish flexible from rigid scoliotic curves. Some postural muscle such as the spinal erector and the psoas major are more likely to reflect the curve flexibility of a scoliotic participant., Level of Evidence: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017., (© 2017 International Society for Magnetic Resonance in Medicine.)

Background: Detection of foreign body oesophagus has always been a challenge for the otolaryngologists. Among different investigations available X -ray is valuable for detection of foreign bodies as it is readily available, inexpensive and easy to operate. However, this still remains to be decided that how accurate it is? The objective of the study is to determine the diagnostic accuracy of plain X ray lateral neck in the diagnosis of foreign bodies in cervical oesophagus keeping esophagoscopy as the gold standard., Methods: This descriptive study was conducted at department of ENT, Ayub Medical Institute (AMI) Abbottabad, from Mar to Sep 2016. A total of 290 patients were included in this study and all the patients had X-ray lateral view of neck, followed by oesophagoscopy (gold standard). Diagnostic accuracy of plain X-ray lateral view of neck was detected by determining sensitivity, specificity and accuracy., Results: The sensitivity, specificity and accuracy of plain X-ray lateral view of neck was 91.7%, 80%, and 89.7%, respectively., Conclusions: X-Ray lateral view of neck is a reliable investigation and should be advised among all the patients with history of foreign body ingestion.

In the field of X-ray microcomputed tomography (μCT) there is a growing need to reduce acquisition times at high spatial resolution (approximate micrometers) to facilitate in vivo and high-throughput operations. The state of the art represented by synchrotron light sources is not practical for certain applications, and therefore the development of high-brightness laboratory-scale sources is crucial. We present here imaging of a fixed embryonic mouse sample using a compact laser-plasma-based X-ray light source and compare the results to images obtained using a commercial X-ray μCT scanner. The radiation is generated by the betatron motion of electrons inside a dilute and transient plasma, which circumvents the flux limitations imposed by the solid or liquid anodes used in conventional electron-impact X-ray tubes. This X-ray source is pulsed (duration <30 fs), bright (>10 10 photons per pulse), small (diameter <1 μm), and has a critical energy >15 keV. Stable X-ray performance enabled tomographic imaging of equivalent quality to that of the μCT scanner, an important confirmation of the suitability of the laser-driven source for applications. The X-ray flux achievable with this approach scales with the laser repetition rate without compromising the source size, which will allow the recording of high-resolution μCT scans in minutes., Competing Interests: The authors declare no conflict of interest., (Copyright © 2018 the Author(s). Published by PNAS.)

Purpose: Clinical procedures that make use of fluoroscopy may expose patients as well as the clinical staff (throughout their career) to non-negligible doses of radiation. The potential consequences of such exposures fall under two categories, namely stochastic (mostly cancer) and deterministic risks (skin injury). According to the "as low as reasonably achievable" principle, the radiation dose can be lowered only if the necessary image quality can be maintained., Methods: Our work improves upon the existing patch-based denoising algorithms by utilizing a more sophisticated noise model to exploit non-local self-similarity better and this in turn improves the performance of low-rank approximation. The novelty of the proposed approach lies in its properly designed and parameterized noise model and the elimination of initial estimates. This reduces the computational cost significantly., Results: The algorithm has been evaluated on 500 clinical images (7 patients, 20 sequences, 3 clinical sites), taken at ultra-low dose levels, i.e. 50% of the standard low dose level, during electrophysiology procedures. An average improvement in the contrast-to-noise ratio (CNR) by a factor of around 3.5 has been found. This is associated with an image quality achieved at around 12 (square of 3.5) times the ultra-low dose level. Qualitative evaluation by X-ray image quality experts suggests that the method produces denoised images that comply with the required image quality criteria., Conclusion: The results are consistent with the number of patches used, and they demonstrate that it is possible to use motion estimation techniques and "recycle" photons from previous frames to improve the image quality of the current frame. Our results are comparable in terms of CNR to Video Block Matching 3D-a state-of-the-art denoising method. But qualitative analysis by experts confirms that the denoised ultra-low dose X-ray images obtained using our method are more realistic with respect to appearance.

Purpose: Talbot-Lau x-ray interferometry provides information about the scattering and refractive properties of an object - in addition to the object's attenuation features. Until recently, this method was ineligible for imaging human-sized objects as it is challenging to adapt Talbot-Lau interferometers (TLIs) to the relevant x-ray energy ranges. In this work, we present a preclinical Talbot-Lau prototype capable of imaging human-sized objects with proper image quality at clinically acceptable dose levels., Methods: The TLI is designed to match a setup of clinical relevance as closely as possible. The system provides a scan range of 120 × 30 cm 2 by using a scanning beam geometry. Its ultimate load is 100 kg. High aspect ratios and fine grid periods of the gratings ensure a reasonable setup length and clinically relevant image quality. The system is installed in a university hospital and is, therefore, exposed to the external influences of a clinical environment. To demonstrate the system's capabilities, a full-body scan of a euthanized pig was performed. In addition, freshly excised porcine lungs with an extrinsically provoked pneumothorax were mounted into a human thorax phantom and examined with the prototype., Results: Both examination sequences resulted in clinically relevant image quality - even in the case of a skin entrance air kerma of only 0.3 mGy which is in the range of human thoracic imaging. The presented case of a pneumothorax and a reader study showed that the prototype's dark-field images provide added value for pulmonary diagnosis., Conclusion: We demonstrated that a dedicated design of a Talbot-Lau interferometer can be applied to medical imaging by constructing a preclinical Talbot-Lau prototype. We experienced that the system is feasible for imaging human-sized objects and the phase-stepping approach is suitable for clinical practice. Hence, we conclude that Talbot-Lau x-ray imaging has potential for clinical use and enhances the diagnostic power of medical x-ray imaging., (© 2018 American Association of Physicists in Medicine.)

On account of the problem that traditional C-arm X-ray apparatus cannot provide precise route guidance for minimally invasive surgeries, we designed and developed a laser positioning and navigation system based on C-arm X-ray apparatus, which can achieve precise positioning function and reduce the exposure of doctors and patients to radiation in minimally invasive surgeries under the linear guidance of a laser beam. Furthermore, this system can enhance the refinement level of surgical operation in minimally invasive surgeries.

Purpose: Single-photon-counting (SPC) and spectroscopic x-ray detectors are under development in academic and industry laboratories for medical imaging applications. The spatial resolution of SPC and spectroscopic x-ray detectors is an important design criterion. The purpose of this article was to extend the cascaded systems approach to include a description of the spatial resolution of SPC and spectroscopic x-ray imaging detectors., Methods: A cascaded systems approach was used to model reabsorption of characteristic x rays, Coulomb repulsion, and diffusion in SPC and spectroscopic x-ray detectors. In addition to reabsorption, diffusion, and Coulomb repulsion, the model accounted for x-ray conversion to electron-hole (e-h) pairs, integration of e-h pairs in detector elements, electronic noise, and energy thresholding. The probability density function (PDF) describing the number of e-h pairs was propagated through each stage of the model and was used to derive new theoretical expressions for the large-area gain and modulation transfer function (MTF) of CdTe SPC x-ray detectors, and the energy bin sensitivity functions and MTFs of CdTe spectroscopic detectors. Theoretical predictions were compared with the results of MATLAB-based Monte Carlo (MC) simulations and published data. Comparisons were also made with the MTF of energy-integrating systems., Results: Under general radiographic conditions, reabsorption, diffusion, and Coulomb repulsion together artificially inflate count rates by 20% to 50%. For thicker converters (e.g. 1000 μm) and larger detector elements (e.g. 500 μm pixel pitch) these processes result in modest inflation (i.e. ∼10%) in apparent count rates. Our theoretical and MC analyses predict that SPC MTFs will be degraded relative to those of energy-integrating systems for fluoroscopic, general radiographic, and CT imaging conditions. In most cases, this degradation is modest (i.e., ∼10% at the Nyquist frequency). However, for thicker converters, the SPC MTF can be degraded by up to 25% at the Nyquist frequency relative to EI systems. Additionally, unlike EI systems, the MTF of spectroscopic systems is strongly dependent on photon energy, which results in energy-bin-dependent spatial resolution in spectroscopic systems., Conclusions: The PDF-transfer approach to modeling signal transfer through SPC and spectroscopic x-ray imaging systems provides a framework for understanding system performance. Application of this approach demonstrated that charge sharing artificially inflates the SPC image signal and degrades the MTF of SPC and spectroscopic systems relative to energy-integrating systems. These results further motivate the need for anticharge-sharing circuits to mitigate the effects of charge sharing on SPC and spectroscopic x-ray image quality., (© 2018 American Association of Physicists in Medicine.)

In medical X-ray imaging, phase contrast imaging is to measure refraction angles caused by the patient. The X-ray dose for a given image quality depends on the sensitivity of the setup, i.e. on the angular measurement range. Measurement ranges of existing phase contrast setups are either too high or too low for perfectly imaging a human finger in air: There is a gap in available measurement ranges, which prevents a reduction of X-ray dose. To fill the gap, this work proposes a novel variant of a Talbot-Lau interferometer. Instead of a single phase grating, it uses two phase gratings, each consisting of tiny prisms. The height of the prisms is an additional factor in the measurement range, which allows to fill the gap. The potential is a dose-reduction by a factor of 5.4 compared to Talbot-Lau setups of same post-patient length. Simulation results indicate a polychromatic visibility of up to 20%.

Background Recent papers suggest that finger joints with positive synovial vascularity (SV) assessed by ultrasonography under clinical low disease activity (CLDA) in rheumatoid arthritis (RA) patients may cause joint space narrowing (JSN) progression. Purpose To investigate the performance of a computer-based method by directly comparing with the conventional scoring method in terms of the detectability of JSN progression in hand radiography of RA patients with CLDA. Material and Methods Fifteen RA patients (13 women, 2 men) with long-term sustained CLDA of >2 years were included. Radiological progression of finger joints was measured or scored using the computer-based method which can detect JSN progression between two radiographic images as the joint space difference index (JSDI), as well as the Genant-modified Sharp score (GSS). We also quantitatively assessed SV of these joints using ultrasonography. Results Out of 270 joints, we targeted 259 finger joints after excluding nine damaged joints (four ankylosis, three complete luxation, and two subluxation) and two improved joints according to the GSS results. The JSDI of finger joints with JSN progression was significantly higher than those without JSN progression ( P = 0.018). The JSDI of finger joints with ultrasonographic SV was significantly higher than those without ultrasonographic SV ( P = 0.004). Progression in JSDI showed stronger associations with ultrasonographic SV than progression in GSS (odds ratio [95% confidence interval]: 7.19 [3.37-15.36] versus 5.84 [2.76-12.33]). Conclusion The computer-based method was comparable to the conventional scoring method regarding the detectability of JSN progression in RA patients with CLDA.

Purpose: Identifying the elbow flexion-extension (F-E) movement axis is important for placing a hinged elbow external fixator. An X-ray fluoroscopy-based method is widely used in clinical practice, exposing the patient and surgeons to high doses of radiation. Additionally, the accuracy and repeatability of the fluoroscopy-based method are very low and affected by subjective factors., Methods: To solve this problem, an X-ray-free method based on kinematics analysis was proposed to identify the elbow F-E movement axis, and a navigation system was built to guide the placement of the elbow external fixator., Results: Our X-ray-free navigation method is more repeatable than the current X-ray fluoroscopy method used clinically. Both our algorithm and the NIST (National Institute of Standards and Technology) algorithm showed high accuracy and repeatability to identify the axis., Conclusions: The method proposed in this study is very promising to avoid a large dose of X-ray radiation and increases the repeatability and performance of identifying the elbow F-E movement axis for the placement of the hinged elbow external fixator.

When screening for Kashin-Beck disease (KBD) in children, hand X-ray examination is the most important measure. However, there is high rate of misdiagnosis because of confusing X-ray signs. We studied the characteristics of positive and confusing hand X-ray signs. Clinical and radiological examinations were conducted in all 7- to 12-year-olds in selected villages from some KBD and non-KBD areas. We analysed the radiological and epidemiological characteristics of the X-ray signs of KBD and the confusing signs. Images from 3,193 children were valid. No cases of KBD were found. Seventeen children (0.53%) had X-ray signs positive for KBD. The confusing X-ray signs included closure reaction of metaphysis-epiphysis (CRME, 14.28%), thumb variation (0.22%), little finger variation (8.89%), the second metacarpal-phalangeal variation (0.13%) and cystic change (3.85%). The onset of CRME in children occurred earlier in girls (9) than in boys (10). The onset occurred earlier in KBD areas (9) than in non-KBD areas (10). The onset occurred earlier in Han children (9) than in Tibetan children (11). In summary, KBD was effectively controlled in all investigated KBD endemic villages, and the age range should be adjusted to 7- to 11-year-olds in Han children to reduce the misdiagnosis rates in KBD surveillance.

Objectives: To establish regression models of stature estimation for Sichuan Han female by the measurement of total vertebral column length in the frontal and lateral X-ray films of whole-spine., Methods: The frontal and lateral X-ray films of whole-spine were collected from 200 Sichuan Han females by large flat-panel multi-functional universal radiography and fluoroscopy system. The data and mean values of frontal and lateral total vertebral column length were measured and calculated in all the samples, respectively. The relationship of combined multi-markers and stature were analysed by linear regression analysis, and the mathematical models of stature estimation were established. The data of 30 new samples were selected and inputted for verifying the accuracy of the mathematical models., Results: The total vertebral column length showed a good correlation with stature, and the mean values of the frontal and lateral X-ray films of total vertebral column length had the highest correlation coefficients. Three established linear regression equation models were statistically significant （ P <0.05）, and the equation established with lateral total vertebral column length showed the highest accuracy., Conclusions: The stature estimation by the measurement of total vertebral column length has high accuracy., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Forensic Medicine.)

An optically stimulated luminescence dosemeter was used to compare the surface dose to both eyes from an X-ray delivered frontally to the skull, and the dose could be reduced depending on image acquisition. The detectors were analysed in advance according to each image acquisition method, and the irradiation condition (mA) was obtained to equate the detective quantum efficiency of the two detectors. The surface doses to both eyes were measured in a human phantom. In the detector using the direct conversion method, the surface doses to both eyes were 0.29 ± 0.01 mSv (Rt. eye) and 0.28 ± 0.01 mSv (Lt. eye). In the detector using the indirect conversion method, the surface doses to both eyes were 0.23 ± 0.01 mSv (Rt. eye) and 0.23 ± 0.01 mSv (Lt. eye). Dose reduction by 18.00 ± 8.9% was permitted by the indirect method as compared with the direct method., (© The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Mono-capillary optics have been applied to increase the performance of X-ray instruments. However, performance of a mono-capillary optic strongly depends on the shape accuracy, which is determined by the diameters of the inner hollow of the capillary along the axial direction., Objective: To precisely determine the inner diameter of the capillary optic used in X-ray imaging technique, which aims to replace the conventional method using a visible microscope., Methods: High spatial resolution X-ray images of the mono-capillary optic were obtained by a synchrotron radiation beamline. The inner diameter of the mono-capillary optic was measured and analyzed by the pixel values of the X-ray image., Result: Edge enhancement effect was quite useful in determining the inner diameter, and the accuracy of the diameter determination was less than 1.32 μm. Many images obtained by scanning the mono-capillary optic along the axial direction were combined, and the axial profile, consisting of diameters along the axial direction, was obtained from the combined image. The X-ray imaging method could provide an accurate measurement with slope error of±19 μrad., Conclusions: Applying X-ray imaging technique to determine the inner diameter of a mono-capillary optic can contribute to increasing fabrication accuracy of the mono-capillary optic through a feedback process between the fabrication and measurement of its diameter.

Portable radiography is available for the patient who is postoperative, severe condition and old. As they have weak immunity, it is important to prevent from hospital infection. Wrapping of 14×14 inch or 14×17 inch X-ray cassette by a plastic (polyethylene) bag a little bit bigger than the cassette was proposed for infection prevention in portable radiography. How to wrap the cassette easily was devised using the sheath of a polyester bag cutting at the bottom. In radiography with the grid, the plastic bag fastens the X-ray grid to the cassette substantially without any other means. In addition, the wrapped cassette, or the cassette with grid covered by the foamed plastic sheet alleviates patient's discomfort.

Background: Chest Radiograph accompanied by clinical and laboratory findings are required for diagnosis and follow-up of patients with suspected ventilatorassociated pneumonia (VAP). However, there are no reliable data whether follow-up chest-X-ray (CXR) is needed or not, moreover, when the physicians request CXR and how many times CXR is required. We aimed to determine association of the clinical improvement with resolution of pulmonary infiltrates as well as time of resolution., Materials and Methods: The patients with a diagnosis of VAP based on Clinical Pulmonary Infection Score (CPIS) were enrolled in this study. Clinical evaluation and follow-up were continued and CXR was performed sequentially in two-day intervals until clinical improvement or occurrence of other events including death. Fischer test was used to analyze the association of clinical improvement with radiographic resolution., Results: Out of the seventy -five patients, pneumonia was clinically improved in 48 cases. Mean duration of the clinical improvement was 5.3±4.5 days. Among these patients, pulmonary infiltrations in 44 patients were resolved completely (13.8±5.8 days). Twentyseven patients had no clinical improvement and all of them revealed no infiltration resolution according to the sequential imaging studies. Resolution of radiographic involvement significantly was associated with clinical improvement (p=0.000)., Conclusion: Radiographic resolution occurs in most of patients who survived VAP and there is strong relationship between radiographic resolution and clinical improvement. Moreover, our data revealed that CXR clearance occurred earlier than anticipated previously. Thus, sequential follow-up CXR in VAP had no further clinical value., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Electronic brachytherapy sources are widely accepted as alternatives to radionuclide-based systems. Yet, formal dosimetry standards for these devices to independently complement the dose protocol provided by the manufacturer are lacking. This article presents a formalism for calculating and independently verifying the absorbed dose to water from a kV x-ray source (The INTRABEAM System) measured in a water phantom with an ionization chamber calibrated in terms of air-kerma. This formalism uses a Monte Carlo (MC) calculated chamber conversion factor, [Formula: see text], to convert air-kerma in a reference beam to absorbed dose to water in the measurement beam. In this work [Formula: see text] was determined for a PTW 34013 parallel-plate ionization chamber. Our results show that [Formula: see text] was sensitive to the chamber plate separation tolerance, with differences of up to 15%. [Formula: see text] was also found to have a depth dependence which varied with chamber plate separation (0 to 10% variation for the smallest and largest cavity height, over 3 to 30 mm depth). However for all chamber dimensions investigated, [Formula: see text] was found to be significantly larger than the manufacturer reported value, suggesting that the manufacturer recommended method of dose calculation could be underestimating the dose to water.

Increasing evidence suggests that intrafraction tumour motion monitoring needs to include both 3D translations and 3D rotations. Presently, methods to estimate the rotation motion require the 3D translation of the target to be known first. However, ideally, translation and rotation should be estimated concurrently. We present the first method to directly estimate six-degree-of-freedom (6DoF) motion from the target's projection on a single rotating x-ray imager in real-time. This novel method is based on the linear correlations between the superior-inferior translations and the motion in the other five degrees-of-freedom. The accuracy of the method was evaluated in silico with 81 liver tumour motion traces from 19 patients with three implanted markers. The ground-truth motion was estimated using the current gold standard method where each marker's 3D position was first estimated using a Gaussian probability method, and the 6DoF motion was then estimated from the 3D positions using an iterative method. The 3D position of each marker was projected onto a gantry-mounted imager with an imaging rate of 11 Hz. After an initial 110° gantry rotation (200 images), a correlation model between the superior-inferior translations and the five other DoFs was built using a least square method. The correlation model was then updated after each subsequent frame to estimate 6DoF motion in real-time. The proposed algorithm had an accuracy (±precision) of  -0.03  ±  0.32 mm, -0.01  ±  0.13 mm and 0.03  ±  0.52 mm for translations in the left-right (LR), superior-inferior (SI) and anterior-posterior (AP) directions respectively; and, 0.07  ±  1.18°, 0.07  ±  1.00° and 0.06  ±  1.32° for rotations around the LR, SI and AP axes respectively on the dataset. The first method to directly estimate real-time 6DoF target motion from segmented marker positions on a 2D imager was devised. The algorithm was evaluated using 81 motion traces from 19 liver patients and was found to have sub-mm and sub-degree accuracy.

The most widely accepted method for shielding design of X-ray facilities is that contained in the National Council on Radiation Protection and Measurements Report 147 whereby the computation of the barrier thickness for primary, secondary and leakage radiations is based on the knowledge of the distances from the radiation sources, the assumptions of the clinical workload, and usage and occupancy of adjacent areas. The shielding methodology used in this report is complex. With this methodology, the shielding designers need to make assumptions regarding the use of the X-ray room and the adjoining areas. Different shielding designers may make different assumptions resulting in different shielding requirements for a particular X-ray room. A more simple and practical method is to base the shielding design on the shielding principle used to shield X-ray tube housing to limit the leakage radiation from the X-ray tube. In this case, the shielding requirements of the X-ray room would depend only on the maximum radiation output of the X-ray equipment regardless of workload, usage or occupancy of the adjacent areas of the room. This shielding methodology, which has been used in South Australia since 1985, has proven to be practical and, to my knowledge, has not led to excess shielding of X-ray installations.

Imaging during pregnancy has increased in frequency. Radiation protection is extremely important although tissue reactions of the conceptus, requiring a threshold dose of around 100mGy, are unlikely in the diagnostic use of X-rays and stochastic effects of cancerogenesis have a rather low risk (around 10 -4 /mGy for childhood cancer due to in utero exposure). This article will review the risk depending on dose and phase of pregnancy and the exposure by frequent examinations; it will then concentrate on the duties of an imaging department: screening for pregnancy, examination justification, planning and optimization, patient information, counseling, involving the patient in the decisions, and managing the situation of pregnant staff members. Typical flowcharts of investigating frequent clinical questions will finally be presented and critically discussed., (Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.)

The occupational exposure incurred by the radiation workers due to the external radiation is estimated using personal dosemeter placed on the human body during the monitoring period. In certain situations, it is required to determine whether the dosemeter alone was exposed accidentally/intentionally in radiation field (static exposure) or was exposed while being worn by a worker moving in his workplace (dynamic exposure). The present thermoluminscent (TL) based personnel monitoring systems are not capable of distinguishing between the above stated (static and dynamic) exposure conditions. The feasibility of a new methodology developed using the charge coupled device based imaging technique for identification of the static/dynamic exposure of CaSO4:Dy based TL detectors for low energy photons has been investigated. The techniques for the qualitative and the quantitative assessments of the exposure conditions are presented in this paper., (© The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Introduction: As proton therapy becomes increasingly well established, there is a need for high-quality clinically relevant in vivo data to gain better insight into the radiobiological effects of proton irradiation on both healthy and tumor tissue. This requires the development of easily applicable setups that allow for efficient, fractionated, image-guided proton irradiation of small animals, the most widely used pre-clinical model., Material and Methods: Here, a method is proposed to perform dual-energy proton radiography for inline positioning verification and treatment planning. Dual-energy proton radiography exploits the differential enhancement of object features in two successively measured two-dimensional (2D) dose distributions at two different proton energies. The two raw images show structures that are dominated by energy absorption (absorption mode) or scattering (scattering mode) of protons in the object, respectively. Data post-processing allowed for the separation of both signal contributions in the respective images. The images were evaluated regarding recognizable object details and feasibility of rigid registration to acquired planar X-ray scans., Results: Robust, automated rigid registration of proton radiography and planar X-ray images in scattering mode could be reliably achieved with the animal bedding unit used as registration landmark. Distinguishable external and internal features of the imaged mouse included the outer body contour, the skull with substructures, the lung, abdominal structures and the hind legs. Image analysis based on the combined information of both imaging modes allowed image enhancement and calculation of 2D water-equivalent path length (WEPL) maps of the object along the beam direction., Discussion: Fractionated irradiation of exposed target volumes (e.g., subcutaneous tumor model or brain) can be realized with the suggested method being used for daily positioning and range determination. Robust registration of X-ray and proton radiography images allows for the irradiation of tumor entities that require conventional computed tomography (CT)-based planning, such as orthotopic lung or brain tumors, similar to conventional patient treatment.

Pediatric patients are more sensitive to ionizing radiation when compared with adults. The aim of this study was to evaluate the radiation doses for some common pediatric x-ray examinations performed with various digital radiography systems. Quality control tests of the digital radiography systems were carried out according to international published protocols before the pediatric dose measurements. Radiation dose measurement was performed by using the x-ray tube outputs and thermoluminescent dosimeter dose measurement methods. In the present study, radiation doses were assessed for 247 chest, 230 pelvis, 194 skull and 73 abdomen x-ray examinations and in total 744 pediatric patients doses were measured. Pediatric patients were classified into four age groups 0-1, 1-5, 5-10 and 10-15 years as given by European Commission guidance. Effective doses were determined for each examination using a PCXMC 2.0 Monte Carlo program. The mean measured entrance skin doses for the age interval 1-5 years and AP projection by using tube output measurement methods were 149 µGy for chest, 304 µGy for pelvis, 387 µGy for skull and 199 µGy for abdomen examinations. The radiation dose results obtained in this study were in the range of the published results in the literature., (© The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Patients often arrive at imaging departments on stretchers, and in certain circumstances they must remain on the stretcher for the imaging examination to reduce the likelihood of exacerbating injuries. Imaging stretcher-bound patients can be challenging, with many physical and technical variables to consider. These challenges occur because of differences between imaging a patient on a tabletop and imaging a patient on a stretcher. This article reviews the issues associated with imaging stretcher-bound patients, including the unavailability of the automatic exposure control, different grids used, geometric factors, and variability in stretcher design., (©2017 American Society of Radiologic Technologists.)

Medical X-ray imaging procedures require digital flat detectors operating at low doses to reduce radiation health risks. Solution-processed organic-inorganic hybrid perovskites have characteristics that make them good candidates for the photoconductive layer of such sensitive detectors. However, such detectors have not yet been built on thin-film transistor arrays because it has been difficult to prepare thick perovskite films (more than a few hundred micrometres) over large areas (a detector is typically 50 centimetres by 50 centimetres). We report here an all-solution-based (in contrast to conventional vacuum processing) synthetic route to producing printable polycrystalline perovskites with sharply faceted large grains having morphologies and optoelectronic properties comparable to those of single crystals. High sensitivities of up to 11 microcoulombs per air KERMA of milligray per square centimetre (μC mGy air -1 cm -2 ) are achieved under irradiation with a 100-kilovolt bremsstrahlung source, which are at least one order of magnitude higher than the sensitivities achieved with currently used amorphous selenium or thallium-doped cesium iodide detectors. We demonstrate X-ray imaging in a conventional thin-film transistor substrate by embedding an 830-micrometre-thick perovskite film and an additional two interlayers of polymer/perovskite composites to provide conformal interfaces between perovskite films and electrodes that control dark currents and temporal charge carrier transportation. Such an all-solution-based perovskite detector could enable low-dose X-ray imaging, and could also be used in photoconductive devices for radiation imaging, sensing and energy harvesting.