Effectiveness of low dose computed tomography to detect fractures in paediatric suspected physical abuse: a systematic review.

PURPOSE: The skeletal survey X-ray series is the current 'gold standard' when investigating suspected physical abuse (SPA) of children, in addition to a non-contrast computed tomography (CT) brain scan. This systematic literature review synthesised findings of published research to determine if low dose computed tomography (LDCT) could detect subtle fractures and therefore replace the skeletal survey X-ray series in the investigation of SPA in children aged under 3 years. METHODS: Five electronic databases and grey literature were systematically searched from their inception to 28 April 2022. Primary studies were included where the population comprised paediatric patients up to 16 years and LDCT was used to detect fractures associated with SPA. Studies involving imaging investigations of the head, standard dose CT examinations or accidental trauma were excluded. RESULTS: Three studies met the inclusion criteria, all of which were case series. These studies did not report many of the criteria required to compare the accuracy of LDCT to X-ray, i.e. they did not meet the criteria for a diagnostic accuracy test. Therefore, it is difficult to conclude from the case series if LDCT is accurate enough to replace X-rays. CONCLUSION: Due to the gap in current literature, a phantom study and subsequent post-mortem CT study are recommended as the primary investigative methods to assess the ability of low-dose CT to identify the subtle fractures associated with SPA and to calculate how low the achievable CT dose can be.

Brainstem processing of cough sensory inputs in chronic cough hypersensitivity.

BACKGROUND: Chronic cough is a prevalent and difficult to treat condition often accompanied by cough hypersensitivity, characterised by cough triggered from exposure to low level sensory stimuli. The mechanisms underlying cough hypersensitivity may involve alterations in airway sensory nerve responsivity to tussive stimuli which would be accompanied by alterations in stimulus-induced brainstem activation, measurable with functional magnetic resonance imaging (fMRI). METHODS: We investigated brainstem responses during inhalation of capsaicin and adenosine triphosphate (ATP) in 29 participants with chronic cough and 29 age- and sex-matched controls. Psychophysical testing was performed to evaluate individual sensitivities to inhaled stimuli and fMRI was used to compare neural activation in participants with cough and control participants while inhaling stimulus concentrations that evoked equivalent levels of urge-to-cough sensation. FINDINGS: Participants with chronic cough were significantly more sensitive to inhaled capsaicin and ATP and showed a change in relationship between urge-to-cough perception and cough induction. When urge-to-cough levels were matched, participants with chronic cough displayed significantly less neural activation in medullary regions known to integrate airway sensory inputs. By contrast, neural activations did not differ significantly between the two groups in cortical brain regions known to encode cough sensations whereas activation in a midbrain region of participants with chronic cough was significantly increased compared to controls. INTERPRETATION: Cough hypersensitivity in some patients may occur in brain circuits above the level of the medulla, perhaps involving midbrain regions that amplify ascending sensory signals or change the efficacy of central inhibitory control systems that ordinarily serve to filter sensory inputs. FUNDING: Supported in part by a research grant from Investigator-Initiated Studies Program of Merck Sharp & Dohme Pty Ltd. The opinions expressed in this paper are those of the authors and do not necessarily represent those of Merck Sharp & Dohme (Australia) Pty Ltd.

Comparison of typical radiation doses and risks using an anthropomorphic 'bone fracture' phantom for commonly performed X-ray projections in a 5-year-old.

INTRODUCTION: Diagnostic reference levels (DRLs) are typical dose levels for medical imaging examinations for groups of standard-sized patients or standard phantoms for broadly defined types of equipment used as a tool to aid optimisation of protection for medical exposures. Currently, there are no paediatric DRLs for conventional radiography (i.e. general X-rays) published in Australia. The aim of this study was to establish typical radiation doses and risks that are representative of those delivered for commonly performed X-ray projections for a 5-year-old/20 kg child using a 5-year-old anthropomorphic 'bone fracture' phantom in three dedicated paediatric radiology departments in Victoria. METHODS: A total of 20 projection images were acquired for a standard 5-year-old/20 kg phantom using digital radiography X-ray equipment. The air kerma-area product (KAP) measured at each centre by a KAP metre, which was calibrated to a national primary standard, was considered to represent the median value for that centre for each X-ray projection. Organ doses and effective dose were estimated using PCXMC software, and risks of radiation-induced cancer and radiation-induced death were calculated based on the BEIR VII report. RESULTS: The typical doses for the individual X-ray projections ranged from 3 mGy•cm2 to 86 mGy•cm2 , whilst the effective doses ranged from 0.00004 to 0.07 mSv. The radiation risks were 'minimal' to 'negligible'. CONCLUSION: The estimation of typical radiation doses and associated risks for a 5-year-old/20 kg phantom study provides reference values for guidance and is a first step in assisting optimisation at other institutions until national DRLs, based on patient data from the clinical setting, are published.

Typical median effective radiation doses using an anthropomorphic bone fracture phantom for initial radiographic skeletal surveys in the investigation of suspected physical abuse.

BACKGROUND: A series of 31 radiographs is recommended by the Royal College of Radiologists (RCR) when investigating suspected physical abuse (SPA). OBJECTIVE: To determine the radiation dose delivered for skeletal surveys performed for SPA in Victorian radiology departments based on their local protocols. MATERIALS AND METHODS: A 5-year-old paediatric bone fracture phantom was radiographed at five radiology sites using both the RCR recommended protocol and, where applicable, the local departmental SPA protocol. The radiation doses were measured and recorded. These were scaled down to estimate the effective radiation doses for a 2-year-old child at each site and the associated radiation risks estimated. RESULTS: The median effective dose for all radiographic projections in the RCR skeletal survey radiographic series was 0.09 mSv. The estimated risk of radiation-induced cancer and radiation-induced death from cancer for 2-year-old children is classified as "very low," with girls having a higher risk than boys. CONCLUSION: The median effective radiation dose for the RCR skeletal survey for imaging in SPA was 0.09 mSv resulting in a "very low" additional risk of radiation-induced cancer. The authors will now aim to ascertain whether whole-body CT skeletal survey can replace the radiographic series for imaging in SPA while maintaining a comparable radiation dose.

Designing a breast support device for phase contrast tomographic imaging: getting ready for a clinical trial.

OBJECTIVE: To design a device that can support the breast during phase-contrast tomography, and characterise its fit parameterisation and comfort rating. METHODS: 27 participants were recruited to trial a system for breast support during simulated phase contrast imaging, including being positioned on a prone imaging table while wearing the device. Participants underwent a photogrammetry analysis to establish the geometric parameterisations. All participants trialled a single-cup design while 14 participants also trialled a double-cup with suction holder and all completed a series of questionnaires to understand subjective comfort. RESULTS: Photogrammetry revealed significant positive correlations between bra cup volume and measured prone volume (p < 0.001), and between "best fit" single-cup holder volume and measured prone volume (p < 0.005). Both holders were suitable devices in terms of subjective comfort and immobilisation while stationary. However, some re-engineering to allow for quick, easy fitting in future trials where rotation through the radiation beam will occur is necessary. Light suction was well-tolerated when required. CONCLUSION: All participants indicated the table and breast support devices were comfortable, and they would continue in the trial. ADVANCES IN KNOWLEDGE: Phase contrast tomography is an emerging breast imaging modality and clinical trials are commencing internationally. This paper describes the biomedical engineering designs, in parallel with optimal imaging, that are necessary to measure breast volume so that adequate breast support can be achieved. Breast support devices have implications for comfort, motion correction and maximising breast tissue visualisation.

Immersive virtual reality simulated learning environment versus role-play for empathic clinical communication training.

INTRODUCTION: The use of immersive virtual reality simulated learning environments (VR SLEs) for improving clinical communication can offer desirable qualities including repetition and determinism in a safe environment. The aim of this study was to establish whether the mode of delivery, VR SLE versus clinical role-play, could have a measurable effect on clinical empathic communication skills for MRI scenarios. METHODS: A split-cohort study was performed with trainee practitioners (n = 70) and qualified practitioners (n = 9). Participants were randomly assigned to four groups: clinician VR (CVR), clinician role-play (CRP), trainee VR (TVR), and trainee RP (TRP). Clinical communication skills were assessed using two methods: firstly, a self-reported measure - the SE-12 communication questionnaire and, secondly, a training and assessment tool developed by a panel of experts. RESULTS: Participants in the VR trainee (TVR) and clinician (CVR) groups reported 11% (P < 0.05) and 7.2% (P < 0.05) improvements in communication confidence post training, whereas trainees assigned to the role-play (TRP) intervention reported a 4.3% (P < 0.05) improvement. Empirical assessment of communication training scores assessing a participant's ability to select empathic statements showed the TVR group performed 5% better on average than their role-play counterparts (P < 0.05). CONCLUSION: The accuracy of participant's selection of appropriate empathic responses was shown to differ significantly following the training intervention designed to improve interactions with patients that present for an MRI scan. The results may demonstrate the capacity for immersion into an emotional narrative in a VR environment to increase the user's susceptibility for recalling and selecting empathic terminology.

Effect of x-ray energy on the radiological image quality in propagation-based phase-contrast computed tomography of the breast.

Purpose: Breast cancer is the most common cancer in women in developing and developed countries and is responsible for 15% of women's cancer deaths worldwide. Conventional absorption-based breast imaging techniques lack sufficient contrast for comprehensive diagnosis. Propagation-based phase-contrast computed tomography (PB-CT) is a developing technique that exploits a more contrast-sensitive property of x-rays: x-ray refraction. X-ray absorption, refraction, and contrast-to-noise in the corresponding images depend on the x-ray energy used, for the same/fixed radiation dose. The aim of this paper is to explore the relationship between x-ray energy and radiological image quality in PB-CT imaging. Approach: Thirty-nine mastectomy samples were scanned at the imaging and medical beamline at the Australian Synchrotron. Samples were scanned at various x-ray energies of 26, 28, 30, 32, 34, and 60 keV using a Hamamatsu Flat Panel detector at the same object-to-detector distance of 6 m and mean glandular dose of 4 mGy. A total of 132 image sets were produced for analysis. Seven observers rated PB-CT images against absorption-based CT (AB-CT) images of the same samples on a five-point scale. A visual grading characteristics (VGC) study was used to determine the difference in image quality. Results: PB-CT images produced at 28, 30, 32, and 34 keV x-ray energies demonstrated statistically significant higher image quality than reference AB-CT images. The optimum x-ray energy, 30 keV, displayed the largest area under the curve ( AUC VGC ) of 0.754 ( p = 0.009 ). This was followed by 32 keV ( AUC VGC = 0.731 , p ≤ 0.001 ), 34 keV ( AUC VGC = 0.723 , p ≤ 0.001 ), and 28 keV ( AUC VGC = 0.654 , p = 0.015 ). Conclusions: An optimum energy range (around 30 keV) in the PB-CT technique allows for higher image quality at a dose comparable to conventional mammographic techniques. This results in improved radiological image quality compared with conventional techniques, which may ultimately lead to higher diagnostic efficacy and a reduction in breast cancer mortalities.

Propagation-Based Phase-Contrast CT of the Breast Demonstrates Higher Quality Than Conventional Absorption-Based CT Even at Lower Radiation Dose.

RATIONALE AND OBJECTIVES: Propagation-based phase-contrast CT (PB-CT) is an advanced X-ray imaging technology that exploits both refraction and absorption of the transmitted X-ray beam. This study was aimed at optimizing the experimental conditions of PB-CT for breast cancer imaging and examined its performance relative to conventional absorption-based CT (AB-CT) in terms of image quality and radiation dose. MATERIALS AND METHODS: Surgically excised breast mastectomy specimens (n = 12) were scanned using both PB-CT and AB-CT techniques under varying imaging conditions. To evaluate the radiological image quality, visual grading characteristics (VGC) analysis was used in which 11 breast specialist radiologists compared the overall image quality of PB-CT images with respect to the corresponding AB-CT images. The area under the VGC curve was calculated to measure the differences between PB-CT and AB-CT images. RESULTS: The highest radiological quality was obtained for PB-CT images using a 32 keV energy X-ray beam and by applying the Homogeneous Transport of Intensity Equation phase retrieval with the value of its parameter γ set to one-half of the theoretically optimal value for the given materials. Using these optimized conditions, the image quality of PB-CT images obtained at 4 mGy and 2 mGy mean glandular dose was significantly higher than AB-CT images at 4 mGy (AUCVGC = 0.901, p = 0.001 and AUCVGC = 0.819, p = 0.011, respectively). CONCLUSION: PB-CT achieves a higher radiological image quality compared to AB-CT even at a considerably lower mean glandular dose. Successful translation of the PB-CT technique for breast cancer imaging can potentially result in improved breast cancer diagnosis.

Development of an automated radiotherapy dose accumulation workflow for locally advanced high-risk prostate cancer - A technical report.

An automated dose accumulation and contour propagation workflow using daily cone beam computed tomography (CBCTs) images for prostate cases that require pelvic lymph nodes irradiation (PLNs) was developed. This workflow was constructed using MIM® software with the intention to provide accurate dose transformations for plans with two different isocentres, whereby two sequential treatment phases were prescribed. The pre-processing steps for data extractions from treatment plans, CBCTs, determination of couch shift information and management of missing CBCTs are described. To ensure that the imported translational couch shifts were in the correct orientation and readable in MIM, phantom commissioning was performed. For dose transformation, rigid registration with corrected setup shifts and scaled fractional dose was performed for pCT to daily CBCTs, which were then deformed onto CBCT1 . Fractional dose summation resulted in the final accumulated dose for the patient allowing differences in dosimetry between the planned and accumulated dose to be analysed. Contour propagations of the prostate, bladder and rectum were performed within the same workflow. Transformed contours were then deformed onto daily CBCTs to generate trending reports for analysis, including Dice Similarity Coefficient (DSC) and Mean Distance to Agreement (MDA). Results obtained from phantom commissioning (DSC = 0.96, MDA = 0.89 mm) and geometrical analysis of the propagated contours for twenty patients; prostate (DSC: 0.9 ± 0.0, MDA: 1.0 ± 0.3 mm), rectum (DSC: 0.8 ± 0.1, mm, MDA: 1.7 ± 0.6 mm) and bladder (DSC: 0.8 ± 0.1, MDA: 2.8 ± 1.0 mm) were within clinically accepted tolerances for both DSC (>0.8) and MDA (< 0.3 mm). The developed workflow is being performed on a larger patient cohort for predictive model building, with the goal of correlating observed toxicity with the actual accumulated dose received by the patient.

Behavioral and Regional Brain Responses to Inhalation of Capsaicin Modified by Painful Conditioning in Humans.

BACKGROUND: Cough is a defense mechanism that protects the airways and lungs in response to airway irritation. The sensory neurons involved in detecting airway irritants and the neural pathways mediating cough share similarities with those that encode pain from the body. Painful conditioning stimuli applied to one body site are known to reduce the perception of pain at another. However, whether the neural regulation of cough is influenced by painful stimuli is not known. RESEARCH QUESTION: What are the behavioral and neural outcomes of painful conditioning stimuli on urge-to-cough (UTC) and cough evoked by inhaled capsaicin? STUDY DESIGN AND METHODS: Sixteen healthy participants underwent psychophysical testing and functional MRI while completing a series of capsaicin inhalations to induce UTC and cough. The responses associated with capsaicin inhalation without pain were compared with those after the application of painful conditioning stimuli. RESULTS: Significant decreases were seen behaviorally of 18.7% ± 17.3% (P < .001) and 47.0% ± 30.8% (P < .001) in participants' UTC ratings and cough frequencies, respectively, during the application of pain. UTC ratings were reduced by 24.2% ± 36.5% (P < .005) and increased by 67% ± 40% (P < .001) for capsaicin and saline inhalation, respectively, during the scanning session. Painful conditioning stimuli were associated with widespread decreases in regional brain responses to capsaicin inhalation (P < .001). Several brain regions showed levels of reduced activation attributable to painful conditioning that correlated with related changes in behavioral responses during scanning (R2 = 0.53). INTERPRETATION: Pain-related decreases of cough and UTC are accompanied by widespread changes in brain activity during capsaicin inhalation, suggesting that pain can modify the central processing of inputs arising from the airways. A mechanistic understanding of how cough and pain processing interact within the brain may help develop more effective therapies to reduce unwanted coughing.

Findings from machine learning in clinical medical imaging applications - Lessons for translation to the forensic setting.

Machine learning (ML) techniques are increasingly being used in clinical medical imaging to automate distinct processing tasks. In post-mortem forensic radiology, the use of these algorithms presents significant challenges due to variability in organ position, structural changes from decomposition, inconsistent body placement in the scanner, and the presence of foreign bodies. Existing ML approaches in clinical imaging can likely be transferred to the forensic setting with careful consideration to account for the increased variability and temporal factors that affect the data used to train these algorithms. Additional steps are required to deal with these issues, by incorporating the possible variability into the training data through data augmentation, or by using atlases as a pre-processing step to account for death-related factors. A key application of ML would be then to highlight anatomical and gross pathological features of interest, or present information to help optimally determine the cause of death. In this review, we highlight results and limitations of applications in clinical medical imaging that use ML to determine key implications for their application in the forensic setting.

Quantification of Student Radiographic Patient Positioning Using an Immersive Virtual Reality Simulation.

INTRODUCTION: Immersive virtual reality (VR) simulation environments facilitate novel ways for users to visualize anatomy and quantify performance relative to expert users. The ability of software to provide positional feedback before a practitioner progresses with subsequent stages of examinations has broad implications for primary and allied healthcare professionals, particularly with respect to health and safety (eg, exposing to x-rays). The effect of training student-radiographers (radiology technicians), with a VR simulation environment was quantitatively assessed. METHODS: Year 1 radiography students (N = 76) were randomly split into 2 cohorts, each of which were trained at performing the same tasks relating to optimal hand positioning for projection x-ray imaging; group 1 was trained using the CETSOL VR Clinic software, whereas group 2 was trained using conventional simulated role-play in a real clinical environment. All participants completed an examination 3 weeks after training. The examination required both posterior-anterior and oblique hand x-ray positioning tasks to be performed on a real patient model. The analysis of images from the examination enabled quantification of the students' performance. The results were contextualized through a comparison with 4 expert radiographers. RESULTS: Students in group 1 performed on average 36% (P < 0.001) better in relation to digit separation, 11% (P ≤ 0.001) better in terms of palm flatness and 23% (P < 0.05) better in terms of central ray positioning onto the third metacarpal. CONCLUSION: A significant difference in patient positioning was evident between the groups; the VR clinic cohort demonstrated improved patient positioning outcomes. The observed improvement is attributed to the inherent task deconstruction and variety of visualization mechanisms available in immersive VR environments.

Development of a simple numerical model for trabecular bone structures.

PURPOSE: Advances in additive manufacturing processes are enabling the fabrication of surrogate bone structures for applications including use in high-resolution anthropomorphic phantoms. In this research, a simple numerical model is proposed that enables the generation of microarchitecture with similar statistical distribution to trabecular bone. METHODS: A human humerus, radius, ulna, and several vertebrae were scanned on the Imaging and Medical beamline at the Australian Synchrotron and the proposed numerical model was developed through the definition of two complex functions that encode the trabecular thickness and position-dependant spacing to generate volumetric surrogate trabecular structures. The structures reproduced those observed at 19 separate axial locations through the experimental bone volumes. The applicability of the model when incorporating a two-material approximation to absorption- and phase-contrast CT was also investigated through simulation. RESULTS: The synthetic structures, when compared with the real trabecular microarchitecture, yielded an average mean thickness error of 2 µm, and a mean difference in standard deviation of 33 µm for the humerus, 24 µm for the ulna and radius, and 15 µm for the vertebrae. Simulated absorption- and propagation-based phase contrast CT projection data were generated and reconstructed using the derived mathematical simplifications from the two-material approximation, and the phase-contrast effects were successfully demonstrated. CONCLUSIONS: The presented model reproduced trabecular distributions that could be used to generate phantoms for quality assurance and validation processes. The implication of utilizing a two-material approximation results in simplification of the additive manufacturing process and the generation of synthetic data that could be used for training of machine learning applications.

Effect of external fixation rod coupling in computed tomography.

External fixation is a common tool in the treatment of complex fractures, correction of limb deformity, and salvage arthrodesis. These devices typically incorporate radio-opaque metal rods/struts connected at varying distances and orientations between rings. Whilst the predominant imaging modality is plain film radiology, computed tomography (CT) may be performed in order for the surgeon to make a more confident clinical decision (e.g. timing of frame removal, assessment of degree of arthrodesis). We used a fractured sheep leg to systematically assess CT imaging performance with a Discovery CT750 HD CT scanner (GE Healthcare) to show how rod coupling in both traditional Ilizarov and hexapod frames distorts images. We also investigated the role of dual-energy CT (DECT) and metal artefact reduction software (MARS) on the visualisation of the fractured leg. Whilst mechanical reasons predominantly dictate the rod/strut configurations when building a circular frame, rod coupling in CT can be minimised. Firstly, ideally, all or all but one rod can be removed during imaging resulting in no rod coupling. If this is not possible, strategies for configuring the rods to minimise the effect of the rod coupling on the region of interest are demonstrated, e.g., in the case of a four-rod construct, switching the two anterior rods to a more central single one will achieve this goal without particularly jeopardising mechanical strength for a short period. It is also shown that the addition of DECT and MARS results in a reduction of artefacts, but also affects tissue and bone differentiation.

Advantages of breast cancer visualization and characterization using synchrotron radiation phase-contrast tomography.

The aim of this study was to highlight the advantages that propagation-based phase-contrast computed tomography (PB-CT) with synchrotron radiation can provide in breast cancer diagnostics. For the first time, a fresh and intact mastectomy sample from a 60 year old patient was scanned on the IMBL beamline at the Australian Synchrotron in PB-CT mode and reconstructed. The clinical picture was described and characterized by an experienced breast radiologist, who underlined the advantages of providing diagnosis on a PB-CT volume rather than conventional two-dimensional modalities. Subsequently, the image quality was assessed by 11 breast radiologists and medical imaging experts using a radiological scoring system. The results indicate that, with the radiation dose delivered to the sample being equal, the accuracy of a diagnosis made on PB-CT images is significantly higher than one using conventional techniques.

The implementation of a haptic feedback virtual reality simulation clinic with dynamic patient interaction and communication for medical imaging students.

INTRODUCTION: An immersive virtual reality (VR) simulation clinic with dynamic patient interaction and communication was developed to facilitate the training of medical radiation science students. The software "CETSOL VR Clinic" was integrated into the Medical Imaging programme at Monash University in 2016 in order to benchmark student experiences against existing simulation techniques (Shaderware™). METHODS: An iterative approach to development, based on two cycles of user feedback, was used to develop and refine the simulated clinical environment. This environment uses realistic 3D models, embedded clinical scenarios, dynamic communication, 3D hand gesture interaction, gaze and positional stereoscopic tracking and online user capabilities using the Unity™ game and physics engines. Students' perceptions of educational enhancement of their positioning skills following the use of the simulation tools were analysed via a 5-point Likert scale questionnaire. RESULTS: Student perception scores indicated a significant difference between simulation modalities in favour of the immersive CETSOL VR Clinic, χ2 (4, N = 92) = 9.5, P-value <0.001. CONCLUSION: Student perception scores on improvement of their clinical and technical skills were higher for the hand-positioning tasks performed with the CETSOL VR Clinic™ than with the comparative benchmark simulation that did not provide dynamic patient interaction and communication.

High-Resolution X-Ray Phase-Contrast 3-D Imaging of Breast Tissue Specimens as a Possible Adjunct to Histopathology.

Histopathological analysis is the current gold standard in breast cancer diagnosis and management, however, as imaging technology improves, the amount of potential diagnostic information that may be demonstrable radiologically should also increase. We aimed to evaluate the potential clinical usefulness of 3-D phase-contrast micro-computed tomography (micro-CT) imaging at high spatial resolutions as an adjunct to conventional histological microscopy. Ten breast tissue specimens, 2 mm in diameter, were scanned at the SYRMEP beamline of the Elettra Synchrotron using the propagation-based phase-contrast micro-tomography method. We obtained pixel size images, which were analyzed and compared with corresponding histological sections examined under light microscopy. To evaluate the effect of spatial resolution on breast cancer diagnosis, scans with four different pixel sizes were also performed. Our comparative analysis revealed that high-resolution images can enable, at a near-histological level, detailed architectural assessment of tissue that may permit increased breast cancer diagnostic sensitivity and specificity when compared with current imaging practices. The potential clinical applications of this method are also discussed.

Validation of a Geant4 model of the X-ray fluorescence microprobe at the Australian Synchrotron.

A Geant4 Monte Carlo simulation of the X-ray fluorescence microprobe (XFM) end-station at the Australian Synchrotron has been developed. The simulation is required for optimization of the scan configuration and reconstruction algorithms. As part of the simulation process, a Gaussian beam model was developed. Experimental validation of this simulation has tested the efficacy for use of the low-energy physics models in Geant4 for this synchrotron-based technique. The observed spectral distributions calculated in the 384 pixel Maia detector, positioned in the standard back-scatter configuration, were compared with those obtained from experiments performed at three incident X-ray beam energies: 18.5, 11.0 and 6.8 keV. The reduced χ-squared (\chi^{2}_{\rm{red}}) was calculated for the scatter and fluorescence regions of the spectra and demonstrates that the simulations successfully reproduce the scatter distributions. Discrepancies were shown to occur in the multiple-scatter tail of the Compton continuum. The model was shown to be particularly sensitive to the impurities present in the beryllium window of the Maia detector and their concentrations were optimized to improve the \chi^{2}_{\rm{red}} parametrization in the low-energy fluorescence regions of the spectra.