Congenital tibial pseudarthrosis: A challenge in pediatric radiology

Congenital pseudarthrosis of the tibia (CPT) is a rare disorder affecting the skeletal system in pediatric population with an estimated incidence of 1:140,000 to 1:250,000 newborns. It is characterized by deformity of the tibia, including anterolateral bowing of the bone diaphysis and/or narrowing of the medullary canal, leading to instability or fracture. CPT can be either idiopathic or associated with underlying conditions such as type 1 neurofibromatosis (NF1), fibrous dysplasia, or Campanacci's osteofibrous dysplasia. Diagnosis is based on clinical and imaging findings, using conventional radiography and magnetic resonance imaging (MRI). The disorder is characterized by recurrent pathological fractures of the tibia or fibula during childhood, often beginning by the age of 2 years. Treatment options include surgical and nonsurgical management.

Deep learning model for pleural effusion detection via active learning and pseudo-labeling: a multisite study

BACKGROUND

The study aimed to develop and validate a deep learning-based Computer Aided Triage (CADt) algorithm for detecting pleural effusion in chest radiographs using an active learning (AL) framework. This is aimed at addressing the critical need for a clinical grade algorithm that can timely diagnose pleural effusion, which affects approximately 1.5 million people annually in the United States.

METHODS

In this multisite study, 10,599 chest radiographs from 2006 to 2018 were retrospectively collected from an institution in Taiwan to train the deep learning algorithm. The AL framework utilized significantly reduced the need for expert annotations. For external validation, the algorithm was tested on a multisite dataset of 600 chest radiographs from 22 clinical sites in the United States and Taiwan, which were annotated by three U.S. board-certified radiologists.

RESULTS

The CADt algorithm demonstrated high effectiveness in identifying pleural effusion, achieving a sensitivity of 0.95 (95% CI: [0.92, 0.97]) and a specificity of 0.97 (95% CI: [0.95, 0.99]). The area under the receiver operating characteristic curve (AUC) was 0.97 (95% DeLong's CI: [0.95, 0.99]). Subgroup analyses showed that the algorithm maintained robust performance across various demographics and clinical settings.

CONCLUSION

This study presents a novel approach in developing clinical grade CADt solutions for the diagnosis of pleural effusion. The AL-based CADt algorithm not only achieved high accuracy in detecting pleural effusion but also significantly reduced the workload required for clinical experts in annotating medical data. This method enhances the feasibility of employing advanced technological solutions for prompt and accurate diagnosis in medical settings.

Synergistic Activity of DNA Damage Response Inhibitors in Combination with Radium-223 in Prostate Cancer

Radium-223 (223Ra) and Lutetium-177-labelled-PSMA-617 (177Lu-PSMA) are currently the only radiopharmaceutical treatments to prolong survival for patients with metastatic-castration-resistant prostate cancer (mCRPC); however, mCRPC remains an aggressive disease. Recent clinical evidence suggests patients with mutations in DNA repair genes associated with homologous recombination have a greater clinical benefit from 223Ra. In this study, we aimed to determine the utility of combining DNA damage response (DDR) inhibitors to increase the therapeutic efficacy of X-rays, or 223Ra. Radiobiological responses were characterised by in vitro assessment of clonogenic survival, repair of double strand breaks, cell cycle distribution, and apoptosis via PARP-1 cleavage. Here, we show that DDR inhibitors increase the therapeutic efficacy of both radiation qualities examined, which is associated with greater levels of residual DNA damage. Co-treatment of ATM or PARP inhibition with 223Ra increased cell cycle arrest in the G2/M phase. In comparison, combined ATR inhibition and radiation qualities caused G2/M checkpoint abrogation. Additionally, greater levels of apoptosis were observed after the combination of DDR inhibitors with 223Ra. This study identified the ATR inhibitor as the most synergistic inhibitor for both radiation qualities, supporting further pre-clinical evaluation of DDR inhibitors in combination with 223Ra for the treatment of prostate cancer.

Direct observations of X-rays produced by upward positive lightning

X-rays have been observed in natural downward cloud-to-ground lightning for over 20 years and in rocket-triggered lightning for slightly less. In both cases, this energetic radiation has been detected during the stepped and dart leader phases of downward negative flashes. More recently, X-rays have also been reported during the dart leader phase of upward negative flashes. In this study, we present the observations of four upward positive lightning flashes from the Säntis Tower (2.5 km ASL) in Switzerland. These consist of the simultaneous records of electric current passing through the tower, and electric field strength and X-ray flux 20 m from the tower base. One of the flashes was captured by a high-speed camera operating at 24,000 frames per second, stills from which are also presented. We detected X-rays during the initial phase of upward negative leader propagation, which can be associated with the leader-stepping process from electric field and current waveforms. To the best of our knowledge, this is the first time that such measurements are reported in the literature. The obtained time-synchronised data confirm that the X-ray emissions detected are associated with the initial steps of the upward negative leader. The frequency and energy of X-ray pulses appear to decrease as functions of time, with pulses disappearing altogether within the first millisecond of the leader initiation. X-ray emission also appears to be correlated with the maximum current-derivative and the electric field change of leader steps, consistent with cold electron runaway. These observations contribute to improving our understanding of upward lightning, which is a primary source of damage to tall structures such as wind turbines and telecommunications towers, as well as aircraft during takeoff and landing.

Recent advances in photosensitizer materials for light-mediated tumor therapy

Photodynamic therapy (PDT) as an emerging therapeutic method has drawn many attentions in the treatment field for cancer. Photosensitizer, which can convert photon energy into cytotoxic species under light irradiation, is the core component in PDT. The design of photosensitizers still faces problems of light absorption, targeting, penetration and oxygen dependence. With the rapid progress of material science, various photosensitizers have been developed to produce cytotoxic species for treatment of tumor with high selectivity, safety, and noninvasiveness. Besides, the applications of photosensitizers have been expanded to diverse cancer treatments such as drug release, optogenetics and immune checkpoint blockade. In this review, we summarize the recent advances of photosensitizers in various therapeutic methods for cancer. Prevailing challenges and further prospects associated with photosensitizers are also discussed.

Muller and mutations: mouse study of George Snell (a postdoc of Muller) fails to confirm Muller's fruit fly findings, and Muller fails to cite Snell's findings

In 1931, Hermann J. Muller's postdoctoral student, George D. Snell (Nobel Prize recipient--1980) initiated research to replicate with mice Muller's X-ray-induced mutational findings with fruit flies. Snell failed to induce the two types of mutations of interest, based on fly data (sex-linked lethals/recessive visible mutations) even though the study was well designed, used large doses of X-rays, and was published in Genetics. These findings were never cited by Muller, and the Snell paper (Snell, Genetics 20:545-567, 1935) did not cite the 1927 Muller paper (Muller, Science 66:84, 1927). This situation raises questions concerning how Snell wrote the paper (e.g., ignoring the significance of not providing support for Muller's findings in a mammal). The question may be raised whether professional pressures were placed upon Snell to downplay the significance of his findings, which could have negatively impacted the career of Muller and the LNT theory. While Muller would receive worldwide attention, and receive the Nobel Prize in 1946 "for the discovery that mutations can be induced by X-rays," Snell's negative mutation data were almost entirely ignored by his contemporary and subsequent radiation genetics/mutation researchers. This raises questions concerning how the apparent lack of interest in Snell's negative findings helped Muller professionally, including his success in using his fruit fly data to influence hereditary and cancer risk assessment and to obtain the Nobel Prize.

Our estimates of neonatal radiation exposure fall short of reality

The purpose of this study is to evaluate radiation exposure in newborns undergoing imaging tests during the first 30 days of neonatal intensive care unit (NICU) hospitalization. A retrospective cohort study was conducted from November 2018 to April 2019 with newborns admitted to the NICU. Thermoluminescent dosimeters (TLD-100™) measured radiation emitted during imaging exams over 1 month, with a comparison between measured and estimated radiation. The cohort exhibited a median gestational age of 33.0 (31.0, 37.0) weeks, a median birth weight of 1840 (1272, 2748) g, and a median length of stay of 25.5 (11.7, 55.0) days. Eighty-four patients underwent 314 imaging tests, with an estimated radiation dose (ERD) per patient of 0.116 mSv and a measured radiation dose (MDR) of 0.158 mSv. ERD consistently underestimated MDR, with a mean difference of -0.043 mSv (-0.049 to -0.036) in the Bland-Altman analysis. The regression equation was as follows: difference MRD - ERD = -1.7 × (mean (MRD + ERD)) + 0.056. The mean estimated radiation dose per exam was 0.030 mSv, and the chest X-rays accounted for 63.26% of total exams. The median number of radiographic incidences per patient was 2 (1, 4), with 5 patients undergoing three or more exams in a single day.

CONCLUSION

Radiation exposure in these newborns was underestimated, emphasizing the need for awareness regarding associated risks and strict criteria for requesting radiological exams. Lung ultrasound is a radiation-free and effective option in managing respiratory diseases in newborns, reducing the reliance on chest X-rays.

WHAT IS KNOWN

• Radiation used in diagnostic exams is not risk-free. • Radiation risk is much higher in small Infants due to the exposure area and the prolonged expectance of life.

WHAT IS NEW

• Radiation exposure is underestimated in the neonatal population. • The study found a mean radiation exposure in neonates about 5% of the mean annual dose in the general population.

X-ray Doses in Relation to Body Mass, Indication, and Substrate During Pediatric Electrophysiological Procedures on the Heart

The main goal of this study is to determine typical values of dose area product (DAP) and difference in the effective dose (ED) for pediatric electrophysiological procedures on the heart in relation to patient body mass. This paper also shows DAP and ED in relation to the indication, the arrhythmia substrate determined during the procedure, and in relation to the reason for using radiation. Organ doses are described as well. The subjects were children who have had an electrophysiological study done with a 3D mapping system and X-rays in two healthcare institutions. Children with congenital heart defects were excluded. There were 347 children included. Significant difference was noted between mass groups, while heavier children had higher values of DAP and ED. Median DAP in different mass groups was between 4.00 (IQR 1.00-14.00) to 26.33 (IQR 8.77-140.84) cGycm2. ED median was between 23.18 (IQR 5.21-67.70) to 60.96 (IQR 20.64-394.04) µSv. The highest DAP and ED in relation to indication were noted for premature ventricular contractions and ventricular tachycardia-27.65 (IQR 12.91-75.0) cGycm2 and 100.73 (IQR 53.31-258.10) µSv, respectively. In arrhythmia substrate groups, results were similar, and the highest doses were in ventricular substrates with DAP 29.62 (IQR 13.81-76.0) cGycm2 and ED 103.15 (IQR 60.78-266.99) µSv. Pediatric electrophysiology can be done with very low doses of X-rays when using 3D mapping systems compared to X-rays-based electrophysiology, or when compared to pediatric interventional cardiology or adult electrophysiology.

A Hybrid Deep Learning CNN model for COVID-19 detection from chest X-rays

Coronavirus disease (COVID-2019) is emerging in Wuhan, China in 2019. It has spread throughout the world since the year 2020. Millions of people were affected and caused death to them till now. To avoid the spreading of COVID-2019, various precautions and restrictions have been taken by all nations. At the same time, infected persons are needed to identify and isolate, and medical treatment should be provided to them. Due to a deficient number of Reverse Transcription Polymerase Chain Reaction (RT-PCR) tests, a Chest X-ray image is becoming an effective technique for diagnosing COVID-19. In this work, the Hybrid Deep Learning CNN model is proposed for the diagnosis COVID-19 using chest X-rays. The proposed model consists of a heading model and a base model. The base model utilizes two pre-trained deep learning structures such as VGG16 and VGG19. The feature dimensions from these pre-trained models are reduced by incorporating different pooling layers, such as max and average. In the heading part, dense layers of size three with different activation functions are also added. A dropout layer is supplemented to avoid overfitting. The experimental analyses are conducted to identify the efficacy of the proposed hybrid deep learning with existing transfer learning architectures such as VGG16, VGG19, EfficientNetB0 and ResNet50 using a COVID-19 radiology database. Various classification techniques, such as K-Nearest Neighbor (KNN), Naive Bayes, Random Forest, Support Vector Machine (SVM), and Neural Network, were also used for the performance comparison of the proposed model. The hybrid deep learning model with average pooling layers, along with SVM-linear and neural networks, both achieved an accuracy of 92%.These proposed models can be employed to assist radiologists and physicians in avoiding misdiagnosis rates and to validate the positive COVID-19 infected cases.

Formalising written preliminary image evaluation by Australian radiographers: a review of practice value

The Medical Radiation Practice Board of Australia (MRPBA) minimum competency framework requires all Australian radiographers to identify significant pathology in radiological images and take appropriate action to alert these urgent findings and ensure patient safety. Despite professional bodies endorsing the provision of preliminary image evaluations (PIE) in written format, radiographer image interpretation often remains inconsistent, informal, or undocumented. The purpose of this narrative review was to assess the literature to determine if PIE in the form of written radiographer comments is of value to the Australian healthcare system. A structured search was completed using four health research databases: CINAHL, Medline, Scopus and Web of Science. Studies have suggested that there is a contextual need for commenting due to increased imaging service pressures, radiologist shortages and subsequent reporting delays. Radiographers appear well placed and willing to provide accurate initial input with evidence that this would be valued and appreciated within the multidisciplinary team. Radiographer commenting has also been shown to reduce diagnostic and communicative errors with the potential to improve patient management. Finally, it was shown that participation in image interpretation practices can enhance recruitment, retention and job satisfaction among radiographers. Therefore, the current literature supports implementation of radiographer commenting within the Australian healthcare system.

Pneumonia classification: A limited data approach for global understanding

As the human race has advanced, so too have the ailments that afflict it. Diseases such as pneumonia, once considered to be basic flu or allergies, have evolved into more severe forms, including SARs and COVID-19, presenting significant risks to people worldwide. In our study, we focused on categorizing pneumonia-related inflammation in chest X-rays (CXR) using a relatively small dataset. Our approach was to encompass a comprehensive view, addressing every potential area of inflammation in the CXR. We employed enhanced class activation maps (mCAM) to meet the clinical criteria for classification rationale. Our model incorporates capsule network clusters (CNsC), which aids in learning different aspects such as geometry, orientation, and position of the inflammation seen in the CXR. Our Capsule Network Clusters (CNsC) rapidly interpret various perspectives in a single CXR without needing image augmentation, a common necessity in existing detection models. This approach significantly cuts down on training and evaluation durations. We conducted thorough testing using the RSNA pneumonia dataset of CXR images, achieving accuracy and recall rates as high as 98.3% and 99.5% in our conclusive tests. Additionally, we observed encouraging outcomes when applying our trained model to standard X-ray images obtained from medical clinics.

X-rays, electrons, and neutrons as probes of atomic matter

X-rays, electrons, and neutrons probe different properties of matter. X-rays feel electron density (ED). Electrons sense the electrostatic potential (ESP) of electrons and nuclei. Neutrons are sensitive to nuclear coherent scattering length (NCSL). While NCSL maps are widely understood to be different, ED and ESP maps are tacitly assumed to be similar. Here, I show that the belief in ED and ESP map equivalence is mistaken, but contains a grain of truth. Using density functional theory (DFT), the Bethe-Mott (BM) relation, and the Thomas-Fermi (TF) and Cromer-Mann (CM) atomic models, I show that ED and ESP maps are indeed more similar to each other than to NCSL maps. Nevertheless, peak and integrated map values depend differently on the atomic order number and on the contributions from electrons in the inner and outer CM shells. ED and ESP maps also differ in the sign and relative magnitude of excess charge effects.

Design of a novel nanoparticle to use X-ray fluorescence of TiO2 to induce photodynamic effects in the presence of PpIX

BACKGROUND

Radiotherapy and photodynamic therapy are the methods of cancer treatment. Although one limitation of photodynamic therapy (PDT) is the limited penetration depth of light through tissue, using X-rays does not have this restriction. Self-lighting nanoparticles can convert X-rays into UV/visible. This study focuses on a newly designed nanostructure containing mesoporous silica nanoparticles (MSN), titanium dioxide nanoparticles (TiO2, anatase grade), and protoporphyrin IX (PpIX) as a photosensitizer to overcome the limitations of photodynamic therapy.

METHODS

After the synthesis and characterization of Ti-MSN/PpIX@PVP nanostructure, two ROSes (OH* and 1O2) were measured when the nanostructures were irradiated with 100 kV and 6 MV photons. The toxicity of Ti-MSN/PpIX@PVP nanostructure in presence and absence of radiation was investigated on DFW and HT-29 cell lines. The in-vitro experiments were analyzed using the MTT assay and colony count assay. Finally, the effect of light exposure in the presence of Ti-MSN/PpIX@PVP nanostructure on the two cell lines was studied. The in-vitro studies were evaluated using the Synergism Index (Syn) and Dose Enhancement Factor (DEF).

RESULTS

Based on the FESEM (field emission scanning electron Microscopy) images and DLS (dynamic light scattering) measurements, the size of Ti-MSN/PpIX nanostructure was determined as (35.2 nm) and (168.4 nm), respectively. Based on the spectrofluorimetry results, 100 kV photons produced more ROSes than 6 MV photons. The results of MTT assay and colony formation for X-PDT show Syn >1, except for 100 kV photons for HT-29 cell line. The nanostructure also reduced colony formation induced by X-PDT more effectively when irradiated by 100 kV photons on DFW cells. The results obtained from conventional PDT showed that the ED 50 of the HT-29 cell line was 6 times higher than that of the DFW cell line.

CONCLUSION

Designing and synthesizing Ti-MSN/PpIX@PVP nanostructures offer a promising strategy for reducing the current challenges in PDT and for developing and advancing X-PDT as an innovative cancer treatment technique.

Arthropathy on X-rays in 363 persons with hemophilia: long-term development, and impact of birth cohort and inhibitor status

Background

Arthropathy following repeated bleeding is common in persons with hemophilia. Since the introduction of prophylaxis, treatment has intensified and joint health has improved. However, data on the long-term development of arthropathy are still scant.

Objectives

To evaluate long-term arthropathy development since the introduction of prophylaxis according to birth cohort, hemophilia severity, and inhibitor status.

Methods

This single-center historic cohort study included persons with severe and moderate hemophilia A and hemophilia B born between 1935 and 2005. Arthropathy on X-rays was evaluated using the Pettersson score. Patient and joint characteristics were studied per birth cohort (<1970, 1970-1980, 1981-1990, and >1990) and compared according to hemophilia severity. The distribution of affected joints and cumulative incidence of arthropathy were analyzed. The association of Pettersson score with birth cohort and inhibitor characteristics was explored using multivariable regression analyses adjusted for age at evaluation.

Results

In total, 1064 X-rays of 363 patients were analyzed. Of persons with severe hemophilia (n = 317, 87.3%), 244 (77.0%) developed arthropathy. Prophylaxis was started at younger ages over time, from a median of 18 to 2.1 years, and concomitantly, arthropathy decreased in consecutive birth cohorts. Ankles were most commonly affected in 188 of 258 (72.9%) patients. Persons with moderate hemophilia (n = 46, 12.7%) had a lower risk of arthropathy (27/46 [58.7%]), but a reduction over time was less pronounced. In the multivariable analyses, birth cohort and age at evaluation were predictors for the development of arthropathy, while inhibitor status showed no association.

Conclusion

The development and severity of arthropathy have decreased over the past decades. However, patients have remained at risk for developing arthropathy, especially in their ankles.

Grating-based x-ray dark-field CT for lung cancer diagnosis in mice

BACKGROUND

The low absorption of x-rays in lung tissue and the poor resolution of conventional computed tomography (CT) limits its use to detect lung disease. However, x-ray dark-field imaging can sense the scattered x-rays deflected by the structures being imaged. This technique can facilitate the detection of small alveolar lesions that would be difficult to detect with conventional CT. Therefore, it may provide an alternative imaging modality to diagnose lung disease at an early stage.

METHODS

Eight mice were inoculated with lung cancers simultaneously. Each time two mice were scanned using a grating-based dark-field CT on days 4, 8, 12, and 16 after the introduction of the cancer cells. The detectability index was calculated between nodules and healthy parenchyma for both attenuation and dark-field modalities. High-resolution micro-CT and pathological examinations were used to crosscheck and validate our results. Paired t-test was used for comparing the ability of dark-field and attenuation modalities in pulmonary nodule detection.

RESULTS

The nodules were shown as a signal decrease in the dark-field modality and a signal increase in the attenuation modality. The number of nodules increased from day 8 to day 16, indicating disease progression. The detectability indices of dark-field modality were higher than those of attenuation modality (p = 0.025).

CONCLUSIONS

Compared with the standard attenuation CT, the dark-field CT improved the detection of lung nodules.

RELEVANCE STATEMENT

Dark-field CT has a higher detectability index than conventional attenuation CT in lung nodule detection. This technique could improve the early diagnosis of lung cancer.

KEY POINTS

• Lung cancer progression was observed using x-ray dark-field CT. • Dark-field modality complements with attenuation modality in lung nodule detection. • Dark-field modality showed a detectability index higher than that attenuation in nodule detection.

Identification of L5 vertebra on lumbar spine radiographs using deep learning

OBJECTIVE

Deep learning is an advanced machine-learning approach that is used in several medical fields. Here, we developed a deep learning model using an object detection algorithm to identify the L5 vertebra on anteroposterior lumbar spine radiographs, and assessed its detection accuracy.

METHODS

We retrospectively recruited 150 participants for whom both anteroposterior whole-spine and lumbar spine radiographs were available. The anteroposterior lumbar spine radiographs of these patients were used as the input data. Of the 150 images, 105 (70%) were randomly selected as the training set, and the remaining 45 (30%) were assigned to the validation set. YOLOv5x, of the YOLOv5 family model, was used to detect the L5 vertebra area.

RESULTS

The mean average precisions 0.5 and 0.75 of the trained L5 detection model were 99.2% and 96.9%, respectively. The model's precision was 95.7% and its recall was 97.8%. Furthermore, 93.3% of the validation data were correctly detected.

CONCLUSION

Our deep learning model showed an outstanding ability to identify L5 vertebrae.

Radiosensitization of Osteosarcoma Cells Using the PARP Inhibitor Olaparib Combined with X-rays or Carbon Ions

Objective: Osteosarcomas are derived from bone-forming mesenchymal cells that are insensitive to radiation. This study aimed to investigate the radiosensitization of osteosarcoma cells (U2OS and K7M2) using the PARP inhibitor olaparib combined with X-rays or carbon ions (C-ions). Methods: The effect of olaparib on the proliferation of osteosarcoma cells after irradiation was assessed using CCK-8 and clone formation assays. Cells were treated with olaparib and/or radiation and the effects of olaparib on the cell cycle and apoptosis were analysed by flow cytometry after 48h. Immunofluorescence was used to stain the nuclei, γ-H2AX, 53BP1, and Rad51 proteins, and the number of γ-H2AX, 53BP1, and Rad51 foci was observed under a fluorescence microscope. The effect of olaparib combined with radiation on double-stranded DNA breaks in osteosarcoma cells was evaluated. Results: At the same radiation dose, olaparib reduced the proliferation and colony formation ability of irradiated osteosarcoma cells (P < 0.05). Olaparib monotherapy induced minimal apoptotic effects and G2/M phase arrest in osteosarcoma cells and irradiation alone induced moderate apoptosis and G2/M phase arrest. However, radiation combined with olaparib significantly increased the percentage of apoptotic cells and G2/M phase arrest in osteosarcoma cells (P < 0.05). Immunofluorescence experiments showed that compared to the radiation group, the formation of γ-H2AX and 53BP1 foci was significantly increased in the combined group (P < 0.05). The expression levels of Rad51 foci in the irradiated group were higher than those in the control group (P < 0.05). However, the number of Rad51 foci in the combined group was significantly decreased (P < 0.05). Conclusion: The PARP inhibitor olaparib combined with irradiation (X-rays or C-ions) enhanced the radiosensitivity of osteosarcoma cell lines (U2OS and K7M2). Our findings provide a potential theoretical basis for the clinical application of olaparib in overcoming radiation resistance in osteosarcoma.

Automated bone age assessment in a German pediatric cohort: agreement between an artificial intelligence software and the manual Greulich and Pyle method

OBJECTIVES

This study aimed to evaluate the performance of artificial intelligence (AI) software in bone age (BA) assessment, according to the Greulich and Pyle (G&P) method in a German pediatric cohort.

MATERIALS AND METHODS

Hand radiographs of 306 pediatric patients aged 1-18 years (153 boys, 153 girls, 18 patients per year of life)-including a subgroup of patients in the age group for which the software is declared (243 patients)-were analyzed retrospectively. Two pediatric radiologists and one endocrinologist made independent blinded BA reads. Subsequently, AI software estimated BA from the same images. Both agreements, accuracy, and interchangeability between AI and expert readers were assessed.

RESULTS

The mean difference between the average of three expert readers and AI software was 0.39 months with a mean absolute difference (MAD) of 6.8 months (1.73 months for the mean difference and 6.0 months for MAD in the intended use subgroup). Performance in boys was slightly worse than in girls (MAD 6.3 months vs. 5.6 months). Regression analyses showed constant bias (slope of 1.01 with a 95% CI 0.99-1.02). The estimated equivalence index for interchangeability was - 14.3 (95% CI -27.6 to - 1.1).

CONCLUSION

In terms of BA assessment, the new AI software was interchangeable with expert readers using the G&P method.

CLINICAL RELEVANCE STATEMENT

The use of AI software enables every physician to provide expert reader quality in bone age assessment.

KEY POINTS

• A novel artificial intelligence-based software for bone age estimation has not yet been clinically validated. • Artificial intelligence showed a good agreement and high accuracy with expert radiologists performing bone age assessment. • Artificial intelligence showed to be interchangeable with expert readers.

Three-dimensional Element-by-element Surface Topography Reconstruction of Compound Samples Using Multisegment Silicon Drift Detectors

Elemental surface topography information in microscopic material characterization contributes to a better understanding of surfaces, interfaces, substrates, and their applications. Here, a general approach based on microbeam proton-induced X-ray emission (micro-PIXE) to reconstruct the three-dimensional (3D) elemental surface topography using the annular multisegment silicon drift detector has been demonstrated. The proposed method includes four main steps: acquiring four two-dimensional elemental concentration maps using the multichannel spectrometer, reconstructing the local inclination angle from the atomic model of ion-matter interaction, calculating the two independent topography gradient components, and numerical surface topography integration. In this study, the general algorithm to obtain the gradient components has been successfully tested on a four-segment configuration to reconstruct the 3D surface topography of compound alloys with different microstructure scales. In synchrotron and accelerator facilities dealing with elemental X-ray mapping where the development of customized multisegment detectors is needed, the introduced method is applicable to elemental surface/interface roughness reconstruction in microscale for cultural heritage samples, fusion plasma-facing materials, and microelectronic devices.

Potential Role of Intrapulmonary Concomitant Lesions in Differentiating Non-Neoplastic and Neoplastic Ground Glass Nodules

Purpose

To determine the value of intrapulmonary concomitant lesions in differentiating non-neoplastic and neoplastic ground-glass nodules (GGNs).

Patients and Methods

From January 2014 to March 2022, 395 and 583 patients with confirmed non-neoplastic and neoplastic GGNs were retrospectively enrolled. Their clinical and chest CT data were evaluated. The CT features of target GGNs and intrapulmonary concomitant lesions in these two groups were analyzed and compared, and the role of intrapulmonary concomitant lesions in improving differentiation was evaluated.

Results

The intrapulmonary concomitant lesions were more common in patients with non-neoplastic GGNs than in those with neoplastic ones (87.88% vs 82.18%, P = 0.015). Specifically, patients with non-neoplastic GGNs had a higher incidence of multiple solid nodules (SNs), patchy ground-glass opacity/consolidation, and fibrosis/calcification in any lung fields (each P < 0.05). Logistic regression analysis indicated that patients < 44 years old, diameter < 7.35 mm, irregular shape, and coarse margin or ill-defined boundary for target GGN, pleural thickening, and concomitant SNs in the same lobe and fibrosis or calcification in any lung field were independent indicators for predicting non-neoplastic GGNs. The AUC of the model for predicting non-neoplastic GGNs increased from 0.894 to 0.926 (sensitivity, 83.10%; specificity, 87.10%) after including the concomitant lesions in the patients' clinical characteristics and CT features of target GGNs (P < 0.0001).

Conclusion

Besides the patients' clinical characteristics and CT features of target GGNs, the concomitant multiple SNs in the same lobe and fibrosis/calcification in any lung field should be considered in further differentiating non-neoplastic and neoplastic GGNs.

Cervicothoracic junction in disaster victim identification: Idiosyncrasies and relevance of body position for advanced chest radiograph comparisons

Standard plain film medical radiographs often form a valuable line of evidence to identify individuals in large-scale fatality events. While commonly available, chest radiographs present a challenge that their analysis is somewhat more involved and complex than radiographic records of other body regions. For example, chest radiographs concern subtler morphological varieties of smaller anatomical features across a larger number of skeletal elements in contrast to frontal sinus comparisons that concern a large, (often) single, highly variable void within one bone. This does not detract from or discount chest radiographs as useful identification aids, but it does demand additional prerequisite skills in radiographic interpretation to ensure valid conclusions are attained. When subjects deviate from standardized antemortem (AM) radiographic positions and/or the image quality decreases, the complexity of a chest radiograph comparison is elevated. Generally, the current body of forensic radiographic comparison literature infrequently addresses these more complex circumstances. In this paper, we use real-world radiographic comparison reference images from a military DVI repatriation context to illustrate these factors and outline some procedures that enable these complexities to be easily recognized and appropriately addressed at case examination. A report for an exemplar case that concurrently highlights multiple factors is presented. For novices learning radiographic comparison methods, this case review saliently demonstrates: (1) why the AM reference radiograph(s) drive(s) the radiographic comparison procedure; (2) why care should be taken for correct positioning of the cervicothoracic junction in postmortem radiography of chest elements.

Noninvasive Treatment of Alzheimer's Disease with Scintillating Nanotubes

Effective and accessible treatments for Alzheimer's disease (AD) are urgently needed. Soluble Aβ oligomers are identified as neurotoxic species in AD and targeted in antibody-based drug development to mitigate cognitive decline. However, controversy exists concerning their efficacy and safety. In this study, an alternative strategy is proposed to inhibit the formation of Aβ oligomers by selectively oxidizing specific amino acids in the Aβ sequence, thereby preventing its aggregation. Targeted oxidation is achieved using biocompatible and blood-brain barrier-permeable multicomponent nanoscintillators that generate singlet oxygen upon X-ray interaction. Surface-modified scintillators interact selectively with Aβ and, upon X-ray irradiation, inhibit the formation of neurotoxic aggregates both in vitro and in vivo. Feeding transgenic Caenorhabditis elegans expressing human Aβ with the nanoscintillators and subsequent irradiation with soft X-ray reduces Aβ oligomer levels, extends lifespan, and restores memory and behavioral deficits. These findings support the potential of X-ray-based therapy for AD and warrant further development.

Performance of an AI algorithm during the different phases of the COVID pandemics: what can we learn from the AI and vice versa

Background

Artificial intelligence (AI) has proved to be of great value in diagnosing and managing Sars-Cov-2 infection. ALFABETO (ALL-FAster-BEtter-TOgether) is a tool created to support healthcare professionals in the triage, mainly in optimizing hospital admissions.

Methods

The AI was trained during the pandemic's "first wave" (February-April 2020). Our aim was to assess the performance during the "third wave" of the pandemics (February-April 2021) and evaluate its evolution. The neural network proposed behavior (hospitalization vs home care) was compared with what was actually done. If there were discrepancies between ALFABETO's predictions and clinicians' decisions, the disease's progression was monitored. Clinical course was defined as "favorable/mild" if patients could be managed at home or in spoke centers and "unfavorable/severe" if patients need to be managed in a hub center.

Results

ALFABETO showed accuracy of 76%, AUROC of 83%; specificity was 78% and recall 74%. ALFABETO also showed high precision (88%). 81 hospitalized patients were incorrectly predicted to be in "home care" class. Among those "home-cared" by the AI and "hospitalized" by the clinicians, 3 out of 4 misclassified patients (76.5%) showed a favorable/mild clinical course. ALFABETO's performance matched the reports in literature.

Conclusions

The discrepancies mostly occurred when the AI predicted patients could stay at home but clinicians hospitalized them; these cases could be handled in spoke centers rather than hubs, and the discrepancies may aid clinicians in patient selection. The interaction between AI and human experience has the potential to improve both AI performance and our comprehension of pandemic management.

Economic and cost considerations of delivering and using mobile X-ray services in residential aged care facilities: A qualitative study

OBJECTIVE

To describe the economic and cost considerations of mobile X-ray services (MXS) in residential aged care facilities (RACFs), according to stakeholders (involved in residents' healthcare), residents living in RACFs and informal carers (ICs) of residents.

METHODS

Semistructured interviews were conducted with 20 residents and 27 ICs recruited from six RACFs across metropolitan Adelaide (South Australia, Australia), and 22 stakeholders, on their perspectives of using MXS in RACFs. Data relating to economic and cost considerations were extracted and analysed using thematic analysis.

RESULTS

Residents' mean age was 85 years, 60% were women and 40% had experienced an MXS in the last 12 months. Most ICs were daughters (70%) and wives (11%) and 30% had a family member who had experienced an MXS in the last 12 months. Stakeholders included RACF staff, GPs, a hospital avoidance program clinician, paramedics, emergency department clinicians, MXS radiographers and manager, and a radiologist. Four themes were presented: (1) business considerations, where private providers found it necessary to charge residents a co-payment to deliver MXS; (2) cost and payment process as a potential barrier to using MXS, with varied willingness and ability to pay for an MXS co-payment, and equity concerns; (3) overcoming cost and payment barriers, with staff and consumers sometimes using strategies to overcome cost barriers; and (4) perceived cost benefits of MXS to the healthcare system, residents and ICs.

CONCLUSIONS

Mobile X-ray services providers charge residents an upfront co-payment for business viability, which can be a barrier to some residents wishing to access MXS.

Proton Compared to X-Irradiation Induces Different Protein Profiles in Oral Cancer Cells and Their Derived Extracellular Vesicles

Extracellular vesicles (EVs) are membrane-bound particles released from cells, and their cargo can alter the function of recipient cells. EVs from X-irradiated cells have been shown to play a likely role in non-targeted effects. However, EVs derived from proton irradiated cells have not yet been studied. We aimed to investigate the proteome of EVs and their cell of origin after proton or X-irradiation. The EVs were derived from a human oral squamous cell carcinoma (OSCC) cell line exposed to 0, 4, or 8 Gy from either protons or X-rays. The EVs and irradiated OSCC cells underwent liquid chromatography-mass spectrometry for protein identification. Interestingly, we found different protein profiles both in the EVs and in the OSCC cells after proton irradiation compared to X-irradiation. In the EVs, we found that protons cause a downregulation of proteins involved in cell growth and DNA damage response compared to X-rays. In the OSCC cells, proton and X-irradiation induced dissimilar cell death pathways and distinct DNA damage repair systems. These results are of potential importance for understanding how non-targeted effects in normal tissue can be limited and for future implementation of proton therapy in the clinic.

Recent Advances in NIR or X-ray Excited Persistent Luminescent Materials for Deep Bioimaging

Due to their persistent luminescence, persistent luminescent (PersL) materials have attracted great interest. In the biomedical field, the use of persistent luminescent nanoparticles (PLNPs) eliminates the need for continuous in situ excitation, thereby avoiding interference from tissue autofluorescence and significantly improving the signal-to-noise ratio (SNR). Although persistent luminescence materials can emit light continuously, the luminescence intensity of small-sized nanoparticles in vivo decays quickly. Early persistent luminescent nanoparticles were mostly excited by ultraviolet (UV) or visible light and were administered for imaging purposes through ex vivo charging followed by injection into the body. Limited by the low in vivo penetration depth, UV light cannot secondary charge PLNPs that have decayed in vivo, and visible light does not penetrate deep enough to reach deep tissues, which greatly limits the imaging time of persistent luminescent materials. In order to address this issue, the development of PLNPs that can be activated by light sources with superior tissue penetration capabilities is essential. Near-infrared (NIR) light and X-rays are widely recognized as ideal excitation sources, making persistent luminescent materials stimulated by these two sources a prominent area of research in recent years. This review describes NIR and X-ray excitable persistent luminescence materials and their recent advances in bioimaging.

Comparison of diagnostic accuracy of ultra low-dose computed tomography and X-ray of the kidneys, ureters and bladder for urolithiasis in the follow-up setting

INTRODUCTION

Urolithiasis is frequently followed up with a low-dose computed tomography of the kidneys ureters and bladder (LD-CTKUB) with doses typically less than 3 millisieverts. Although X-ray is a lower dose (0.5-1.1 mSv) alternative for follow up, it has lower diagnostic accuracy and is limited to radiopaque calculi. This study aims to compare the diagnostic accuracy of sub-millisievert ultra-low dose CT (ULD-CTKUB) against X-ray KUB for the follow up of urolithiasis when both are compared against the standard of care of a low-dose CT KUB (LD-CTKUB).

METHODS

This prospective study included patients with a known diagnosis of urolithiasis on prior CTKUB presenting for follow up. Each patient underwent a repeat reference LD-CTKUB, ULD-CTKUB and X-ray KUB. All imaging studies were interpreted by three readers. The radiation dose and quantitative noise was calculated for each CT. Both CT and X-ray were assessed for the presence, number and size of all calculi ≥2 mm.

RESULTS

A total of 58 patients were included in this study. LD-CTKUB identified 197 calculi. ULD-CTKUB in our study had a mean effective dose of 0.5 mSv compared to X-ray KUB where doses range in the literature from 0.5 to 1.1 mSv. Per-patient pooled analysis for intrarenal calculi when comparing ULD-CTKUB versus X-ray KUB against a reference LD-CTKUB found a sensitivity of 90% versus 67% (P < 0.01) and specificity of 93% versus 98% (P = 0.18) respectively. For ureteric calculi, the sensitivity was 67% versus 33% (P < 0.01) and specificity 94% versus 94% (P = 1.00) respectively. Per-stone pooled analysis detection rate was 79% for ULD-CTKUB versus 48% for X-ray (P < 0.01) when each was compared to the reference LD-CTKUB. Interobserver agreement was high for intrarenal calculi and moderate for ureteric calculi.

CONCLUSION

Sub-millisievert ULD-CTKUB had lower doses and higher sensitivity than X-ray in patients requiring follow up of known urolithiasis.

Assessing the barriers and enablers to the implementation of the diagnostic radiographer musculoskeletal X-ray reporting service within the NHS in England: a systematic literature review

INTRODUCTION

The United Kingdom (UK) government's healthcare policy in the early 1990s paved the way adoption of the skills mix development and implementation of diagnostic radiographers' X-ray reporting service. Current clinical practice within the public UK healthcare system reflects the same pressures of increased demand in patient imaging and limited capacity of the reporting workforce (radiographers and radiologists) as in the 1990s. This study aimed to identify, define and assess the longitudinal macro, meso, and micro barriers and enablers to the implementation of the diagnostic radiographer musculoskeletal X-ray reporting service in the National Healthcare System (NHS) in England.

METHODS

Multiple independent databases were searched, including PubMed, Ovid MEDLINE; Embase; CINAHL, and Google Scholar, as well as journal databases (Scopus, Wiley), healthcare databases (NHS Evidence Database; Cochrane Library) and grey literature databases (OpenGrey, GreyNet International, and the British Library EthOS depository) and recorded in a PRISMA flow chart. A combination of keywords, Boolean logic, truncation, parentheses and wildcards with inclusion/exclusion criteria and a time frame of 1995-2022 was applied. The literature was assessed against Joanna Briggs Institute's critical appraisal checklists. With meta-aggregation to synthesize each paper, and coded using NVivo, with context grouped into macro, meso, and micro-level sources and categorised into subgroups of enablers and barriers.

RESULTS

The wide and diverse range of data (n = 241 papers) identified barriers and enablers of implementation, which were categorised into measures of macro, meso, and micro levels, and thematic categories of context, culture, environment, and leadership.

CONCLUSION

The literature since 1995 has reframed the debates on implementation of the radiographer reporting role and has been instrumental in shaping clinical practice. There has been clear influence upon both meso (professional body) and macro-level (governmental/health service) policies and guidance, that have shaped change at micro-level NHS Trust organisations. There is evidence of a shift in culturally intrenched legacy perspectives within and between different meso-level professional bodies around skills mix acceptance and role boundaries. This has helped shape capacity building of the reporting workforce. All of which have contributed to conceptual understandings of the skills mix workforce within modern radiology services.

A comprehensive segmentation of chest X-ray improves deep learning-based WHO radiologically confirmed pneumonia diagnosis in children

OBJECTIVES

To investigate a comprehensive segmentation of chest X-ray (CXR) in promoting deep learning-based World Health Organization's (WHO) radiologically confirmed pneumonia diagnosis in children.

METHODS

A total of 4400 participants between January 2016 and June 2021were identified for a cross-sectional study and divided into primary endpoint pneumonia (PEP), other infiltrates, and normal groups according to WHO's diagnostic criteria. The CXR was divided into six segments of left lung, right lung, mediastinum, diaphragm, ext-left lung, and ext-right lung by adopting the RA-UNet. To demonstrate the benefits of lung field segmentation in pneumonia diagnosis, the segmented images and images that were not segmented, which constituted seven segmentation combinations, were fed into the CBAM-ResNet under a three-category classification comparison. The interpretability of the CBAM-ResNet for pneumonia diagnosis was also performed by adopting a Grad-CAM module.

RESULTS

The RA-UNet achieved a high spatial overlap between manual and automatic segmentation (averaged DSC = 0.9639). The CBAM-ResNet when fed with the six segments achieved superior three-category diagnosis performance (accuracy = 0.8243) over other segmentation combinations and deep learning models under comparison, which was increased by around 6% in accuracy, precision, specificity, sensitivity, F1-score, and around 3% in AUC. The Grad-CAM could capture the pneumonia lesions more accurately, generating a more interpretable visualization and enhancing the superiority and reliability of our study in assisting pediatric pneumonia diagnosis.

CONCLUSIONS

The comprehensive segmentation of CXR could improve deep learning-based pneumonia diagnosis in childhood with a more reasonable WHO's radiological standardized pneumonia classification instead of conventional dichotomous bacterial pneumonia and viral pneumonia.

CLINICAL RELEVANCE STATEMENT

The comprehensive segmentation of chest X-ray improves deep learning-based WHO confirmed pneumonia diagnosis in children, laying a strong foundation for the potential inclusion of computer-aided pediatric CXR readings in precise classification of pneumonia and PCV vaccine trials efficacy in children.

KEY POINTS

• The chest X-ray was comprehensively segmented into six anatomical structures of left lung, right lung, mediastinum, diaphragm, ext-left lung, and ext-right lung. • The comprehensive segmentation improved the three-category classification of primary endpoint pneumonia, other infiltrates, and normal with an increase by around 6% in accuracy, precision, specificity, sensitivity, F1-score, and around 3% in AUC. • The comprehensive segmentation gave rise to a more accurate and interpretable visualization results in capturing the pneumonia lesions.

A Panoramic X-ray as a Supportive Diagnostic Tool for the Screening of Osteoporosis in Patients with Hemophilia A and B

BACKGROUND

Hemophilia is associated with an increased risk of developing osteoporosis and osteopenia. The aim of the study was to interpret the usefulness of fractal analysis of the trabecular bone of the mandible (FD) and selected radiomorphic indices (the antegonial index (AI) and Klemetti index (KI)) to assess the risk of reduced bone mineral density (BMD) in patients with hemophilia A/B.

METHODS

The study group consisted of 50 patients with type A/B hemophilia. The control group consisted of 25 males without congenital bleeding disorders. The patients had a panoramic radiograph taken with the same X-ray machine (Vistapano S, Durr Dental, Bietigheim-Bissingen, Germany). The AudaXCeph software (Audax d.o.o., Ljubljana, Slovenia) was used to evaluate the AI index, and the ImageJ, software with a specially prepared script, was used to evaluate the FD. The mandibular cortex was assessed distal to the mental foramen using the Klemetti index.

RESULTS

There were no statistically significant differences between the AI, KI and FD values between the study group and the control group.

CONCLUSIONS

This study indicated the lack of usefulness of AI, KI and fractal analysis in identifying patients with hemophilia at risk of reduced bone mass.

Deep learning applications in osteoarthritis imaging

Deep learning (DL) is one of the most exciting new areas in medical imaging. This article will provide a review of current applications of DL in osteoarthritis (OA) imaging, including methods used for cartilage lesion detection, OA diagnosis, cartilage segmentation, and OA risk assessment. DL techniques have been shown to have similar diagnostic performance as human readers for detecting and grading cartilage lesions within the knee on MRI. A variety of DL methods have been developed for detecting and grading the severity of knee OA and various features of knee OA on X-rays using standardized classification systems with diagnostic performance similar to human readers. Multiple DL approaches have been described for fully automated segmentation of cartilage and other knee tissues and have achieved higher segmentation accuracy than currently used methods with substantial reductions in segmentation times. Various DL models analyzing baseline X-rays and MRI have been developed for OA risk assessment. These models have shown high diagnostic performance for predicting a wide variety of OA outcomes, including the incidence and progression of radiographic knee OA, the presence and progression of knee pain, and future total knee replacement. The preliminary results of DL applications in OA imaging have been encouraging. However, many DL techniques require further technical refinement to maximize diagnostic performance. Furthermore, the generalizability of DL approaches needs to be further investigated in prospective studies using large image datasets acquired at different institutions with different imaging hardware before they can be implemented in clinical practice and research studies.

Knowledge and practice of radiation safety in Brazilian equine veterinarians are less than optimal: An online survey

Exposure to ionizing radiation is an occupational risk for veterinarians due to the potential for carcinogenesis, reproductive disorders, cataracts, and hereditary genetic changes. This survey study aimed to identify the radiological protection practices routinely used by veterinarians who work with portable digital X-ray equipment in horses in Brazil and assess their knowledge regarding current legislation. A total of 120 voluntary participation questionnaires were sent to veterinarians who used portable digital radiographic equipment in horses nationwide. The frequencies of the answers were analyzed using the chi-square test and logistic regression models. Thirty-five veterinarians responded (29% response rate). Of these, there was a greater participation of professionals in public institutions (40%, 14/35, p < .001), with 69% from the southeast region (24/35, p < .001) and 69% (24/35, p = .028) being male. We found that self-employed veterinarians had a higher odds ratio (OR) (9.00; 95% confidence interval (CI) [1.39-58.44]; p = .021) of not using personal protective equipment compared with those in professional public institutions. In addition, not knowing the current legislation Collegiate Directorate Resolution 611/22 was a potential risk factor for lower radiological protection (OR, 8.00; 95% CI, [0.79-81.33]; p = 0.079). In conclusion, findings indicated that Brazilian equine veterinarians generally do not adopt adequate radiological protection against ionizing radiation during radiographic examinations and have low knowledge of the current legislation. Results can be used as background for the formulation of specific radiation protection guidelines for veterinarians and incentive educational and training strategies to reduce risks inherent to occupational exposure.

Safety and Functional Integrity of Continuous Glucose Monitoring Sensors When Used During Radiologic Procedures Under High Exposure Conditions

BACKGROUND

We investigated wearable components of the Abbott Diabetes Care FreeStyle Libre® (continuous glucose monitoring [CGM 1), FreeStyle Libre® 2 (CGM 2), and FreeStyle Libre® 3 (CGM 3) systems in simulated diagnostic radiologic procedures.

METHODS

Sensors were loaded with simulated glucose data and exposed to X-ray scanning, computed tomography (CT), and magnetic resonance imaging (MRI) to simulate radiotherapeutic procedures. The exposure settings were representative of maximum in clinical settings. After the simulations, bench tests were used to assess data integrity and responsiveness of sensors to various concentrations of aqueous glucose.

RESULTS

All sensors passed all acceptance criteria following each session of X-ray, CT, and MRI exposures. During the 3 T MRI simulation, the displacement forces for the CGM 1, CGM 2, and CGM 3 sensors were 0.132, 0.109, and 0.063 N, respectively, which are more than 100× smaller than the force of 15.97 N required to dislodge the sensor from the body. Data stored in the sensors prior to the exposures remained intact.

CONCLUSION

The sensors maintained functionality following a series of high exposure conditions in both X-ray and CT scanning systems, and the sensors were easily visible and identifiable when scanned using clinically relevant scanning parameters. Therefore, patients can continue to wear and use their sensors during and after imaging. The nonclinical MRI testing demonstrated that the sensors can be worn under the specified MRI conditions.

Acute normal tissue responses in a murine model following fractionated irradiation of the head and neck with protons or X-rays

BACKGROUND

The purpose of this study was to investigate acute normal tissue responses in the head and neck region following proton- or X-irradiation of a murine model.

MATERIALS AND METHODS

Female C57BL/6J mice were irradiated with protons (25 or 60 MeV) or X-rays (100 kV). The radiation field covered the oral cavity and the major salivary glands. For protons, two different treatment plans were used, either with the Bragg Peak in the middle of the mouse (BP) or outside the mouse (transmission mode; TM). Delivered physical doses were 41, 45, and 65 Gy given in 6, 7, and 10 fractions for BP, TM, and X-rays, respectively. Alanine dosimetry was used to assess delivered doses. Oral mucositis and dermatitis were scored using CTC v.2.0-based tables. Saliva was collected at baseline, right after end of irradiation, and at day 35.

RESULTS

The measured dose distribution for protons (TM) and X-rays was very similar. Oral mucositis appeared earlier, had a higher score and was found in a higher percentage of mice after proton irradiation compared to X-irradiation. Dermatitis, on the other hand, had a similar appearance after protons and X-rays. Compared to controls, saliva production was lower right after termination of proton- and X-irradiation. The BP group demonstrated saliva recovery compared to the TM and X-ray group at day 35.

CONCLUSION

With lower delivered doses, proton irradiation resulted in similar skin reactions and increased oral mucositis compared to X-irradiation. This indicates that the relative biological effectiveness of protons for acute tissue responses in the mouse head and neck is greater than the clinical standard of 1.1. Thus, there is a need for further investigations of the biological effect of protons in normal tissues.

Developing an artificial intelligence diagnostic tool for paediatric distal radius fractures, a proof of concept study

INTRODUCTION

In the UK, 1 in 50 children sustain a fractured bone yearly, yet studies have shown that 34% of children sustaining an injury do not have a visible fracture on initial radiographs. Wrist fractures are particularly difficult to identify because the growth plate poses diagnostic challenges when interpreting radiographs.

METHODS

We developed Convolutional Neural Network (CNN) image recognition software to detect fractures in radiographs from children. A consecutive data set of 5,000 radiographs of the distal radius in children aged less than 19 years from 2014 to 2019 was used to train the CNN. In addition, transfer learning from a VGG16 CNN pretrained on non-radiological images was applied to improve generalisation of the network and the classification of radiographs. Hyperparameter tuning techniques were used to compare the model with the radiology reports that accompanied the original images to determine diagnostic test accuracy.

RESULTS

The training set consisted of 2,881 radiographs with a fracture and 1,571 without; 548 radiographs were outliers. With additional augmentation, the final data set consisted of 15,498 images. The data set was randomly split into three subsets: training (70%), validation (10%) and test (20%). After training for 20 epochs, the diagnostic test accuracy was 85%.

DISCUSSION

A CNN model is feasible in diagnosing paediatric wrist fractures. We demonstrated that this application could be utilised as a tool for improving diagnostic accuracy. Future work would involve developing automated treatment pathways for diagnosis, reducing unnecessary hospital visits and allowing staff redeployment to other areas.

The Influence of Slice Thickness, Sharpness, and Contrast Adjustments on Inferior Alveolar Canal Segmentation on Cone-Beam Computed Tomography Scans: A Retrospective Study

This retrospective study aims to investigate the impact of cone-beam computed tomography (CBCT) viewing parameters such as contrast, slice thickness, and sharpness on the identification of the inferior alveolar nerve (IAC). A total of 25 CBCT scans, resulting in 50 IACs, were assessed by two investigators using a three-score system (good, average, and poor) on cross-sectional images. Slice thicknesses of 0.25 mm, 0.5 mm, and 1 mm were tested, along with varying sharpness (0, 6, 8, and 10) and contrast (0, 400, 800, and 1200) settings. The results were statistically analyzed to determine the optimal slice thickness for improved visibility of IAC, followed by evaluating the influence of sharpness and contrast using the optimal thickness. The identified parameters were then validated by performing semi-automated segmentation of the IACs and structure overlapping to evaluate the mean distance. Inter-rater and intra-rater reliability were assessed using Kappa statistics, and inferential statistics used Pearson's Chi-square test. Inter-rater and intra-rater reliability for all parameters were significant, ranging from 69% to 83%. A slice thickness of 0.25 mm showed consistently "good" visibility (80%). Sharpness values of zero and contrast values of 1200 also demonstrated high frequencies of "good" visibility. Overlap analysis resulted in an average mean distance of 0.295 mm and a standard deviation of 0.307 mm across all patients' sides. The study revealed that a slice thickness of 0.25 mm, zero sharpness value, and higher contrast value of 1200 improved the visibility and accuracy of IAC segmentation in CBCT scans. The individual patient's characteristics, such as anatomical variations, decreased bone density, and absence of canal walls cortication, should be considered when using these parameters.

Cytokine Levels in Saliva Are Associated with Salivary Gland Fibrosis and Hyposalivation in Mice after Fractionated Radiotherapy of the Head and Neck

Cytokines are mediators of inflammation that could lead to fibrosis. The aim was to monitor cytokine levels in saliva and serum after locally fractionated radiotherapy of the head and neck in mice and investigate associations with salivary gland fibrosis and hyposalivation. C57BL/6 mice were randomized to sham or X-ray irradiation of 66 Gy in 10 fractions over 5 days. Blood and saliva were collected on days -7, 5, 35, 80, and 105 following cytokine analysis. The harvested submandibular salivary gland was assessed for the presence of fibrosis. Decision tree regression analysis was used to investigate whether cytokine levels could predict late endpoints in terms of hyposalivation or fibrosis. Significant formation of fibrosis in gland tissue and reduced saliva production was found after irradiation. The pro-inflammatory cytokines IL-1α, TNF, TIMP1, G-CSF, KC, and MIP-1α showed increased levels in saliva in irradiated mice and a strong correlation with late endpoints. The decision tree analysis largely separated controls from irradiated animals, with IL-1α being the strongest predictor. Pro-inflammatory cytokines in saliva, but not in serum, were associated with late endpoints. This indicates that cytokine expression in saliva is a good biomarker for local salivary gland damage with IL-1α as the strongest single predictor.

Shape-Driven Response of Gold Nanoparticles to X-rays

Radiotherapy (RT) involves delivering X-ray beams to the tumor site to trigger DNA damage. In this approach, it is fundamental to preserve healthy cells and to confine the X-ray beam only to the malignant cells. The integration of gold nanoparticles (AuNPs) in the X-ray methodology could be considered a powerful tool to improve the efficacy of RT. Indeed, AuNPs have proven to be excellent allies in contrasting tumor pathology upon RT due to their high photoelectric absorption coefficient and unique physiochemical properties. However, an analysis of their physical and morphological reaction to X-ray exposure is necessary to fully understand the AuNPs' behavior upon irradiation before treating the cells, since there are currently no studies on the evaluation of potential NP morphological changes upon specific irradiations. In this work, we synthesized two differently shaped AuNPs adopting two different techniques to achieve either spherical or star-shaped AuNPs. The spherical AuNPs were obtained with the Turkevich-Frens method, while the star-shaped AuNPs (AuNSs) involved a seed-mediated approach. We then characterized all AuNPs with Transmission Electron Microscopy (TEM), Uv-Vis spectroscopy, Dynamic Light Scattering (DLS), zeta potential and Fourier Transform Infrared (FTIR) spectroscopy. The next step involved the treatment of AuNPs with two different doses of X-radiation commonly used in RT, namely 1.8 Gy and 2 Gy, respectively. Following the X-rays' exposure, the AuNPs were further characterized to investigate their possible physicochemical and morphological alterations induced with the X-rays. We found that AuNPs do not undergo any alteration, concluding that they can be safely used in RT treatments. Lastly, the actin rearrangements of THP-1 monocytes treated with AuNPs were also assessed in terms of coherency. This is a key proof to evaluate the possible activation of an immune response, which still represents a big limitation for the clinical translation of NPs.

A Novel Imaging Protocol for Investigating Arabidopsis thaliana Siliques and Seeds Using X-rays

Understanding silique and seed morphology is essential to developmental biology. Arabidopsis thaliana is one of the best-studied plant models for understanding the genetic determinants of seed count and size. However, the small size of its seeds, and their encasement in a pod known as silique, makes investigating their numbers and morphology both time consuming and tedious. Researchers often report bulk seed weights as an indicator of average seed size, but this overlooks individual seed details. Removal of the seeds and subsequent image analysis is possible, but automated counts are often impossible due to seed pigmentation and shadowing. Traditional ways of analyzing seed count and size, without their removal from the silique, involve lengthy histological processing (24-48 h) and the use of toxic organic solvents. We developed a method that is non-invasive, requires minimal sample processing, and obtains data in a short period of time (1-2 h). This method uses a custom X-ray imaging system to visualize Arabidopsis siliques at different stages of their growth. We show that this process can be successfully used to analyze the overall topology of Arabidopsis siliques and seed size and count. This new method can be easily adapted for other plant models. Key features • No requirement for organic solvents for imaging siliques. • Easy image capture and rapid turnaround time for obtaining data. • Protocol may be easily adapted for other plant models.

Experimental Investigation of X-Ray Radiation Shielding and Radiological Properties for Various Natural Composites

BACKGROUND

Shielding from radiation and plan dose verification is vital during the potential applications in industrial and medical applications. A number of natural composites have been investigated for protecting against high-energy X-ray shielding.

OBJECTIVE

The aim is to learn about how natural composites behave under various X-ray energies at STP.

MATERIAL AND METHODS

The radiological parameters of wood samples were determined using computed tomography imaging, specifically relative electron density (RED), Hounsfield units (HUs), and mass density (MD). Percentage attenuation was measured using a semiflux ionization chamber incorporated with a brass build-up cap and an ionization chamber placed at the beam Isocenter for a different type of natural composite. Measurements are being carried out on a Linear accelerator at an SSD of 110 cm with different collimator sizes.

RESULTS

Measured values of  HUs, RED, and MD were -232 ± 40, 0.738 ± 0.039, 0.768 ± 0.024 g/cc,-368 ± 41, 0.662 ± 0.047, 0.632 ± 0.024 g/cc, -334 ± 44, 0.639 ± 0.042, 0.666 ± 0.026 g/cc, -370±61, 0.604±0.059, 0.63± 0.036 g/cc, -433±39, 0.543±0.038, 0.608 ± 0.035 g/cc, -382±54, 0.5±0.052, 0.618 ± 0.0316 g/cc, -292±68, 0.680±0.066, 0.708 ± 0.039 g/cc, -298±27, 0.680±0.0229, 0.702± 0.131 g/cc, for Acacia Nilotica, Mangifera Indica, Azadirachta Indica, Tectona Grandis L, Ficus Religiosa, Tecomella Undulata, Sesamum Indicum, Pinus respectively.

CONCLUSION

Measurements show that attenuation is affected by the energy of incident photons, collimator opening, and the type of density of the wood. Various radiological parameters were determined for wood samples that can be utilized to create inhomogeneous phantoms in dosimetry. The largest attenuation is found in Acacia Nilotica and Sesamum Indicum, while the lowest attenuation is found in Ficus religiosa.

Radiation damage to biological macromolecules∗

In this review, we describe recent research developments into radiation damage effects in macromolecular X-ray crystallography observed at synchrotrons and X-ray free electron lasers. Radiation damage in small molecule X-ray crystallography, small angle X-ray scattering experiments, microelectron diffraction, and single particle cryo-electron microscopy is briefly covered.

Imaging of the post-operative hallux valgus: what do radiologists need to know?

Hallux valgus surgery concerns many patients and various techniques are performed. The assessment of the first toe deformity correction is mainly visual and imaging is required to analyze the intermetatarsal angle and depict complications. However, it is often difficult for the radiologist to distinguish normal and pathological conditions, especially in case of osteotomies which may show various aspects of bone mineralization and healing. In this review, the most relevant imaging features of the post-operative hallux valgus are summarized.

How useful is pre-referral pediatric spine imaging?

PURPOSE

Primary care physicians rely on radiology reports to confirm a scoliosis diagnosis and inform the need for spine specialist referral. In turn, spine specialists use these reports for triage decisions and planning of care. The objectives were to determine (1) the adequacy of index images to inform treatment decisions at the initial consultation and (2) the utility of index radiology reports for appropriate triage decisions.

METHODS

A retrospective chart review was conducted including all idiopathic scoliosis patients seen for initial consultation, aged three to 18 years, between January 1 and April 30, 2021. A score out of five was generated based on the adequacy of index images to provide accurate Cobb angle measurements and determine skeletal maturity. Index images were considered inadequate if repeat imaging was necessary. Index radiology reports, associated imaging, and new imaging, if obtained at the initial consultation, were compared.

RESULTS

Of the 94 patients reviewed, 79% (n = 74) required repeat imaging at the initial consultation, of which 74% (n = 55) were due to insufficient quality and/or limited field of view. Of index images available for review at the initial consult (n = 80), 41.2% scored five out of five, and 32.5% scored two or below. Comparing index radiology reports to initial visit evaluation with ≤ 60 days between imaging (n = 49), discrepancies in Cobb angle were found in 24.5% (95% CI 14.6, 38.1) of patients. The Risser stage was reported in 14% of index radiology reports.

CONCLUSION

Although pre-referral pediatric spine radiographs serve a diagnostic purpose, most are inadequate for comprehensive idiopathic scoliosis evaluation.

LEVEL OF EVIDENCE

III.

Deep Learning-Based Classification of Chest Diseases Using X-rays, CT Scans, and Cough Sound Images

Chest disease refers to a variety of lung disorders, including lung cancer (LC), COVID-19, pneumonia (PNEU), tuberculosis (TB), and numerous other respiratory disorders. The symptoms (i.e., fever, cough, sore throat, etc.) of these chest diseases are similar, which might mislead radiologists and health experts when classifying chest diseases. Chest X-rays (CXR), cough sounds, and computed tomography (CT) scans are utilized by researchers and doctors to identify chest diseases such as LC, COVID-19, PNEU, and TB. The objective of the work is to identify nine different types of chest diseases, including COVID-19, edema (EDE), LC, PNEU, pneumothorax (PNEUTH), normal, atelectasis (ATE), and consolidation lung (COL). Therefore, we designed a novel deep learning (DL)-based chest disease detection network (DCDD_Net) that uses a CXR, CT scans, and cough sound images for the identification of nine different types of chest diseases. The scalogram method is used to convert the cough sounds into an image. Before training the proposed DCDD_Net model, the borderline (BL) SMOTE is applied to balance the CXR, CT scans, and cough sound images of nine chest diseases. The proposed DCDD_Net model is trained and evaluated on 20 publicly available benchmark chest disease datasets of CXR, CT scan, and cough sound images. The classification performance of the DCDD_Net is compared with four baseline models, i.e., InceptionResNet-V2, EfficientNet-B0, DenseNet-201, and Xception, as well as state-of-the-art (SOTA) classifiers. The DCDD_Net achieved an accuracy of 96.67%, a precision of 96.82%, a recall of 95.76%, an F1-score of 95.61%, and an area under the curve (AUC) of 99.43%. The results reveal that DCDD_Net outperformed the other four baseline models in terms of many performance evaluation metrics. Thus, the proposed DCDD_Net model can provide significant assistance to radiologists and medical experts. Additionally, the proposed model was also shown to be resilient by statistical evaluations of the datasets using McNemar and ANOVA tests.

Multi-Scale X-ray Imaging of the Pigment Discoloration Processes Triggered by Chlorine Compounds in the Upper Basilica of Saint Francis of Assisi

In this paper, the chromatic alteration of various types of paints, present on mural painting fragments derived from the vaults of The Upper Basilica of Saint Francis of Assisi in Italy (12th-13th century), is studied using synchrotron radiation. Six painted mural fragments, several square centimeters in size, were available for analysis, originating from the ceiling paintings attributed to Cimabue and Giotto; they correspond to originally white, blue/green, and brown/yellow/orange areas showing discoloration. As well as collecting macroscopic X-ray fluorescence and diffraction maps from the entire fragments in the laboratory and at the SOLEIL synchrotron, corresponding paint cross-sections were also analyzed using microscopic X-ray fluorescence and powder diffraction mapping at the PETRA-III synchrotron. Numerous secondary products were observed on the painted surfaces, such as (a) copper tri-hydroxychloride in green/blue areas; (b) corderoite and calomel in vermillion red/cinnabar-rich paints; (c) plattnerite and/or scrutinyite assumed to be oxidation products of (hydro)cerussite (2PbCO3·Pb(OH)2) in the white areas, and (d) the calcium oxalates whewellite and weddellite. An extensive presence of chlorinated metal salts points to the central role of chlorine-containing compounds during the degradation of the 800-year-old paint, leading to, among other things, the formation of the rare mineral cumengeite (21PbCl2·20Cu(OH)2·6H2O).

LITE-1 mediates behavioral responses to X-rays in Caenorhabditis elegans

Rapid sensory detection of X-ray stimulation has been documented across a wide variety of species, but few studies have explored the underlying molecular mechanisms. Here we report the discovery of an acute behavioral avoidance response in wild type Caenorhabditis elegans to X-ray stimulation. The endogenous C. elegans UV-photoreceptor protein LITE-1 was found to mediate the locomotory avoidance response. Transgenic expression of LITE-1 in C. elegans muscle cells resulted in paralysis and egg ejection responses to X-ray stimulation, demonstrating that ectopic expression of LITE-1 can confer X-ray sensitivity to otherwise X-ray insensitive cells. This work represents the first demonstration of rapid X-ray based genetically targeted (X-genetic) manipulation of cellular electrical activity in intact behaving animals. Our findings suggest that LITE-1 has strong potential for use in this minimally invasive form of neuromodulation to transduce transcranial X-ray signals for precise manipulation of neural activity in mammals, bypassing the need for invasive surgical implants to deliver stimulation.

Applications of X-Ray-Based Characterization in MXene Research

X-rays are a penetrating form of high-energy electromagnetic radiation with wavelengths ranging from 10 pm to 10 nm. Similar to visible light, X-rays provide a powerful tool to study the atoms and elemental information of objects. Different characterization methods based on X-rays are established, such as X-ray diffraction, small- and wide-angle X-ray scattering, and X-ray-based spectroscopies, to explore the structural and elemental information of varied materials including low-dimensional nanomaterials. This review summarizes the recent progress of using X-ray related characterization methods in MXenes, a new family of 2D nanomaterials. These methods provide key information on the nanomaterials, covering synthesis, elemental composition, and the assembly of MXene sheets and their composites. Additionally, new characterization methods are proposed as future research directions in the outlook section to enhance understanding of MXene surface and chemical properties. This review is expected to provide a guideline for characterization method selection and aid in precise interpretation of the experimental data in MXene research.

Comparative analysis of the molecular response characteristics in Platycodon grandiflorus irradiated with heavy ion beams and X-rays

The response of plants to radiation is an essential topic in both space plant cultivation and mutation breeding by radiation. In this study, heavy ion beams (HIB) generated by the ground accelerator and X-rays (XR) were used as models of high linear energy transfer (LET) and low LET radiation to study the molecular response mechanism of Platycodon grandiflorus (P. grandiflorus) seedlings after irradiation. The gene and protein expression profiles of P. grandiflorus after 15 Gy HIB and 20 Gy XR radiation were analyzed by transcriptome and proteome. The results showed that the number of differentially expressed genes (DEGs) induced by HIB radiation was less than that of XR group, but HIB radiation induced more differentially expressed proteins (DEPs). Both HIB and XR radiation activated genes of RNA silencing, double-strand break repair and cell catabolic process. DNA replication and cell cycle related genes were down-regulated. The genes of cell wall and external encapsulating structure were up-regulated after HIB radiation. The gene expression of protein folding and glucan biosynthesis increased after XR radiation. Protein enrichment analysis indicated that HIB radiation resulted in differential protein enriched in photosynthesis and secondary metabolite biosynthesis pathways, while XR radiation induced differential protein of glyoxylate and dicarboxylate metabolism and carbon metabolism. After HIB and XR radiation, the genes of antioxidant system and terpenoid and polyketide metabolic pathways presented different expression patterns. HIB radiation led to the enrichment of non-homologous end-joining pathway. The results will contribute to understanding the biological effects of plants under space radiation.

A Stability-Based Management Protocol for Isolated Lateral Malleolar Ankle Fractures at the Level of the Syndesmosis Reduces the Need for Surgical Intervention

Purpose

The study aimed to establish and subsequently improve the rate of stability assessments of fractures with uncertain stability and the impact on the avoidance of potentially unnecessary surgery.

Methods

Two independent audit cycles were conducted from October 2019 to May 2020. All patients had closed isolated lateral malleolar fractures at the level of the tibiotalar syndesmosis involving skeletally mature bone. A stability-based management protocol was introduced, incorporating an education programme and management guideline.

Results

75 ankles fractures were included. In the initial audit cycle, 13 patients did not undergo stability X-rays within 2 weeks of injury. Interestingly, only one stability assessment was performed for five operated ankles in the first audit, versus a 100% compliance rate in the second cycle. We observed more accurate documentation following education and awareness of clinical importance.

Conclusion

By implementing a stability-based management guideline, there was an improvement in compliance with guidance towards stability assessments of ankle fractures. This potentially led to the avoidance of unnecessary surgery on fractures where stability assessments supported non-operative management.