Alternative Imaging Research Articles

Diagnostic performance of dual-energy CT with electron-density reconstruction for lumbar disc herniation

Background: Magnetic resonance imaging (MRI) is used for the evaluation of degenerative spinal disease. However, its utility is restricted in routine practice because of contraindications and a lack of widespread availability. Dual-energy computed tomography (DECT) is a newer technique for the evaluation of degenerative spinal disease.Objectives: This study aimed to evaluate the diagnostic performance of DECT with electron-density (ED) image reconstruction compared to standard CT for the detection of lumbar disc herniation, with MRI as the gold standard.Method: The retrospective study included 84 patients between 01 July 2023 to 31 December 2023 who underwent DECT and 1.5-T MRI within 1 week. Four radiologists, blinded to the clinical and MRI information, independently evaluated the standard CT series and DECT series with ED reconstructions for lumbar disc herniation and spinal nerve root impingement. The gold standard for comparison was lumbar spine MRI, and diagnostic accuracy was measured with sensitivity and specificity.Results: MRI revealed 417 lumbar disc herniations. Dual-energy computed tomography with ED reconstruction showed higher sensitivity (86.36% [532/616] vs. 57.79% [356/616]) and specificity (96.86% [1019/1052] vs. 95.82% [1008/1052]) for the detection of lumbar disc herniation compared to standard CT.Conclusion: Dual-energy computed tomography with ED reconstruction shows better diagnostic performance for the detection of lumbar disc herniation compared to standard CT and can be a useful alternative imaging modality when MRI is contraindicated or unavailable.Contribution: This study shows the usefulness of DECT as an alternative imaging technique for screening of degenerative spinal disease whenever MRI is contraindicated or unavailable.

EGS SO21 - The undifferentiated general surgical take over 10 years: Emergency imaging

Abstract Background The undifferentiated emergency general surgical take in July 2013 and July 2023, at a District General Hospital, was reviewed with the aim of understanding increasing pressures on the surgical and radiology departments, and subsequently identifying areas in which we could adapt to facilitate these demands. Method Patients were identified retrospectively if they had been cared for by the emergency general surgical team in July 2013 or July 2023. Further information was collected from electronic notes, with a focus on admission and initial imaging modalities. Patients were excluded if information was not available electronically. Results Of the 395 patients in July 2013, and 594 in July 2023, 55% and 61% respectively had imaging studies within 7 days of admission. 11% (n=44/395) of patients in 2013 had abdominal X-ray without further imaging, compared to 6% (n=33/594) in 2023. Computed Tomography (CT) use increased by 35%, whilst ultrasound scanning (USS) increased only by 11%. Time from admission to scans of all types has reduced from 0.79 days (+/-0.16, p=0.02) in 2013 to 0.60 (+/-0.1, p=0.02) days in 2023. Conclusion Overall volume of imaging has increased slightly, although the proportion of patients being scanned is largely unchanged, with subtle variation in preferred imaging modalities. CT is marginally more common, whilst USS remains mostly unchanged. The use of abdominal x-ray without subsequent imaging has decreased, demonstrating its reducing use in clinical judgement and reliance on alternative imaging techniques. Time from admission to scan of all kinds has reduced, despite increasing demands on radiology departments.

Biomass-Derived Organonanomaterials as Contrast Agents for Efficient Magnetic Resonance Imaging.

Magnetic resonance imaging (MRI) is a popular imaging tool that is valuable for the early detection and monitoring of malignancies because it does not involve radiation and is noninvasive. Metal-based contrast agents (CAs) are commonly used in clinical settings despite concerns about the toxicity of free metals. Therefore, finding alternative nontoxic imaging probes is vital. In this work, we have synthesized and effectively utilized sustainable biomass lignin-based all-organic nanoconjugates linked with nitroxide radicals as MRI CAs. Lignin grafted with poly(4-glycidyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl) (LPGT) exhibits a longitudinal relaxivity of 0.54 mM-1 s-1. LPGT shows exceptional characteristics, including resistance to reduction and nontoxicity toward living organisms. LPGT displays enhanced MRI contrast in the BALB/c mouse model for a duration exceeding 4.35 h. Our primary goal is to design MRI agents that are exceptionally effective sustainable biomass-derived materials and do not require the use of metals. Nicely, LPGT offers adequate contrast enhancement at 5-fold lower (0.020 mmol/kg) than the standard dose (0.1 mmol/kg), easing worries about toxic metal buildup. Consequently, LPGT shows promise as a feasible CA for metal-free MRI.

Clinical utility of echocardiography in internal medicine: a narrative review

Echocardiography has emerged as an invaluable tool in internal medicine, providing real-time, non-invasive evaluation of cardiac structure and function. Its clinical utility spans a wide range of applications, including the diagnosis and management of heart failure, valvular heart diseases, and cardiomyopathies, as well as systemic conditions like sepsis and chronic kidney disease. The ability to perform bedside echocardiography has made it particularly useful in critical care settings, allowing for rapid assessment of cardiac function in hemodynamically unstable patients. Echocardiography also plays a key role in guiding therapeutic interventions, from fluid management to valvular repair and replacement procedures. Despite its many advantages, echocardiography is not without limitations. Image quality may be compromised in patients with obesity, lung disease, or prior thoracic surgery, necessitating alternative imaging modalities like cardiac magnetic resonance imaging or computed tomography. Operator expertise is another critical factor influencing diagnostic accuracy, underscoring the importance of proper training. Recent advancements, including artificial intelligence integration and portable devices, are expected to further expand the role of echocardiography, making it more accessible in diverse clinical settings. This narrative review highlights the broad clinical utility of echocardiography in internal medicine, its challenges, and the future directions that promise to enhance its role in patient care.

Chest pain and AI interpretation: The essential role of clinical judgment and quality data

Chest pain is a common and complex condition in emergency departments, often complicating the diagnostic process due to its wide range of potential causes. This case report presents a 72-year-old man with chest pain and ST-segment elevation on ECG, initially suggestive of acute coronary syndrom. AI-assisted ECG analysis reinforced this suspicion; however, angiography revealed patent coronary arteries. When his symptoms persisted, further investigation uncovered a pneumothorax. Additional evaluation identified a digitization error affecting the AI interpretation. This case underscores the importance of a comprehensive clinical approach for chest pain and highlights the need for quality data input and alternative imaging, such as thoracic ultrasound, for accurate and timely differential diagnoses.

A Dual-Module System for Copyright-Free Image Recommendation and Infringement Detection in Educational Materials

Images are extensively utilized in educational materials due to their efficacy in conveying complex concepts. However, unauthorized use of images frequently results in legal issues related to copyright infringement. To mitigate this problem, we introduce a dual-module system specifically designed for educators. The first module, a copyright infringement detection system, employs deep learning techniques to verify the copyright status of images. It utilizes a Convolutional Variational Autoencoder (CVAE) model to extract significant features from copyrighted images and compares them against user-provided images. If infringement is detected, the second module, an image retrieval system, recommends alternative copyright-free images using a Vision Transformer (ViT)-based hashing model. Evaluation on benchmark datasets demonstrates the system’s effectiveness, achieving a mean Average Precision (mAP) of 0.812 on the Flickr25k dataset. Additionally, a user study involving 65 teachers indicates high satisfaction levels, particularly in addressing copyright concerns and ease of use. Our system significantly aids educators in creating educational materials that comply with copyright regulations.

Intracardiac vs transesophageal echocardiography for percutaneous LAA occlusion: a meta-analysis

Abstract Background Percutaneous left atrial appendage occlusion (LAAO) is typically performed under the guidance of transesophageal echocardiography (TEE) and fluoroscopy. Intracardiac echocardiography (ICE) appears to be a potential alternative to guide implantation. Purpose We sought to perform a meta-analysis comparing ICE and TEE for endocardial LAAO. Methods A comprehensive literature search was performed in PubMed and Google Scholar regarding published abstracts and manuscripts on July 1, 2023. Studies reporting clinical outcomes comparing ICE vs TEE for endocardial LAAO were included. Results A total of 16 studies with 123,444 patients (ICE-5,122 patients and TEE-122,667 patients) (mean age 75±4 years, 59%male) fulfilled the criteria. Five included Watchman, four included the Amplatzer Cardiac Plug/ Amulet device, and seven included both devices. There was no significant difference in CHA2DS2VASC or HAS-BLED scores between both groups. Outcomes assessed including procedural success between ICE vs TEE (risk ratio [RR], 1.01; 95% CI, 1.00-1.01), fluoroscopy time (mean difference [MD], 1.25 minutes; 95% CI, -1.63- 4.14) and total procedure time (MD, −3.74 minutes; 95% CI, − 13.42-5.94) were found to be similar between both groups. There was also no significant difference in complications including vascular complications, bleeding events, device embolization, and stroke between both groups. Of note, patients undergoing LAA closure under ICE guidance had higher risk for pericardial effusion and/or cardiac tamponade compared to those in the TEE group (RR 1.72; 95% CI, 1.32-2.23). Conclusions Although TEE is the gold standard for perioperative guidance of LAAO, imaging with ICE is a feasible alternative associated with similar efficacy outcomes in LAAO procedures. However, further studies needed to clarify safety of ICE as an alternative perioperative imaging technique.

Imaging for upper tract urothelial carcinoma: update of the evidence and a glimpse into the future.

Upper tract urothelial carcinoma (UTUC) is a rare malignancy posing significant diagnostic and management challenges. This review provides an overview of the evidence supporting various imaging modalities and offers insights into future innovations in UTUC imaging. With the growing use of advancements in computed tomography (CT) technologies for both staging and follow-up of UTUC patients, continuous innovations aim to enhance performance and minimize the risk of excessive exposure to ionizing radiation and iodinated contrast medium. In patients unable to undergo CT, magnetic resonance imaging serves as an alternative imaging modality, though its sensitivity is lower than CT. Positron emission tomography, particularly with innovative radiotracers and theranostics, has the potential to significantly advance precision medicine in UTUC. Endoscopic imaging techniques including advanced modalities seem to be promising in improved visualization and diagnostic accuracy, however, evidence remains scarce. Radiomics and radiogenomics present emerging tools for noninvasive tumor characterization and prognosis. The landscape of imaging for UTUC is rapidly evolving, with significant advancements across various modalities promising improved diagnostic accuracy, patient outcomes, and safety.

Diffuse correlation tomography: a technique to characterize tissue blood flow abnormalities in benign and malignant breast lesions

Accurate assessment and quantification of neoangiogenesis associated with breast cancer could be potentially used to improve the sensitivity and specificity of non-invasive diagnosis, as well as predict outcomes and monitor treatment effects. In this study, we adapted an emerging technology, namely diffuse correlation tomography (DCT), to image microvascular blood flow in breast tissues and evaluate the potential for discriminating between benign and malignant lesions. A custom-made DCT system was designed for breast blood flow imaging, with both the source-detector array and reconstruction algorithm optimized to ensure precise imaging of breast blood flow. The global features and local features of three-dimensional blood flow images were extracted from the relative blood flow index (rBFI), which was obtained from most of the breasts targeted to the lesion. A total of 37 women with 19 benign and 18 malignant lesions were included in the study. Significant differences between malignant and benign groups were found in 12 image features. Moreover, when selecting the lesion mean relative blood flow index (MrBFI) as a single indicator, the malignant and benign tumors were discriminated with an accuracy of 89.2%. The blood flow features were found to successfully identify malignant and benign tumors, suggesting that DCT, as an alternate functional imaging modality, has the potential to be translated into clinical practice for diagnosis and assessment of breast cancers. There is potential to reduce the need for biopsy of benign lesions by improving the specificity of diagnostic imaging, as well as monitoring response to breast cancer treatment.

Exploring intercultural perspectives of migration futures in a super-diverse city through intercultural participatory futures workshops: The case of Istanbul

Most migration futures studies focus on reacting to migration issues such as flows and crises rather than exploring alternative images of futures centered on individual’s migration experiences. Addressing the limitations of existing practices criticized for their short-term, problem-oriented, and predominantly western, male-dominated, and colonized perspectives, this article presents intercultural participatory futures workshops as a novel technique for exploring more inclusive and intercultural migration futures. This approach enabled participants to collaboratively envision, build, and discuss alternative futures of migration for Istanbul in 2050 in eight workshop sessions with 35 intercultural participants. Additionally, it fostered a space to share experiences, and thoughts on futures, while meaningfully interacting with one another. Therefore, the contribution of this article to the migration futures field is two-fold: first, it showcases the potential of intercultural participatory futures workshops for exploring and constructing inclusive and participatory visions of migration futures, while contrasting collective visions and individual concerns; and second, it explains the relevance of this approach as a unique opportunity to foster intercultural meaningful social interactions, a key kind of interaction for social inclusion between individuals with migration backgrounds and host society.

Multiple myeloma segmentation net (MMNet): an encoder-decoder-based deep multiscale feature fusion model for multiple myeloma segmentation in magnetic resonance imaging.

Patients with multiple myeloma (MM), a malignant disease involving bone marrow plasma cells, shows significant susceptibility to bone degradation, impairing normal hematopoietic function. The accurate and effective segmentation of MM lesion areas is crucial for the early detection and diagnosis of myeloma. However, the presence of complex shape variations, boundary ambiguities, and multiscale lesion areas, ranging from punctate lesions to extensive bone damage, presents a formidable challenge in achieving precise segmentation. This study thus aimed to develop a more accurate and robust segmentation method for MM lesions by extracting rich multiscale features. In this paper, we propose a novel, multiscale feature fusion encoding-decoding model architecture specifically designed for MM segmentation. In the encoding stage, our proposed multiscale feature extraction module, dilated dense connected net (DCNet), is employed to systematically extract multiscale features, thereby augmenting the model's sensing field. In the decoding stage, we propose the CBAM-atrous spatial pyramid pooling (CASPP) module to enhance the extraction of multiscale features, enabling the model to dynamically prioritize both channel and spatial information. Subsequently, these features are concatenated with the final output feature map to optimize segmentation outcomes. At the feature fusion bottleneck layer, we incorporate the dynamic feature fusion (DyCat) module into the skip connection to dynamically adjust feature extraction parameters and fusion processes. We assessed the efficacy of our approach using a proprietary dataset of MM, yielding notable advancements. Our dataset comprised 753 magnetic resonance imaging (MRI) two-dimensional (2D) slice images of the spinal regions from 45 patients with MM, along with their corresponding ground truth labels. These images were primarily obtained from three sequences: T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), and short tau inversion recovery (STIR). Using image augmentation techniques, we expanded the dataset to 3,000 images, which were employed for both model training and prediction. Among these, 2,400 images were allocated for training purposes, while 600 images were reserved for validation and testing. Our method showed increase in the intersection over union (IoU) and Dice coefficients by 7.9 and 6.7 percentage points, respectively, as compared to the baseline model. Furthermore, we performed comparisons with alternative image segmentation methodologies, which confirmed the sophistication and efficacy of our proposed model. Our proposed multiple myeloma segmentation net (MMNet), can effectively extract multiscale features from images and enhance the correlation between channel and spatial information. Furthermore, a systematic evaluation of the proposed network architecture was conducted on a self-constructed, limited dataset. This endeavor holds promise for offering valuable insights into the development of algorithms for future clinical applications.

Thrombectomy Outcomes for Anterior Circulation Stroke in the 6-24 h Time Window Solely Based On NCCT and CTA: ASingle Center Study.

Since perfusion imaging may be unavailable in smaller hospitals, alternative imaging selection methods for acute ischemic stroke can improve outcomes and optimize resources. This study assessed the safety and effectiveness of using imaging criteria other than DEFUSE3 and DAWN for thrombectomy beyond 6 h from symptom onset in patients stroke in the anterior circulation. This is aretrospective, single-center analysis of consecutive patients with large vessel occlusion in the anterior circulation undergoing thrombectomy. Patients were categorized into two groups based on the collateral status (moderate collaterals and good collaterals). Among 198 patients, 106 (54%) met the inclusion criteria and were analyzed. Good collateral status was observed in 78 (74%) patients. Patients with good collaterals showed significantly lower mRS scores at discharge and at 90days compared to their counterparts with moderate collateral status (4 (3-4) vs.4 (4-5); p = 0.001 and 2 (0-4) vs.6 (3-6); p < 0.001, respectively). More patients with good collateral status achieved favorable outcomes at 90days compared to those with moderate status (48 (61.5%) vs.5 (17.9%); p < 0.001). Good collaterals were an independent predictor of good clinical outcomes at 90days (OR = 1.31, 95% CI: 1.13-1.53, p < 0.001). Selecting patients for endovascular treatment of acute ischemic stroke using non-contrast CT and CT angiography shows 90-day outcomes similar to the DAWN and DEFUSE-3trials. Using collateral status on CT angiography can predict favorable outcomes after mechanical thrombectomy in resource-limited settings where perfusion imaging is unavailable.

Incidence of Ipsilateral Femoral Neck and Shaft Fractures in Pediatric and Adolescent Patients

OBJECTIVES: To identify the incidence, patient characteristics, and effectiveness of radiographic screening methods for detecting ipsilateral femoral neck and shaft fractures in pediatric and adolescent trauma patients. METHODS: Design: Retrospective cohort study. Setting: This study was conducted at a tertiary pediatric trauma hospital. Patient Selection Criteria: Patients younger than 18 years treated for a femoral shaft fracture between 2004 and 2018 were reviewed. Pathologic (metabolic bone disease or bone lesion), periprosthetic, and penetrating traumatic femoral shaft fractures were excluded. Outcome Measurements and Comparisons: Patient demographics, mechanisms of injury, treatment methods, and associated injuries were analyzed. Pretreatment x-rays and computed tomography (CT) scans were reviewed for the identification of ipsilateral femoral neck and shaft fractures. RESULTS: Among the 840 pediatric patients included in this study, 4 patients (0.5%) sustained ipsilateral femoral neck and shaft fractures. All the femoral neck fractures were observed in adolescents (aged 13–17 years) and involved in high-energy traumas. In adolescents involved in high-energy trauma, the incidence increased to 1.7%. Pretreatment sensitivity of both x-rays and CT scans was only 50% for the detection of femoral neck fractures. CONCLUSIONS: This study reveals that ipsilateral femoral neck and shaft fractures in pediatric patients are rare, occurring in adolescents involved in high-energy trauma. The findings suggest the need for a selective, rather than routine, use of CT scans based on the patient's age and the mechanism of injury. The use of alternative imaging methods such as magnetic resonance imaging should be considered to balance diagnostic accuracy while minimizing radiation exposure. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Environmental and patient safety: Advances in radiological techniques to reduce radiation exposure

The growing concern for environmental and patient safety in medical imaging has driven significant advancements in radiological techniques aimed at reducing radiation exposure. This review explores these developments, emphasizing the dual focus on minimizing harm to patients and addressing the broader environmental impact of radiological practices. Recent innovations include the optimization of imaging protocols, the introduction of low-dose imaging technologies, and the integration of advanced software algorithms that enhance image quality while reducing the need for higher radiation doses. The implementation of iterative reconstruction techniques, for instance, has allowed for significant dose reductions in computed tomography (CT) scans without compromising diagnostic accuracy. Additionally, the use of alternative imaging modalities such as magnetic resonance imaging (MRI) and ultrasound, which do not involve ionizing radiation, is increasingly recommended where clinically appropriate, further mitigating radiation risks. Furthermore, the shift towards personalized imaging protocols, where radiation doses are adjusted based on individual patient characteristics, marks a critical advance in patient safety. This approach not only reduces unnecessary exposure but also enhances the overall effectiveness of diagnostic procedures. Environmental safety considerations have also led to the development of more sustainable radiological practices, including the safe disposal of radioactive materials and the reduction of energy consumption in imaging facilities. These efforts are aligned with broader healthcare initiatives to lower the carbon footprint of medical practices. The advancements in radiological techniques to reduce radiation exposure reflect a growing commitment to patient-centered care and environmental stewardship in healthcare. As technology continues to evolve, ongoing research and collaboration between medical professionals, physicists, and environmental scientists will be crucial in furthering these goals. By continuing to innovate and implement safer radiological practices, the medical community can significantly mitigate the risks associated with radiation exposure, ensuring better health outcomes for patients and reducing the environmental impact of radiological services.

Improving Therapy for Children with Scoliosis through Reducing Ionizing Radiation by Using Alternative Imaging Methods-A Study Protocol.

Patients with scoliosis often require multiple imaging modalities. The aim of this study was to find out whether primary diagnosis, including surgical planning, could be carried out entirely without computed tomography (CT) scans and whether follow-up could be replaced with alternative methods without the use of X-rays. In order to reduce the radiation exposure in the diagnosis and treatment of severe scoliosis, we expect to replace X-rays with radiation-free or less-intensive radiation examinations. This study protocol is interdisciplinary. A total of 50 male and female patients (children and adolescents, aged 7-18 years) treated for scoliosis will be analyzed. In addition to routine projection radiographs, preoperative CT, and/or X-ray stereoradiography (EOS) examinations, thin-slice 3D magnetic resonance imaging (MRI) sequences will be retrospectively reformatted during the preoperative MRI examination. A three-dimensional back scan (video-raster stereography) and an intraoral scan will also be obtained. The following questions should be answered at the end of the project: (1) Can MRI examination with additional thin-slice 3D reconstruction answer all relevant questions for preoperative planning instead of CT? (2) Are EOS or whole-spine X-ray examinations in combination with MRI data sufficient for the evaluation of the pedicles and spinal deformity? (3) Does the Cobb angle in the radiograph correlate with the calculations from the back scanner image and can follow-up checks be replaced? (4) Are there any correlations between dental anomalies and scoliosis? Until now, pediatric patients with scoliosis have been diagnosed, monitored, and treated with numerous independent specialist disciplines, such as pediatricians, orthopedic surgeons, neurosurgeons, and general practitioners with different radiological issues. The aim of this project is to reduce radiation and lower perioperative risks by creating a preoperative and follow-up-related standard protocol in close interdisciplinary and targeted cooperation between all the specialist disciplines involved. In line with the holistic examination approach, the associated accompanying diseases and developmental disorders such as dental and neuronal malformations will also be examined. On the one hand, CT-based questions could be replaced with the reconstruction of thin-slice MRI sequences. In addition, it may be possible to use the three-dimensional back scan as an intermediate diagnostic procedure instead of X-rays in the monitoring of severe scoliosis. Insofar as correlations or causalities between scoliosis and occlusal anomalies, early orthodontic intervention could positively benefit the duration of therapy at a later stage.

Management of neonatal head injuries: A retrospective cohort study

AbstractAimThe aim of this study is to describe circumstances, management and short‐term outcomes of neonatal head trauma, and adherence to the Paediatric Emergency Care Applied Research Network (PECARN) head trauma prediction rule for children under 2 years.MethodsMulticentre retrospective cohort study of neonates (&lt;29 days) with head trauma across 25 emergency departments (ED) from January 2017 to June 2021.ResultsA total of 492 neonates (median age 17 days, range 0–28 days) with non‐trivial head trauma were enrolled. Falls were the most common injury mechanism (375/492, 76.2%). Imaging was performed in 150/492 (30.5%) neonates.Clinically important traumatic brain injury (ciTBI), defined as death, neurosurgery, prolonged intubation, or extended hospitalisation from injury, occurred in 7/492 (1.4%) cases. Notably, 286/492 (58.1%) neonates were managed by short‐term observation (&lt;48 h), and 126/492 (25.6%) were admitted.Among high‐risk neonates per PECARN criteria, 17/21 (80.9%) did not undergo recommended head CT scans but were observed within ED short observation units or underwent alternative imaging, with no ciTBI diagnoses among those discharged without CT.ConclusionSevere neonatal head injuries are rare, and most neonatal head injuries have a favourable outcome, making observation a suitable approach, while remaining vigilant for signs of non‐accidental injuries.

Ultrasound Imaging of Various Ingested Foreign Bodies in an Ex Vivo Intestinal Model.

Foreign body ingestion is an increasingly prevalent issue for children who are in the preverbal to early verbal stages of life. Foreign bodies lodged in the gastrointestinal tract can cause issues such as obstruction, perforation, and fistulae. Radiographic imaging can often locate most foreign bodies; however, radiolucent objects may be missed. Ultrasound is an alternative imaging modality that can be used to locate and track foreign objects as they pass through the bowel. The objective of this study was to characterize the sonographic appearance of various ingested foreign bodies of varying characteristics in an ex vivo gastrointestinal tract segment. A GE Logiq 9 ultrasound machine with a linear transducer at a frequency of 15 MHz was used to examine various ingested foreign bodies placed in a segment of pig intestinal tract. Imaged objects varied in visual appearance from echogenicity, texture, size, and shape; acoustic shadows and reverberation artifacts cast were particularly distinguishing characteristics. Ultrasound evaluation to assess foreign body ingestion in the pediatric population may provide a useful alternative or supportive imaging modality in confirming the location and real-time tracking of the ingested item. This may be especially useful for objects of varying radiodensities that cannot always be reliably seen in traditional radiographs.

EP278 - The undifferentiated general surgical take over 10 years: emergency imaging

Abstract Aims The undifferentiated emergency general surgical take in July 2013 and July 2023, at a District General Hospital, was reviewed with the aim of understanding increasing pressures on the surgical and radiology departments, and subsequently identifying areas in which we could adapt to facilitate these demands. Methods Patients were identified retrospectively if they had been cared for by the emergency general surgical team in July 2013 or July 2023. Further information was collected from electronic notes, with a focus on admission and initial imaging modalities. Patients were excluded if information was not available electronically. Results Of the 395 patients in July 2013, and 594 in July 2023, 55% and 61% respectively had imaging studies within 7 days of admission. 11% (n=44/395) of patients in 2013 had abdominal X-ray without further imaging, compared to 6% (n=33/594) in 2023. Computed Tomography (CT) use increased by 35%, whilst ultrasound scanning (USS) increased only by 11%. Time from admission to scans of all types has reduced from 0.79 days (+/-0.16, p=0.02) in 2013 to 0.60 (+/-0.1, p=0.02) days in 2023. Conclusion Overall volume of imaging has increased slightly, although the proportion of patients being scanned is largely unchanged, with subtle variation in preferred imaging modalities. CT is marginally more common, whilst USS remains mostly unchanged. The use of abdominal x-ray without subsequent imaging has decreased, demonstrating its reducing use in clinical judgement and reliance on alternative imaging techniques. Time from admission to scan of all kinds has reduced, despite increasing demands on radiology departments.

ThP8.6 - A real-world diagnostic algorithm for identifying carotid artery stenosis

Abstract Aim Eighty-five percent of ischaemic strokes are caused by extracranial atheromatous lesions involving a narrowing of the Internal Carotid Artery so accurate and timely diagnosis is vital for management. The aim of this study was to correlate CT angiogram (CTA) and ultrasound doppler (US) derived measurements of carotid artery stenosis (CAS), with a view to identify those cases where second modality is required to reduce potential errors. Methods All consecutive carotid US and CTA examinations performed in 2021 and 2022 were included for comparison in this retrospective cohort study. Collected data was then reviewed and evaluated by a multidisciplinary team. North American Symptomatic Carotid Endarterectomy Trial (NASCET) and St Mary’s criteria were used to narrow down the percentage stenosis. Result There were fifty-one patients (102 carotid arteries) over this period who had both studies performed. Twenty-nine males and twenty-three females with a median age of seventy-three. Initial data analysis showed no discrepancy in ninety-one (90%) carotid arteries between both modalities. After MDT review, there were eight (7.1%) false positive results and three (2.9%) true positive (2 symptomatic &amp; 1 asymptomatic). In three (2.9%) cases quantification was significantly inaccurate in the initial imaging modality because of heavily calcified vessels. Conclusion This study supports the use of US or CTA as a single modality in grading CAS. Heavily calcified vessels on the first test should be a ‘red flag’ for triggering further alternative imaging to reduce the risk of error. Persistent discrepancies even after the second modality will require a further modality e.g. enhanced magnetic resonance angiography.

Nanoscale subsurface imaging by non-steady-state electron beam-driven scanning thermoelectric capacitance microscopy

Nanoscale subsurface characterization technologies based on the scanning electron microscope platform offer incomparable advantages of nondestructiveness and penetration depths up to the micrometer scale. However, the electron beam can serve not just as a mechanical/electrical excitation source but also as an excellent nanoscale thermal excitation source, which can facilitate the development of nanoscale subsurface imaging methods based on the Seebeck effect in semiconducting materials. In this work, a subsurface nondestructive imaging technology, scanning thermoelectric capacitance microscopy (STeCM), was developed based on the interaction between a non-steady-state electron beam and semiconducting materials, exploiting the Seebeck effect. In STeCM, a square wave-modulated hot electron beam with huge kinetic energy excites a “thermal wave” in the subsurface local region of the semiconducting sample. The heated local region, acting as a thermoelectric capacitor, undergoes cyclic charging and discharging, leading to the generation of periodic current due to non-equilibrium carrier migration. The second-order harmonic component of this current is demodulated to visualize embedded local thermal/thermoelectric inhomogeneities. Amazingly, for STeCM sample, only a smooth or polished surface is required, eliminating the need for any microfabrication, which will effectively decrease the configuration difficulty in the experiment. STeCM offers an alternative subsurface nondestructive imaging technology for more efficient, simple, and robust characterization.