Nonionic Contrast Research Articles

Occult Pheochromocytoma and Acute Ischaemic Stroke in Young Adult: Cause or Association

Pheochromocytoma is a rare catecholamine-secreting tumours of chromaffin tissues that cause a constellation of symptoms. It is closely associated with endocrine hypertension that can be masked, sustained or paroxysmal leading to hypertensive crisis, resulting in vascular and non-vascular complications and rarely cerebral ischaemia and stroke. A healthy 22 year old male reported with acute Right upper limb(RUL) monoplegia and Motor aphasia for five days with raised blood pressure levels. hypertonia was present, deep tendon reflexes were exaggerated in RUL and Right Plantar was extensor. General and systemic findings were nonsignificant . Routine investigations showed thrombocytosis and M.R.I. Brain was suggestive of acute infarction of Left Parieto-Temporal region. Renal doppler, Carotid Intima Media Thickness, Cerebral Angiogram, 2D-E.C.H.O. and Fundoscopy were normal. AntinuclearAntibody was negative. Contrast CT of abdomen revealed right adrenal mass suggestive of isolated Pheochromocytoma. Vanyl-Mandelic Acid was positive. Patient was stabilised and managed conservatively for 4 weeks followed by adrenalectomy and appropriate medical therapy. Patient is on regular followup and does not seem to require any antihypertensives or any other intervention. Pheochromocytoma is a notorious tumor and a great masquerader specially in young adults. A keen eye, routine checkups and evaluation is the key to detecting and preventing its associated morbidity and mortality.

Lateral Decubitus Dynamic CT Myelography with Real-Time Bolus Tracking (dCTM-BT) for Evaluation of CSF-Venous Fistulas: Diagnostic Yield Stratified by Brain Imaging Findings.

CSF-venous fistulas (CVFs) associated with spontaneous intracranial hypotension (SIH) may have a transient appearance, relative to contrast arrival, which may influence the diagnostic performance of lateral decubitus CT myelography (CTM). We developed a dynamic CTM protocol using real-time bolus-tracking (dCTM-BT) to improve the temporal resolution and standardize the timing of CTM acquisitions post-intrathecal contrast administration. The purpose of our study was to evaluate the feasibility of the dCTM-BT technique and evaluate its diagnostic yield for CVF detection, stratified by brain MRI SIH findings. Patients with suspected SIH without extradural fluid collection on spine MRI who underwent dCTM-BT were retrospectively reviewed. CT bolus monitoring was performed at the upper thoracic level. Following the visualization of dense intrathecal contrast, at least 3 CTM acquisitions of the spine were obtained and reviewed by 2 neuroradiologists. The Bern SIH score was calculated on the brain MRI. The diagnostic yield for CVF detection was evaluated, stratified by Bern score categories and a receiver operating characteristic (ROC) analysis. Out of 48 patients, 23 (48%) had a CVF on dCTM-BT, located at T1-5 (n = 4), T6-12 (n = 18), L1 (n = 1), with 70% on the right. CVF was identified in 22/22 (100%) of patients who had a high Bern score, 1/7 (14%) of those who had an intermediate score, and 0/19 (0%) of those who had a low score. The area under the ROC curve was 0.99 (95% CI, 0.98-1.00). The optimal cutoff was a Bern score of ≥5 (96% sensitivity, 100% specificity). dCTM-BT is feasible and has excellent diagnostic performance for CVF identification/localization. The Bern score is strongly associated with CVF detection and may help inform who will benefit from dCTM-BT.

99mTc-MDP MYOCARDIAL SCINTIGRAPHY IN DIAGNOSIS OF AMYLOID CARDIOMYOPATHY AT FV HOSPITAL, HCM CITY

Retrospective study of 99mTc-MDP myocardial scintigraphy for restrictive cardiomyopathy with suspicion of amyloidosis from Feb 2021-Nov 2021 at FV hospital. Total 10 patients (7 male and 3 female patients) of age 37-85 years. Injected dose 15-20 (555-740 MBq), Thorax planar and SPECT/low dose non contrast CT acquisition at 1 hour following tracer injection. Qualitative analysis with Visual score and quantitative H/CL ratio Positive scan is concluded in case of diffuse uptake in myocardium with Visual score 2-3 and H/CL ratio >1.5. The procedure was performed safely with no side effect, no allergic to radiotracer recognized.
 Results: Two male patients out of ten are positive for TTR-CA, at age 37 and 67. No myocardial biopsy is indicated for differential diagnosis between AL and TTR-CA. Eight patients are negative scintigraphically not specific for TTR-CA with H/CL <1.5 and Visual score 0.
 Conclusion: 99mTc-MDP cardiac scintigraphy is a safe, reliable, noninvasive nuclear imaging applicated for early and differential diagnosis of cardiac amyloidosis replacing to myocardial biopsy. This approach contributes to reveal an undiagnosed disease at not so advanced cardiac involvement and with the progress of recent medical treatment, the survival is increasing. Other bone-avid tracers are encuraged for myocardial imaging depending on their availability

ANALYSIS OF THE STRUCTURE OF LOCAL COMPLICATIONS TO ACUTE NECROTIC PANCREATITIS USING RADIATION DIAGNOSTICS METHODS

The use of multispiral computed tomography and ultrasound examination in pancreatic necrosis makes it possible to determine the shape, volume and localization, to distinguish four types of lesions. The aim of the study was to determine the incidence rate and the structure of local aseptic and purulent complications in acute necrotic pancreatitis using radiation diagnostics methods, to assess complications impact on the course and prognosis of the disease. Materials and methods. 63 patients with pancreatic necrosis who underwent treatment were examined during 2 years. The results of these examinations were analyzed. Two groups were identified: 1st – patients with infected pancreatic necrosis 29 (46%), 2nd – patients with sterile one 34 (54%). Ultrasound examination was performed on expert-class scanners, multispiral computed tomography with bolus tracking was performed on an Aguilion Prim device manufactured by Toshiba. Statistical processing of the results was performed in the Microsoft Excel 2017 database, the calculation of average values, standard distribution errors was made, the analysis of conjugate frequencies was given – the xi-squared test (c2) was used. Study results. Four types of infiltrative-necrotic lesions were identified: 21 cases (33.3%) of model-1 (central type); 13 cases (20.7%) of model-2 (left type); 9 cases (14.3%) of model-3 (right type); 20 cases (31.7%) of model-4 (mixed type). In group 1, severe pancreatic necrosis was significantly more often identified – in 17 out of 29 (58.6%) (c2 = 5.414; p = 0.020), mixed type (model-4) – 14 of 29 (48.3%) (c2 = 5.436; p = 0,020); in the 2nd group that of moderate severity was found more often – 21 out of 34 (61.6%) (c2 = 8.511; p = 0.004), mainly the central type (model-1) – 17 of 34 (50%) (c2 = 7.675; p = 0.006). There are no differences in the structure of local complications in group 2 depending on the severity of necrosis, in group 1, widespread parapancreatitis was more common in 22 out of 29 cases (75.9%) (p < 0.001). Mortality in infected and sterile pancreatic necrosis did not significantly differ – 24.1% and 23.5%, the highest mortality was in the mixed type of lesion in both groups (model-4) was 9 out of 20 (c2 = 5.643; p = 0.018). Conclusions. Radiation examination methods give the opportunity to predict early the pancreatic necrosis course and outcome. The development of local complications and their structure depend on the volume of necrosis, the prevalence and type of localization of destructive and inflammatory changes in retroperitoneal space.

CIDN: A context interactive deep network with edge-aware for X-ray angiography images segmentation

Accurate segmentation of X-ray angiography images is imperative for cardiovascular disease diagnosis. Despite significant strides in segmentation through deep learning, challenges persist in precisely delineating vessel edges. This paper introduces a Context Interactive Deep Network (CIDN) tailored for coronary vessel segmentation. CIDN integrates a Bio-inspired Attention Block (BAB) and a Multi-scale Interactive Block (MIB) to optimize the capture of spatial and edge information. The encoder-decoder facilitates optimal interaction between low-level features and high-level semantics. A compound loss function, amalgamating binary cross-entropy and active contour elasticity loss, enhances the recognition of intricate vessel edges. In experiments conducted on both public and private X-ray contrast images, the CIDN exhibits superior performance compared to the state-of-the-art Spatial Multi-scale Attention U-improved Network (SMAU-Net). Specifically, on dataset DCA1, the F1 value reached 0.7675, with an accuracy of 0.9795. Furthermore, on dataset JMA, the CIDN model achieved an F1 value of 0.8732, coupled with an accuracy of 0.9757. Accurate segmentation provides clinicians with precise vessel depictions, aiding in the identification of coronary stenosis and facilitating more informed diagnostic and therapeutic decisions.

Рrevention of contrast-induced nephropathy during interventional treatment of acute coronary syndrome

The aim of the work was to determine the risk factors of contrast-induced nephropathy in patients with acute coronary syndrome and to evaluate the effectiveness of methods of its prevention. There were examined 62 patients admitted to the interventional cardiology department during 9 months of routine practice with a diagnosis of acute coronary syndrome and concomitant chronic kidney disease. Among them, 56.45% have diabetic nephropathy, 21% – hypertensive nephro­pathy, 19.35% – chronic pyelonephritis, 3.2% – gouty nephropathy. According to the stages of chronic kidney disease: I stage – 8.1%, II stage – 46.8%, III A stage – 30.6%, III B stage – 14.5% of patients. The control group consisted of 32 patients with acute coronary syndrome without kidney pathology. All patients underwent urgent percutaneous coronary intervention using a water-soluble low-osmolarity radiocontrast medium. The risk of contrast-induced nephropathy was determined according to the Mehran scale. Contrast-induced nephropathy was diagnosed by an increase in serum creatinine over 24-48 hours by >25%. Prevention of contrast-induced nephropathy according to existing recommendations was carried out by prescribing early statin therapy and diuresis-controlled combined hydration in 22 patients with concomitant chronic kidney disease. Mathematical processing was performed using Statistica 8.0 software (StatSoft Inc, USA). Patients with chronic kidney disease had a high and very high risk of contrast-induced nephropathy in 19.4% and 3.2% of cases, among them in 91.6% of high and in 100% very high-risk contrast-induced nephropathy developed. Patients in the control group had a low to moderate risk, none of them developed contrast-induced nephropathy. It has been shown that the risk of contrast-induced nephropathy depends on the stage of chronic kidney disease and is associated with a decrease in the ejection fraction of the left ventricle (≤40%), acute left ventricle failure of the III and IV classes according to Killip, a decrease in diuresis in the first 12-24 hours after urgent percutaneous coronary intervention up to ≤0.6 ml/h/kg; in patients with diabetic nephropathy taking metformin 6-12 hours before the administration of the X-ray contrast medium and the glomerular filtration rate ≤45 ml/min./1.73 m2. In patients who underwent prevention of contrast-induced nephropathy in its entirety, its development was not registered.

X-Ray Visible Protein Scaffolds by Bulk Iodination.

Protein-based biomaterial use is expanding within medicine, together with the demand to visualize their placement and behavior in vivo. However, current medical imaging techniques struggle to differentiate between protein-based implants and surrounding tissue. Here a fast, simple, and translational solution for tracking transplanted protein-based scaffolds is presented using X-ray CT-facilitating long-term, non-invasive, and high-resolution imaging. X-ray visible scaffolds are engineered by selectively iodinating tyrosine residues under mild conditions using readily available reagents. To illustrate translatability, a clinically approved hernia repair mesh (based on decellularized porcine dermis) is labeled, preserving morphological and mechanical properties. In a mouse model of mesh implantation, implants retain marked X-ray contrast up to 3 months, together with an unchanged degradation rate and inflammatory response. The technique's compatibility is demonstrated with a range of therapeutically relevant protein formats including bovine, porcine, and jellyfish collagen, as well as silk sutures, enabling a wide range of surgical and regenerative medicine uses. This solution tackles the challenge of visualizing implanted protein-based biomaterials, which conventional imaging methods fail to differentiate from endogenous tissue. This will address previously unanswered questions regarding the accuracy of implantation, degradation rate, migration, and structural integrity, thereby accelerating optimization and safe translation of therapeutic biomaterials.

Towards Safer Batteries- 4D Imaging of Abuse Mechanisms in Lithium-Ion Batteries Using Synchrotron X-Ray Computed Tomography

Higher energy density materials are being pushed by the research community to make lithium-ion batteries a better competitor to chemical fossil fuels for transport applications. This increases potential risk of lithium-ion batteries and therefore safety investigations are highly important for application purposes. Operando Computer Tomography provides a non-destructive investigation method of different abuse mechanisms.Application of X-ray computed tomography (XCT) for studying lithium-ion batteries has gained interest among the research community especially in the past decade [1]. This technique is widely used for ex-situ samples to measure porosity and tortuosity [2], particle size and volume distribution [3] in the graphite anode as well as different cathode materials such as LiCoOx and NiMnCoOx. [4]. In situ measurements of commercial batteries are also often carried out to detect defects induced in a cell by a safety abuse test or manufacturing process [5]. Operando CT of large cells (for example 18650 form factor) is conducted at synchrotron facilities with high flux of high energy photons, however at a cost of details due to the large field of view [6].Thanks to their high brilliance, synchrotron beam facilitates us to do a full Computed Tomography in a short time. This enables us to measure batteries while being cycled with a reasonable time resolution to record morphological changes. In this presentation we illustrate how one can utilize this ability to investigate abuse mechanisms on an actual commercially available lithium-ion battery from cell level to electrode level.In this work, lab-based and synchrotron X-ray computed tomography is applied to commercial lithium-ion batteries. It is shown how to find most suitable imaging settings to study available lithium-ion batteries on different size scales, from cell level to particle level. We also demonstrate how to optimize contrast as well as both temporal and spatial resolutions to study in-situ and operando processes in a commercial battery using attenuation and phase contrast SXCT. Manufacturing defects and inconsistencies on cell level as well as the electrode and microstructure on material level are shown in our study.Using the presented methodic, some abuse conditions are induced and imaged in operando on a commercially available li-ion battery. In this work, deep discharge mechanism is visualized and quantified in detail for the first time in 4 dimensions.This oral presentation is aimed to present SXCT and lab XCT imaging as an important tool for studying state of safety of lithium-ion batteries from cell level down to particle level. It is shown how to find most suitable imaging settings to study available lithium-ion batteries on different size scales. We also demonstrate how to optimize contrast as well as both temporal and spatial resolutions to study in-situ and operando processes in a commercial battery using attenuation and phase contrast SXCT. Manufacturing defects and inconsistencies on cell level as well as the electrode and microstructure on material level are shown in our study. Moreover, some abuse conditions are imaged in operando in a commercially available li-ion battery. Le Houx, J. and D. Kramer, X-ray tomography for lithium ion battery electrode characterisation — A review. Energy Reports, 2021. 7: p. 9-14. Eastwood, D.S., et al., The application of phase contrast X-ray techniques for imaging Li-ion battery electrodes. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2014. 324: p. 118-123. Finegan, D.P., et al., Investigating lithium-ion battery materials during overcharge-induced thermal runaway: an operando and multi-scale X-ray CT study. Phys Chem Chem Phys, 2016. 18(45): p. 30912-30919. Ebner, M., et al., Tortuosity Anisotropy in Lithium-Ion Battery Electrodes. Advanced Energy Materials, 2014. 4(5). Patel, D., et al., Thermal Runaway of a Li-Ion Battery Studied by Combined ARC and Multi-Length Scale X-ray CT. Journal of The Electrochemical Society, 2020. 167(9). Finegan, D.P., et al., In-operando high-speed tomography of lithium-ion batteries during thermal runaway. Nat Commun, 2015. 6: p. 6924.

Synthesis of Single Nanometer-Sized Au Nanoparticles Coated with Silica Toward X-Ray Contrast Agent

In this study, we proposed a method for fabricating diagnostic imaging nanoparticles composed of Au nanoparticles and silica shells (Au/SiO2). The proposed method consisted of two steps. The first step was the synthesis of Au nanoparticles. In sodium hydroxide (NaOH) solution, hydrogen tetrachloroaurate (III) trihydrate was reduced with tetrakis(hydroxymethyl)phosphonium chloride to synthesize Au nanoparticles with a diameter of 1.7 ± 0.3 nm. The Au nanoparticles were then coated with silica in the following step. The silica coating was achieved via a sol–gel reaction of tetraethyl orthosilicate in the presence of Au nanoparticles in water/ethanol dissolved in NaOH. The Au/SiO2 nanoparticles degraded faster in saline or phosphate-buffered saline than in water, and the X-ray imaging capability was retained.

Impaired Aortic Growth in Neuroblastoma Patients After Intensive Treatment

PurposeThis study evaluated the abdominal aortic diameter in high-risk neuroblastoma (NB) patients and the risk of aortic narrowing following intensive treatment. MethodsWe measured the aortic diameter at four specific levels of the abdominal aorta (diaphragmatic crus, celiac axis, and the root of the superior (SMA) and inferior (IMA) mesenteric arteries) on contrast CT scans. The control group consisted of 56 children with non-oncologic disorders, while the NB group included 35 patients with high-risk abdominal NB. We used regression analysis of age and aortic diameter to determine the regression formula for each level in each group and performed intergroup comparisons using t-test. ResultsWe evaluated a total of 160 contrast-enhanced CTs performed in the 35 eligible cases. The aortic diameter of pretreated NB patients was not significantly different from the controls. After receiving any treatment, the aortic diameter was significantly smaller in the NB group (p < 0.01 each). Patients who underwent radical surgery, particularly gross total resection (n = 26), had smaller aortic diameters at all levels compared to controls (p < 0.01 each). Patients treated with radiotherapy (RT) had smaller aortic diameters than controls. External beam radiotherapy (EBRT) patients (n = 24) had smaller aortic diameters at all levels except the celiac axis (crus, SMA, IMA; p < 0.01 each), and intraoperative radiotherapy (IORT) ± EBRT patients (n = 5) had smaller aortic diameters at all levels (p < 0.01 each). ConclusionPatients with NB may experience impaired development of the abdominal aorta after multimodal therapy, particularly after RT. Close observation and long-term follow-up is essential to monitor for catastrophic vascular complications. Level of EvidenceLEVEL III.

Cerebral Abscess In A Child With Unknown Origin Of Infection

Introduction: The incidence of brain abscesses is higher in developing countries. The classic triad of fever, headache, and focal neurological signs was seen in 9–28% of the pediatric cases. Brain abscesses occur infrequently with potentially life-threatening conditions. Case Report: The patient was a child 1 year 8 months old with a main complaint of weakness in the left arm and leg progressively for one month. She had a local seizure on her left arm and leg one month before admission with a duration of 30 minutes. She was irritable for the last two weeks. The strength of the upper and lower extremities was 3 respectively. The physiology reflex was hyper-reflex on the upper and lower extremities. A Head non-contrast CT scan showed a hypodense lesion on the right parietal with a perifocal edema lesion. A head contrast CT scan showed a hypodense lesion on the right parietal with ring enhancement measuring approximately 6,2 cm x 4,5 cm. Craniotomy evacuation abscess with near total capsulectomy was done on initial and capsule resection was done. Discussion: Brain abscess is a focal pyogenic infection of the brain parenchyma, and the frontotemporal lobe is the most common site of brain abscess, followed by frontal-parietal, parietal, occipital lobes, and cerebellar. The most common risk factors that predispose a child to the formation of a brain abscess include congenital heart disease, sinus and otogenic infections, and poor dental hygiene. The triad of brain abscess, including headache, fever, and neurological symptoms is only present in (15%) of the cases reported. Medical treatment is recommended in patients without increased intracranial pressure, with symptoms of less than 1 week long and abscess of less than 2 cm seen in tomography. The suggested time of treatment is between 6 and 8 weeks with intravenously administered antibiotics. A full recovery rate from the infection of about 60–70% is reported in the case of early diagnosis and proper therapy Conclusion: Cerebral abscess in pediatrics with unknown origin of infection may happen in 12%. Early diagnosis and treatment of pediatric cerebral abscesses can reduce morbidity and mortality rates. A broadspectrum antibiotic is an optimal treatment in the postoperative evacuation of cerebral abscess cases with unknown origin infection.

Rare Case of Candida Parapsilosis Empyema Thoracis

BACKGROUND: This case report describes a patient with pleural empyema that grew Candida parapsilosis, an unexpected finding, especially in an immunocompetent individual with no prior surgery or trauma to the area. Candida empyema is a rare infection associated with mortality rates as high as 61.9%. METHODS: A 63-year-old male with a past medical history of pulmonary emboli was in his usual state of health when he developed worsening left-sided chest pain over 3 days, with associated shortness of breath and productive cough that was blood-tinged on occasion. Extensive imaging and a diagnostic thoracentesis confirmed an expanding left-sided parapneumonic effusion that was drained and found to grow Streptococcus anginosis and Candida parapsilosis. During his hospitalization, the patient also demonstrated increased alkaline phosphatase levels without abdominal pain or elevation in AST, ALT, or bilirubin, prompting further diagnostic imaging. Ultrasound of the abdomen showed a large, heterogeneous liver; follow-up CT scan, which was done without contrast due to worsening acute kidney injury, did not rule out liver masses. The patient’s clinical condition began to significantly improve following drainage of the pleural effusion and removal of the chest tube. After his kidney function returned to baseline, the patient was discharged with the remainder of his 18-day courses of amoxicillin-clavulanate and fluconazole, with a contrasted CT of the abdomen scheduled in the outpatient setting. CONCLUSION: This is an unusual case of fungal empyema, a severe manifestation of invasive candidiasis with a poor prognosis. Given the paucity of studies on Candida empyema, there is no definitive treatment for this deadly infection. A 2021 retrospective study of 81 patients with Candida empyema at two academic centers posited that optimal management included pleural drainage and fluconazole treatment. The same study found that 20% of Candida empyema originated from intra-abdominal sources. As for the patient in this case report, there remains the possibility that upcoming outpatient contrasted CT imaging of the abdomen will reveal the source of his infection.

A Literature Review of Infracolic Gastrostomy Techniques and Outcomes

AbstractPercutaneous radiologic gastrostomies are traditionally done using a supracolic approach due to the perceived increased risk of postprocedural hemorrhage associated with an infracolic approach. Many interventional radiologists will decline attempts at placing a gastrostomy tube in situations of colonic interposition, requiring patients to undergo surgery. The goal of this review was to understand the safety and technique of infracolic gastrostomies to assess the validity of these concerns. There were 12 cases of infracolic gastrostomies identified across two retrospective studies and one case report. All gastrostomy tubes were inserted successfully with no abandoned procedures with the only minor variation in technique being that the colon was displaced superiorly as opposed to inferiorly like in the traditional supracolic approach. Across the two retrospective studies, the percentage of infracolic gastrostomies done during the study period was 1.18% (6 out of 508) and 0.43% (5 out of 1,156). There were no immediate postprocedural complications reported in the study done with six patients who underwent infracolic gastrostomies, but there were two deaths during the follow-up period, both of which were attributed to disease progression. In the study with five patients who had undergone infracolic gastrostomies, there was one minor complication of site soreness along with one case of death due to sepsis secondary to aspiration of the barium contrast used to delineate the colon prior to the procedure. This is a rare complication that can occur when a barium swallow is done, especially in this case where the patient was older and had comorbidities that increased the aspiration risk. Evidently, infracolic gastrostomies have been inserted in the past with minimal complications. However, due to the limited sample size, the safety of this technique cannot be established without future prospective studies.

Effective processing pipeline PACE 2.0 for enhancing chest x-ray contrast and diagnostic interpretability

Preprocessing is an essential task for the correct analysis of digital medical images. In particular, X-ray imaging might contain artifacts, low contrast, diffractions or intensity inhomogeneities. Recently, we have developed a procedure named PACE that is able to improve chest X-ray (CXR) images including the enforcement of clinical evaluation of pneumonia originated by COVID-19. At the clinical benchmark state of this tool, there have been found some peculiar conditions causing a reduction of details over large bright regions (as in ground-glass opacities and in pleural effusions in bedridden patients) and resulting in oversaturated areas. Here, we have significantly improved the overall performance of the original approach including the results in those specific cases by developing PACE2.0. It combines 2D image decomposition, non-local means denoising, gamma correction, and recursive algorithms to improve image quality. The tool has been evaluated using three metrics: contrast improvement index, information entropy, and effective measure of enhancement, resulting in an average increase of 35% in CII, 7.5% in ENT, 95.6% in EME and 13% in BRISQUE against original radiographies. Additionally, the enhanced images were fed to a pre-trained DenseNet-121 model for transfer learning, resulting in an increase in classification accuracy from 80 to 94% and recall from 89 to 97%, respectively. These improvements led to a potential enhancement of the interpretability of lesion detection in CXRs. PACE2.0 has the potential to become a valuable tool for clinical decision support and could help healthcare professionals detect pneumonia more accurately.

Quantitative phase contrast X-ray tomography of aluminium metal matrix composite

The quantitative assessment of micro-structure and load-induced damages in Al–SiC metal matrix composites (MMC) is important for its design optimization, performance evaluation and structure-property correlation. X-ray Phase contrast micro-tomography is potentially used for evaluation of its 3 dimensional micro-structure manifested in the form of voids, cracks, embedded particles, and load-induced damages. However, the contrast between Al matrix and SiC particles is insufficient for their clear morphological identification and quantitative assessment. In the present study, we have proposed and applied single image-based phase retrieval as a pre-processing step to micro-tomography reconstruction for improved assessment of micro-structure and cohesion-induced damages in Al–SiC MMC. The advantages of applying different phase retrieval techniques in the enhancement of image quality and morphological quantification of SiC particles, pores and cohesion damages are discussed. It is observed that the Paganin method offers the best improvement in contrast to noise ratio for the measurement of SiC particles embedded in the Al matrix.

Anthropomorphic breast phantoms for radiology imaging: a review

Phantoms are used to validate diagnostic imaging methods or improve the skills of medical professionals. For instance, they allow conducting an unlimited number of imaging studies during medical training, assessing image quality, optimizing radiation dose, and testing novel techniques and equipment. Researchers in breast imaging use anthropomorphic models to validate, assess, and optimize new methods for diagnosing breast diseases. Such models also facilitate control over the quality of diagnostic systems, help optimize clinical protocols, and improve image reconstruction algorithms. Realistic simulation of the breast tissue is essential to address the challenges of advancing X-ray mammary gland studies. The review aimed to describe phantoms currently available for diagnostic imaging and the way they were fabricated. In this literature review, PubMed, eLIBRARY, and Google Scholar databases were screened for relevant articles. Thus, 72 articles and 13 conference papers were included. The study two major types of breast phantoms: computational and physical. Specifically, computational phantoms are classified into subgroups depending on the data they use. These include mathematical models, tissue samples, and medical images of the breast. The classification of the physical phantoms is based on their manufacturing process: casting silicone-like substances, 3D printing with resins and plastics, or printing on paper using X-ray contrast ink. Computational phantoms are generally advantageous with respect to versatility, efficiency, precision, and safety and allow the generation of large amounts of virtual data. Physical phantoms provide the most realistic diagnostic images without the need for a patient and allow performing an unlimited number of radiological studies.

Celiac Disease and Intussusception: A Common Association in Children.

In young childhood, intestinal intussusception (IS) is the most common cause of small bowel obstruction. A lead point such as Meckel diverticulum, polyps, tumors, enlarged lymph nodes, cystic fibrosis, and Schoenlein-Henoch purpura are recognized causes. Association between celiac disease (CD) and IS has been well recognized in adults but rarely in children. Data on causes and outcome of intussusception among Saudi children are lacking in the literature. Our objectives were to characterize the pattern of IS among Saudi children and investigate the frequency, clinical presentation, and outcome of intussusception among children with CD. We searched the hospital's picture archiving and communications system for abdominal imaging studies (ultrasound, magnetic resonance imaging, computed tomography scan, and barium contrast studies), performed between 2008 and 2019, using "intussusception" as a search key word. The hospital medical records of the identified cases of intussusception (aged 0-14 years) were then retrospectively reviewed to collect demographic, clinical, laboratory and imaging findings, management, and outcome. During the study period, 57 cases were identified as confirmed IS (31 boys, median age 1.95 years, range 0.33-11 years). Abdominal ultrasound was the diagnostic imaging study in 93%. An underlying cause (secondary IS) could be identified in 19 (33.3%) cases: CD in 6, malignancy and Henoch-Schoenlein purpura, 5 each, and Meckel diverticulum in 3; the remaining 38 (66.6%) cases of IS were idiopathic (primary IS). The presence of hypoalbuminemia and abdominal distension were significantly associated with secondary IS as compared with primary IS ( P < 0.001, P = 0.006, respectively). All of the 6 cases of IS associated with CD resolved spontaneously, but 3 were recurrent. Secondary causes contributed to a large proportion of IS in our study cohort (33%) as compared with 5% to 10% in the literature. Celiac disease is an underrecognized cause of IS among children. A child with IS and hypoalbuminemia, anemia, or chronic diarrhea needs to be investigated for CD to avoid unnecessary surgery.

Cardiac computed tomography angiography with and without bolus tracking methods in infants with congenital heart disease.

The study investigated radiation dose, vascular computed tomography (CT) enhancement and image quality of cardiac computed tomography angiography (CCTA) with and without bolus tracking (BT) methods in infants with congenital heart disease (CHD). The volume CT dose index (CTDIvol) and dose length product (DLP) were recorded for all CT scans, and the effective dose was obtained using a conversion factors. The CT number for the ascending aorta (AO) and pulmonary artery (PA), image noise of muscle tissue and contrast-to-noise ratio (CNR) were measured and calculated. The median values in the groups with and without BT were 2.20mGy versus 0.44mGy for CTDIvol, 8.10mGy·cm versus 6.20mGy·cm for DLP, and 0.66mSv versus 0.51mSv for effective dose (p<0.001). There were no statistical differences in vascular CT enhancement, image noise, and CNR. CCTA without BT methods can reduce the radiation dose while maintaining vascular CT enhancement and image quality compared to CCTA with BT methods.

Imaging Voids and Defects Inside Li-Ion Cathode LiNi0.6Mn0.2Co0.2O2 Single Crystals.

Li-ion battery cathode active materials obtained from different sources or preparation methods often exhibit broadly divergent performance and stability despite no obvious differences in morphology, purity, and crystallinity. We show how state-of-the-art, commercial, nominally single crystalline LiNi0.6Mn0.2Co0.2O2 (NMC-622) particles possess extensive internal nanostructure even in the pristine state. Scanning X-ray diffraction microscopy reveals the presence of interlayer strain gradients, and crystal bending is attributed to oxygen vacancies. Phase contrast X-ray nano-tomography reveals two different kinds of particles, welded/aggregated, and single crystal like, and emphasizes the intra- and interparticle heterogeneities from the nano- to the microscale. It also detects within the imaging resolution (100 nm) substantial quantities of nanovoids hidden inside the bulk of two-thirds of the overall studied particles (around 3000), with an average value of 12.5%v per particle and a mean size of 148 nm. The powerful combination of both techniques helps prescreening and quantifying the defective nature of cathode material and thus anticipating their performance in electrode assembly/battery testing.

Flow-based basophil activation test in immediate drug hypersensitivity. An EAACI task force position paper.

Diagnosing immediate drug hypersensitivity reactions (IDHRs) can pose a significant challenge and there is an urgent need for safe and reliable tests. Evidence has emerged that the basophil activation test (BAT), an invitro assay that mirrors the invivo response, can be a complementary test for many drugs. In this position paper, members of Task Force (TF) "Basophil activation test in the evaluation of Drug Hypersensitivity Reactions" from the European Academy of Allergy and Clinical Immunology (EAACI) present the data from a survey about the use and utility of BAT in IDHRs in Europe. The survey results indicate that there is a great interest for using BAT especially for diagnosing IDHRs. However, there are still main needs, mainly in the standardization of the protocols. Subsequently consensus-based recommendations were formulated for: (i) Technical aspects of BAT in IDHRs including type of sample, management of drugs, flow cytometry protocols, interpretation of the results; and (ii) Drug-specific aspects that should be taken into account when performing BAT in relation to betalactams, neuromuscular blocking agents, fluoroquinolones, chlorhexidine, opioids, radio contrast media, chemotherapeutics, biological agents, nonsteroidal anti-inflammatory drugs, COVID vaccine, and excipients. Moreover, aspects in the evaluation of pediatric population have also been considered. All this indicates that BAT offers the clinician and laboratory a complementary tool for a safe diagnostic for IDHRs, although its place in the diagnostic algorithm depends on the drug class and patient population (phenotype, geography, and age). The standardization of BAT is important for generalizing this method beyond the individual laboratory.