Nonionic Contrast Research Articles

Complex congenital heart and lung defects as a cause of hydrops fetalis in French bulldogs –micro-CT with contrast study

Limited data are available on the causes of hydrops fetalis in dogs. Congenital heart defects may be an important contributing factor. Standard autopsy often fails to provide a comprehensive and accurate diagnosis on very small hearts. This study was carried out on five French bulldog puppies all presenting with advanced hydrops fetalis and four diagnosed with pulmonary hypoplasia at autopsy. The body weight of the dogs ranged from 142 to 687 g and the heart with lungs weighed from 4.5 to 23.6 g. The hearts and pulmonary vessels were filled with barium contrast, and micro-CT scans of the physiologically connected heart and lungs were performed. In all five puppies, we confirmed congenital heart defects including: Puppy #1. Perimembranous ventricular septal defect and aortic dextroposition; Puppy #2. Interrupted aortic arch with aortic valve dysplasia and aortic stenosis; Puppy #3. Tricuspid valve dysplasia and bicuspid pulmonary trunk valve; Puppy #4. Aortic stenosis and ventricular septal defect; Puppy #5. Tricuspid valve dysplasia. Additionally, four puppies had pulmonary vascular hypoplasia. Contrast-enhanced micro-CT can provide highly accurate diagnosis of complex congenital heart and lung defects. Examination of the heart in conjunction with the lungs appears to be a rational approach in animals with hydrops fetalis.

Radiopaque hydrogel-in-liposomes towards theranostic applications for malignant tumors.

A radiopaque hydrogel-in-liposome (RHL) system was developed for micro-computed tomography (μCT) imaging of tumor tissue and simultaneous delivery of a cytotoxic agent. Iopamidol (IPD) and doxorubicin (DOX) were incorporated as the CT contrast and anti-cancer agents, respectively. The presence of a polyethylene glycol hydrogel core in the liposomes was confirmed via attenuated total reflectance Fourier transform infrared, proton nuclear magnetic resonance, and selective solvent extraction. Nano-sized (∼160 nm) spherical DOX/IPD-loaded RHLs with a narrow size distribution and negative zeta potential were successfully fabricated. The RHLs demonstrated enhanced cellular uptake of DOX in SCCVII cells compared to conventional radiopaque liposomes, likely due to clathrin-mediated endocytosis. Additionally, pH-dependent DOX release and reduced IPD leakage were observed. In vivo studies using SCCVII tumor-xenografted mice showed that RHLs exhibited improved CT contrast efficiency and anti-tumor efficacy, along with systemic biocompatibility, attributed to enhanced tumor-targeting properties. These findings suggest that the RHL system could serve as a promising nano-platform for tumor theranostics.

Radiation dose proportions of localizer radiograph and bolus tracking in low-dose pediatric cardiothoracic computed tomography.

Optimization of localizer radiograph and bolus tracking doses is necessary, as their dose proportion may increase with a decreasing diagnostic scan dose in pediatric cardiothoracic computed tomography (CT). To evaluate the radiation dose proportions of the localizer radiograph and bolus tracking in low-dose pediatric cardiothoracic CT. For low-dose pediatric cardiothoracic CT, a posteroanterior localizer radiograph was acquired with 80 kV, and 35 mA or 20 mA in 852 infants (age<1 year). Propensity score matching was employed in comparing the 35 mA and 20 mA groups on dose proportion, over z-axis proportion, visibility of anatomic landmarks, and image noise. The over z-axis coverage proportion was correlated with the dose proportion of the localizer radiograph in both groups. Additionally, bolus tracking was performed in 1,015 children (≤2 years). The effects of the number of monitoring scan, dose-length product of the diagnostic scan, age, and water-equivalent area of the scanned patient body on the radiation dose proportion of bolus tracking were evaluated. The dose proportion of the localizer radiograph was significantly lower in the 20 mA group (2.5%, n= 94) than in the 35 mA group (6.5%, n= 94) (P< 0.001). While image noise was higher in the 20 mA group (2.1 Hounsfield units versus 1.0 Hounsfield units of the 35 mA-group, P< 0.001), all the anatomic landmarks remained visible in all cases. The over z-axis coverage proportion demonstrated high correlations with the dose proportion for both groups (R= 0.736, P< 0.001 for the 35 mA group and R= 0.660, P< 0.001 for the 20 mA group). The bolus tracking dose-length product proportion demonstrated the strongest positive correlation with the number of monitoring scans (R= 0.93, P< 0.001), while age, diagnostic scan dose-length product, and water-equivalent area showed weak negative correlations (R-values = -0.46~-0.50, P-values < 0.001). In low-dose pediatric cardiothoracic CT, the dose proportion of the localizer radiograph can be substantially reduced with a low tube current setting while maintaining image quality. Additionally, minimization of the over z-axis coverage proportion merits attention. The number of monitoring scans is the most significant factor for increasing the radiation dose proportion of bolus tracking, especially in young ages.

Artificial intelligence-assisted platform performs high detection ability of hepatocellular carcinoma in CT images: an external clinical validation study

BackgroundAccurate detection of hepatocellular carcinoma (HCC) in multiphasic contrast CT is essential for effective treatment and surgical planning. However, the variety of CT images, the misdiagnosis and missed diagnosis, and the inconsistent diagnosis among different radiologists pose challenges to accurate detection which demands sufficient clinical experience and can be time-consuming and labor-intensive.PurposeTo evaluate the detection performance of an artificial intelligence (AI)-assisted platform for HCC by the external validation dataset.MethodsCT images pathologically diagnosed with HCC from December 2021 to June 2023 were retrospectively analyzed to evaluate the detection ability of the AI-assisted platform. The AI-assisted platform is designed based on a two-phase segmentation approach, integrating coarse and fine segmentation techniques to accurately identify and delineate hepatic lesions. The CT images were annotated and confirmed by the experienced radiologists using InferScholar software as the “gold standard”. The automatic HCC segmentation performed by the AI-assisted platform was used to compare with the annotation of radiologists. Furthermore, we also did subgroup analysis depending on the size and location of HCC to explore the impact factors of HCC detectability. The segmentation accuracies were evaluated by Dice coefficient (Dice), accuracy, recall, precision, and F1-score. Our study focused on evaluating the efficacy of the AI-assisted platform in clinical settings.ResultsOne Hundred Forty HCC patients were finally included in this study. The artificial intelligence (AI)-assisted platform’s performance was rigorously assessed by comparing the segmentation outcomes with standard diagnostic criteria. The average dice score of the AI-assisted platform is 0.8819, which showed a high detection performance for HCC. Besides, for the subgroup analysis, the model also demonstrated high performance in diameter greater than 20 mm with all results exceeding 0.9, and all final evaluation index values for the location analysis were consistently exceeding 0.97. All the results showed comparable performance with radiologists. Our results demonstrate that the product not only accurately segments HCC lesions but also provides valuable insights into lesion characteristics that are essential for effective treatment planning.ConclusionThis study validates the effectiveness of the artificial intelligence-assisted platform in detecting HCC lesions and analyzing lesion size and location. It can serve as an auxiliary tool to help radiologists identify, locate, and assess lesions.

Quantifying structural changes in organised biomineralized surfaces using synchrotron Polarisation-Induced Contrast X-ray Fluorescence.

The quantitative characterization of the structure of biomineral surfaces is needed for guiding regenerative strategies. Current techniques are compromised by a requirement for extensive sample preparation, limited length-scales, or the inability to repeatedly measure the same surface over time and monitor structural changes. We aim to address these deficiencies by developing Calcium (Ca) K-edge Polarisation Induced Contrast X-ray Fluorescence (PIC-XRF) to quantify hydroxyapatite (HAp) crystallite structural arrangements in high and low textured surfaces. Minimally prepared human dental enamel was used as an exemplar to quantify initial surface structures, and the disruption caused by short dietary acid exposures. By measuring surfaces at different rotational angles relative to a polarised focused (2×2 µm) monochromatic X-ray source (at either 4049.2 and 4051.1 eV) it was possible to discriminate the principal and secondary orientations of surface crystallites, along with their texture. It was also possible to quantify the organisation of crystallites in both low (enamel cross-sections) and highly textured (facial enamel) surfaces including the identification of crystallites aligned perpendicular to the surface-a challenge for other synchrotron techniques. Surface modifications following short term acid erosion (affecting <20 µm of the enamel surface depth) were detected as significant shifts in principal crystallite orientation (p < 0.001) and as a marked reduction in surface texture (p < 0.001). Findings suggest preferential dissolution of HAp based on crystallite angular orientation. We demonstrate that PIC-XRF is a powerful tool to quantify biomineral surfaces, with minimal sample preparation that enables monitoring of surface structural changes through repeated measurements. STATEMENT OF SIGNIFICANCE: This study introduces Calcium (Ca) K-edge Polarisation Induced Contrast X-ray Fluorescence (PIC-XRF) as a method for quantifying the structure of biomineral surfaces, addressing limitations in existing techniques that require extensive sample preparation and cannot repeatedly measure the same surface. By using minimally prepared dental enamel, PIC-XRF successfully discriminated between principal and secondary orientations of hydroxyapatite crystallites, including end-on crystallites-a challenge for other synchrotron methods. Additionally, PIC-XRF detected significant structural changes due to short-term acid erosion. This technique's potential to repeatedly and non-invasively analyze biomineral surfaces offers new opportunities for understanding surface dynamics and guiding regenerative treatments.

External negative pressure improves lung aeration in near-term rabbit kittens at risk of developing respiratory distress.

As airway liquid is cleared into lung interstitial tissue after birth, the chest wall must expand to accommodate this liquid and the incoming air. We examined the effect of applying external positive and negative pressures to the chest wall on lung aeration in near-term rabbit kittens at risk of developing respiratory distress. Rabbit kittens (30 days; term ∼31 days) were randomised into Control and Elevated Liquid (EL) groups. Lung liquid was drained in Control kittens to simulate expected volumes following vaginal delivery. EL kittens had lung liquid drained before 30 ml/kg was returned to simulate expected volumes after caesarean section. Kittens were delivered, placed in a water-filled plethysmograph and the external pressure was adjusted to -6 (negative), 0 (atmospheric), or +6 (positive) cmH2O. Kittens were ventilated with an 8 ml/kg tidal volume and PEEP of 0 cmH2O and lungs imaged using phase contrast x-ray imaging. Compared to external atmospheric pressures, external negative pressures expanded the chest (by 2100 ± 43 vs. 1805 ± 59 mm2; Control kittens; P = 0.028), directed tidal ventilation into lower, larger lung regions and increased functional residual capacity (FRC) levels in both Control (26.7 ± 2.0 vs. 12.6 ± 2.2 ml/kg; P < 0.001) and EL (19.6 ± 1.6 vs. 10.0 ± 2.9 ml/kg; P < 0.01) kittens. External positive pressures reduced FRC levels in Control (6.3 ± 0.8 vs. 12.6 ± 2.2 ml/kg; P < 0.05), but not in EL kittens, and directed tidal ventilation into upper lung regions. External negative pressures increased lung aeration and resulted in a more evenly distributed tidal ventilation immediately after birth in near-term rabbit kittens, whereas external positive pressures reduced lung aeration and compliance.

Are we systematically overdosing women? Revisiting standardized contrast protocols for thoracoabdominal CT scans.

The purpose of this study was to evaluate whether the iodine contrast in blood and solid organs differs between men and women and to evaluate the effect of BMI, height, weight, and blood volume (BV) on sex-specific contrast in staging CT. Patients receiving a venous-phase thoracoabdominal Photon-Counting Detector CT (PCD-CT) scan with 100- or 120-mL CM between 08/2021 and 01/2022 were retrospectively included in this single-center study. Image analysis was performed by measuring iodine contrast in the liver, portal vein, spleen, left atrium, left ventricle, pulmonary trunk, ascending and descending aorta on spectral PCD-CT datasets. Univariable and multivariable analyses were performed to assess the impact of sex, age, BMI, height, weight, and BV on the iodine contrast. A total of 274 patients were included (mean age 68 years ± 12 SD, 168 men). Iodine contrast in organs and blood attenuation was significantly higher in women when using the same volume of CM. Sex, age, BMI, height, weight, and BV significantly influenced iodine contrast. After adjusting for confounding variables, sex remained a significant factor, with women having higher parenchymal and vascular iodine contrast. Standardized or weight-adapted use of CM in venous-phase thoracoabdominal CT scans results in significantly higher contrast in women compared to men. Customizing the CM dose to the patient's BV could result in a similar contrast between sexes. This approach has the potential to reduce the amount of CM, resulting in cost savings, and to decrease the risks associated with CM, particularly for the female sex. Question This study addresses whether current standardized iodinated contrast media protocols lead to systematically higher iodine enhancement in women than in men during thoracoabdominal CT. Findings Women consistently show greater iodine enhancement in blood and abdominal organs compared to BMI-matched men when receiving identical volumes of contrast media. Clinical relevance Adjusting contrast media dosage based on blood volume in venous-phase CT scans could equalize parenchymal and intravascular iodine enhancement across sexes. This approach may reduce unnecessary contrast exposure in women, lower associated risks, and optimize healthcare resource allocation.

Induction of macrophage efferocytosis in pancreatic cancer via PI3Kγ inhibition and radiotherapy promotes tumour control

BackgroundThe immune suppression mechanisms in pancreatic ductal adenocarcinoma (PDAC) remain unknown, but preclinical studies have implicated macrophage-mediated immune tolerance. Hence, pathways that regulate macrophage phenotype are of strategic interest, with...

The Effect of the Size of Gold Nanoparticle Contrast Agents on CT Imaging of the Gastrointestinal Tract and Inflammatory Bowel Disease.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD). CT imaging with contrast agents is commonly used for visualizing the gastrointestinal (GI) tract in UC patients. Contrast agents that provide enhanced imaging performance are highly valuable in this field. Recent studies have made significant progress in developing better contrast agents for imaging the gastrointestinal tract using nanoparticles. However, the impact of nanoparticle size on this application remains unexplored. Gold nanoparticles (AuNPs) serve as an ideal model to investigate the effect of nanoparticle size on imaging of the gastrointestinal tract due to their controllable synthesis across a broad size range. In this study, we synthesized AuNPs with core sizes ranging from 5 to 75 nm to examine the effect of the size in this setting. AuNPs were coated with poly(ethylene glycol) (PEG) to enhance stability and biocompatibility. In vitro tests show that gold nanoparticles are cytocompatible with macrophage cells (∼100% cell viability) and remain stable under acidic conditions, with no significant size changes over time. Phantom imaging studies using a clinical CT scanner indicated that there was no effect of nanoparticle size on CT contrast production, as previously demonstrated. In vivo imaging using a mouse model of acute colitis revealed a strong contrast generation throughout the GI tract for all agents tested. For the most part, in vivo contrast was independent of AuNP size, although AuNP outperformed iopamidol (a clinically approved control agent). In addition, differences in attenuation trends were observed between healthy and colitis mice. We also observed almost complete clearance at 24 h of all formulations tested (less than 0.7% ID/g was retained), supporting their value as a model platform for studying nanoparticle behavior in imaging. In conclusion, this study highlights the potential of nanoparticles as effective contrast agents for CT imaging of the gastrointestinal tract (GIT) in the UC. Further systemic research is needed to explore contrast agents that can specifically image disease processes in this disease setting.

Strategic Management of Anterior Skull Base Schwannomas and Their Outcomes

Abstract Objective Endoscopic endonasal approach has revolutionized the surgery of benign nose and paranasal sinus tumors. In this study we describe our experience with this approach for schwannomas of anterior skull base which are extremely rare, vascular tumors of this region. We also discuss the strategic management and their outcomes to enlighten the existing literature. Design Ambispective study. Setting and Participants A total of eight cases of anterior skull base schwannoma were included. These cases were operated between 2018 and 2023 at a tertiary institute. Institutional ethical committee approval was obtained. Main Outcomes Measured Medical records were obtained, and perioperative details (intraoperative findings, imaging findings, complications) were noted. Postoperative follow-up was done to note the outcomes of the patient. Results There were five male and three female patients. All patients were between 20 and 40 years of age. All patients underwent contrast CT as well as MRI preoperatively. Most common symptoms in our series were nasal obstruction and intermittent epistaxis. The various sites involved were ethmoid labyrinth, maxillary sinus, septum, and olfactory fossa. All the cases were operated endoscopically. Conclusion Endoscopic approach can be utilized in almost all cases of benign anterior skull base tumors with superior postoperative outcomes. Although there is a steep learning curve, use of subtle modifications of this technique help achieve better results. At the same time, it is imperative to understand that the surgeon should also be well versed with open approaches to help navigate difficult cases.

Biodistribution of gold nanoparticles in vivo

Gold nanoparticles have unique physical, chemical and optical properties, due to which they are used to develop promising drugs: radiosensitisers, X-ray contrast media, agents for photothermal therapy, drugs for targeted delivery. In each case, the choice of nanoparticle parameters is determined not only by the field of application, but also by the biodistribution in the living organism: blood circulation time and accumulation in target organs and tissues, including the tumor. For long blood circulation, nanoparticles should avoid phagocytosis by liver macrophages. The aim of this review was to systematise information on the influence of gold nanoparticle parameters on their pharmacokinetic properties and biodistribution in intact and tumor-bearing small laboratory animals. Size, shape and stabilising coating were considered. Smaller nanoparticles tend to circulate longer in the bloodstream and accumulate more slowly in the liver. Various coatings such as citrate, bovine serum albumin or polyethylene glycol are used to protect nanoparticles against aggregation, opsonisation and phagocytosis. The influence of nanoparticle shape on biodistribution is not completely understood; presumably, it is less important than size and coating. In general, the available data indicate that gold nanoparticles with a diameter of up to 50 nm with a polymer coating have optimal pharmacokinetic properties for biomedical application.

Optimized contrast enhancement and homogeneity in aortic CT angiography: bolus tracking with personalized post-trigger delay.

The bolus tracking technique has been used for decades, yet still faces the challenging task of determining the optimal scanning time for individuals. Our study aimed to assess the feasibility of a novel bolus tracking method with a personalized post-trigger delay (PTD) to optimize scanning time and achieve optimized enhancement and contrast homogeneity in aortic computed tomography angiography (CTA). Participants undergoing aortic CTA with bolus tracking were prospectively assigned to two different groups: Group A with a fixed 6-second PTD and Group B with a personalized PTD. A reader assessed objective image quality and evaluated enhancement level and contrast homogeneity; two readers rated subjective image quality. Student's t-test or Mann-Whitney U test was used to determine quantitative data, whereas the Chi-square test compared categorical variables between the two groups. Group A comprised 70 participants [13 female; mean ± standard deviation (SD) age 58±11 years], whereas Group B included 70 participants (18 female, mean ± SD age 59±12 years) with the personalized PTD ranging from 7.8 to 14.1 seconds (mean ± SD, 11.2±1.5 seconds). Group B demonstrated improved mean attenuation and contrast-to-noise ratio (CNR) of aortoiliac artery [417.55±71.55 vs. 345.71±60.41 Hounsfield units (HU), 16 vs. 13, both P<0.001, respectively]. Enhancement level (78.6% vs. 37.1%, P<0.001), contrast homogeneity (94.3% vs. 64.3%, P<0.001), and subjective ratings (scores greater than or equal to 4, 91.4% vs. 68.6%, P<0.001) were superior in Group B compared to Group A. Enhancement level of abdominal aortic branches in aortic dissection or aortic aneurysm patients was optimized in Group B (74.5% vs. 23.3%, P<0.001). Bolus tracking with a personalized PTD can improve enhancement level and contrast homogeneity in aortic CTA due to reliable scan timing.

The greater palatine nerve and artery both supply the maxillary teeth: An anatomic and radiologic study.

It is generally accepted that the greater palatine nerve and artery supply the palatal mucosa, gingiva, and glands, but not the bone or tooth adjacent to those tissues. When the bony palate is observed closely, multiple small foramina are seen on the palatal surface of the alveolar process. The authors hypothesized that the greater palatine nerve and artery might supply the maxillary teeth via the foramina on the palatal surface of the alveolar process and the superior alveolar nerve and artery. The authors aimed to investigate the palatal innervation and blood supply of the maxillary teeth. Eight cadaveric maxillae containing most teeth or alveolar sockets were selected. The mean age at the time of death was 82.4 years. The samples were examined with colored water injection, latex injection, microcomputed tomography with contrast dye, gross anatomic dissection, and histologic observation. Through both injection studies and microcomputed tomographic analysis, the authors found that the small foramina on and around the greater palatine groove connected to the alveolar process and tooth sockets. The small foramina in the greater palatine and incisive canal also continued inside the alveolar process and the tooth sockets. The alveolar branches of the greater palatine nerve and artery as well as the nasopalatine nerve and sphenopalatine artery supply maxillary teeth, alveolar bone, and periodontal tissue via the palatal alveolar foramina with superior alveolar nerves and arteries. This knowledge is essential for dentists when administering local anesthetic to the maxillary teeth and performing an osteotomy. Anatomic and dental textbooks should be updated with this new knowledge for better patient care.

Adult Wilms Tumor With Inferior Vena Cava Thrombus on an Incomplete Duplex Collecting System Ureter Fissus Proximalis Managed at a Tertiary Hospital in Tanzania: A Case Report and Literature Review.

Wilms' tumor (WT), also known as nephroblastoma, is a malignant embryonal kidney tumor composed of embryonic cells and is the most prevalent tumor among children, but isolated cases occur infrequently in the adult population. Adult WT is defined according to the criteria of Kilton, Matthews, and Cohen, which comprise age above 15 years and histological patterns characteristic of WT. We report a case of an adult WT with venous thrombus on an incomplete duplex collecting system. To the best of our knowledge, this is the first case of adult WT with such a presentation. A 28-year-old female patient presented to our department with a 4-month history of right flank pain and flank mass and was diagnosed by abdominal contrasted CT to have a right renal tumor with tumor thrombi in the renal vein and the inferior vena cava. The CT scan also revealed a bilateral duplex collecting system with a partial (ureter fissus proximalis) on the tumor side and a complete duplex system on the contralateral side. Right radical nephrectomy with complete tumor thrombectomy via venacavotomy was performed successfully. Histopathological examination of the specimen revealed a triphasic nephroblastoma with immunohistochemistry confirmation. Postoperatively, adjuvant chemotherapy was initiated. The increasing incidence of non-syndromic WT cases associated with duplex collecting systems suggests a potential shared pathogenesis, necessitating further research.

Sustainable approach for the degradation of Contrast dye Evans blue by Enterobacter cloacae strain SD4-1

BackgroundDischarge of dye complexes through industrial effluents continues to be a never-ending problem for the environment. Several degradation techniques have been experimented with, of which utilizing biological entities for the effective degradation of these dye molecules is extensively studied and still being explored. The present study focuses on (i) isolation of bacterial strains from the contaminated agricultural lands (ii) screening the isolates for their decolourization efficiency of Evans blue dye (iii) optimization of culture parameters such as temperature, pH, concentration of dye and nitrogen source for effective decolourization (iv) analysing the effect of degradation of diazo dye Evan's blue by the selected strain using GCMS analysis. MethodsThe bacterial strains were isolated from contaminated agricultural lands in Chennai, Tamil Nadu, India. The collected samples were aseptically transferred to the laboratory and stored for further studies. The collected samples were serially diluted, and the colonies with distinct morphology were pure-cultured. The isolated strains were studied for their efficiency to decolourize the dye Evans blue dye. The strain with higher decolourization efficiency was selected and optimized for parameters such as temperature, pH, nitrogen source and concentration of dye. The degradation of dye by the isolate was analysed by GCMS. Significant FindingsThe investigation unveiled that the strain SD4-1 of Enterobacter cloacae effectively decolorizes Evans blue dye at 37°C and pH 6.0, utilizing Sodium nitrate as the nitrogen source. SD4-1 exhibited an impressive dye decolourization efficiency of approximately 75%. The comprehensive GCMS analysis verified the bacterium's capability to fully degrade the azo dye Evans blue. Consequently, this study concludes that the SD4-1 Enterobacter cloacae strain holds promising potential for the efficient biodegradation of Evan's blue dye. Its application as a highly effective biological agent in the practical removal of dyes from textile industries is envisaged. Notably, this organism demonstrates superior performance in comparison to other studies where a mixture of dyes or consortia of microorganisms were employed for dye decolourization.

Geant4 simulation and XCOM theory in CT contrast agents mass attenuation coefficient research

Geant4 simulation and XCOM theory in CT contrast agents mass attenuation coefficient research

Controllable synthesis and biomedical applications of bismuth-based nanospheres: enhanced photothermal therapy and CT imaging efficiency.

The advancement and utilization of nano-scale biomaterials in the diagnosis and treatment of tumors have been notable over the last few decades, primarily owing to their appealing characteristics such as small particle size, adjustable properties, and remarkable biocompatibility. The creation of nanomaterials possessing versatility and a customizable nature, consequently, holds great promise for advancing healthcare and improving patient outcomes. Here, we report the controllable synthesis of monodisperse bismuth-based (Bi2S3, Bi, and Bi2O3) nanoparticles with uniform spherical morphology and size distribution, and evaluate their potential for CT imaging and photothermal therapy applications. Monodisperse Bi2S3 nanospheres were initially synthesized in aqueous solution using a low-temperature precipitation method. Subsequently, Bi and Bi2O3 nanospheres were prepared through the NaBH4 reduction and the H2O2 oxidation of the as-synthesized Bi2S3 templates, respectively. Photothermal conversion and CT imaging characterizations confirm the superiority of Bi nanospheres over Bi2S3 and Bi2O3 nanospheres in terms of their excellent photothermal conversion efficiency (∼40.10%) and CT contrast efficiency (∼34.32 HU mL mg-1). Furthermore, it is demonstrated that Bi nanospheres exhibit significant advantages in CT imaging and photothermal effects by using the glioma mouse model, notably achieving a tumor area temperature increase to 53.6 °C after near-infrared laser irradiation. This work furnishes theoretical and experimental evidence for bismuth-based nanomaterials as valuable tools in various biomedical applications.

The use of ethanol as contrast enhancer in synchrotron X-ray phase-contrast imaging leads to heterogeneous myocardial tissue shrinkage: a case report.

One of the main limitations of conventional absorption-based X-ray micro-computed tomography imaging of biological samples is the low inherent X-ray contrast of soft tissue. To overcome this limitation, the use of ethanol as contrast agent has been proposed to enhance image contrast of soft tissues through dehydration. Some authors have shown that ethanol shrinks and hardens the tissue too much, also causing small tissue ruptures due to fast dehydration. However, the local tissue deformation occurring as a consequence of tissue dehydration and whether tissue shrinkage can modify myocardial architecture has not been quantified yet. The aim of this paper is to quantify the local myocardial tissue deformation due to ethanol dehydration based on 3D non-rigid registration and perform a detailed characterization of its myocardial tissue organization, before and after ethanol dehydration. A rat adult heart was imaged with synchrotron-radiation-based X-ray phase contrast imaging (X-PCI) three times: before, 9 h after and 342 h after ethanol immersion. The total volume shrinkage as well as changes in the left ventricular myocardial thickness were computed. Then, to determine local deformation of the heart caused by ethanol dehydration, the related 3D tomographic datasets were registered by means of a non-rigid registration algorithm. Finally, changes on the orientation and organization of myocytes were assessed. Our results show that the use of ethanol in synchrotron X-PCI can improve image contrast, but the tissue shrinkage is not homogeneous thus changing the local myocardial organization.

Pediatric Echinococcosis: diagnosis, urgent surgical intervention, and treatment – case report

Echinococcus tapeworms cause human echinococcosis, which causes hydatid cysts, most commonly in the liver and lungs but also in other organs. Delays in symptom onset can lead to diagnostic issues, especially in children. Pediatric cases are rare and often lead to unintentional diagnoses. Living in a rural area increases risk. Imaging and serological testing are essential for diagnosis. This case is rare since it involves pediatric echinococcosis. Children rarely get echinococcosis, and symptoms are often vague; thus, diagnosis is mainly by accident. Case report: A 10-year-old female child developed symptoms and signs such as tachycardia, fever, and facial urticaria. On the first clinical examination, classic signs of an acute abdomen were present, indicating a possible abdominal emergency. Laboratory results showed significantly high levels of inflammatory markers, including CRP and WBC, indicating an active inflammatory process, most likely caused by infection or tissue injury. Imaging examinations, particularly a contrast CT scan of the abdomen, revealed two burst liver cysts in the peritoneal cavity, confirming the diagnosis of echinococcal cysts in the liver. We undertook an urgent surgical intervention to address the burst cysts and avert potential complications like peritonitis or sepsis. Post-operative treatment included constant monitoring of the patient's condition, antibiotic and antihelminthic medication to control infection, pain management, and supportive measures to help with recovery. Echinococcosis in children manifests as nonspecific symptoms, which often leads to a rare suspicion and coincidental diagnosis. Echinococcosis is often considered a possible cause of stomach discomfort. The standard treatment for echinococcosis usually involves a combination of antiparasitic medication and surgical removal of the cyst.

Real-world evaluation of intracardiac echocardiography guided radio-frequency catheter ablation for atrial fibrillation: a retrospective cohort study

Intracardiac echocardiography (ICE) has been used to guide radio-frequency catheter ablation (RFCA) for better catheter navigation and less radiation exposure in treating atrial fibrillation (AF). This retrospective cohort study enrolled 227 AF patients undergoing ICE- or traditional fluoroscopy (TF)-guided RFCA for AF in a tertiary hospital. ICE was used more often in patients with atrial tachycardia [odds ratio (OR) 3.692, p = 0.062], a higher score of Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile INR, Elderly, Drugs/alcohol concomitantly (OR 1.541, p = 0.050), or heart failure (OR 2.098, p = 0.156). Based on the comparisons of 47 propensity score-matched pairs from 156 patients only undergoing pulmonary vein isolation (PVI), patients using ICE exhibited a significantly higher success rate in the first transseptal puncture (100% vs. 87.2%, p = 0.041) and less radiation exposure [utilization of radiographic contrast agent (2.7 ml vs. 6.0 ml, p < 0.001), fluoroscopy time (5.7 min vs. 7.6 min, p = 0.026), and fluoroscopy dose (208.4 mGy vs. 332.3 mGy, p = 0.024)] than patients using TF. Other perioperative efficacy outcomes (PVI success, free from AF after RFCA and complications) showed no difference between the matched pairs. ICE can enhance procedural safety and efficiency of RFCA, particularly for more complex patient profiles, in real-world setting.