CT and X-ray contrast agents: Current clinical challenges and the future of contrast

Simultaneous determination of three iodinated contrast media in human plasma by LC/MS-MS and its clinical application

Iodinated contrast media (ICM), including iohexol, iopromide and iodixanol, have significantly enhanced diagnostic accuracy, particularly in cardiovascular and cerebrovascular diseases. The three ICM is tailored to specific patient needs and diagnostic contexts. However, excessive doses of ICM may induce adverse reactions, including nephrotoxicity. Accurate measurement of ICM concentration is essential for reducing renal burden and ensuring patient safety. Current methods for quantifying ICM are often limited to single-analyte detection (especially iohexol), which is inefficient for clinical practice. Therefore, this method aims to develop and validate a rapid, generic LC-MS/MS method for simultaneously quantifying iohexol, iopromide, and iodixanol in human plasma to improve patient management and prognosis. An LC-MS/MS-based approach was established utilizing an C18 column coupled with a Xevo TQ-S triple quadrupole mass spectrometer. Sample preparation involved protein precipitation, while chromatographic separation was achieved using acetonitrile and 0.1 % formic acid in water. The developed LC-MS/MS method achieved satisfactory separation of the three ICM within 1.5 min. Calibration curves for iohexol, iopromide, and iodixanol showed good linearity in 5.00-5000, 5.00-5000 and 10.0 ∼ 10000 µg/mL, respectively. The method was effectively applied to analyze 71 plasma samples from 9 patients, highlighting its clinical utility. A rapid and generic LC-MS/MS method streamlines sample preparation and standardizes laboratory workflows, making it suitable for clinical bio-samples.

Large-scale synthesis of non-ionic bismuth chelate for computed tomography imaging in vivo

High atomic number elements-based X-ray computed tomography (CT) contrast agents offer a promising solution to address the inherent deficiencies of FDA-approved iodine contrast agents. However, they face substantial challenges in balancing imaging performance, safety, and large-scale production for clinical translation. Herein, inspired by the history of clinical gadolinium- and iodine-based contrast agents, we report a large-scale approach for synthesizing non-ionic bismuth (Bi) chelate for high-performance CT imaging in vivo. Bi-HPDO3A can be easily obtained from low-cost precursor within 4 steps at 6 g-scale. The non-ionic macrocyclic structure endows it with low osmolality, low viscosity, high stability, good renal clearable capability and biocompatibility. Additionally, Bi-HPDO3A realizes superior imaging performance across various in vivo applications, including gastrointestinal imaging, renal imaging, and computed tomography angiography (CTA). Especially, Bi-HPDO3A exhibits superior spectral imaging capability owing to the high K-edge of element Bi, achieving metal artifact-free CTA in vivo. The proposed Bi-HPDO3A that balances overall performance can serve as a high-performance CT contrast agent with potential for clinical translation.

Advances in Ultrasmall Inorganic Nanoparticles for Nanomedicine: From Diagnosis to Therapeutics

Inorganic nanoparticles possess unique physicochemical properties that make them attractive candidates for diverse applications in nanomedicine, including as contrast agents and as therapeutics. However, many inorganic nanoparticles are composed of high-atomic-number elements, raising safety concerns due to potential long-term retention in the body. However, ultrasmall inorganic nanoparticles (UINPs), i.e., those that are less than ∼5 nm in diameter, can offer the advantage of rapid renal clearance from the body, reducing toxicity risks associated with prolonged exposure and thereby creating a path toward clinical translation. In this review, we discuss current knowledge on the design and functionalization of UINPs, exploring their capabilities from diagnosis to therapeutics, with examples including radiosensitization, photothermal, and anti-inflammatory catalytic therapies. In addition, we discuss their limitations, the approaches taken to solve their limitations, and progress of UINPs toward clinical translation. Through this discussion, we aim to provide a comprehensive perspective on how UINPs are advancing the field of nanomedicine, underscoring their potential to significantly improve bioimaging and therapeutic outcomes.

Real-Time in Vivo Bacterial Imaging by Computed Tomography and Fluorescence Using Phage-Gold Nanorod Bioconjugates as Contrast Agents

Real-time in vivo imaging of bacterial infections is an important goal to aid the study and treatment of bacterial infections. Phages can be genetically engineered to ensure a particular biomolecular target specificity, and gold nanomaterials can be conjugated to phages for a variety of applications including biosensing. In this paper, we describe methods to use phage-gold nanorod conjugates for in vivo detection and imaging of the bacterial species Pseudomonas aeruginosa in mice. The imaging modalities are computed tomography (CT), using gold as a contrast agent, and fluorescence, which can be applied when the FDA-approved near-infrared (NIR) dye indocyanine green (ICG) is also chemically cross-linked to the bioconjugates. In addition, rapid protocols for validating bioconjugate synthesis and the initial assessment of toxicity are given. In this example, the phage-gold nanorod probe is shown to specifically highlight P. aeruginosa without cross-reactivity to another Gram-negative organism (V. cholerae) in vivo and appears to be biocompatible. Phage-directed imaging probes may thus be useful for the characterization and diagnosis of bacterial infections.

Iodinated contrast media (ICM)-induced thyroid dysfunction: a review of potential mechanisms and clinical management

Iodinated contrast media (ICM) are extensively utilized in medical imaging to enhance tissue contrast, yet their impact on thyroid function has attracted increasing attention in recent years. ICM can induce thyroid dysfunction, with reported prevalence ranging from 1 to 15% and a higher incidence observed in individuals with pre-existing thyroid conditions or other risk factors like age, gender, underlying health issues, and repeated ICM exposure. This review summarized the classification of ICM and the potential mechanisms, risk assessment, and clinical management of ICM-induced thyroid dysfunction, especially in vulnerable populations such as pregnant women and elderly patients. Despite advancements that have enriched our understanding of the pathophysiology and treatment of ICM-induced thyroid dysfunction, critical knowledge gaps remain, such as the long-term effects of ICM on thyroid function, the dose-response relationship between ICM volume and thyroid dysfunction risk, and the ecological impacts of ICM. Therefore, further exploration of the underlying mechanisms of ICM-induced thyroid dysfunction and optimization of the management strategies will be crucial for the safe and effective use of ICM in clinical practice, and collaborative efforts between clinicians and researchers are essential to ensure that the risks of thyroid dysfunction do not outweigh the benefits of imaging.

Image quality evaluation of imaging skins, a novel stretchable X-ray detector for intraoperative tumour imaging

This paper presents the development of a novel X-ray detector composed of silicone elastomer and GOS:Tb, which we refer to as imaging skins. These detectors were integrated into a custom X-ray system to convert radiation into visible light. Our study focused on how fabrication parameters such as thickness and concentration impact sensor linearity, considering their potential application directly on the skin or organs to identify tumour margins during surgery. In addition, we examined how the stretching capabilities of these detectors influenced the image quality. Our imaging detection stack demonstrated consistent linearity across various fabrication parameters with the coefficient of determination ([Formula: see text]) more than 0.99998, showing that the silicone elastomer does not affect the conversion of the X-ray into light. We achieved a spatial resolution of 1.16-1.42 lp/mm at 10% of the Spatial Frequency Response using a 0.5-mm thick sensor. This study represents a first step towards integrating stretchable X-ray detectors into clinical settings, particularly on curved surfaces, to unlock their full potential in complex surgical configurations. It also highlights the need for a deeper understanding of the interactions between X-rays and detector materials to fully interpret the observed effects.

Recent Developments and Future Perspectives in Magnetic Resonance Imaging and Computed Tomography Contrast Media

ABSTRACT

This review provides a comprehensive analysis of recent advancements in computed tomography (CT) and magnetic resonance imaging (MRI) contrast media, offering a critical evaluation of current trends and exploring future directions in the field. New clinical developments within the last 5-8 years are considered as well as clinical efficacy and safety aspects.For CT, the general safety of low- and iso-osmolar iodinated contrast agents and their effect on renal and thyroid function are reviewed. Special attention is given to contrast-enhanced mammography and a short outlook to photon-counting CT is provided.For MRI, a brief update on general safety, nephrogenic systemic fibrosis and the presence of gadolinium in the brain is given. The 2 new high-relaxivity gadolinium-based contrast agents, gadopiclenol and gadoquatrane (in late-stage clinical development), are highlighted.The review also describes targeted gadolinium-based contrast agents, superparamagnetic iron oxide particles, and developments of manganese-based contrast agents. It also introduces the emerging field of glymphatic imaging.

Feasibility of Ultra-low Radiation and Contrast Medium Dosage in Aortic CTA Using Deep Learning Reconstruction at 60 kVp: An Image Quality Assessment

OBJECTIVE

To assess the viability of using ultra-low radiation and contrast medium (CM) dosage in aortic computed tomography angiography (CTA) through the application of low tube voltage (60kVp) and a novel deep learning image reconstruction algorithm (ClearInfinity, DLIR-CI).

METHODS

Iodine attenuation curves obtained from a phantom study informed the administration of CM protocols. Non-obese participants undergoing aortic CTA were prospectively allocated into two groups and then obtained three reconstruction groups. The conventional group (100kVp-CV group) underwent imaging at 100kVp and received 210 mg iodine/kg in combination with a hybrid iterative reconstruction algorithm (ClearView, HIR-CV). The experimental group was imaged at 60kVp with 105 mg iodine/kg, while images were reconstructed with HIR-CV (60kVp-CV group) and with DLIR-CI (60kVp-CI group). Student's t-test was used to compare differences in CM protocol and radiation dose. One-way ANOVA compared CT attenuation, image noise, SNR, and CNR among the three reconstruction groups, while the Kruskal-Wallis H test assessed subjective image quality scores. Post hoc analysis was performed with Bonferroni correction for multiple comparisons, and consistency analysis conducted in subjective image quality assessment was measured using Cohen's kappa.

RESULTS

The radiation dose (1.12 ± 0.23mSv vs. 2.03 ± 0.82mSv) and CM dosage (19.04 ± 3.03mL vs. 38.11 ± 6.47mL) provided the reduction of 45% and 50% in the experimental group compared to the conventional group. The CT attenuation, SNR, and CNR of 60kVp-CI were superior to or equal to those of 100kVp-CV. Compared to the 60kVp-CV group, images in 60kVp-CI showed higher SNR and CNR (all P < 0.001). There was no difference between the 60kVp-CI and 100kVp-CV group in terms of the subjective image quality of the aorta in various locations (all P > 0.05), with 60kVp-CI images were deemed diagnostically sufficient across all vascular segments.

CONCLUSION

For non-obese patients, the combined use of 60kVp and DLIR-CI algorithm can be preserving image quality while enabling radiation dose and contrast medium savings for aortic CTA compared to 100kVp using HIR-CV.

Exploring the role of graphene-metal hybrid nanomaterials as Raman signal enhancers in early stage cancer detection

Molecular diagnosis plays a significant role in detection of biomolecules linked to early stage cancer since it offers greater sensitivity and reliability for identification of biomarker level changes as the disease progresses. The application of vibrational spectroscopy in biomarker detection is defined by the fingerprint spectrum of a molecule originating from single-molecule vibrations. This characteristic makes surface enhanced Raman spectroscopy (SERS) a promising tool for identification of biomarkers. The performance of the SERS technique largely depends on the material being used as the SERS substrate. Graphene, with its large surface area and abundance of aromatic regions, is considered advantageous as SERS substrate. Combining graphene with metal nanomaterials considerably increases SERS signal intensity, thereby enhancing detection sensitivity. Therefore, this review emphasizes the significance of selecting graphene-metal nanohybrids as suitable SERS substrates for signal amplification. The detail understanding of the mechanism of graphene-metal hybrid in SERS based detection of early stage cancer is also presented. Furthermore, several examples demonstrated the application of graphene-metal hybrid nanomaterials in detecting biomarkers and cancer cell differentiation using SERS imaging.

Advanced Nanomaterials for Cancer Therapy: Gold, Silver, and Iron Oxide Nanoparticles in Oncological Applications

Cancer remains one of the most challenging health issues globally, demanding innovative therapeutic approaches for effective treatment. Nanoparticles, particularly those composed of gold, silver, and iron oxide, have emerged as promising candidates for changing cancer therapy. This comprehensive review demonstrates the landscape of nanoparticle-based oncological interventions, focusing on the remarkable advancements and therapeutic potentials of gold, silver, and iron oxide nanoparticles. Gold nanoparticles have garnered significant attention for their exceptional biocompatibility, tunable surface chemistry, and distinctive optical properties, rendering them ideal candidates for various cancer diagnostic and therapeutic strategies. Silver nanoparticles, renowned for their antimicrobial properties, exhibit remarkable potential in cancer therapy through multiple mechanisms, including apoptosis induction, angiogenesis inhibition, and drug delivery enhancement. With their magnetic properties and biocompatibility, iron oxide nanoparticles offer unique cancer diagnosis and targeted therapy opportunities. This review critically examines the recent advancements in the synthesis, functionalization, and biomedical applications of these nanoparticles in cancer therapy. Moreover, the challenges are discussed, including toxicity concerns, immunogenicity, and translational barriers, and ongoing efforts to overcome these hurdles are highlighted. Finally, insights into the future directions of nanoparticle-based cancer therapy and regulatory considerations, are provided aiming to accelerate the translation of these promising technologies from bench to bedside.

Innovative applications of advanced nanomaterials in cerebrovascular imaging

Cerebrovascular imaging is essential for the diagnosis, treatment, and prognosis of cerebrovascular disease, including stroke, aneurysms, and vascular malformations. Conventional imaging techniques such as MRI, CT, DSA and ultrasound have their own strengths and limitations, particularly in terms of resolution, contrast and safety. Recent advances in nanotechnology offer new opportunities for improved cerebrovascular imaging. Nanomaterials, including metallic nanoparticles, magnetic nanoparticles, quantum dots, carbon-based nanomaterials, and polymer nanoparticles, show great potential due to their unique physical, chemical, and biological properties. This review summarizes recent advances in advanced nanomaterials for cerebrovascular imaging and their applications in various imaging techniques, and discusses challenges and future research directions. The aim is to provide valuable insights for researchers to facilitate the development and clinical application of these innovative nanomaterials in cerebrovascular imaging.

Nanomedicine and clinical diagnostics part I: applications in conventional imaging (MRI, X-ray/CT, and ultrasound)

Integrating nanotechnologies in diagnostic imaging presents a promising step forward compared to traditional methods, which carry certain limitations. Conventional imaging routes, such as X-ray/computed tomography and magnetic resonance imaging, derive significant advantages from nanoparticles (NPs), which allow researchers and clinicians to overcome some of the limitations of traditional imaging agents. In this literature review, we explore recent advancements in nanomaterials being applied in conventional diagnostic imaging techniques by exploring relevant reviews and original research papers (e.g. experimental models and theoretical model studies) in the literature. Collectively, there are numerous nanomaterials currently being examined for use in conventional imaging modalities, and each imaging technique has unique NPs with properties that can be manipulated to answer an array of clinical questions specific to that imaging modality. There are still challenges to consider, including getting regulatory approval for clinical research and routine use about long-term biocompatibility, which collectively emphasize the need for continued research to facilitate the integration of nanotechnology into routine clinical practice. Most importantly, there is a continued need for strong, collaborative efforts between researchers, biomedical engineers, clinicians, and industry stakeholders, which are necessary to bridge the persistent gap between translational ideas and implementation in clinical settings.

3D-CEUS/MRI-CEUS fusion imaging vs 2D-CEUS after locoregional therapies for hepatocellular carcinoma: a multicenter prospective study of therapeutic response evaluation

OBJECTIVES

To compare the diagnostic accuracy of 3D contrast-enhanced ultrasound (CEUS)/MRI-CEUS fusion imaging with 2D-CEUS in assessing the response of hepatocellular carcinoma (HCC) to locoregional therapies in a multicenter prospective study.

MATERIALS AND METHODS

A consecutive series of patients with HCC scheduled for locoregional treatment were enrolled between April 2021 and March 2023. Patients were randomly divided into 3D-CEUS/MRI-CEUS fusion imaging group (3D/fusion group) or 2D-CEUS group (2D group). CEUS was performed 1 week before and 4-6 weeks after locoregional treatment. Contrast-enhanced MRI (CE-MRI) 4-6 weeks after treatment was set as the reference standard. CEUS images were evaluated for the presence or absence of viable tumors. Diagnostic performance criteria, including sensitivity, specificity, accuracy, and area under the curve (AUC), were determined for each modality.

RESULTS

A total of 140 patients were included, 70 patients in the 2D group (mean age, 60.2 ± 10.4 years) and 70 patients in the 3D/fusion group (mean age, 59.8 ± 10.6 years). The sensitivity of the 3D/fusion group was 100.0% (95% CI: 75.9, 100.0), higher than that of the 2D group (55.6%, 95% CI: 22.7, 84.7; p = 0.019). The specificity of the 3D/fusion group was 96.3% (95% CI: 86.2, 99.4), which was comparable to that of the 2D group (98.4%, 95% CI: 90.0, 99.9; p = 0.915). The AUC of the 3D/fusion group was 0.98 (95% CI: 0.95, 1.00), higher than that of the 2D group (0.77, 95% CI: 0.56, 0.98; p = 0.020).

CONCLUSION

3D-CEUS/MRI-CEUS fusion imaging exhibits superior diagnostic accuracy in evaluating the treatment response to locoregional therapies for HCC.

CLINICAL RELEVANCE STATEMENT

3D-CEUS/MRI-CEUS fusion imaging can be applied for post-treatment assessment of residual tumors in HCC undergoing locoregional treatment, offering potential benefits in terms of accurate diagnosis and clinical management.

KEY POINTS

Evaluating for HCC recurrence following locoregional therapy is important. 3D-CEUS/MRI-CEUS fusion imaging achieved a higher sensitivity than 2D-CEUS in assessing residual tumors after locoregional therapies. 3D-CEUS/MRI-CEUS fusion imaging can help clinicians intervene early in residual HCC lesions after locoregional treatment.

Application value of high-pressure-resistant peripherally inserted central catheters in enhanced computer tomography of diabetic patients with malignant tumors

BACKGROUND

Individuals with diabetes mellitus have a higher risk of developing malignant tumors, and diagnosing these tumors can be challenging.

AIM

To confirm the benefits of using peripherally inserted central catheters (PICCs) in contrast-enhanced computerized tomography (CECT) for diagnostic imaging in diabetic patients with malignant tumors and to provide a research basis for follow-up research.

METHODS

This retrospective study analyzed 204 diabetic patients with malignancies treated at The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, from January 2024 to June 2024. The patients were divided into two groups: A control group (n = 102) with indwelling peripheral intravenous catheters and a research group (n = 102) with high-pressure-resistant PICC. The study compared baseline data, the incidence of iodine contrast extravasation during CECT, the incidence of adverse events (discomfort, redness and swelling at the puncture site, and blood oozing), imaging quality, nursing time, intubation success rate, number of venipuncture attempts, and catheter maintenance cost.

RESULTS

Male patients accounted for 51.96% in the control group and 55.88% in the research group; the average age was (59.68 ± 11.82) years in the control group and (61.41 ± 12.92) years in the research group; the proportions of lung cancer, colorectal cancer, and gastric cancer patients in the control group were 42.16%, 38.24%, and 19.61%, respectively, while those in the research group were 34.31%, 37.25%, and 28.43%, respectively. Except for the gender distribution, age, and cancer type mentioned above, other general information such as underlying diseases, puncture location, and long-term chemotherapy shows no significant differences as tested (P > 0.05). The results showed that the research group had significantly reduced incidence of iodine contrast extravasation (7 vs 1, P = 0.031), similar incidence of adverse events (11 vs 7, P = 0.324), reduced nursing time [(18.50 ± 2.68) minutes vs (13.26 ± 3.00) minutes, P = 0.000], fewer venipuncture attempts [(2.21 ± 0.78) times vs (1.49 ± 0.58) times, P = 0.000], lower catheter maintenance cost [(1251.79 ± 205.47) China yuan (CNY) vs (1019.25 ± 117.28) CNY, P = 0.000], increased intubation success rate (16.67% vs 58.82%, P = 0.000), and better imaging quality (85.29% vs 94.12%, P = 0.038).

CONCLUSION

High-pressure-resistant PICCs can lessen the physical burden of diabetic patients during nursing, reduce treatment costs, and improve the efficiency and quality of imaging for diagnosis malignant tumors.

TRINet: Team Role Interaction Network for automatic radiology report generation

In recent years, the automatic generation of radiology reports as an auxiliary solution for expert diagnosis has garnered considerable attention from researchers. However, due to the complexity of medical image interpretation, current models exhibit issues such as aleatoric uncertainty and epistemic uncertainty, leading to a lack of stability in the content description of the generated medical reports. To address these issues, we propose a Team Role Interaction Network (TRINet) for the automatic generation of radiology reports, which is composed of multiple Team-member role models and a Team-leader role model. Specifically, we proposed a Cross-Modal Communication Mechanism (CMCM) among Team-members, enabling each Team-member to interact with image features and textual features output by its adjacent Team-member role model through a predefined grid-shaped parameter plane queries, thereby facilitating cross-modal information exchange among Team-members. Additionally, the Team-leader role model employs a Multi-Modal Fusion Mechanism (MMFM), performing sequence-to-sequence operations on the multidimensional outputs generated by the Team-member role models and the original inputs, aggregating the knowledge of each Team-member to produce the final medical report. We tested TRINet on two public benchmark datasets (IU X-ray and MIMIC-CXR), demonstrating the effectiveness and state-of-the-art performance of our model. The BLEU-4 indicator on the MIMIC-CXR test set reached the latest 0.144, 3.6 points higher than the previous best technique. Further research has shown that TRINet can effectively leverage the complementary information between the modalities perceived by each Team-member role model, simulating the collaborative process of an expert team, thereby significantly improving the system's accuracy and robustness.

Computed tomography technologies to measure key structural features of polymeric biomedical implants from bench to bedside

Implanted polymeric devices, designed to encourage tissue regeneration, require porosity. However, characterizing porosity, which affects many functional device properties, is non-trivial. Computed tomography (CT) is a quick, versatile, and non-destructive way to gain 3D structural information, yet various CT technologies, such as benchtop, preclinical and clinical systems, all have different capabilities. As system capabilities determine the structural information that can be obtained, seamless monitoring of key device features through all stages of clinical translation must be engineered intentionally. Therefore, in this study we tested feasibility of obtaining structural information in pre-clinical systems and high-resolution micro-CT (μCT) under physiological conditions. To overcome the low CT contrast of polymers in hydrated environments, radiopaque nanoparticle contrast agent was incorporated into porous devices. The size of resolved features in porous structures is highly dependent on the resolution (voxel size) of the scan. As the voxel size of the CT scan increased (lower resolution) from 5 to 50 μm, the measured pore size was overestimated, and percentage porosity was underestimated by nearly 50%. With the homogeneous introduction of nanoparticles, changes to device structure could be quantified in the hydrated state, including at high-resolution. Biopolymers had significant structural changes post-hydration, including a mean increase of 130% in pore wall thickness that could potentially impact biological response. By incorporating imaging capabilities into polymeric devices, CT can be a facile way to monitor devices from initial design stages through to clinical translation.

Novel intravascular tantalum oxide-based contrast agent achieves improved vascular contrast enhancement and conspicuity compared to Iopamidol in an animal multiphase CT protocol

BACKGROUND

To assess thoracic vascular computed tomography (CT) contrast enhancement of a novel intravenous tantalum oxide nanoparticle contrast agent (carboxybetaine zwitterionic tantalum oxide, TaCZ) compared to a conventional iodinated contrast agent (Iopamidol) in a rabbit multiphase protocol.

METHODS

Five rabbits were scanned inside a human-torso-sized encasement on a clinical CT system at various scan delays after intravenous injection of 540 mg element (Ta or I) per kg of bodyweight of TaCZ or Iopamidol. Net contrast enhancement of various arteries and veins, as well as image noise, were measured. Randomized scan series were reviewed by three independent readers on a clinical workstation and assessed for vascular conspicuity and image artifacts on 5-point Likert scales.

RESULTS

Overall, net vascular contrast enhancement achieved with TaCZ was superior to Iopamidol (p ≤ 0.036 with the exception of the inferior vena cava at 6 s (p = 0.131). Vascular contrast enhancement achieved with TaCZ at delays of 6 s, 40 s, and 75 s was superior to optimum achieved Iopamidol contrast enhancement at 6 s (p ≤ 0.036. Vascular conspicuity was higher for TaCZ in 269 of 300 (89.7%) arterial and 269 of 300 (89.7%) venous vessel assessments, respectively (p ≤ 0.005), with substantial inter-reader reliability (κ = 0.61; p < 0.001) and strong positive monotonic correlation between conspicuity scores and contrast enhancement measurements (ρ = 0.828; p < 0.001).

CONCLUSION

TaCZ provides absolute and relative contrast advantages compared to Iopamidol for improved visualization of thoracic arteries and veins in a multiphase CT protocol.

RELEVANCE STATEMENT

The tantalum-oxide nanoparticle is an experimental intravenous CT contrast agent with superior cardiovascular and venous contrast capacity per injected elemental mass in an animal model, providing improved maximum contrast enhancement and prolonged contrast conspicuity. Further translational research on promising high-Z and nanoparticle contrast agents is warranted.

KEY POINTS

There have been no major advancements in intravenous CT contrast agents over decades. Iodinated CT contrast agents require optimal timing for angiography and phlebography. Tantalum-oxide demonstrated increased CT attenuation per elemental mass compared to Iopamidol. Nanoparticle contrast agent design facilitates prolonged vascular conspicuity.

Contrast media for hysterosalpingography: systematic search and review providing new guidelines by the Contrast Media Safety Committee of the European Society of Urogenital Radiology

OBJECTIVES

Hysterosalpingography (HSG) is widely used for evaluating the fallopian tubes; however, controversies regarding the use of water- or oil-based iodine-based contrast media (CM) remain. The aim of this work was (1) to discuss reported pregnancy rates related to the CM type used, (2) to validate the used CM in published literature, (3) to discuss possible complications and side effects of CM in HSG, and (4) to develop guidelines on the use of oil-based CM in HSG.

METHODS

A systematic literature search was conducted for original RCT studies or review/meta-analyses on using water-based and oil-based CM in HSG with fertility outcomes and complications. Nine randomized controlled trials (RCTs) and 10 reviews/meta-analyses were analyzed. Grading of the literature was performed based on the Oxford Centre for Evidence-Based Medicine (OCEBM) 2011 classification.

RESULTS

An approximately 10% higher pregnancy rate is reported for oil-based CM. Side effects are rare, but oil-based CM have potentially more side effects on the maternal thyroid function and the peritoneum.

CONCLUSIONS

1. HSG with oil-based CM gives approximately 10% higher pregnancy rates. 2. External validity is limited, as in five of nine RCTs, the CM used is no longer on the market. 3. Oil-based CM have potentially more side effects on the maternal thyroid function and on the peritoneum. 4. Guideline: Maternal thyroid function should be tested before HSG with oil-based CM and monitored for 6 months after.

CLINICAL RELEVANCE STATEMENT

Oil-based CM is associated with an approximately 10% higher chance of pregnancy compared to water-based CM after HSG. Although side effects are rare, higher iodine concentration and slower clearance of oil-based CM may induce maternal thyroid function disturbance and peritoneal inflammation and granuloma formation.

KEY POINTS

• It is unknown which type of contrast medium, oil-based or water-based, is the optimal for HSG. • Oil-based contrast media give a 10% higher chance of pregnancy after HSG, compared to water-based contrast media. • From the safety perspective, oil-based CM can cause thyroid dysfunction and an intra-abdominal inflammatory response in the patient.

Future challenges of contrast media in radiology

Contrast media (CM) were first used soon after the discovery of X-rays in 1895. Ever since, continuous technological development and pharmaceutical research has led to tremendous progress in radiology, more available techniques and contrast media, and expanded knowledge around their indications. A greater prevalence of chronic diseases, population ageing, and the rise in diagnosis and survival times among cancer patients have resulted in a growing demand for diagnostic imaging and an increased consumption of CM. This article presents the main lines of research in CM development which seek to minimise toxicity and maximise efficacy, opening up new diagnostic and therapeutic possibilities through new molecules or nanomedicine. The sector, which is continuously evolving, faces challenges such as shortages and the need for more equitable and sustainable practices.

Advancements in hydrogel-based embolic agents: Categorized by therapeutic mechanisms

BACKGROUND

Transcatheter arterial embolization (TAE) is a crucial technique in interventional radiology. Hydrogel-based embolic agents show promise due to their phase transition and drug-loading capabilities. However, existing categorizations of these agents are confusing.

AIMS

This review tackles the challenge of categorizing hydrogel-based embolic agents based on their therapeutic mechanisms, including transportation, accumulation, interaction, and elimination. It also addresses current challenges and controversies in the field while highlighting future directions for hydrogel-based embolicagents.

MATERIALS AND METHODS

We conducted a systematic review of papers published in PUBMED from 2004 to 2024, focusing primarily on preclinical trials.

RESULTS

Various kinds of hydrogel embolic agents were introduced according to their therapeutic mechanisms.

DISCUSSION

Most hydrogel embolic agents were specifically designed for effective accumulation and interaction. Recent advancement highlight the potential of multifunctional hydrogel embolic agents.

CONCLUSION

This new categorizations provided valuable insights into hydrogel embolic agents, potentially guiding material scientists and interventional radiologists in the development of novel hydrogel embolic agents in transarterial embolization.

Diagnosis and treatment status of inoperable locally advanced breast cancer and the application value of inorganic nanomaterials

Locally advanced breast cancer (LABC) is a heterogeneous group of breast cancer that accounts for 10-30% of breast cancer cases. Despite the ongoing development of current treatment methods, LABC remains a severe and complex public health concern around the world, thus prompting the urgent requirement for innovative diagnosis and treatment strategies. The primary treatment challenges are inoperable clinical status and ineffective local control methods. With the rapid advancement of nanotechnology, inorganic nanoparticles (INPs) exhibit a potential application prospect in diagnosing and treating breast cancer. Due to the unique inherent characteristics of INPs, different functions can be performed via appropriate modifications and constructions, thus making them suitable for different imaging technology strategies and treatment schemes. INPs can improve the efficacy of conventional local radiotherapy treatment. In the face of inoperable LABC, INPs have proposed new local therapeutic methods and fostered the evolution of novel strategies such as photothermal and photodynamic therapy, magnetothermal therapy, sonodynamic therapy, and multifunctional inorganic nanoplatform. This article reviews the advances of INPs in local accurate imaging and breast cancer treatment and offers insights to overcome the existing clinical difficulties in LABC management.

A comprehensive review on recent progress in chitosan composite gels for biomedical uses

Chitosan (CS) composite gels have emerged as promising materials with diverse applications in biomedicine. This review provides a concise overview of recent advancements and key aspects in the development of CS composite gels. The unique properties of CS, such as biocompatibility, biodegradability, and antimicrobial activity, make it an attractive candidate for gel-based composites. Incorporating various additives, such as nanoparticles, polymers, and bioactive compounds, enhances the mechanical, thermal, and biological and other functional properties of CS gels. This review discusses the fabrication methods employed for CS composite gels, including blending and crosslinking, highlighting their influence on the final properties of the gels. Furthermore, the uses of CS composite gels in tissue engineering, wound healing, drug delivery, and 3D printing highlight their potential to overcome a number of the present issues with drug delivery. The biocompatibility, antimicrobial properties, electroactive, thermosensitive and pH responsive behavior and controlled release capabilities of these gels make them particularly suitable for biomedical applications. In conclusion, CS composite gels represent a versatile class of materials with significant potential for a wide range of applications. Further research and development efforts are necessary to optimize their properties and expand their utility in pharmaceutical and biomedical fields.

Radiopaque, Self-Immolative Poly(benzyl ether) as a Functional X-ray Contrast Agent: Synthesis, Prolonged Visibility, and Controlled Degradation

A self-immolative radiocontrast polymer agent has been newly designed for this study. The polymer agent is composed of a degradable poly(benzyl ether)-based backbone that enables complete and spontaneous depolymerization upon exposure to a specific stimulus, with iodophenyl pendant groups that confer a radiodensity comparable to that of commercial agents. In particular, when incorporated into a biodegradable polycaprolactone matrix, the agent not only reinforces the matrix and provides prolonged radiopacity without leaching but also governs the overall degradation kinetics of the composite under basic aqueous conditions, allowing for X-ray tracking and exhibiting a predictable degradation until the end of its lifespan. Our design would be advanced with various other components to produce synergistic functions and extended for applications in implantable biodegradable devices and theragnostic systems.

Nanotechnology's frontier in combatting infectious and inflammatory diseases: prevention and treatment

Inflammation-associated diseases encompass a range of infectious diseases and non-infectious inflammatory diseases, which continuously pose one of the most serious threats to human health, attributed to factors such as the emergence of new pathogens, increasing drug resistance, changes in living environments and lifestyles, and the aging population. Despite rapid advancements in mechanistic research and drug development for these diseases, current treatments often have limited efficacy and notable side effects, necessitating the development of more effective and targeted anti-inflammatory therapies. In recent years, the rapid development of nanotechnology has provided crucial technological support for the prevention, treatment, and detection of inflammation-associated diseases. Various types of nanoparticles (NPs) play significant roles, serving as vaccine vehicles to enhance immunogenicity and as drug carriers to improve targeting and bioavailability. NPs can also directly combat pathogens and inflammation. In addition, nanotechnology has facilitated the development of biosensors for pathogen detection and imaging techniques for inflammatory diseases. This review categorizes and characterizes different types of NPs, summarizes their applications in the prevention, treatment, and detection of infectious and inflammatory diseases. It also discusses the challenges associated with clinical translation in this field and explores the latest developments and prospects. In conclusion, nanotechnology opens up new possibilities for the comprehensive management of infectious and inflammatory diseases.