iRadiology最新文献

Contrast agents have transformed the field of medical imaging, significantly enhancing the visualisation of internal structures and improving diagnostic accuracy across X-rays, computed tomography, magnetic resonance imaging (MRI), and ultrasound. This review explores the historical development, physicochemical properties, and mechanisms of action of iodinated, gadolinium-based, barium sulfate, microbubble, and nanoparticle contrast agents. It highlights key advancements, including the transition from high-osmolar to low- and iso-osmolar iodinated agents, the integration of gadolinium in MRI, and the innovative use of microbubbles and nanoparticles. The review critically examines the safety profiles and adverse reactions of these contrast agents, categorising them into hypersensitivity and physiological reactions. It outlines risk factors, common misconceptions, and management strategies for adverse reactions, emphasising the importance of personalised approaches in clinical practice. Additionally, it delves into broader implications, including ethical considerations, environmental impact, and global accessibility of contrast media. The review also discusses technological advancements such as targeted contrast agents and the integration of artificial intelligence to optimise contrast dosage. By synthesising current knowledge and emerging trends, this review underscores the pivotal role of contrast agents in advancing medical imaging. It aims to equip clinicians, researchers, and policymakers with a thorough understanding to enhance diagnostic efficacy, ensure patient safety, and address ethical and environmental challenges, thereby informing future innovations and regulatory frameworks to promote equitable access to advanced imaging technologies globally.

Sun T, Chen R, Liu J, Zhou Y. Current progress and future perspectives in total-body PET imaging, part I: data processing and analysis. iRADIOLOGY. 2024; 2(2): 173–90.

On page 178, Section 3.2, the text reads:

“Muller et al. [49] used deep learning to denoise dynamic PET data from a Quadra scanner and investigated…”

This should be corrected to:

“Muller et al. [49] used deep learning to denoise dynamic PET data from a PennPET Explorer scanner and investigated…”

We apologize for this error.

The development of 7-Tesla (7T) magnetic resonance imaging systems has opened new avenues for exploring the advantages of diffusion imaging at higher field strengths, especially in neuroscience research. This review investigates whether 7T diffusion imaging offers significant benefits over lower field strengths by addressing the following: Technical challenges and corresponding strategies: Challenges include achieving shorter transverse relaxation/effective transverse relaxation times and greater B0 and B1 inhomogeneities. Advanced techniques including high-performance gradient systems, parallel imaging, multi-shot acquisition, and parallel transmission can mitigate these issues. Comparison of 3-Tesla and 7T diffusion imaging: Technologies such as multiplexed sensitivity encoding and deep learning reconstruction (DLR) have been developed to mitigate artifacts and improve image quality. This comparative analysis demonstrates significant improvements in the signal-to-noise ratio and spatial resolution at 7T with a powerful gradient system, facilitating enhanced visualization of microstructural changes. Despite greater geometric distortions and signal inhomogeneity at 7T, the system shows clear advantages in high b-value imaging and high-resolution diffusion tensor imaging. Additionally, multiplexed sensitivity encoding significantly reduces image blurring and distortion, and DLR substantially improves the signal-to-noise ratio and image sharpness. 7T diffusion applications in structural analysis and disease characterization: This review discusses the potential applications of 7T diffusion imaging in structural analysis and disease characterization.

Cerebral toxoplasmosis is a common opportunistic infectious disease in immunocompromised patients that usually involves the central nervous system. The clinical features and neuroimaging findings of cerebral toxoplasmosis are often similar to brain abscess and tuberculoma. We report a case of hepatitis C with cerebral toxoplasmosis, with the aim of enhancing understanding of the imaging manifestations of cerebral toxoplasmosis and thereby improving the differential diagnosis of brain space-occupying lesions.

Targeted alpha (α) therapy (TAT) is an emerging therapeutic strategy for cancer treatment. To evaluate the safety and efficacy of targeted α-therapy, the biodistribution and internal radiation dose of α-emitting radionuclides should be determined. In vivo imaging of these radionuclides often involves the detection of gamma rays, X-rays, and positrons generated during their complex decay processes. This review aims to classify the α-emitting radionuclides (astatine-211, actinium-225, radium-223, bismuth-212, bismuth-213, thorium-227, and terbium-149) according to their imageable signals. Additionally, this study summarizes various imaging modalities, including gamma camera imaging, single-photon emission computed tomography, positron emission tomography, Compton imaging, bremsstrahlung imaging, and Cerenkov luminescence imaging, which hold potential for imaging α-emitting radionuclides, to explore their biomedical applications in qualitative nuclide tracing and diagnosis, quantifying pharmacokinetics, and assessing prognosis and response to therapy.

Cardiac-cerebral vascular diseases (CCVDs) are acknowledged as a major threat to public health, leading to more than one-third of all deaths worldwide. The complex anatomical structure and immune features of blood vessels significantly affect the development of CCVDs, and magnetic resonance angiography (MRA) is one of the main diagnostic approaches for the accurate diagnosis and prognosis of CCVDs. However, MRA suffers from intrinsic problems derived from its blood flow-dependency, and the clinical Gd-chelating contrast agents are limited by their rapid vascular extravasation. Over the past decade, spurred on by nanoscience and nanotechnology, numerous contrast agents based on magnetic nanomaterials have been developed to enhance the contrast of MRA, with these including iron oxide nanoparticles, rare earth-doped nanoparticles, and metal-organic coordination polymers. The molecular MR imaging of vasculopathy using specific nanoprobes has been explored to obtain a better understanding of the molecular aspects of CCVDs. In this review, the state of the art in MRA nanoprobes is introduced, and recent achievements in the diagnosis of CCVDs using MR imaging are summarized. Additionally, the future prospects and limitations of MRA based on nanoprobes are discussed. The current review provides methodological designs and ideas for subsequent MRA nanoprobes.