Almost the entire world, not only China, is currently experiencing the outbreak of a novel coronavirus that causes respiratory disease, severe pneumonia, and even death. The outbreak began in Wuhan, ...China, in December of 2019 and is currently still ongoing. This novel coronavirus is highly contagious and has resulted in a continuously increasing number of infections and deaths that have already surpassed the SARS-CoV outbreak that occurred in China between 2002 and 2003. It is now officially a pandemic, announced by WHO on the 11th of March. Currently, the 2019 novel coronavirus (SARS-CoV-2) can be identified by virus isolation or viral nucleic acid detection; however, false negatives associated with the nucleic acid detection provide a clinical challenge and thus make the imaging examination crucial. Imaging exams have been a main clinical diagnostic criteria for the 2019 novel coronavirus disease (COVID-19) in China. Imaging features of multiple patchy areas of ground glass opacity and consolidation predominately in the periphery of the lungs are characteristic manifestations on chest CT and extremely helpful in the early detection and diagnosis of this disease, which aids prompt diagnosis and the eventual control of this emerging global health emergency.
Key Points
• In December 2019, China, an outbreak of pneumonia caused by a novel, highly contagious coronavirus raised grave concerns and posed a huge threat to global public health.
• Among the infected patients, characteristic findings on CT imaging include multiple, patchy, ground-glass opacity, crazy-paving pattern, and consolidation shadows, mainly distributed in the peripheral and subpleural areas of both lungs, which are very helpful for the frontline clinicians.
• Imaging examination has become the indispensable means not only in the early detection and diagnosis but also in monitoring the clinical course, evaluating the disease severity, and may be presented as an important warning signal preceding the negative RT-PCR test results.
Antivascular therapy is a promising approach to the treatment of non-small cell lung cancer (NSCLC), where an imaging modality capable of longitudinally monitoring treatment response could provide ...early prediction of the outcome. In this study, we sought to investigate the feasibility of using intravoxel incoherent motion (IVIM) diffusion MRI to quantitatively assess the efficacy of the treatments of a vascular-disrupting agent CA4P or its combination with bevacizumab on experimental NSCLC tumors. CA4P caused a strong but reversible effect on tumor vasculature; all perfusion-related parameters-D*, f, fD*, and K
-initially showed a decrease of 30% to 60% at 2 hours and then fully recovered to baseline on day 2 for CA4P treatment or on days 4 to 8 for CA4P + bevacizumab treatment; the diffusion coefficient in tumors decreased initially at 2 hours and then increased from day 2 to day 8. We observed a good correlation between IVIM parameters and dynamic contrast-enhanced MRI (DCE-MRI; K
). We also found that the relative change in f and fD* at 2 hours correlated well with changes in tumor volume on day 8. In conclusion, our results suggest that IVIM is a promising alternative to DCE-MRI for the assessment of the change in tumor perfusion as a result of antivascular agents and can be used to predict the efficacy of antivascular therapies without the need for contrast media injection.
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Sugar‐based biopolymers have been recognized as attractive materials to develop macromolecule‐ and nanoparticle‐based cancer imaging and therapy. However, traditional biopolymer‐based imaging ...approaches rely on the use of synthetic or isotopic labeling, and because of it, clinical translation often is hindered. Recently, a novel magnetic resonance imaging (MRI) technology, chemical exchange saturation transfer (CEST), has emerged, which allows the exploitation of sugar‐based biopolymers as MRI agents by their hydroxyl protons‐rich nature. In the study, we reviewed recent studies on the topic of CEST MRI detection of sugar‐based biopolymers. The CEST MRI property of each biopolymer was briefly introduced, followed by the pre‐clinical and clinical applications. The findings of these preliminary studies imply the enormous potential of CEST detectable sugar‐based biopolymers in developing highly sensitive and translatable molecular imaging agents and constructing image‐guided biopolymer‐based drug delivery systems.
This article is categorized under:
Diagnostic Tools > in vivo Nanodiagnostics and Imaging
Therapeutic Approaches and Drug Discovery > Emerging Technologies
With the magnetic resonance imaging (MRI) technology of chemical exchange saturation transfer (CEST), sugar‐based biopolymers can be directly used as novel imaging agents for a broad spectrum of biomedical applications.
The blood-brain barrier (BBB) is the main obstacle to the effective delivery of therapeutic agents to the brain, compromising treatment efficacy for a variety of neurological disorders. ...Intra-arterial (IA) injection of hyperosmotic mannitol has been used to permeabilize the BBB and improve parenchymal entry of therapeutic agents following IA delivery in preclinical and clinical studies. However, the reproducibility of IA BBB manipulation is low and therapeutic outcomes are variable. We demonstrated that this variability could be highly reduced or eliminated when the procedure of osmotic BBB opening is performed under the guidance of interventional MRI. Studies have reported the utility and applicability of this technique in several species. Here we describe a protocol to open the BBB by IA injection of hyperosmotic mannitol under the guidance of MRI in mice. The procedures (from preoperative preparation to postoperative care) can be completed within ~1.5 h, and the skill level required is on par with the induction of middle cerebral artery occlusion in small animals. This MRI-guided BBB opening technique in mice can be utilized to study the biology of the BBB and improve the delivery of various therapeutic agents to the brain.
Molecular imaging is becoming an indispensable tool to pursue precision medicine. However, quickly translating newly developed magnetic resonance imaging (MRI) agents into clinical use remains a ...formidable challenge. Recently, Chemical Exchange Saturation Transfer (CEST) MRI is emerging as an attractive approach with the capability of directly using low concentration, exchangeable protons-containing agents for generating quantitative MRI contrast. The ability to utilize diamagnetic compounds has been extensively exploited to detect many clinical compounds, such as FDA approved drugs, X-ray/CT contrast agents, nutrients, supplements, and biopolymers. The ability to directly off-label use clinical compounds permits CEST MRI to be rapidly translated to clinical settings. In this review, the current status of CEST MRI based on clinically available compounds will be briefly introduced. The advancements and limitations of these studies are reviewed in the context of their pre-clinical or clinical applications. Finally, future directions will be briefly discussed.
While carbon dots (C‐dots) have been extensively investigated pertaining to their fluorescent, phosphorescent, electrochemiluminescent, optoelectronic, and catalytic features, their inherent chemical ...exchange saturation transfer magnetic resonance imaging (CEST MRI) properties are unknown. By virtue of their hydrophilicity and abundant exchangeable protons of hydroxyl, amine, and amide anchored on the surface, we report here that C‐dots can be adapted as effective diamagnetic CEST (diaCEST) MRI contrast agents. As a proof‐of‐concept demonstration, human glioma cells were labeled with liposomes with or without encapsulated C‐dots and implanted in mouse brain. In vivo CEST MRI was able to clearly differentiate labeled cells from non‐labeled cells. The present findings may encourage new applications of C‐dots for in vivo imaging in deep tissues, which is currently not possible using conventional fluorescent (near‐infrared) C‐dots.
Think differently: Metal‐free carbon dots (C‐dots) can be used as magnetic resonance imaging (MRI) agents owing to the chemical exchange of surface‐anchored protons with water. This inherent chemical exchange saturation transfer (CEST) magnetic resonance property of C‐dots enables them to be visualized in vivo in deep tissues.
Gait disturbance is a manifestation of cerebral small vessel disease (CSVD). The posterolateral thalamus (PL), whose blood is mainly supplied by the P2 segment of posterior cerebral artery (P2-PCA), ...plays pivotal roles in gait regulation. We investigated the influence of the distance between P2-PCA and PL on gait with varying CSVD burden. 71 participants were divided into low and high CSVD burden groups. The distance from P2-PCA to PL was measured using 7 T TOF-MRA and categorized into an immediate or distant PCA-to-thalamus pattern. Functional connectivity (FC) and voxel-based morphometry were assessed to evaluate functional and structural alterations. In the low CSVD burden group, immediate PCA-to-thalamus supply strongly correlates with longer step length and higher wave phase time percent, and exhibited enhanced FCs in left supplementary motor area, right precentral cortex (PreCG.R). While in the high CSVD burden group, no association between PCA-to-thalamus pattern and gait was found, and we observed reduced FC in PreCG.R with immediate PCA-to-thalamus pattern. Higher CSVD burden was associated with decreased gray matter density in bilateral thalamus. However, no significant structural thalamic change was observed between the two types of PCA-to-thalamus patterns in all patients. Our study demonstrated patients with immediate PCA-to-thalamus supply exhibited better gait performance in low CSVD burden populations, which also correlated with enhanced FCs in motor-related cortex, indicating the beneficial effects of the immediate PCA-to-thalamus supply pattern. In the higher burden CSVD populations, the effects of PCA-to-thalamus pattern on gait are void, attributable to the CSVD-related thalamic destruction and impairment of thalamus-related FC.
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