scholarly journals An Activatable T1-Weighted MR Contrast Agent: A Noninvasive Tool for Tracking the Vicinal Thiol Motif of Thioredoxin in Live Cells

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2018
Author(s):  
Jongeun Kang ◽  
Eunha Hwang ◽  
Hyunseung Lee ◽  
Mi Young Cho ◽  
Sanu Karan ◽  
...  
Keyword(s):  
Contrast Agent ◽  
Contrast Agents ◽  
Live Cells ◽  
Spectral Studies ◽  
Protein Motif ◽  
Preferential Binding ◽  
T1 Contrast ◽  
Magnetic Resonance Imaging Mri ◽  
Single Water Molecule ◽  
Mcf 7

We have synthesized new magnetic resonance imaging (MRI) T1 contrast agents (CA1 and CA2) that permit the activatable recognition of the cellular vicinal thiol motifs of the protein thioredoxin. The contrast agents showed MR relaxivities typical of gadolinium complexes with a single water molecule coordinated to a Gd3+ center (i.e., ~4.54 mM−1s−1) for both CA1 and CA2 at 60 MHz. The contrast agent CA1 showed a ~140% relaxivity enhancement in the presence of thioredoxin, a finding attributed to a reduction in the flexibility of the molecule after binding to thioredoxin. Support for this rationale, as opposed to one based on preferential binding, came from 1H-15N-HSQC NMR spectral studies; these revealed that the binding affinities toward thioredoxin were almost the same for both CA1 and CA2. In the case of CA1, T1-weighted phantom images of cancer cells (MCF-7, A549) could be generated based on the expression of thioredoxin. We further confirmed thioredoxin expression-dependent changes in the T1-weighted contrast via knockdown of the expression of the thioredoxin using siRNA-transfected MCF-7 cells. The nontoxic nature of CA1, coupled with its relaxivity features, leads us to suggest that it constitutes a first-in-class MRI T1 contrast agent that allows for the facile and noninvasive monitoring of vicinal thiol protein motif expression in live cells.

scholarly journals Quantitative Parameter Mapping of Contrast Agent Concentration and Relaxivity and Brain Tumor Extracellular pH

2021 ◽  
Author(s):  
Yuki Matsumoto ◽  
Masafumi Harada ◽  
Yuki Kanazawa ◽  
Yo Taniguchi ◽  
Masaharu Ono ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Contrast Agent ◽  
Contrast Agents ◽  
Extracellular Ph ◽  
Quantitative Parameter ◽  
Contrast Agent Concentration ◽  
Parameter Mapping ◽  
Clinical Magnetic Resonance Imaging ◽  
Contrast Enhanced ◽  
Magnetic Resonance Imaging Mri

Abstract In clinical magnetic resonance imaging (MRI), gadolinium-based contrast agents are most commonly used for evaluating brain tumors. However, contrast-enhanced MRI can only provide relative signal changes such as mixed information with longitudinal relaxivity (r1) and contrast agent concentration. Herein, we present a new method to evaluate r1 and contrast agent concentration separately in contrast-enhanced lesions using quantitative parameter mapping. We demonstrated that it is possible to evaluate pathophysiological tumor changes owing to therapeutic efficacy. Furthermore, the r1 value can be used as an extracellular pH tumor marker. We believe that our method has an easy clinical application and demonstrates how acidic environments affect the T1 relaxation time of contrast agents. In conclusion, these indices can be useful for brain tumor management.

Clinical Analysis of Magnetic Nanoparticle Contrast Agent in the Diagnosis of Occult Fracture by Multislice Spiral CT and MRI

2020 ◽  
Vol 20 (10) ◽  
pp. 6568-6576
Author(s):  
Jian Guo ◽  
Longchao Xu ◽  
Haina Zhang ◽  
Qingfen Yang
Keyword(s):  
Contrast Agent ◽  
Contrast Agents ◽  
Multislice Ct ◽  
Spiral Ct ◽  
Clinical Analysis ◽  
Control Group ◽  
Observation Group ◽  
Multislice Spiral Ct ◽  
Occult Fractures ◽  
Magnetic Resonance Imaging Mri

To investigate the differences in the diagnosis and treatment of occult fractures between multi-slice spiral CT (CT) and magnetic resonance imaging (MRI) using I/Fe3O4 nanometer contrast agent. This retrospective study analyzed the clinical data of 60 patients with occult fractures and compared the diagnosis results of multislice CT (observation group) and MRI (control group). All the contrast agents used were I/Fe3O4 nanometer contrast agents. In the control group, 55 cases (91.67%) were detected on T1-weighted imaging versus 58 cases (96.67) on T2-weighted imaging. In the observation group, 47 cases (78.33%) were diagnosed. The intergroup difference was significant (P < 0.05). Clinically, I/Fe3O4 nanometer contrast agent can be used to affect imaging. The detection rate of MRI is higher than that of CT, and the ability to obtain detailed data of occult fractures is better.

Preparation of linear poly(glycerol) as a T1 contrast agent for tumor-targeted magnetic resonance imaging

2016 ◽  
Vol 4 (41) ◽  
pp. 6716-6725 ◽  
Author(s):  
Yi Cao ◽  
Min Liu ◽  
Kunchi Zhang ◽  
Jingjin Dong ◽  
Guangyue Zu ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Contrast Agents ◽  
Small Molecule ◽  
Resonance Imaging ◽  
T1 Contrast Agent ◽  
T1 Contrast ◽  
Linear Poly

Macromolecular contrast agents (CAs) labeled with targeting molecules are gaining remarkable interest as promising materials overcoming the defects of small-molecule CAs.

scholarly journals Magnetic resonance thermometry using a GdIII-based contrast agent

2021 ◽  
Vol 57 (14) ◽  
pp. 1770-1773
Author(s):  
S. A. Amali S. Subasinghe ◽  
Jonathan Romero ◽  
Cassandra L. Ward ◽  
Matthew D. Bailey ◽  
Donna R. Zehner ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Contrast Agents ◽  
Resonance Imaging ◽  
Magnetic Resonance Thermometry

The complexes described here serve as contrast agents for magnetic resonance imaging thermometry.

Biocompatible dextran-coated gadolinium-doped cerium oxide nanoparticles as MRI contrast agents with high T1 relaxivity and selective cytotoxicity to cancer cells

2021 ◽  
Author(s):  
Anton Popov ◽  
Maxim Artemovich Abakumov ◽  
Irina Savintseva ◽  
Artem Ermakov ◽  
Nelly Popova ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Cerium Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Resonance Imaging ◽  
Mri Contrast ◽  
Selective Cytotoxicity ◽  
Magnetic Resonance Imaging Mri

Gd-based complexes are widely used as magnetic resonance imaging (MRI) contrast agents. The safety of previously approved contrast agents is questionable and is being re-assessed. The main causes of concern...

scholarly journals Quantitative dual contrast photon-counting computed tomography for assessment of articular cartilage health

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Petri Paakkari ◽  
Satu I. Inkinen ◽  
Miitu K. M. Honkanen ◽  
Mithilesh Prakash ◽  
Rubina Shaikh ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Articular Cartilage ◽  
Contrast Agent ◽  
Contrast Agents ◽  
Photon Counting ◽  
Spectral Imaging ◽  
Ct Scanning ◽  
Photon Counting Detector ◽  
Tissue Contrast ◽  
Reference Parameters

AbstractPhoton-counting detector computed tomography (PCD-CT) is a modern spectral imaging technique utilizing photon-counting detectors (PCDs). PCDs detect individual photons and classify them into fixed energy bins, thus enabling energy selective imaging, contrary to energy integrating detectors that detects and sums the total energy from all photons during acquisition. The structure and composition of the articular cartilage cannot be detected with native CT imaging but can be assessed using contrast-enhancement. Spectral imaging allows simultaneous decomposition of multiple contrast agents, which can be used to target and highlight discrete cartilage properties. Here we report, for the first time, the use of PCD-CT to quantify a cationic iodinated CA4+ (targeting proteoglycans) and a non-ionic gadolinium-based gadoteridol (reflecting water content) contrast agents inside human osteochondral tissue (n = 53). We performed PCD-CT scanning at diffusion equilibrium and compared the results against reference data of biomechanical and optical density measurements, and Mankin scoring. PCD-CT enables simultaneous quantification of the two contrast agent concentrations inside cartilage and the results correlate with the structural and functional reference parameters. With improved soft tissue contrast and assessment of proteoglycan and water contents, PCD-CT with the dual contrast agent method is of potential use for the detection and monitoring of osteoarthritis.

scholarly journals A single pot template reaction towards a manganese based T1 contrast agent

2021 ◽  
Author(s):  
Sellamuthu Anbu ◽  
Sabrina H. L. Hoffmann ◽  
Fabio Carniato ◽  
Lawrence Kenning ◽  
Thomas W. Price ◽  
...  
Keyword(s):  
Contrast Agent ◽  
T1 Contrast Agent ◽  
T1 Contrast ◽  
Template Reaction

scholarly journals Study on Establishing Reference Safe Concentrations of MRI Contrast Agents for Optimized Images: Paramagnetic Gd-DTPA-BMEA and Superparamagnetic Ferucarbotran

2021 ◽  
Vol 11 (3) ◽  
pp. 1165
Author(s):  
Wen-Tien Hsiao ◽  
Yi-Hong Chou ◽  
Jhong-Wei Tu ◽  
Ai-Yih Wang ◽  
Lu-Han Lai
Keyword(s):  
Contrast Agent ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Mri Contrast Agent ◽  
In Vitro Experiments ◽  
Mri Contrast ◽  
In Vivo Experiments ◽  
Contrast Agent Injection

The purpose of this study is to establish the minimal injection doses of magnetic resonance imaging (MRI) contrast agents that can achieve optimized images while improving the safety of injectable MRI drugs. Gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) and ferucarbotran, commonly used in clinical practice, were selected and evaluated with in vitro and in vivo experiments. MRI was acquired using T1-weighted (T1W) and T2-weighted (T2W) sequences, and the results were quantitatively analyzed. For in vitro experiments, results showed that T1W and T2W images were optimal when Gd-DTPA-bisamide (2-oxoethyl) (Gd-DTPA-BMEA) and ferucarbotran were diluted to a volume percentage of 0.6% and 0.05%; all comparisons were significant differences in grayscale statistics using one-way analysis of variance (ANOVA). For in vivo experiments, the contrast agent with optimal concentration percentages determined from in vitro experiments were injected into mice with an injection volume of 100 μL, and the images of brain, heart, liver, and mesentery before and after injection were compared. The statistical results showed that the p values of both T1W and T2W were less than 0.001, which were statistically significant. Under safety considerations for MRI contrast agent injection, optimized MRI images could still be obtained after reducing the injection concentration, which can provide a reference for the safety concentrations of MRI contrast agent injection in the future.

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