scholarly journals Methemoglobin Modulation as an Intravascular Contrast Agent for Magnetic Resonance Imaging: Proof of Concept

2019 ◽  
Vol 6 ◽  
Author(s):  
J. Scott McNally ◽  
Jared A. Jaffey ◽  
Seong-Eun Kim ◽  
Matthew D. Alexander ◽  
Kate L. Shumway ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Proof Of Concept ◽  
Resonance Imaging ◽  
Intravascular Contrast Agent

Quantitative renal cortical perfusion in human subjects with magnetic resonance imaging using iron-oxide nanoparticles: influence of t1 shortening

2008 ◽  
Vol 49 (8) ◽  
pp. 955-962 ◽  
Author(s):  
A. Morell ◽  
H. Ahlstrom ◽  
S. O. Schoenberg ◽  
A. Abildgaard ◽  
M. Bock ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Iron Oxide ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Iron Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Resonance Imaging ◽  
Quantitative Perfusion ◽  
Intravascular Contrast Agent ◽  
Cortical Perfusion

Background: Using conventional contrast agents, the technique of quantitative perfusion by observing the transport of a bolus with magnetic resonance imaging (MRI) is limited to the brain due to extravascular leakage. Purpose: To perform quantitative perfusion measurements in humans with an intravascular contrast agent, and to estimate the influence of the T1 relaxivity of the contrast agent on the first-pass response. Material and Methods: Renal cortical perfusion was measured quantitatively in six patients with unilateral renal artery stenosis using a rapid gradient double-echo sequence in combination with an intravenous bolus injection of NC100150 Injection, an intravascular contrast agent based on iron-oxide nanoparticles. The influence of T1 relaxivity was measured by comparing perfusion results based on single- and double-echo data. Results: The mean values of cortical blood flow, cortical blood volume, and mean transit time in the normal kidneys were measured to 339±60 ml/min/100 g, 41±8 ml/100 g, and 7.3±1.0 s, respectively, based on double-echo data. The corresponding results based on single-echo data, which are not compensated for the T1 relaxivity, were 254±47 ml/min/100 g, 27±3 ml/100 g, and 6±1.2 s, respectively. Conclusion: The use of a double-echo sequence enabled elimination of confounding T1 effects and consequent systematic underestimation of the perfusion.

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.

scholarly journals Silica-Coated Fe3O4 Nanoparticles as a Bifunctional Agent for Magnetic Resonance Imaging and ZnII Fluorescent Sensing

2021 ◽  
Vol 20 ◽  
pp. 153303382110365
Author(s):  
Lin Qiu ◽  
Shuwen Zhou ◽  
Ying Li ◽  
Wen Rui ◽  
Pengfei Cui ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Quantum Interference ◽  
Inductively Coupled Plasma ◽  
Fluorescence Emission ◽  
Mri Contrast Agent ◽  
Core Shell ◽  
Resonance Imaging

Bifunctional magnetic/fluorescent core-shell silica nanospheres (MNPs) encapsulated with the magnetic Fe3O4 core and a derivate of 8-amimoquinoline (N-(quinolin-8-yl)-2-(3-(triethoxysilyl) propylamino) acetamide) (QTEPA) into the shell were synthesized. These functional MNPs were prepared with a modified stöber method and the formed Fe3O4@SiO2-QTEPA core-shell nanocomposites are biocompatible, water-dispersible, and stable. These prepared nanoparticles were characterized by X-ray power diffraction (XRD), transmission electron microscopy (TEM), thermoelectric plasma Quad II inductively coupled plasma mass spectrometry (ICP-MS), superconducting quantum interference device (SQUID), TG/DTA thermal analyzer (TGA) and Fourier transform infrared spectroscopy (FTIR). Further application of the nanoparticles in detecting Zn2+ was confirmed by the fluorescence experiment: the nanosensor shows high selectivity and sensitivity to Zn2+ with a 22-fold fluorescence emission enhancement in the presence of 10 μM Zn2+. Moreover, the transverse relaxivity measurements show that the core-shell MNPs have T2 relaxivity (r2) of 155.05 mM−1 S−1 based on Fe concentration on the 3.0 T scanner, suggesting that the compound can be used as a negative contrast agent for MRI. Further in vivo experiments showed that these MNPs could be used as MRI contrast agent. Therefore, the new nanosensor provides the dual modality of magnetic resonance imaging and optical imaging.

Contrast-agent free evaluation of cardiomyopathies with T1 mapping and the new fast strain-encoded (fSENC) magnetic resonance imaging

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
K Hirschberg ◽  
O Paul ◽  
J Salatzki ◽  
F Andre ◽  
J Riffel ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
T1 Mapping ◽  
Hypertensive Heart Disease ◽  
Study Groups ◽  
Resonance Imaging ◽  
Gadolinium Enhancement ◽  
Scan Time ◽  
Normal Individuals

Abstract Background Cardiomyopathies (CMP) may cause impairment of cardiac function and structure. Cardiac Magnetic Resonance Imaging (CMR) is used for analysis and risk stratification of CMP by Late Gadolinium Enhancement (LGE). However, T1 mapping (T1) and fast strain encoded (f-SENC) sequences allow contrast-free and faster exams. The aim of this study was to characterize CMP by T1 and f-SENC to develop a faster and safer CMR protocol (fast-CMR). Methods CMP scans from our CMR database were retrospectively analyzed. All patients were scanned at 1.5T/3T scanner. Study groups were divided as follows: Patients with normal findings, dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), hypertensive heart disease (HHD) and cardiac amyloidosis. Global T1 times, longitudinal (GLS) and circumferential (GCS) strain using f-SENC of study groups were compared to healthy individuals (controls). Scan time and amount of gadolinium-based contrast agent (CA) in CMR-protocol with LGE were compared to fast-CMR. Results 174 patients and 31 controls were recruited. T1 times, GLS and GCS were similar between controls and normal individuals. T1 times were significantly increased (p<0.05), while GLS and GCS were significantly reduced (p<0.05) in all CMR study groups compared to controls (Table 1). Using fast-CMR 21 (±6) min of scan time were saved, about 47%, and 9 (±2) ml of CA were saved per patient. Conclusion Normal findings could be identified by fast-CMR without contrast agent. Fast CMR might also be a useful tool to identify different forms of CMP. Funding Acknowledgement Type of funding source: None

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