Design and characterization of tissue‐mimicking gel phantoms for diffusion kurtosis imaging

Portakal, Z.G.; Jenkins, Christopher W.; Spezi, Emiliano; Perrett, T.; Tunçel, Nina; Phillips, Jonathan

doi:10.1002/mp.12907

Cited by 16 publications

(20 citation statements)

References 43 publications

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“…On the other hand, the SAR values of the Co 0.2 Mn 0.8 Fe 2 O 4 nanoparticles show a non-linear dependency on the frequency of the AMF. This behavior is different from the linear behavior suggested by the linear response theory, which hints at the role of inter-particle interactions [ 35 ]. At the low frequencies of 390.15, 349.20, and 333.45 kHz, the SAR values of the Co 0.2 Mn 0.8 Fe 2 O 4 sample are smaller than those of the CoFe 2 O 4 nanoparticles.…”

Section: Resultscontrasting

confidence: 72%

Specific Absorption Rate Dependency on the Co2+ Distribution and Magnetic Properties in CoxMn1-xFe2O4 Nanoparticles

Narayanaswamy

Al‐Omari

Kamzin³

et al. 2021

Nanomaterials

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Mixed ferrite nanoparticles with compositions CoxMn1-xFe2O4 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) were synthesized by a simple chemical co-precipitation method. The structure and morphology of the nanoparticles were obtained by X-ray diffraction (XRD), transmission electron microscope (TEM), Raman spectroscopy, and Mössbauer spectroscopy. The average crystallite sizes decreased with increasing x, starting with 34.9 ± 0.6 nm for MnFe2O4 (x = 0) and ending with 15.0 ± 0.3 nm for CoFe2O4 (x = 1.0). TEM images show an edge morphology with the majority of the particles having cubic geometry and wide size distributions. The mixed ferrite and CoFe2O4 nanoparticles have an inverse spinel structure indicated by the splitting of A1g peak at around 620 cm−1 in Raman spectra. The intensity ratios of the A1g(1) and A1g(2) peaks indicate significant redistribution of Co2+ and Fe3+ cations among tetrahedral and octahedral sites in the mixed ferrite nanoparticles. Magnetic hysterics loops show that all the particles possess significant remnant magnetization and coercivity at room temperature. The mass-normalized saturation magnetization is highest for the composition with x = 0.8 (67.63 emu/g), while CoFe2O4 has a value of 65.19 emu/g. The nanoparticles were PEG (poly ethylene glycol) coated and examined for the magneto thermic heating ability using alternating magnetic field. Heating profiles with frequencies of 333.45, 349.20, 390.15, 491.10, 634.45, and 765.95 kHz and 200, 250, 300, and 350 G field amplitudes were obtained. The composition with x = 0.2 (Co0.2Mn0.8Fe2O4) with saturation magnetization 57.41 emu/g shows the highest specific absorption rate (SAR) value of 190.61 W/g for 10 mg/mL water dispersions at a frequency of 765.95 kHz and 350 G field strength. The SAR values for the mixed ferrite and CoFe2O4 nanoparticles increase with increasing concentration of particle dispersions, whereas for MnFe2O4, nanoparticles decrease with increasing the concentration of particle dispersions. SARs obtained for Co0.2Mn0.8Fe2O4 and CoFe2O4 nanoparticles fixed in agar ferrogel dispersions at frequency of 765.95 kHz and 350 G field strength are 140.35 and 67.60 W/g, respectively. This study shows the importance of optimizing the occupancy of Co2+ among tetrahedral and octahedral sites of the spinel system, concentration of the magnetic nanoparticle dispersions, and viscosity of the surrounding medium on the magnetic properties and heating efficiencies.

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Section: Resultscontrasting

confidence: 72%

Specific Absorption Rate Dependency on the Co2+ Distribution and Magnetic Properties in CoxMn1-xFe2O4 Nanoparticles

Narayanaswamy

Al‐Omari

Kamzin³

et al. 2021

Nanomaterials

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“…The “natural” phantoms based on cream and asparagus (12, 13, 22) provide single “untunable” kurtosis parameter value and perish quickly. Synthetic phantoms comprising the polyethylene particle suspensions (23) and most recently suggested microbead impregnated gels (24) are more stable, but still suffer from limited range of provided kurtosis parameters (K app < 0.7) and limited precision owing to microscopic sample inhomogeneity, chemical shift (23), and/or low signal-to-noise ratio (SNR) (short T2) (24). Our recent pilot study (25) proposed the development of novel kurtosis phantoms based on lamellar (amorphous layers) and vesicular (fluid-filled microsacs) phases of liquid crystal systems.…”

Section: Introductionmentioning

confidence: 99%

Multicenter Repeatability Study of a Novel Quantitative Diffusion Kurtosis Imaging Phantom

et al. 2019

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Quantitative kurtosis phantoms are sought by multicenter clinical trials to establish accuracy and precision of quantitative imaging biomarkers on the basis of diffusion kurtosis imaging (DKI) parameters. We designed and evaluated precision, reproducibility, and long-term stability of a novel isotropic (i)DKI phantom fabricated using four families of chemicals based on vesicular and lamellar mesophases of liquid crystal materials. The constructed iDKI phantoms included negative control monoexponential diffusion materials to independently characterize noise and model-induced bias in quantitative kurtosis parameters. Ten test–retest DKI studies were performed on four scanners at three imaging centers over a six-month period. The tested prototype phantoms exhibited physiologically relevant apparent diffusion, D app , and kurtosis, K app , parameters ranging between 0.4 and 1.1 (×10 −3 mm 2 /s) and 0.8 and 1.7 (unitless), respectively. Measured kurtosis phantom K app exceeded maximum fit model bias (0.1) detected for negative control (zero kurtosis) materials. The material-specific parameter precision [95% CI for D app : 0.013–0.022(×10 −3 mm 2 /s) and for K app : 0.009–0.076] derived from the test–retest analysis was sufficient to characterize thermal and temporal stability of the prototype DKI phantom through correlation analysis of inter-scan variability. The present study confirms a promising chemical design for stable quantitative DKI phantom based on vesicular mesophase of liquid crystal materials. Improvements to phantom preparation and temperature monitoring procedures have potential to enhance precision and reproducibility for future multicenter iDKI phantom studies.

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“…The thin PEG coating of the IONPs is expected to have a minimal influence on their relaxivity. 31 Agar phantoms are well known to display proton density and diffusion properties similar to those observed in biological tissues 32 so that the obtained relaxation times are comparable to those of human tissue. Thus, PEG-coated IONPs were diluted with deionized water at different Fe concentrations and later embedded in 2% agar.…”

Section: Resultsmentioning

confidence: 94%

Label-Free Iron Oxide Nanoparticles as Multimodal Contrast Agents in Cells Using Multi-Photon and Magnetic Resonance Imaging

Reynders¹,

Zundert²,

Silva³

et al. 2021

IJN

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Introduction The inherent fluorescence properties of iron oxide nanoparticles (IONPs) were characterized, and their applicability for multiphoton imaging in cells was tested in combination with their magnetic resonance imaging (MRI) capabilities. Methods Superparamagnetic iron oxide nanoparticles were synthesized and subsequently coated with polyethylene glycol to make them water-dispersible. Further characterization of the particles was performed using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), dynamic light scattering (DLS), superconducting quantum interference device (SQUID) and magnetic resonance relaxivity measurements. MRI and fluorescence properties of bare IONPs were first studied in solution and subsequently in A549-labeled cells. Results The particles, with a core size of 11.3 ± 4.5 nm, showed a good negative MRI contrast in tissue-mimicking phantoms. In vitro studies in mammalian A549 cells demonstrate that these IONPs are biocompatible and can also produce significant T2/T2* contrast enhancement in IONPs-labeled cells. Furthermore, excitation-wavelength dependent photoluminescence was observed under one- and two-photon excitation. Discussion The obtained results indicated that IONPs could be used for fluorescence label-free bioimaging at multiple wavelengths, which was proven by multiphoton imaging of IONPs internalization in A549 cancer cells.

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Design and characterization of tissue‐mimicking gel phantoms for diffusion kurtosis imaging

Abstract: Glass microspheres can be used to effectively modify diffusion properties of gel phantoms and achieve a range of kurtosis values comparable to those reported for a variety of tissues.

Cited by 16 publications

References 43 publications

Specific Absorption Rate Dependency on the Co2+ Distribution and Magnetic Properties in CoxMn1-xFe2O4 Nanoparticles

Specific Absorption Rate Dependency on the Co2+ Distribution and Magnetic Properties in CoxMn1-xFe2O4 Nanoparticles

Multicenter Repeatability Study of a Novel Quantitative Diffusion Kurtosis Imaging Phantom

Label-Free Iron Oxide Nanoparticles as Multimodal Contrast Agents in Cells Using Multi-Photon and Magnetic Resonance Imaging

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