MRI of perfluorocarbon emulsion kinetics in rodent mammary tumours

Fan, Xiaobing; River, Jonathan N.; Muresan, Adrian S; Popescu, Carmen; Zamora, Marta; Culp, Rita M.; Karczmar, Gregory S.

doi:10.1088/0031-9155/51/2/002

Cited by 27 publications

(84 citation statements)

References 21 publications

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“…PFCE 2g, Lipoïd 0.12g, glycerin 0.09g and deionized water 2.91g, larger particles were obtained with a hydrodynamic diameter (Z-ave) ~ 250nm and a higher polydispersity index (PdI ~ 0.25). Interestingly, those nanoparticles are however comparable in size with those obtained using the high-energy process described by Fan et al [35].…”

Section: Pfce-lnc Formulationsupporting

confidence: 78%

“…In the literature, sonication in combination with high pressure is often used to obtain PFCELNCs [35,36]. In our case, sonication at atmospheric pressure was used to improve the dispersion of the oil and water phases before the phase-inversion process.…”

Section: Pfce-lnc Formulationmentioning

confidence: 99%

“…Indeed, using Fan's formulation composition [35], i.e. PFCE 2g, Lipoïd 0.12g, glycerin 0.09g and deionized water 2.91g, larger particles were obtained with a hydrodynamic diameter (Z-ave) ~ 250nm and a higher polydispersity index (PdI ~ 0.25).…”

Section: Pfce-lnc Formulationmentioning

confidence: 99%

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Perfluorocarbon-loaded lipid nanocapsules as oxygen sensors for tumor tissue pO2 assessment

Lemaire

Bastiat

Franconi

et al. 2013

European Journal of Pharmaceutics and Biopharmaceutics

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Section: Pfce-lnc Formulationsupporting

confidence: 78%

Section: Pfce-lnc Formulationmentioning

confidence: 99%

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Perfluorocarbon-loaded lipid nanocapsules as oxygen sensors for tumor tissue pO2 assessment

Lemaire

Bastiat

Franconi

et al. 2013

European Journal of Pharmaceutics and Biopharmaceutics

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“…Since then, 19 F imaging has also been utilized for cell-tracking [39,40], tumor imaging [41], and especially in imaging of inflammation [42][43][44][45][46][47]. The C-F bond in perfluorocarbons is amongst the strongest chemical bonds known to man; consequently, PFCs are some of the most stable and inert molecules available for any application.…”

Section: Second-color Mrimentioning

confidence: 99%

“…Despite several examples of successful 19 F in vivo imaging [39][40][41][42][43][44][45][46][47], the MR experiment is inherently limited by low signal sensitivity, and fluorine MRI is often hindered by low SNR due to the limited number of fluorine nuclei that can be delivered to an area of interest. In order to obtain reasonable voxel sizes during an in vivo imaging session, dozens or hundreds of averaging scans are often used, resulting in lengthy examination times.…”

Section: Introductionmentioning

confidence: 99%

New Cardiovascular Applications of the Turbo Spin Echo Sequence in Magnetic Resonance Imaging

Fielden¹

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The advent of fast sequences based on the Rapid Acquisition with Relaxation Enhancement (RARE) sequence allowed T 2 -weighted imaging to be performed in clinically feasible scan times and these sequences have become the workhorse for spin-echo imaging in Magnetic Resonance Imaging (MRI). In this work, we propose several variants and applications of the 3D Turbo Spin Echo (TSE) sequence designed to efficiently image endogenous and exogenous long-T 2 species in the body.There has been renewed interest in developing and utilizing non-contrast MRA methods because of the risk of nephrogenic systemic fibrosis (NSF) in patients with kidney dysfunction. TSE sequences are capable of generating excellent contrast between blood and surrounding tissue based on T 2 differences, but conventional TSE sequences are susceptible to flow-related artifacts and signal loss.Here, a new, hybrid pulse sequence that shares characteristics with the TSE and balanced Steady State Free Precession (bSSFP) sequence is introduced. Desirable T 2 contrast is provided by the TSE-like pulse sequence design and the improved flow-performance characteristics of bSSFP imaging are gained through fully-refocused gradients and refocusing ii iii pulse phase alternation of RF pulses. The principles of flow-independent angiography in the context of this new TSE sequence, including a description of tissue contrast properties, are described. Additionally, a method for fat/water separation based on phase detection is presented for this application which relies on catalyzation of the TSE echo train. This sequence is capable of performing non-contrast enhanced angiography of the peripheral arterial tree by exploiting the T 2 differences between blood and surrounding tissue.In order to take advantage of some of the unique properties afforded by non-Cartesian imaging, a 3D TSE sequence which utilizes spiral readouts was developed. For peripheral angiography, spoiler gradients placed in the through-plane direction remove spurious fat signal, and longer echo spacings are available due to spiral sampling, leading to improved venous suppression. To most efficiently acquire the data, partial k-space coverage along with variable density spirals are used to undersample k-space in a controlled and well-understood manner. Additional techniques to prevent spiral artifacts (blurring) from concomitant and B 0 fields as well as corrections to spiral trajectories are applied.The major focus of MRI research has been on improving resolution, contrast, and shortening acquisition times of standard anatomical images; however, patient outcomes may also be improved by acquiring secondary, functional information about the patient. Yet functionalizing MRI is still in early stages, and much work needs to be done before it is ready to enter the clinic in an impactful way. In a departure from angiography, the TSE sequence is used as an efficient method to generate and utilize signal from fluorine, a secondary nucleus which is of interest for cellular and molecular imaging. Here, th...

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Perfluorooctyl Bromide Polymeric Capsules as Dual Contrast Agents for Ultrasonography and Magnetic Resonance Imaging

Pisani

Tsapis

Galaz

et al. 2008

Adv Funct Materials

120

144

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Polymeric capsules with a thick shell made of biodegradable and biocompatible polymer and a liquid core of perfluorooctyl bromide (PFOB) were evaluated for stability as well as for ultrasound and magnetic resonance imaging (MRI) contrast enhancement. The method of preparation allows the mean capsule diameter to be regulated between 70 nm and 25 µm and the capsule thickness‐to‐radius ratio from 0.25 to 0.54. Capsule diameter remains stable at 37 °C in phosphate buffer for at least 4 and 6 h for nanocapsules and microcapsules, respectively. The in vitro ultrasound signal‐to‐noise ratio (SNR) was measured from 40 to 60 MHz for 6 µm and 150 nm capsules: the SNR increases with capsule concentration up to 20–25 mg mL−1, and then reaches a plateau that depends on capsule diameter (13.5 ± 1.5 dB for 6 µm and 6 ± 2 dB for the 150 nm capsules). The ultrasound SNR is stable for up to 20 min for microcapsules and for several hours for nanocapsules. For nanocapsules, the thinner the shell, the larger the SNR and the more compressible the capsules. Nanocapsule suspensions imaged in vitro with a commercial ultrasound imaging system (normal and tissue harmonic imaging modes, 7–14 MHz probe) were detected down to concentrations of 12.5 mg mL−1. Injections of nanocapsules (200 µg ml−1) in mice in vivo reveal that the initial bolus passage presents significant ultrasound enhancement of the blood pool during hepatic imaging (7–14 MHz probe, tissue harmonic imaging mode). 19F‐MRI images were obtained in vitro at 9.4T using spin‐echo and gradient echo sequences and allow detecting nanocapsules in suspension (50 mg mL−1). In conclusion, these results show initial feasibility for development of these capsules toward a dual‐modality contrast agent.

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MRI of perfluorocarbon emulsion kinetics in rodent mammary tumours

Cited by 27 publications

References 21 publications

Perfluorocarbon-loaded lipid nanocapsules as oxygen sensors for tumor tissue pO2 assessment

Perfluorocarbon-loaded lipid nanocapsules as oxygen sensors for tumor tissue pO2 assessment

New Cardiovascular Applications of the Turbo Spin Echo Sequence in Magnetic Resonance Imaging

Perfluorooctyl Bromide Polymeric Capsules as Dual Contrast Agents for Ultrasonography and Magnetic Resonance Imaging

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