Application of Magnetic Particle Imaging to Pulmonary Imaging Using Nebulized Magnetic Nanoparticles

Nishimoto, Kohei; Mimura, Atsushi; Aoki, Marina; Banura, Natsuo; Murase, Kenya

doi:10.4236/ojmi.2015.52008

Cited by 39 publications

(38 citation statements)

References 22 publications

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“…This work on MPI lung perfusion adds to previous work on MPI preclinical imaging in the torso region, including on lung ventilation, whole body blood pool imaging and whole body stem cell tracking (showing 200 cell sensitivity) (Nishimoto et al 2015; Keselman et al 2016; Zheng, Vazin, et al 2015; Zheng, See, et al 2016). Collectively, the high quality images and range of applications demonstrated in the literature suggest the general utility of MPI for lung imaging.…”

Section: Discussionmentioning

confidence: 71%

“…Previously, Nishimoto (Nishimoto et al 2015) demonstrated promise for MPI in lung imaging with the first in vivo MPI ventilation studies in mice using a nebulized microsprayer to deliver Resovist to the lungs. Here, we report a method for preparing a novel MPI lung perfusion imaging agent, macroaggregated albumin-SPIOs (MAA-SPIOs), and demonstrate its efficacy and biodistribution for in vivo MPI lung perfusion imaging in rats.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Firstin vivomagnetic particle imaging of lung perfusion in rats

Zhou¹,

Jeffris²,

Yu³

et al. 2017

Phys. Med. Biol.

102

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Pulmonary embolism (PE), along with the closely related condition of deep vein thrombosis, affect an estimated 600,000 patients in the US per year. Untreated, PE carries a mortality rate of 30%. Because many patients experience mild or non-specific symptoms, imaging studies are necessary for definitive diagnosis of PE. Iodinated CT pulmonary angiography (CTPA) is recommended for most patients, while nuclear medicine-based ventilation/perfusion (V/Q) scans are reserved for patients in whom the use of iodine is contraindicated. Magnetic particle imaging (MPI) is an emerging tracer imaging modality with high image contrast (no tissue background signal) and sensitivity to superparamagnetic iron oxide (SPIO) tracer. Importantly, unlike CT or nuclear medicine, MPI uses no ionizing radiation. Further, MPI is not derived from magnetic resonance imaging (MRI); MPI directly images SPIO tracers via their strong electronic magnetization, enabling deep imaging of anatomy including within the lungs, which is very challenging with MRI. Here, the first high-contrast in vivo MPI lung perfusion images of rats are shown using a novel lung perfusion agent, MAA-SPIOs.

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Section: Discussionmentioning

confidence: 71%

Section: Introductionmentioning

confidence: 99%

Firstin vivomagnetic particle imaging of lung perfusion in rats

Zhou¹,

Jeffris²,

Yu³

et al. 2017

Phys. Med. Biol.

102

View full text Add to dashboard Cite

show abstract

“…MPI has been used in several in vivo application domains to date, including cell tracking (Zheng, Vazin, et al 2015; Zheng, See, et al 2016), cancer imaging (Yu et al 2016), blood pool and perfusion imaging (Orendorff et al 2016), angiography and cardiac imaging (J Weizenecker et al 2009), lung ventilation and perfusion studies (Nishimoto et al 2015; Zhou et al 2016), and predicting the effect of MFH (Kuboyabu et al 2016). These results highlight the strengths of MPI: zero background signal, zero depth attenuation of the signal, high sensitivity, linear quantification, and no half-life associated with the tracer signal such that physiologic clearance times determine the time horizons available in longitudinal studies.…”

Section: Introductionmentioning

confidence: 99%

Combining magnetic particle imaging and magnetic fluid hyperthermia in a theranostic platform

et al. 2017

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Magnetic particle imaging (MPI) is a rapidly developing molecular and cellular imaging modality. Magnetic fluid hyperthermia (MFH) is a promising therapeutic approach where magnetic nanoparticles are used as a conduit for targeted energy deposition, such as in hyperthermia induction and drug delivery. The physics germane to and exploited by MPI and MFH are similar, and the same particles can be used effectively for both. Consequently, the method of signal localization by using gradient fields in MPI can also be used to spatially localize MFH, allowing for spatially selective heating deep in the body and generally providing greater control and flexibility in MFH. Furthermore, MPI and MFH may be integrated together in a single device for simultaneous MPI-MFH and seamless switching between imaging and therapeutic modes. Here we show simulation and experimental work quantifying the extent of spatial localization of MFH using MPI systems: We report the first combined MPI-MFH system and demonstrate on-demand selective heating of nanoparticle samples separated by only 3 mm (up to 0.4 C/s heating rates and 150 W/g SAR deposition). We also show experimental data for MPI performed at a typical MFH frequency and show preliminary simultaneous MPI-MFH data.

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“…MPI is best compared to gold-standard tracer imaging techniques, such as nuclear medicine, but without the limitations of radiation safety or radionuclide half-life for longitudinal imaging. As such, MPI shows excellent promise for clinical applications such as angiography (Haegele et al 2012; Salamon et al 2016), stem cell tracking and vitality assessment (Fidler et al 2015; Them et al 2016; Zheng, Vazin, et al 2015; Zheng, von See, et al 2016), brain perfusion (Orendorff et al 2016), lung perfusion (Zhou et al 2016),lung ventilation (Nishimoto et al 2015), cancer imaging (E. Yu et al 2016), and localized hyperthermia (Murase, Aoki, et al 2015; Hensley et al 2016).…”

Section: Introductionmentioning

confidence: 99%

The relaxation wall: experimental limits to improving MPI spatial resolution by increasing nanoparticle core size

Tay

Hensley

Vreeland³

et al. 2017

Biomed. Phys. Eng. Express

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Magnetic Particle Imaging (MPI) is a promising new tracer modality with zero attenuation in tissue, high contrast and sensitivity, and an excellent safety profile. However, the spatial resolution of MPI is currently around 1 mm in small animal scanners. Especially considering tradeoffs when scaling up MPI scanning systems to human size, this resolution needs to be improved for clinical applications such as angiography and brain perfusion. One method to improve spatial resolution is to increase the magnetic core size of the superparamagnetic nanoparticle tracers. The Langevin model of superparamagnetism predicts a cubic improvement of spatial resolution with magnetic core diameter. However, prior work has shown that the finite temporal response, or magnetic relaxation, of the tracer increases with magnetic core diameter and eventually leads to blurring in the MPI image. Here we perform the first wide ranging study of 5 core sizes between 18–32 nm with experimental quantification of the spatial resolution of each. Our results show that increasing magnetic relaxation with core size eventually opposes the expected Langevin behavior, causing spatial resolution to stop improving after 25 nm. Different MPI excitation strategies were experimentally investigated to mitigate the effect of magnetic relaxation. The results show that magnetic relaxation could not be fully mitigated for the larger core sizes and the cubic resolution improvement predicted by the Langevin was not achieved. This suggests that magnetic relaxation is a significant and unsolved barrier to achieving the high spatial resolutions predicted by the Langevin model for large core size SPIOs.

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Application of Magnetic Particle Imaging to Pulmonary Imaging Using Nebulized Magnetic Nanoparticles

Cited by 39 publications

References 22 publications

Firstin vivomagnetic particle imaging of lung perfusion in rats

Firstin vivomagnetic particle imaging of lung perfusion in rats

Combining magnetic particle imaging and magnetic fluid hyperthermia in a theranostic platform

The relaxation wall: experimental limits to improving MPI spatial resolution by increasing nanoparticle core size

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