OS-MPI: an open-source magnetic particle imaging project

Mattingly, Eli; Mason, Erica; Herb, Konstantin; Śliwiak, Monika; Brandt, Katrin; Cooley, Clarissa Zimmerman; Wald, Lawrence

doi:10.18416/ijmpi.2020.2009059

Cited by 4 publications

(2 citation statements)

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“…We present a versatile and sensitive device capable of many different methods of particle characterization across a wide dynamic range of particle masses. The hardware is specified on a publicly available repository as part of the broader Open-source MPI project at os-mpi.github.io 60 alongside the software to allow for replication and modifications.…”

Section: Discussionmentioning

confidence: 99%

Open-source device for high sensitivity magnetic particle spectroscopy, relaxometry, and hysteresis loop tracing

Mattingly,

Barksdale,

Śliwiak

et al. 2024

Review of Scientific Instruments

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Magnetic nanoparticles (MNPs) are used extensively across numerous disciples, with applications including Magnetic Particle Imaging (MPI), targeted hyperthermia, deep brain stimulation, immunoassays, and thermometry. The assessment of MNPs, especially those being designed for MPI, is performed with magnetic particle spectrometers, relaxometers, loop tracers, or similar devices. Despite the many applications and the need for particle assessment, there are few consolidated resources for designing or building such a MNP assessment system. Here, we describe the design and performance of an open-source device capable of spectroscopy, relaxometry, and loop tracing. We show example measurements from the device and quantify the detection sensitivity by measuring a dilution series of Synomag-D 70 nm (from 0.5 mg Fe/ml to 7 ng Fe/ml) with a 10 mT drive field at 23.8 kHz. The device measures 260 pg Fe with SNR = 1 and 1.3 ng at SNR = 5 in spectroscopy mode in under one second of measurement time. The system has a dynamic range of 60 μg to 260 pg Fe without changing the hardware configuration. As an example application, we characterize Synomag-D’s relaxation time constant for drive fields 2–18 mT and compare the magnetization responses of two commonly used MNPs.

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Section: Discussionmentioning

confidence: 99%

Open-source device for high sensitivity magnetic particle spectroscopy, relaxometry, and hysteresis loop tracing

Mattingly,

Barksdale,

Śliwiak

et al. 2024

Review of Scientific Instruments

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“…Magnetic particle imaging was performed using a previously described (Mattingly et al 2022 ) home-built rodent FFL MPI scanner, the design of which has been made available via the Open-Source MPI project (Mattingly et al 2020 ). It was designed for sensitive, stable, continuous rotation allowing time-series imaging over multi-hour experiments.…”

Section: Methodsmentioning

confidence: 99%

Functional magnetic particle imaging (fMPI) of cerebrovascular changes in the rat brain during hypercapnia

et al. 2023

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Objective. Non-invasive functional brain imaging modalities are limited in number, each with its own complex trade-offs between sensitivity, spatial and temporal resolution, and the directness with which the measured signals reflect neuronal activation. Magnetic Particle Imaging (MPI) directly maps the cerebral blood volume (CBV), and its high sensitivity derives from the nonlinear magnetization of the superparamagnetic iron oxide nanoparticle (SPION) tracer confined to the blood pool. Our work evaluates functional MPI (fMPI) as a new hemodynamic functional imaging modality by mapping the CBV response in a rodent model where CBV is modulated by hypercapnic breathing manipulation. Approach. The rodent fMPI time-series data were acquired with a mechanically rotating field-free line MPI scanner capable of 5 sec temporal resolution and 3 mm spatial resolution. The rat's CBV was modulated for 30 minutes with alternating 5 min hyper-/hypocapnic states, and processed using conventional fMRI tools. We compare our results to fMRI responses undergoing similar hypercapnia protocols found in the literature, and reinforce this comparison in a study of one rat with 9.4T BOLD fMRI using the identical protocol.Main results. The initial image in the time-series showed mean resting brain voxel SNR values, averaged across rats, of 99.9 following the first 10 mg/kg SPION injection and 134 following the second. The time-series fit a conventional General Linear Model (GLM) with a 15-40% CBV change and a peak pixel CNR between 12 and 29, 2-6x higher than found in fMRI.Significance. This work introduces a functional modality with high sensitivity, although currently limited spatial and temporal resolution. With future clinical-scale development, a large increase in sensitivity could supplement other modalities and help transition functional brain imaging from a neuroscience tool focusing on population averages to a clinically relevant modality capable of detecting differences in individual patients.

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Concept for using magnetic particle imaging for intraoperative margin analysis in breast-conserving surgery

Mason

Mattingly

Herb

et al. 2021

Sci Rep

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Breast-conserving surgery (BCS) is a commonly utilized treatment for early stage breast cancers but has relatively high reexcision rates due to post-surgical identification of positive margins. A fast, specific, sensitive, easy-to-use tool for assessing margins intraoperatively could reduce the need for additional surgeries, and while many techniques have been explored, the clinical need is still unmet. We assess the potential of Magnetic Particle Imaging (MPI) for intraoperative margin assessment in BCS, using a passively or actively tumor-targeted iron oxide agent and two hardware devices: a hand-held Magnetic Particle detector for identifying residual tumor in the breast, and a small-bore MPI scanner for quickly imaging the tumor distribution in the excised specimen. Here, we present both hardware systems and demonstrate proof-of-concept detection and imaging of clinically relevant phantoms.

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OS-MPI: an open-source magnetic particle imaging project

Cited by 4 publications

References 0 publications

Open-source device for high sensitivity magnetic particle spectroscopy, relaxometry, and hysteresis loop tracing

Open-source device for high sensitivity magnetic particle spectroscopy, relaxometry, and hysteresis loop tracing

Functional magnetic particle imaging (fMPI) of cerebrovascular changes in the rat brain during hypercapnia

Concept for using magnetic particle imaging for intraoperative margin analysis in breast-conserving surgery

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