Clinical

Magnetic Particle Imaging in Medicine

Magnetic Particle Imaging (MPI) is a new imaging technology that answers a clinical need for a safe, rapid 3D angiography technique without ionizing radiation or toxic tracers to image intracranial diseases such as stenosis (stroke), aneurysm, vasospasms and malformations. The MPI tracer is made with super-paramagnetic iron oxide (SPIO) , significantly safer than iodine (used in CT and fluoroscopy), and gadolinum (used in MRI). The safe tracer and absence of harmful radiation leads to reduced long-term medical costs for patient undergoing diagnostic angiography, and especially patients undergoing repeated diagnostic angiography procedures associated with long-term care.

MPI will bring benefit to a broad application portfolio such as contrast enhanced imaging for cancer detection, and uniquely enable therapeutic cell tracking to sites of pathology such as inflammation, cancer, cardiac and neuronal damage (Figure 1).

Addressing Safe Imaging for the 21st Century

Unlike CT, MRI and PET, Magnetic Particle Imaging does not require toxic contrast agents or use mutagenic radiation. MPI’s safety is driven by the use of a clinically approved SPIO nanoparticles, which have been proven safe for patients with weak or damaged kidneys. These nanometer-sized particles are easily broken down in the body and turned into hemoglobin. MPI perfectly supports long term diagnostic monitoring without cumulative radiation or toxicities.

MPI ECHO
(US)
PET/
SPECT
MRI CT
Emerging
Applications
in Clinical
Imaging
Early Stage
Inflammation
+++ +/-
Vulnerable
Plaques
+++ +/-
Screening/
Staging

(Safe, non-ionizing)
+++ +++ +++ +/-
Current
Methods
Functional
(Perfusion, viability)
+++ +++ +++ +++ +/-

Figure 1: Requirements in cardiovascular and inflammation imaging. As a tracer imaging modality that does not use radiation, MPI has the potential for screening for early stage, asymptomatic cardiovascular disease. MPI should also be able to assess cerebral and cardiovascular blood flow and perfusion.

 

High Contrast for Clear Decisions

Since MPI directly detects a tracer and does not see tissue, it creates a “Positive Contrast” image. This means that, when performing angiography, vasculature shows up bright against a black background.

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Figure 2: Experimental MPI image of a human coronary artery phantom filled with diluted tracer approved for human use in the EU, Resovist. 10 min acquisition, 5 x 10 x 3.75 cm FOV.

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Figure 3: Volume rendering of MPI perfusion. Yellow depicts major artery and veins, while blue are areas of tissue perfusion. All areas can be quantified to the nanogram of SPIO in a function of space and time.

Exquisite Sensitivity

MPI’s ultra-high sensitivity will not only enable earlier diagnostic detection, but support new methods in translational protocols to track cells in humans to allow early determination of therapeutic efficacy. For example, MPI is ideally suited for the developing field of immune and stem cell tracking as no other technology can follow small cell populations within a human for extended periods of time.