A Single-Sided Magnetic Particle Imaging Scanner for In Vivo Breast Cancer Imaging - This proposal focuses on developing a novel specialized Magnetic Particle Imager. Magnetic Particle Imaging
(MPI) is an emerging non-invasive tomographic imaging modality; like CT or MRI, it could be applied in clinical
and research settings as a safe diagnostic technique, but without ionizing radiation or toxic tracers. One of the
major MPI challenges toward clinical translation has been the ability to scale up the coils to surround a human
body while being able to generate and drive the sufficiently strong magnetic field gradient required for high
spatial resolution. These requirements, however, demand prohibitively high power consumption in a device
with cylindrical geometry; therefore, alternative topologies, such as an open geometry scanner, would be highly
desirable. The goal of this renewal proposal is to develop a novel single-sided MPI imager and demonstrate in
vivo cancer imaging in rodents. The single-sided device has all the hardware on one side of the imaging
volume; therefore, such a device can be used equally well on small animals and humans for multidimensional
diagnostic imaging and as an MPI spectrometer (MPS). In our unique approach, we will develop a single-sided
MPI imager with much more promising field topology, namely, field-free line (FFL) as opposed to the more
common and relatively easier to implement field-free point (FFP) geometry, for a potential 10-fold increase of
SNR, more robust image reconstruction, and larger field of view.
To date, we have built a first prototype of a single-sided scanner with the FFL geometry that consists of all the
required coils in a unilateral configuration. We further validated our device by demonstrating 1D and 2D
imaging as well as high sensitivity signal detection using a point-source phantom. Developing a fully capable
3D scanner based on single-sided geometry has direct clinical relevance in breast cancer imaging.
We pursue two specific aims: 1) Develop a single-sided scanner for dynamic multislice 3D MPI imaging with
mechanical rotation. The main objective of this aim is to demonstrate 3D imaging with our MPI scanner. We
will upgrade the hardware and signal automation, such as the height control of the FFL for 3D imaging,
gradient strength adjustment, and imaging sequence. 2) Validate scanner performance in tumor-bearing mice
in in vivo imaging studies. The diagnostic capability of the MPI scanner, such as sensitivity and spatio-temporal
resolution, will be analyzed using functionalized and nonfunctionalized tracers.
The overall strength of the proposed research lies in developing the first ever MPI scanner with open geometry
that could potentially be translated to clinical settings. Specifically, we hope to deliver a more sensitive and
non-invasive tool for breast cancer screening that has a direct impact on women health.
