TCSUH.NET --> Ultra-Low Field Magnetic Imaging
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Dr. Audrius Brazdeikis |
Research Associate Professor of Physics
Project Leader, HTS Biomagnetic Imaging & Nanomedicine Laboratory
audrius {at] uh [dot} eduThe main focus of this Laboratory is to develop and investigate the use of Superconducting QUantum Interference Device (SQUID)-based sensors for new emerging biomedical imaging and diagnostic applications. |
Current Projects/Achievements: |
PRENATAL DIAGNOSTICS & NEUROASSESMENT |
There is a strong need to assess the physiological development of the fetus, as more pre- and full-term babies survive with various disorders. Important parameter for the diagnostic use is the basal fetal heart rate (FHR) disclosing the presence or absence of accelerations and decelerations and baseline variability associated with the development of Autonomic Nervous System (ANS). In the last few years, advantages and medical relevance of the fetal magnetocardiography (fetal-MCG) have been shown. Fetal-MCG is the measurement of magnetic fields (a few pT in amplitude) emitted by the fetal heart from small currents by electrically active cells of the heart muscle. The measurements are taken by SQUID sensors in one or several spatial locations above the pregnant abdomen and provide information which is complementary to that provided by direct, contact electro-physiological measurements. Typically, the quality of fetal-magnetocardiographic recording is significantly higher than that of the corresponding electric or Doppler recordings. Fetal biomagnetic signals are unaffected by poor electrical conductivity of the vernix caseosa, a waxy substance which forms on the fetal skin at about 25 weeks’ gestation and impedes the transmission of fetal bioelectric signals. |
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Our research focuses on development of ultra-sensitive superconducting sensor technology for a reliable detection of true electrophysiological events with the precision of 1-5 ms to accurately quantify beat-to-beat heart rate variability in unshielded clinical settings. |
NANOPARTICLE IMAGING & BIOMEDICAL DIAGNOSTICS |
A distinct advantage of choosing magnetic nanoparticles is the transparency of tissue to magnetic fields permitting detection, localization and manipulation of nanoparticle sources within the body. There are many potential applications such as study of cell biophysics, novel bio-assays and bio-forensics, drug delivery, detection and removal of bio-toxins. |
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Our research focuses on development of novel nanoparticle sensing and imaging technologies based on SQUID sensors for detecting early signs of acute graft rejection in organ transplantation, myocardial tissue injury, and to characterize vulnerable plaque. We use COMSOL modeling to design and optimize practical implementations of new high magnetic gradient devices for more precise targeting of magnetic nanocarriers in human and animal models. |
MAGNETIC SENSING TECHNOLOGIES FOR STAGING & TREATMENT OF CANCER |
Many primary tumors spread via lymphatic drainage, therefore lymph node staging and localization of pathological lymph nodes remains a cornerstone in choosing the most appropriate intervention. Non-invasive methods such as ultrasonography, CT, PET to stage regional lymph nodes have not shown to be accurate. Sentinel lymph nodes (SLN) can also be mapped using MRI techniques, but this application does not allow probe guided surgery. |
| One of the successes of the first “UK-Texas Bioscience Collaboration Initiative” was the development of a proof-of-concept HTS SQUID-based device that detects very small concentrations of iron oxide based contrast agents used for MRI. For the purpose of SLN detection, the probe was configured to detect a commercially available, FDA-approved dextran-coated superparamagnetic iron oxide. An initial clinical evaluation of the magnetometer was undertaken at the University College London Hospital. Ten patients with newly diagnosed breast cancer underwent sentinel node biopsy with Endorem® (Feridex I.V.), blue dye and radiocolloid injections. In some cases pre-operative MRI was performed as well as lymphoscintigraphy to compare the imaging capabilities of the different methods. In each of the 10 patients, the SLN biopsy procedure was successful, and a total of 19 sentinel nodes were retrieved using the prototype hand-held magnetometer. |
Our group has recently built an improved HTS SQUID system (SentiMag-One) for magnetically guided surgery. The SQUID system is installed at the Guy’s Hospital in London and currently being used in a clinical trial of breast cancer run by our collaborator Michael Douek, MD. |
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The SentiMag technology was licensed toEndomagnetics Ltd. in 2009. |
The presence of metastases in regional lymph nodes is important not just in breast cancer but in a variety of cancers. Our current research focuses on multimodal imaging capability and developing ultra-sensitive specialized probes for both preoperative planning and intraoperative use. For further information contact the project leader Dr. Audrius Brazdeikis |
