Bruno Madore¹, Cheng-Chieh Cheng², and Frank Preiswerk^3
1Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States, ²Computer Science and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan, ³Amazon Robotics, Westborough, MA, United States

Physiological motion continues to be a problem in MRI and PET, as it can cause blurring and other types of artifacts. We developed a compact, clonable ultrasound-based sensor system that monitors internal motion directly. Alternative means of motion monitoring often involve hardware (including the scanner itself) that is attached to floors, walls and/or ceilings and thus cannot follow the patient from one room to another, from one procedure to the next. The present sensors attach to the skin, they can follow the patient, and as such they may help link different procedures in ways that take internal motion into account.

Isabelle Saniour¹, Fraser Robb², Victor Taracila², Jana Vincent², Henning U. Voss¹, Michael G. Kaplitt³, J. Levi Chazen¹, and Simone Angela Winkler^1
1Weill Cornell Medicine, New York, NY, United States, ²MR Engineering, GE Healthcare, Aurora, OH, United States, ³Department of Neurological Surgery, Weill Cornell Medicine, New York, NY, United States

Magnetic resonance guided focused ultrasound (MRgFUS) is a non-invasive therapeutic modality for neurodegenerative diseases that allows real-time imaging of the targeted regions. However, MR image quality is poor and severely limits the technology due to the use of the body coil for focal targeting. Acoustic simulations demonstrated an acoustic transparency (signal loss <1%) of the coil when used for thalamic sonication. In vivo results showed increase of the SNR over the body coil by a factor of 7.3 and 7.6 in a brain image with and without the presence of the transducer, respectively.

Xiaoyu Yang¹, Thomas Eastlake¹, Tsinghua Zheng¹, Shireen Geimer², Timothy Raynolds², Paul Meaney², and Keith Paulsen^2
1Innovation, Quality Electrodynamics, LLC, Mayfield Village, OH, United States, ²Thayer School of Engineering, Dartmouth College, Hanover, NH, United States

MR breast imaging has high sensitivity but not high specificity. Microwave Tomography (MT) provides complimentary permittivity information that may improve specificity. MT has poor spatial resolution. Combining MR and MT may address both spatial and specificity issues. Previous MT and MR work demonstrated the MT-MR combination potential. However, there is no dedicated MR coil available for MT-MR combination. The only available coils are the whole-body coil or a single-loop coil that have poor MR image quality. A dedicated 3-ch MRI coil is proposed here for superior MRI imaging quality which enables the next step MT-MR volunteer evaluation. 

Jo Lee^1,2, Ziru Sang^1,2, Yongfeng Yang^1,2, Xiaoliang Zhang³, and Ye Li^1,2
1Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China, ²Shenzhen Key Laboratory for MRI, Shenzhen, China, ³Department of Biomedical Engineering, State University of New York, Buffalo, NY, United States

Simultaneous positron emission tomography/ magnetic resonance imaging(PET/MR) provides advantages in clinical and research applications of human’s brain. The two systems, MRI and PET, can work complementary to provide more information for medical diagnosis. As most research and clinical institutes already have MRI systems, an insert PET and matched MRI coil would be a more economical choice than a PET/MR system. In this study, we designed and built a dedicated quadrature birdcage/47Rx head coil array for PET insert on human’s brain study. The flip-angle maps and SNR performances were measured through a dedicated phantom. Anatomical images were scanned on a volunteer.

Bilal Tasdelen^1,2, Mustafa Utkur^1,2, Ergin Atalar^1,2, and Emine Ulku Saritas^1,2
1Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey, ²National Magnetic Resonance Research Center (UMRAM), Ankara, Turkey

In magnetic particle imaging (MPI), simultaneous excitation and signal acquisition leads to direct feedthrough interference. While this interference can be mitigated up to some extent with passive compensation, its time-varying nature necessitates active compensation methods to achieve the sensitivity levels needed for applications such as stem cell tracking. We have recently proposed an active compensation technique for MRI, which uses a vector modulator and a lookup-table-based algorithm for reducing the direct feedthrough in the analog domain. Here, we adapt this technique to MPI, demonstrating a successful recovery of the fundamental frequency and a significant increase in detection sensitivity.

Michael Seeg¹, Martin Rueckert¹, Stefan Herz², Thomas Kampf^1,3, Thorsten Bley², Volker Behr¹, and Patrick Vogel^1
1Experimental Physics V, Julius-Maximilians-University, Wuerzburg, Germany, ²Department of Diagnostic and Interventional Radiology, University Hospital, Wuerzburg, Germany, ³Department of Diagnostic and Interventional Neuroradiology, University Hospital, Wuerzburg, Germany

X-ray-guided endovascular interventions are important treatment approaches for many cardiovascular diseases such as myocardial infarction, stroke or occlusive peripheral arterial  disease. However, they pose the risk of radiation exposure to patients and staff. Magnetic particle imaging may provide a radiation-free alternative for diagnostic and image guided treatment. A new open bore scanner concept, based on a traveling field free line and super paramagnetic iron oxide tracers is developed especially for interventional treatments. Due to the open design the scanner provides good accessibility to the patient.

Lorne W Hofstetter¹, J Rock Hadley¹, Robb Merrill¹, and Dennis L Parker^1
1Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, United States

Combining the unparalleled soft-tissue imaging capabilities of MR imaging with the precision of robotic-assisted surgeries has the potential to revolutionize image-guided surgical interventions. However, strong magnetic fields generated by the MR system prevent the use of conventional robotic servo motor technologies. Here we present a direct current electromagnetic motor design that uses the electromagnetic interaction between the MR B0 field and currents in the rotor windings to generate rotational mechanical actuation. The motor stall torque and interactions caused by simultaneous motor operation and MR imaging are characterized. This new motor may be useful for robotic assisted interventions performed under MR-guidance.

Guoping Xu^1,2, Yogesh Rathi^2,3, Joan A Camprodon^3,4, and Lipeng Ning^2,3
1Wuhan Institute of Technology, Wuhan, China, ²Brigham and Women's Hospital, Boston, MA, United States, ³Harvard Medical School, Boston, MA, United States, ⁴Massachusetts General Hospital, Boston, MA, United States

Transcranial magnetic stimulation (TMS) is an effective treatment approach for mental disorders. Accurate and rapid prediction of TMS-evoked electric field (E-field) in brain tissue is important for accurate targeting and to understand the mechanism of treatment response. The standard method for E-field prediction is based on physical modeling which usually takes long computational time. In this work, we introduce a method based on deep neural networks (DNNs) for real-time E-field prediction. We show that the trained DNN can predict high-precision whole-brain E-field in 0.24 seconds. Moreover, diffusion-MRI based tissue conductivity tensor can improve the prediction accuracy of E-field.

Lucia Navarro de Lara^1,2, Padmavathi Sundaram ^1,2, Lena Nohava³, Elmar Laistler³, Mohammad Daneshzand^1,2, Lawrence Wald^1,2, Jason Stockmann^1,2, and Aapo Nummenmaa^1,2
1Martinos Center - MGH, Charlestown, MA, United States, ²Harvard Medical School, Boston, MA, United States, ³High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria

To enable concurrent non-invasive stimulation (TMS) and whole-head multimodal imaging (EEG-fMRI), we propose to apply flexible RF coil technology to build a first-of-its-kind TMS compatible integrated multimodal imaging array, the “RF-EEG cap”. The proposed system allows unrestricted positioning of the TMS coil across the entire scalp. We built a 2-channel prototype and conducted a feasibility study analyzing the effects of a TMS coil and EEG-electrodes on the imaging quality (SNR/B0 maps), the in-bore EEG data quality and EPI timeseries stability. Our results indicate that the flexible coaxial RF technology is a feasible choice to build the proposed “RF-EEG Cap”.

Erica Silvestri^1,2,3, Marco Castellaro^1,4, Alessandra Zorz⁵, Andrea Bettinelli ^1,5, Cristina Campi⁶, Marta Paiusco⁵, Diego Cecchin^2,7, and Alessandra Bertoldo^1,2
1Department of Information Engineering, University of Padova, Padova, Italy, ²Padova Neuroscience Center, University of Padova, Padova, Italy, ³Department of Neuroscience, University of Padova, Padova, Italy, ⁴Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy, ⁵Department of Medical Physics, Veneto Institute of Oncology IOV - IRCCS, Padova, Italy, ⁶Department of Math, University of Padova, Padova, Italy, ⁷Department of Medicine, Unit of Nuclear Medicine, University of Padova, Padova, Italy

Simultaneous trimodal EEG-PET-MR imaging can be a tool to delve deeper in the healthy human brain functioning. One of the aspects scarcely investigated is the interplay between HD-EEG net and PET signal detection and reconstruction. In this work, we assess the impact of HD-EEG on both attenuation corrected (AC) and non-attenuation corrected (NAC) PET images. We found that HD-EEG net attenuates PET signal in NAC images in both phantom and human brain, respectively of 3.01%(±3.69%) and of 0.53%(±5.89%). AC images show an opposite behaviour: attenuation correction factor tends to be overestimated in CT- and UTE-derived UMAP obtained with HD-EEG net.

Kazuya Okamoto¹, Takafumi Ohishi², Sojuro Kato¹, Ryuichi Nanaumi³, Kenji Oyama³, and Kazuhiko Fukutani^3
1Advanced MRI Development PJ Team, Canon Medical Systems Corp., Kawasaki, Japan, ²Advanced Technology Research Department, Research and Development Center, Canon Medical Systems Corp., Kawasaki, Japan, ³Medical Products Technology Development Center, R&D Headquarters, Canon Inc., Tokyo, Japan

   New non-contact cardiac and respiratory gating method have been developed, which includes an antenna monitoring heart and respiration movement, and independent triggering pulse generation unit with signal processing software. The resonance frequency of the dipole antenna was tuned to around 550MHz on the chest. The triggering pulse generation unit detected and digitized the S11 signals from the antenna. IIR filter removed the low frequency component and a template matching technique was used to seek the triggering points at the inflection point of filtered waveform. As a result, the prospective gating cardiac imaging was successfully performed for volunteers.

Nicolai Spicher¹, Ramon Barakat¹, and Thomas Martin Deserno^1
1Peter L. Reichertz Institute for Medical Informatics, TU Braunschweig and Hannover Medical School, Braunschweig, Germany

In the last years, research in MRI has expanded towards portable technology, e.g., trailer units carrying conventional scanners or bedside scanners with low-field strengh. The increased portability and shift away from the centralized hospital environment requires wireless data transmission with appropriate data rates to unfold its full potential. In this work, we made use of current fifth-generation (5G) cellular networks for transmitting DICOM data. We demonstrate the potential of reaching more than 50 Mbit/s upload speed using consumer-grade hard- and software. This holds great potential for cellular transmission of data from portable scanners, allowing to increase access to MRI technology.

Audrey Chan¹, Fraser Robb², John Pauly³, Shreyas Vasanawala⁴, and Greig Cameron Scott^5
1Victoria University of Wellington, Wellington, New Zealand, ²GE Healthcare, Aurora, OH, United States, ³Stanford University, Stanford, CA, United States, ⁴Radiology, Stanford University, Stanford, CA, United States, ⁵Electrical Engineering, Stanford University, Stanford, CA, United States

We developed a test system to perform pseudo-random binary sequence (PRBS) generation and clock/data recovery to assess high speed serial link performance of wireless and optical signal integrity for MRI data interfacing. We demonstrate applications using up to 1Gbps signal rates and show impairments for wireless amplitude shift keyed data transmission, as well as plastic fiber optical interfacing.

Wei Qian¹ and Chunqi Qian^1
1Michigan State University, East Lansing, MI, United States

With a compact and batteryless design, the wireless powered parametric oscillator can simultaneously down-convert and frequency encode locally detected MR signals, and wirelessly transmit them to remotely coupled external receivers, thus maintaining superior sensitivity of localized detectors over larger distance separations.

Keerthi Sravan Ravi^1,2, John Thomas Vaughan Jr.², and Sairam Geethanath^2
1Biomedical Engineering, Columbia University, New York, NY, United States, ²Columbia Magnetic Resonance Research Center, New York, NY, United States

This work shows the feasibility of employing  a Raspberry Pi (RPi) single-board computer as a deep learning capable MR workstation. RPi’s ability to run a Tensorflow-Lite optimized brain tumour segmentation model is demonstrated. A comparison of data upload across fixed broadband, cellular broadband (LTE, 3G) and satellite terminal methods of internet access is presented. Finally, the setup described in this work is compared with a conventional fixed MRI workstation and a portable MRI workstation.

Aravind Nagulu¹, Ahmed Kord¹, Gehua Tong¹, Michael Garwood², Lance DelaBarre², Djaudat Idiyatullin², SungMin Sohn³, J. Thomas Vaughan¹, and Harish Krishnaswamy^1
1Columbia University, New York, NY, United States, ²University of Minnesota, Minneapolis, MN, United States, ³Arizona State Univeristy, Tempe, AZ, United States

Traditional MRI employs time division duplexing between the receiver (RX) and transmitter (TX) to avoid RX saturation from TX self-interference. Large switching time between the TX and RX modes demands large TX power and constricts the imaging to tissues with large relaxation times. In this work, we propose a magnetic-free, switch-transmission line circulator which is fully compatible with MRI systems and achieve simultaneous transmit and receive (STAR) MRI.

Christopher Vassos¹, Fraser Robb², Shreyas Vasanawala³, John Pauly¹, and Greig Scott^1
1Electrical Engineering, Stanford University, Stanford, CA, United States, ²GE Healthcare, Aurora, OH, United States, ³Radiology, Stanford University, Stanford, CA, United States

A 5.7mW Silicon Germanium Pre-Amplifier was constructed, characterized, and its potential impact on image quality demonstrated. The amplifier demonstrates significant power savings relative to current implementations at the cost of increased device non-linearity and decreased input impedance. A benchtop measurement setup was constructed to simulate coils signals in conjunction with a physical receive chain. Measured image distortion began at peak input powers of -25dBm. This corresponds to high bandwidth, high dynamic range imaging sequences. For small coil sizes this distortion may not play a role, reducing the power barrier to wireless receive arrays. 

Yue Zhu^1,2, William A Grissom^1,2,3,4, John C Gore^1,2,3,4, and Xinqiang Yan^1,2
1Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, ²Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, ³Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, ⁴Electrical and Computer Engineering, Vanderbilt University, Nashville, TN, United States

A low loss ratio adjustable power splitter (RAPS) was designed with a Wilkinson Splitter, a pair of transmission lines, and a hybrid coupler. There are some potential issues with the previous RAPS: 1. Build a high-performance RAPS circuit with lumped elements is challenging and laborious at 298 MHz. 2. The 100-Ohm RF decoupling resistor poses a safety hazard to the patient. In this abstract, the Wilkinson splitter was replaced with a hybrid coupler, and the adjustable transmission lines are replaced with printed microstrip lines to mitigate the problems mentioned above.

Greig Cameron Scott¹, Audrey Chan², Wonje Lee³, Fraser Robb⁴, John Pauly⁵, and Shreyas Vasanawala^6
1Electrical Engineering, Stanford University, Stanford, CA, United States, ²Victoria University of Wellington, Wellington, New Zealand, ³Pediatric Radiology, Stanford University, Stanford, CA, United States, ⁴GE Healthcare, Aurora, OH, United States, ⁵Stanford University, Stanford, CA, United States, ⁶Radiology, Stanford University, Stanford, CA, United States

A major challenge of wireless MRI is how to implement the data link. Here, progress is made using amplitude shift keyed diode ring modulators, serializer/deserializer components and clock/data recovery to demonstrate bit rate transmissions up to 600 Mbps. High gain biquad reflector antennas and UWB antennas are compared for carriers between 3 and 5 GHz.  These prototypes also demonstrate bandwidth limitations and  electrodynamic interactions in a birdcage test bore on wireless signal integrity. Even if dedicated wireless ICs are not possible, we believe components exist to make an easily integrated modulator for MRI wireless data transmission.

Michael Bock¹, Thomas Lottner¹, and Ali Caglar Özen^1,2
1Radiology - Medical Physics, University Medical Center, Medical Faculty, University Freiburg, Freiburg, Germany, ²German Consortium for Translational Cancer Research (DKTK), Freiburg, Germany

Energy harvesting of the RF fields has been proposed to power small milliwatt RF amplifiers. In this work we demonstrate that the time-varying gradient fields can deliver much higher power levels up to a kW which we used to energize a conventional drip coffee machine. A large pick-up coil was designed in which voltages of 100-200V were induced by rapidly oscillating gradients. The coil was connected to a commercial coffee machine in the magnet, and coffee was prepared in and with the MRI in just 5min.