Traditional Posters: Miscellaneous

Timo Frederik Sattel¹, Tobias Knopp¹, Sven Biederer¹, Thorsten M. Buzug<sup>1

1</sup>Institute of Medical Engineering, University, Luebeck, Germany

Magnetic particle imaging is a method capable of determining the spatial distribution of super-paramagnetic iron oxide particles. To obtain information about the particle distribution, a field-free point is steered on a trajectory through the field-of-view. For magnetic field generation and particle signal reception, electromagnetic coils are used. In their original paper, Gleich and Weizenecker proposed a tube-like scanner setup. In this contribution, a new coil geometry is introduced. It provides lateral access to the specimen and thus allows for interventional MPI. To prove feasibility, 2D FFP trajectories are simulated, which give promising results.

946. Reconstruction of Phase Rotation Spectroscopy Data on Partial Parallel Array MRI Systems

Sarah Andrea Wijtenburg^1,2, Jack Knight-Scott<sup>1

1</sup>Radiology, Children's Healthcare of Atlanta, Atlanta, GA, United States; ²Biomedical Engineering, University of Virginia, Charlottesville, VA, United States

Current algorithms for combining coil signals from partial parallel array MRI systems negate the effects of the phase rotation technique in ¹H-MRS. Here, we present an altered processing method to overcome these challenges.

947. A New Detection Scheme for Ultrafast 2D COSY

Shuhui Cai¹, Mingfang Zhao¹, Zhong Chen<sup>1

1</sup>Department of Physics, Xiamen University, Xiamen, Fujian, China

Two-dimensional NMR techniques greatly extend the application fields of NMR spectroscopy. Unfortunately, the collection of numerous t₁ increments leads 2D experiments fairly time-consuming. The spatial encoding ultrafast technique enables fast acquisition of 2D NMR spectra. In this abstract, a new ultrafast 2D COSY method based on continuous constant-time phase-modulated spatial encoding was proposed. Compared to the previous real-time phase-modulated method, the present method not only gives much better spectral signal-to-noise ratio and resolution, but also is much easier to implement.

948. Characterizing Intermolecular Multiple-Quantum Coherence Signals Between Spin-1/2 and Spin-3/2 Nuclei

Wen Zhang¹, Shuhui Cai¹, Zhong Chen<sup>1

1</sup>Department of Physics, Xiamen University, Xiamen, Fujian, China

The intermolecular multiple-quantum coherence (iMQC) signals between ¹H (spin-1/2) and ²³Na (spin-3/2) nuclei were studied theoretically and experimentally using the CRAZED pulse sequence. The results show that no matter which spin is detected, the dependences of the iMQC signal intensities on the RF pulse flip angles follow the same rules and are identical to those for other heteronuclear systems, implying that heteronuclear iMQCs have same properties in liquid NMR.

949. Removal of FM Sidebands Artifacts in NWS MRS by QZ-Bac Algorithm

Jyh-Miin Lin¹, Hsiao-Wen Chung², Shang-Yueh Tsai<sup>3

1</sup>Department of Radiology, Mackay Memorial Hospital, Taipei, Taiwan; ²Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan; ³Department of Electrical Engineering, Chang Gung University, Tao Yuan, Taiwan

1H non-water suppressed(NWS) MRS is a developing technique to in vivo metabolites concentration, with high accuracy than conventional water suppressed(WS) MRS. In NWS MRS, complete removal of water signal is critical for quantifying metabolites concentration. We propose a novel postacqusitional (QZ-bac) algorithm to eliminate water peaks and water related sidebands. With this method, the water related frequency modulation signals were completely removed by exploiting the antisymmetry property. Computer simulations and in vivo demonstration were shown.

950. High Precision Calibration of MRS Thermometry Using Validated Temperature Standards

Elena Vescovo¹, Andrew Levick², Sha Zhao¹, Graham Machin², Charmaine Childs³, Timothy Rainey³, Steve Williams<sup>1

1</sup>Imaging Science and Biomedical Engineering, The University of Manchester, Manchester, Greater Manchester, United Kingdom; ²Temperature Group, National Physical Laboratory, Teddington, Middlesex, United Kingdom; ³Brain Injury Research Group, The University of Manchester, Manchester, Greater Manchester, United Kingdom

Estimation of temperature by MRS from the chemical shift of water relative to N-acetylaspartate (NAA) relies on a calibration curve. To date these have never been related back to primary standards. We describe extremely stable temperature control of an MRS phantom at 1.5T using a circulating water bath and organic fixed-point materials, with measurements related back to the International Temperature Scale 1990 (ITS-90) at the UK National Physical Laboratory. Frequency differences (water-NAA) were highly reproducible (SD<10-4 ppm) at fixed temperature and R2 for the fit was 0.9996. Ionic strength affected the intercept but not slope of the temperature calibration.

951. In Vivo Temperature Brain Map Using Jmrui V4.X: A Plugin Development