Traditional Posters: Miscellaneous

Spectroscopy Localization & Imaging Methodology

Hall B Monday 14:00-16:00

957. Simultaneous Acquisition of Metabolite and Water Signals in 3D Echo Planar Spectroscopic Imaging

Toru Shirai¹, Satoshi Hirata¹, Yoshitaka Bito<sup>1

1</sup>Central Research Laboratory, Hitachi, Ltd., Kokubunji, Tokyo, Japan

We have developed a technique for simultaneously acquiring of metabolite and water signals in 3D echo planar spectroscopic imaging (EPSI). The pulse sequence of this technique includes three CHESS pulses the amplitude of which is switched alternately in accordance with slice encoding steps to reverse the polarity of the water signal. The metabolite signal is separable from the water signal, because the water signal is shifted to the top and bottom of the reconstructed 3D image. The results of phantom experiments showed that this technique effectively corrected the eddy current influence, suggesting the usefulness of the proposed method.

958. Accelerated Reconstruction Using Parallel Computing for Spiral Spectroscopic Imaging

Dong-Hyun Kim¹, Yoon-Ho Oh¹, Yoon-Ho Nam¹, Meng Gu², Won-Woo Ro<sup>1

1</sup>Electrical and Electronic Engineering, Yonsei University, Seoul, Korea, Republic of; ²Radiology, Stanford University, Stanford, United States

Fast spectroscopic imaging such as spiral CSI can be used for applications such as real time metabolite imaging or real time temperature mapping. While methods to reduce the data acquisition time have been continuously developed, reconstruction times have been prolonged. We demonstrate the usage of parallel computing to reduce the reconstruction time of spiral CSI. By using a multi-threading approach, reconstruction times during the gridding routine can be shortened to by a factor of eight.

959. Water Suppression for Diffusion-Weighted Line-Scan Echo-Planar Spectroscopic Imaging

Yoshitaka Bito¹, Koji Hirata¹, Toshihiko Ebisu², Yuko Kawai³, Yosuke Otake¹, Satoshi Hirata¹, Toru Shirai¹, Yoshihisa Soutome¹, Hisaaki Ochi¹, Masahiro Umeda³, Toshihiro Higuchi⁴, Chuzo Tanaka<sup>4

1</sup>Central Research Laboratory, Hitachi, Ltd., Kokubunji-shi, Tokyo, Japan; ²Neurosurgery, Nantan General Hospital, Nantan-shi, Kyoto, Japan; ³Medical Informatics, Meiji University of Integrative Medicine, Nantan-shi, Kyoto, Japan; ⁴Neurosurgery, Meiji University of Integrative Medicine, Nantan-shi, Kyoto, Japan

A water suppression (WS) technique for diffusion-weighted line-scan echo-planar spectroscopic imaging (DW-LSEPSI) is presented. DW-LSEPSI uses a single chemical shift selective (CHESS) pulse for WS at each acquisition of a line suitable for a short acquisition time and to reduce a water signal using a steady state effect. The signal attenuation of the water signal is numerically analyzed and demonstrated by applying this technique to phantoms and a rat brain in vivo.

960. An Investigation of the Acceleration Factor in TE-Averaged Data-Sharing Radial Proton Echo Planar Spectroscopic Imaging (DsrPEPSI)

Chin-Yu Lu¹, Yi-Ru Lin², Stefan Posse^3,4, Shang-Yueh Tsai<sup>5

1</sup>Biomedical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan; ²Eletronic Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan; ³Department of Neurology, University of New Mexico School of Medicine, Albuquerque, Albuquerque, New Mexico 87131, United States; ⁴Electrical and Computer Engineering Department, University of New Mexico, Albuquerque, NM, United States; ⁵Electrical Engineering, Chang Gung University, Taoyuan, Taiwan

Previous dsrPEPSI study which measured glutamate (Glu) shown the feasibility to reduce scan time from 16 mins to 1min. However, as scan time reduced, the SNR decreased and poor spectra qualities were observed. This study conducted to investigate and optimize the spectra quality versus scan time by tuning the arrangement of radial trajectories and TEs. From our result, 4-fold dsrPEPSI is feasible to acquire Glu at a 3T system while maintaining spectral quality. And the scan time was 4 minutes, which was a reasonable length for clinical use.

961. High-Speed GABA Mapping in Human Brain with MEGA-PEPSI at 3 Tesla