A minimum-phase Shinnar-Le Roux spectral-spatial excitation RF pulse for simultaneous water and lipid suppression in 1H-MRSI of body extremities

Paul Kyu Han; Chao Ma; Kexin Deng; Shuang Hu; Kyung-Wook Jee; Kui Ying; Yen-Lin Chen; Georges El Fakhri

doi:10.1016/j.mri.2017.09.008

A minimum-phase Shinnar-Le Roux spectral-spatial excitation RF pulse for simultaneous water and lipid suppression in ¹H-MRSI of body extremities

Magn Reson Imaging. 2018 Jan:45:18-25. doi: 10.1016/j.mri.2017.09.008. Epub 2017 Sep 14.

Authors

Paul Kyu Han¹, Chao Ma¹, Kexin Deng², Shuang Hu³, Kyung-Wook Jee⁴, Kui Ying⁵, Yen-Lin Chen⁶, Georges El Fakhri⁷

Affiliations

¹ Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.
² Biomedical Engineering, Tsinghua University, Beijing, People's Republic of China.
³ Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States; Department of Nuclear Medicine, West China Hospital, Sichuan University, Sichuan, People's Republic of China.
⁴ Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.
⁵ Engineering Physics, Tsinghua University, Beijing, People's Republic of China.
⁶ Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States; Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.
⁷ Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States. Electronic address: elfakhri.georges@mgh.harvard.edu.

Abstract

Purpose: To develop a spectral-spatial (SPSP) excitation RF pulse for simultaneous water and lipid suppression in proton (¹H) magnetic resonance spectroscopic imaging (MRSI) of body extremities.

Methods: An SPSP excitation pulse is designed to excite Creatine (Cr) and Choline (Cho) metabolite signals while suppressing the overwhelming water and lipid signals. The SPSP pulse is designed using a recently proposed multidimensional Shinnar-Le Roux (SLR) RF pulse design method. A minimum-phase spectral selectivity profile is used to minimize signal loss from T₂^⁎ decay.

Results: The performance of the SPSP pulse is evaluated via Bloch equation simulations and phantom experiments. The feasibility of the proposed method is demonstrated using three-dimensional, short repetition-time, free induction decay-based ¹H-MRSI in the thigh muscle at 3T.

Conclusion: The proposed SPSP excitation pulse is useful for simultaneous water and lipid suppression. The proposed method enables new applications of high-resolution ¹H-MRSI in body extremities.

Keywords: (1)H-MRSI; Lipid suppression; Multidimensional SLR pulse; Spectral-spatial pulse; Water suppression.

Publication types

Research Support, Non-U.S. Gov't
Research Support, N.I.H., Extramural

MeSH terms

Algorithms
Humans
Image Processing, Computer-Assisted / methods*
Leg / diagnostic imaging
Leg / physiology*
Lipids
Magnetic Resonance Spectroscopy / methods*
Muscle, Skeletal / diagnostic imaging
Muscle, Skeletal / physiology*
Phantoms, Imaging
Protons
Water

Substances

Lipids
Protons
Water

Abstract

Publication types

MeSH terms

Substances

Grants and funding