High speed 1H spectroscopic imaging in human brain by echo planar spatial-spectral encoding

Area of Science:

• Magnetic Resonance Imaging
• Neuroimaging
• Spectroscopy

Background:

• Conventional proton spectroscopic imaging (PSI) is limited by long acquisition times.
• Long scan durations in PSI can lead to motion artifacts, reducing image quality.
• There is a need for faster PSI methods to improve in vivo brain imaging.

Purpose of the Study:

• To introduce a fast and robust spatial-spectral encoding method for human brain proton spectroscopic imaging.
• To enable high-resolution, short echo time (13 ms) imaging with reduced acquisition times.
• To improve the flexibility and reduce motion artifacts in in vivo spectroscopic imaging.

Main Methods:

• A modified echo-planar spectroscopic imaging (EPSI) method was implemented on a 1.5 Tesla scanner.
• Spatial and spectral information were simultaneously encoded using a series of read-out gradients.
• Superficial lipid signals were suppressed using a novel double outer volume suppression technique.

Main Results:

• High-resolution proton spectroscopic images of the human brain were acquired in as little as 64 seconds using surface coils.
• Spectral resolution and signal-to-noise ratio (SNR) for key metabolites (NAA, choline, creatine, inositol) were comparable to conventional methods.
• The rapid encoding time significantly reduced motion artifacts.

Conclusions:

• The developed spatial-spectral encoding method offers a fast and robust approach for in vivo brain spectroscopic imaging.
• This technique enhances flexibility by allowing for shorter scan times and acquisition of multiple datasets.
• The method provides comparable spectral quality to conventional techniques while drastically reducing acquisition time.