PH-weighted MRI using fast amine chemical exchange saturation transfer (CEST) imaging

A system for performing pH-weighted chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI), comprising:

• (a) a magnetic resonance imaging scanner adapted to image a subject;
• (b) an imaging controller with a computer processor coupled to the imaging scanner;
• and
• (c) a non-transitory computer-readable memory storing instructions executable by the computer processor;
• (d) wherein said instructions, when executed by the computer processor, perform steps comprising:
• (i) applying radiofrequency saturation pulse trains of approximately 300 ms in duration at a range of frequency offsets with frequencies off-resonance from bulk water;
• (ii) applying excitation pulses;
• (iii) applying imaging readout pulses to acquire CEST data;
• and
• (iv) producing pH-weighted images from the CEST data;
• and
• (e) a display configured to display the pH-weighted images.

A method for obtaining a magnetic resonance image or spectrum, the method comprising:

• (a) applying a radiofrequency saturation pulse train of three 100-ms pulses with a frequency off-resonance from bulk water;
• (b) applying a spoiler gradient;
• (c) applying a 1-2-1 water-only RF excitation pulse;
• (d) applying an echo planar imaging readout pulse train to acquire pH-weighted image data;
• and
• (e) producing an image from the pH-weighted image data, with one full image acquired at a range of frequency offsets.