A method for performing pH-weighted chemical exchange saturation transfer (CEST) magnetic resonance imaging by using a magnetic resonance imaging scanner, the method comprising: (a) applying a radiofrequency saturation pulse train with an off-resonance saturation frequency that is off-resonance from bulk water; (b) applying an excitation pulse at a water proton resonance; (c) applying a readout formed of at least one imaging readout pulse; (d) repeating steps (a)-(c) for a range of frequency offsets with off-resonance saturation frequencies, with one full image acquired at each frequency offset, wherein the images are acquired at off-resonance saturation frequencies of +/- 0, 0.1, 0.2, 0.3, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, and 3.5 ppm; and (e) producing asymmetry images from the acquired images, wherein producing asymmetry images from the acquired images comprises: obtaining a reference S 0 image using the same imaging parameters as the acquired images and without a radiofrequency saturation pulse train; and calculating asymmetry around 2.8-3.2 ppm for each image voxel, wherein calculating asymmetry comprises subtracting an integral of signal for positive frequencies between + 2.8 to + 3.2 ppm from an integral of signal for negative frequencies between -2.8 to -3.2 ppm, and dividing by a signal intensity of the S 0 image; wherein the asymmetry images are pH-weighted and show increasing positive contrast with decreasing pH within a physiologically relevant range; wherein said radiofrequency saturation pulse train consists of three 100 ms Gaussian pulses at a high amplitude of at least 6 μT. (a) applying a radiofrequency saturation pulse train with an off-resonance saturation frequency that is off-resonance from bulk water; (b) applying an excitation pulse at a water proton resonance; (c) applying a readout formed of at least one imaging readout pulse; (d) repeating steps (a)-(c) for a range of frequency offsets with off-resonance saturation frequencies, with one full image acquired at each frequency offset, wherein the images are acquired at off-resonance saturation frequencies of +/- 0, 0.1, 0.2, 0.3, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, and 3.5 ppm; and (e) producing asymmetry images from the acquired images, wherein producing asymmetry images from the acquired images comprises: obtaining a reference S 0 image using the same imaging parameters as the acquired images and without a radiofrequency saturation pulse train; and calculating asymmetry around 2.8-3.2 ppm for each image voxel, wherein calculating asymmetry comprises subtracting an integral of signal for positive frequencies between + 2.8 to + 3.2 ppm from an integral of signal for negative frequencies between -2.8 to -3.2 ppm, and dividing by a signal intensity of the S 0 image; wherein the asymmetry images are pH-weighted and show increasing positive contrast with decreasing pH within a physiologically relevant range; wherein said radiofrequency saturation pulse train consists of three 100 ms Gaussian pulses at a high amplitude of at least 6 μT. obtaining a reference S 0 image using the same imaging parameters as the acquired images and without a radiofrequency saturation pulse train; and calculating asymmetry around 2.8-3.2 ppm for each image voxel, wherein calculating asymmetry comprises subtracting an integral of signal for positive frequencies between + 2.8 to + 3.2 ppm from an integral of signal for negative frequencies between -2.8 to -3.2 ppm, and dividing by a signal intensity of the S 0 image; wherein the asymmetry images are pH-weighted and show increasing positive contrast with decreasing pH within a physiologically relevant range; wherein said radiofrequency saturation pulse train consists of three 100 ms Gaussian pulses at a high amplitude of at least 6 μT.