Methods, systems, and computer readable media for in vivo phase incrementing magnetic resonance spectroscopic imaging (pi-mrsi) for multi-biomarker imaging and for simultaneous imaging of zero quantum-->double quantum (zq-->dq) and dq-->zq coherence pathways

A system for in vivo phase incrementing magnetic resonance spectroscopic imaging (MRSI), the system comprising:

• a magnetic resonance imaging (MRI) spectrometer including a radio frequency (RF) coil;
• and
• a pulse sequence generator and signal acquisition module for applying frequency selective RF pulses at frequencies in a first set of frequencies to the RF coil of the MRI spectrometer to induce multiple-quantum coherences and single-quantum transitions in a first chemical substance in a subject, applying frequency-selective RF pulses at frequencies in a second set of frequencies to the RF coil to induce multiple-quantum coherences or single-quantum transitions in a second chemical substance in the subject, applying a phase encoding gradient to the gradient coil to phase encode signals generated by the multiple quantum coherences or the single-quantum transitions induced in the first and second chemical substances as a result of the frequency-selective RF pulses at the frequencies in the first and second sets of frequencies, wherein applying the phase encoding gradient includes varying an amplitude of the phase encoding gradient, synchronously with amplitude changes in the phase encoding gradient, phase incrementing phases of the RF pulses at the frequencies in the first set of frequencies and phase decrementing or phase incrementing differently phases of the RF pulses at the frequencies in the second set of frequencies, and detecting, during an image acquisition period, signals generated by the induced multiple quantum coherences or single-quantum transitions in the first and second chemical substances as a result of the phase incremented RF pulses at the frequencies in the first set of frequencies, the phase decremented or differently phase incremented RF at the frequencies in the second set of frequencies, and the phase encoding gradient.

A non-transitory computer readable medium having stored thereon executable instructions that when executed by a processor of a computer control the computer to perform steps comprising:

• applying frequency-selective RF pulses at frequencies in a first set of frequencies to a radio frequency (RF) coil of a magnetic resonance imaging (MRI) spectrometer to induce multiple-quantum coherences and single-quantum transitions in a first chemical substance in a subject;
• applying frequency-selective RF pulses at frequencies in a second set of frequencies to the RF coil to induce multiple-quantum coherences or single-quantum transitions in a second chemical substance in the subject;
• applying a phase encoding gradient to the gradient coil to phase encode signals generated by the multiple-quantum coherences and single-quantum transitions induced in first and second chemical substances as a result of the frequency-selective pulses at the frequencies in the first and second sets of frequencies, wherein applying the phase encoding gradient includes varying an amplitude of the phase encoding gradient;
• synchronously with amplitude changes in the phase encoding gradient, phase incrementing phases of the frequency-selective pulses at the frequencies in the first set of frequencies and phase decrementing or phase incrementing differently phases of the frequency-selective pulses at the frequencies in the second set of frequencies;
• and
• detecting, during an image acquisition period, signals generated by the induced multiple-quantum coherences and single-quantum transitions in the first and second chemical substances as a result of the phase incremented RF pulses at the frequencies in the first set of frequencies, the phase decremented or differently phase incremented RF pulses at the frequencies in the second set of frequencies, and the phase encoding gradient.

A method for simultaneous detection of zero quantum→double quantum (ZQ→DQ) and DQ→ZQ coherence transfer pathways in a chemical substance of interest, the method comprising:

• applying a pulse sequence to a radio frequency (RF) coil of a magnetic resonance imaging (MRI) spectrometer to induce multiple quantum coherences and single quantum transitions in a chemical substance in a subject;
• applying a phase encoding gradient to the gradient coil to phase encode signals generated by multiple quantum coherences induced in a chemical substance as a result of the pulse sequence, wherein applying the phase encoding gradient includes varying an amplitude of the phase encoding gradient;
• synchronously with amplitude changes in the phase encoding gradient, phase incrementing or phase decrementing a radio frequency (RF) phase of a pulse in the pulse sequence;
• and
• simultaneously detecting, during at least one image acquisition period, signals resulting from DQ→ZQ and ZQ→DQ quantum coherence transfer pathways in the chemical substance.

A non-transitory computer readable medium having stored thereon executable instructions that when executed by a processor of a computer control the computer to perform steps comprising:

• applying a pulse sequence to a radio frequency (RF) coil of a magnetic resonance imaging (MRI) spectrometer to induce multiple quantum coherences and single quantum transitions in a chemical substance in a subject;
• applying a phase encoding gradient to the gradient coil to phase encode signals generated by multiple quantum coherences induced in a chemical substance as a result of the pulse sequence, wherein applying the phase encoding gradient includes varying amplitude of the phase encoding gradient;
• synchronously with amplitude changes in the phase encoding gradient, phase incrementing or phase decrementing an RF phase of a pulse in the pulse sequence;
• and
• simultaneously detecting, during at least one image acquisition period, signals resulting from DQ→ZQ and ZQ→DQ coherence transfer pathways in the chemical substance.