Systems and methods for MR multitasking-based dynamic imaging for cerebrovascular evaluation

A system for performing magnetic resonance (MR) imaging on a subject, comprising:

• a magnet operable to provide a magnetic field;
• a transmitter operable to transmit to a region within the magnetic field;
• a receiver operable to receive a magnetic resonance signal from the region with the magnetic field;
• and
• one or more processors operable to control the transmitter and the receiver, the one or more processors being configured to cause the following method to be performed:
• injecting a contrast agent into a region of interest of the subject;
• applying a pulse sequence to the region of interest of the subject, wherein the pulse sequence comprises a plurality of repetition time periods, each repetition time period including:
• (i) a non-selective saturation recovery preparation pulse to generate T1 recovery along a magnetization z-axis, (ii) a plurality of excitation pulses, and (iii) a plurality of sets of readout lines, each set of readout lines following one of the excitation pulses and including two or more readout lines, the readout lines of each set following a T2* decay, thereby forming multi-echo fast low-angle shot (FLASH) readouts;
• collecting auxiliary data for the region of interest of the subject, the auxiliary data being related to one or more time-varying parameters of the subject within the region of interest;
• determining a temporal factor Φ from the auxiliary data;
• collecting imaging data for the region of interest of a brain of the subject, the imaging data being related to one or more spatially-varying parameters of the brain within the region of interest;
• determining a spatial factor Ur from the imaging data;
• modeling a multi-dimensional image sequence as I=UrΦ, denoted as I(r, rT1, tT2*, tCE), where tT1 refers to T1 recovery, tT2* refers to T2* decay, and tCE refers to a contrast enhancement time course;
• deriving dynamic T1 and T2* maps from the multi-dimensional image sequence;
• and
• deriving at least a first metric and a second metric from the dynamic T1 and T2* maps, the first metric being a kinetic parameter associated with dynamic contrast enhanced (DCE) imaging comprising (i) a fractional plasma volume vp of the region of interest, (ii) a fractional extravascular-extracellular volume ve of the region of interest, (iii) a transfer constant Ktrans of the region of interest, or (iv) any combination of (i)-(iii), and the second metric being a hemodynamic parameter associated with dynamic susceptibility contrast (DSC) imaging comprising (i) a cerebral blood volume (CBV) measurement, (ii) a cerebral blood flow measurement, or (iii) any combination of (i)-(ii).

A non-transitory machine-readable medium having stored thereon instructions for performing magnetic resonance (MR) imaging on a subject, which when executed by at least one processor, cause the following method to be performed:

• injecting a contrast agent into a region of interest of the subject;
• applying a pulse sequence to the region of interest of the subject, wherein the pulse sequence comprises a plurality of repetition time periods, each repetition time period including:
• (i) a non-selective saturation recovery preparation pulse to generate T1 recovery along a magnetization z-axis, (ii) a plurality of excitation pulses, and (iii) a plurality of sets of readout lines, each set of readout lines following one of the excitation pulses and including two or more readout lines, the readout lines of each set following a T2* decay, thereby forming multi-echo fast low-angle shot (FLASH) readouts;
• collecting auxiliary data for the region of interest of a brain of the subject, the auxiliary data being related to one or more time-varying parameters of the brain within the region of interest;
• determining a temporal factor Φ from the auxiliary data;
• collecting imaging data for the region of interest of the subject, the imaging data being related to one or more spatially-varying parameters of the subject within the region of interest;
• determining a spatial factor Ur from the imaging data;
• modeling a multi-dimensional image sequence as I=UrΦ, denoted as I(r, rT1, tT2*, tCE), where tT1 refers to T1 recovery, tT2* refers to T2* decay, and tCE refers to a contrast enhancement time course;
• deriving dynamic T1 and T2* maps from the multi-dimensional image sequence;
• and
• deriving at least a first metric and a second metric from the dynamic T1 and T2* maps, the first metric being a kinetic parameter associated with dynamic contrast enhanced (DCE) imaging comprising (i) a fractional plasma volume vp of the region of interest, (ii) a fractional extravascular-extracellular volume ve of the region of interest, (iii) a transfer constant Ktrans of the region of interest, or (iv) any combination of (i)-(iii), and the second metric being a hemodynamic parameter associated with dynamic susceptibility contrast (DSC) imaging comprising (i) a cerebral blood volume (CBV) measurement, (ii) a cerebral blood flow measurement, or (iii) any combination of (i)-(ii).