Systems and methods for myocardial perfusion MRI without the need for ECG gating and additional systems and methods for improved cardiac imaging

A magnetic resonance imaging system, 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;
• and
• a processor operable to control the transmitter and the receiver;
• wherein the processor is configured to direct the transmitter and receiver to execute a sequence, comprising:
• applying a pulse sequence with continuous radial k-space sampling to a volume of interest (VOI) comprising a region of a heart of a subject, T1 weighting of the VOI being provided by a steady state magnetization of the pulse sequence resulting from the continuous radial k-space sampling, the pulse sequence having a flip angle selected so as to maximize a ratio of (i) a contrast-to-noise ratio of hypoperfused tissue to (ii) a contrast-to-noise ratio of non-perfused tissue;
• acquiring magnetic resonance data from the VOI in the subject;
• and
• generating one or more images based on the magnetic resonance data using a model-based, iterative image reconstruction technique that includes a sliding windows scheme, the one or more images being indicative of passage of a contrast agent through at least the region of the heart of the subject.

A non-transitory machine-readable medium having machine executable instructions for causing one or more processors of a magnetic resonance imaging (MRI) machine to execute a method, comprising:

• applying a pulse sequence with continuous radial k-space sampling to a volume of interest (VOI) comprising a region of a heart of a subject, T1 weighting of the VOI being provided by a steady state magnetization of the pulse sequence resulting from the continuous radial k-space sampling, the pulse sequence having a flip angle selected so as to maximize a ratio of (i) a contrast-to-noise ratio of hypoperfused tissue to (ii) a contrast-to-noise ratio of non-perfused tissue;
• acquiring magnetic resonance data from the VOI in the subject;
• and
• generating one or more images based on the magnetic resonance data using a model-based, iterative image reconstruction technique that includes a sliding windows scheme, the one or more images being indicative of passage of a contrast agent through at least the region of the heart of the subject.