Methods and systems for an adaptive perfusion scan

A method for an imaging system, comprising:

• upon an injection of a contrast agent, performing a contrast scan of an anatomical region of interest (ROI) of a subject at a first temporal sampling rate;
• processing projection data of the anatomical ROI acquired during the contrast scan to measure a contrast signal of the contrast agent;
• identifying a peak in the contrast signal within a predetermined time frame;
• if the peak in the contrast signal is identified within the predetermined time frame, adjusting the first temporal sampling rate to a second temporal sampling rate at a first transition time that is determined based on the contrast signal;
• and
• if the peak in the contrast signal is not identified within the predetermined time frame, adjusting the first temporal sampling rate to the second temporal sampling rate at a second transition time that is a fixed duration relative to a beginning of the contrast scan and independent of the contrast signal.

A system, comprising:

• an x-ray source that emits a beam of x-rays toward a subject to be imaged;
• a detector that receives the x-rays attenuated by the subject;
• a data acquisition system (DAS) operably connected to the detector;
• and
• a computer operably connected to the DAS and configured with instructions in non-transitory memory that when executed cause the computer to:
• upon an injection of a contrast agent, initiate a contrast scan of an anatomical region of interest (ROI) of the subject according to a fallback scan prescription;
• process projection data from the DAS during a portion of the contrast scan to measure a contrast signal of the contrast agent;
• identify a peak in the contrast signal prior to a threshold time;
• if the peak in the contrast signal is identified within the threshold time, perform a remainder of the contrast scan according to an adapted scan prescription that is dependent on the contrast signal, the adapted scan prescription including a transition to a lower temporal sampling rate at a first time point that is based on the contrast signal;
• and
• if the peak in the contrast signal is not identified prior to the threshold time, complete the remainder of the contrast scan according to the fallback scan prescription, where the fallback scan prescription is independent of the contrast signal, the fallback scan prescription including the transition to the lower temporal sampling rate at a second time point that is a fixed duration relative to a beginning of the contrast scan and independent of the contrast signal.