Real-time cardiac cine imaging with SPIDER: steady-state projection imaging with dynamic echo-train readout

Area of Science:

• Magnetic Resonance Imaging
• Cardiovascular Imaging
• Medical Physics

Background:

• Real-time cardiac cine imaging is crucial for assessing heart function.
• Existing techniques face challenges with scan time efficiency and image quality.
• TrueFISP sequences offer good contrast but can be time-consuming.

Purpose of the Study:

• To introduce and evaluate the Steady-state projection imaging with dynamic echo-train readout (SPIDER) pulse sequence.
• To assess SPIDER's feasibility for real-time cardiac cine imaging.
• To combine the benefits of TrueFISP contrast with enhanced scan efficiency.

Main Methods:

• Developed a multiecho radial k-space trajectory TrueFISP sequence (SPIDER).
• Minimized repetition time (TR) using a 3-echo train with asymmetric acquisition.
• Employed undersampled projection reconstruction and a factor of 2 view sharing scheme.
• Achieved a temporal resolution of 45 ms with TR/TE1/TE2/TE3 of 3.24/0.6/1.6/2.6 ms.

Main Results:

• Phantom studies showed minimal signal weighting differences but off-resonance modulation.
• In vivo experiments demonstrated successful real-time cardiac short-axis imaging.
• The SPIDER sequence achieved high temporal resolution for dynamic cardiac imaging.

Conclusions:

• SPIDER is a feasible multiecho radial TrueFISP sequence for real-time cardiac cine MRI.
• It combines superior SNR and contrast with improved scan time efficiency.
• SPIDER shows promise for dynamic cardiovascular assessments.