Using cardiac phase to order reconstruction (CAPTOR): a method to improve diastolic images

Area of Science:

• Cardiovascular imaging
• Medical physics
• Cardiac MRI

Background:

• Accurate depiction of the entire cardiac cycle is crucial for assessing cardiac function.
• Conventional prospective reconstruction methods often result in temporal gaps, limiting analysis.
• Beat-to-beat heart rate variability can affect the accuracy of cardiac phase determination.

Purpose of the Study:

• To develop and validate a novel method for reconstructing multiphase cardiac images.
• To improve the accuracy and completeness of cardiac cycle visualization.
• To overcome limitations of existing prospective reconstruction techniques.

Main Methods:

• Modification of a segmented, gradient-recalled-echo sequence (FASTCARD) for continuous data acquisition.
• Retrospective image reconstruction based on cardiac phase, not time from QRS.
• Utilizing a model to calculate cardiac phase that compensates for heart rate variations.
• Implementation of cardiac phase to order reconstruction (CAPTOR).

Main Results:

• CAPTOR reconstructs images depicting the complete cardiac cycle without temporal gaps.
• Time-volume curves accurately capture atrial contraction's contribution to end-diastolic volume (EDV).
• Transmitral flow measurements reveal a second inflow peak (alpha wave) previously absent in standard sequences.

Conclusions:

• CAPTOR provides a more comprehensive and accurate representation of cardiac dynamics.
• The method enhances the reliability of measuring EDV, stroke volume, and ejection fraction.
• CAPTOR offers potential for improved clinical assessment of cardiac performance.