Recording Cardiac Output Measurements in an MRI

Acting to support researchers affiliated with UC Santa Barbara’s Department of Psychological & Brain Sciences, BIOPAC developed a specialized Noninvasive Cardiac Output amplifier module designed for operation in an MRI. The team successfully captured and analyzed impedance cardiography (ICG) from a subject during fMRI. Titled “Simultaneous acquisition of functional magnetic resonance images and impedance cardiography,” the study indicates that ICG can be recorded during EPI and, with specific signal processing, can be interpreted similarly as to when recorded outside the MRI.

The group performed BOLD fMRI while simultaneously recording the Electrocardiogram (ECG) and impedance Cardiogram (ICG) using carbon-fiber electrodes, MRI compatible cabling, patch panel filters and BIOPAC MRI Smart Amplifiers. They were able to produce ECG and ICG waveforms of sufficient resolution to be used to measure stroke volume, cardiac output, pre-ejection period, and left ventricular ejection time during imaging. The data suggests that measuring ICG during an MRI can be a powerful technique for future studies measuring central and autonomic nervous system activities.

BIOPAC offers MRI Smart Amplifier modules for this specific application—see NICO100C-MRI and ECG100C-MRI.

To read more about the full experiment, head over to the Psychophysiology journal online for the abstract or, with subscription, the full article.

Cieslak, M., Ryan, W. S., Macy, A., Kelsey, R. M., Cornick, J. E., Verket, M., Blascovich, J. and Grafton, S. (2014), Simultaneous acquisition of functional magnetic resonance images and impedance cardiography. Psychophysiology. doi: 10.1111/psyp.12385

Article first published online: 20 NOV 2014