title: Simultaneous acquisition of functional magnetic resonance images and impedance cardiography.
abstract: While simultaneous acquisition of electrocardiography (ECG) data during MRI is a widely used clinical technique, the effects of the MRI environment on impedance cardiography (ICG) data have not been characterized. We collected echo planar MRI scans while simultaneously recording ECG and thoracic impedance using carbon fiber electrodes and customized amplifiers. Here, we show that the key changes in impedance (dZ/dt) and features of the ECG waveforms are not obstructed during MRI. We present a method for ensemble averaging ICG/ECG signals collected during MRI and show that it performs comparably with signals collected outside the MRI environment. These results indicate that ICG can be used during MRI to measure stroke volume, cardiac output, preejection period, and left ventricular ejection time.
authors.affiliation: Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, California, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Cieslak
authors.forename: William S
authors.initials: WS
authors.lastname: Ryan
authors.forename: Alan
authors.initials: A
authors.lastname: Macy
authors.forename: Robert M
authors.initials: RM
authors.lastname: Kelsey
authors.forename: Jessica E
authors.initials: JE
authors.lastname: Cornick
authors.forename: Marlo
authors.initials: M
authors.lastname: Verket
authors.forename: Jim
authors.initials: J
authors.lastname: Blascovich
authors.forename: Scott
authors.initials: S
authors.lastname: Grafton
mesh_terms: D001921:Brain / Q000502:physiology*; D002302:Cardiac Output / Q000502:physiology; D002307:Cardiography, Impedance / Q000379:methods*; D005260:Female; D006321:Heart / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012815:Signal Processing, Computer-Assisted; D013318:Stroke Volume / Q000502:physiology
keywords: Autonomic nervous system; Impedance cardiography; MRI