Left ventricular pressure gating in ovine cardiac studies: a software-based method.
Cardiac imaging using magnetic resonance requires a gating signal in order to compensate for motion. Human patients are routinely scanned using an electrocardiogram (ECG) as a gating signal during imaging. However, we found that in sheep the ECG is not a reliable method for gating. We developed a software based method that allowed us to use the left ventricular pressure (LVP) as a reliable gating signal. By taking the time derivative of the LVP (dP/dt), we were able to start imaging at both end-diastole for systolic phase images, and end-systole for diastolic phase images. We also used MR tissue tagging to calculate 3D strain information during diastole. Using the LVP in combination with our digital circuit provided a reliable and time efficient method for ovine cardiac imaging. Unlike the ECG signal the left ventricular pressure was a clean signal and allowed for accurate, nondelay based triggering during systole and diastole.
Gabriel
G
Acevedo-Bolton
Takamaro
T
Suzuki
Deepak
D
Malhotra
Zhihong
Z
Zhang
Arthur W
AW
Wallace
Julius M
JM
Guccione
David A
DA
Saloner
Mark B
MB
Ratcliffe
D000818:Animals; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D004562:Electrocardiography; D011312:Pressure; D012756:Sheep; D012984:Software; D016277:Ventricular Function, Left