Bjoern Schoennagel MD, Presenter: Nothing to Disclose

Chressen Catharina Much, Abstract Co-Author: Nothing to Disclose

Gerhard B. Adam MD, Abstract Co-Author: Nothing to Disclose

Hendrick Kooijmann PhD, Abstract Co-Author: Employee, Koninklijke Philips Electronics NV

Jin Yamamura MD, Abstract Co-Author: Nothing to Disclose

Ulrike Wedegaertner MD, Abstract Co-Author: Nothing to Disclose

To investigate applicability and accuracy of a newly developed MR compatible Doppler-ultrasound (DUS) device for triggering cardiac magnetic resonance imaging (MRI) and blood flow measurements in comparison with conventional electrocardiogram (ECG) - gating in a sheep model.

In 5 adult sheep cardiac MRI (1.5T imager) was performed using both, a newly developed MR compatible DUS device and a conventional ECG for cardiac triggering. The Doppler-ultrasound sensor was placed on the chest above the heart and fixed with a belt. The recorded signal was transferred to the ECG trigger unit of the MR scanner and used for cardiac triggering. Cine series (25 phases) from short axis-, 2- and 4- chamber views were acquired to determine LV function. Additionally, blood flow velocities were determined in the aorta descendens using both triggering methods. Images were evaluated comparing image quality, LV function and aortic blood flow velocity.

Cine series of a whole cardiac cycle could be obtained in all animals with both triggering techniques. Quality of DUS-gated images was comparable to that of ECG-gated images. LV function (mean LVEF 46.1% (±7.0) vs. 48.1% (±4.4), p=0.65) and blood flow peak velocities (mean 78.8 (±19.9) vs. 76.2 (±5.4) cm/s, p=0.79) could be determined with both techniques, revealing no significant differences.

Both DUS- and ECG- triggering techniques allowed cardiac imaging and blood flow measurements with comparable image quality. Accuracy of the new DUS – triggering method could be demonstrated, revealing no significant differences of LV function and aortic blood flow velocity compared with ECG-gated examinations.

The MR compatible Doppler-ultrasound device is a new triggering method for cardiac MRI. Its application might be faster and easier compared to ECG.

Schoennagel, B, Much, C, Adam, G, Kooijmann, H, Yamamura, J, Wedegaertner, U, A New Method to Trigger Cardiac MRI and Blood Flow Measurements: MR Compatible Doppler-Ultrasound Device in Comparison to ECG.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12030624.html