[MRI of the heart following implantation of a left ventricular apico-aortic conduit].
OBJECTIVE
To investigate the potential of ECG-triggered MRI for the evaluation of postoperative anatomy and function of the heart and conduit following implantation of a left-ventricular apico-aortic conduit.


METHODS
5 patients (2 female, 3 male, mean age 72.5 years) were examined using a 1.5 Tesla whole-body MRI (Gyroscan Intera, Philips Medical Systems, Best, The Netherlands) following apico-aortic conduit surgery due to severe aortic valve stenosis. The reason for performing conduit implantation instead of aortic valve replacement was the risk of injuring a bypass graft from prior coronary artery bypass surgery. Cine steady-state-free-precession (SSFP) sequences were used to assess ventricular function, navigator-gated 3D-SSFP and breath-hold, time-resolved contrast-enhanced MR angiography was used to display the postoperative anatomy, and 2D-gradient echo sequences with an inversion pulse to suppress the signal of the healthy myocardium were used to evaluate potential myocardial scarring. Flow sensitive gradient echo sequences were performed to determine the blood flow in the conduit.


RESULTS
In all patients the apico-aortic conduit proved to be open with a maximum flow velocity of 126 (+ 43) cm/s. The postoperative anatomy was able to be evaluated in all patients and perioperative myocardial infarction was able to be ruled out. The mean ejection fraction of the left ventricle was 44.2 + 6.2 % with a mean volume of 80 + 20.6 ml per heart beat.


CONCLUSIONS
ECG-triggered MRI is a reliable method for the evaluation of postoperative anatomy and function following implantation of a left ventricular apico-aortic conduit.
Ruhl
K M
KM
Klinik für Radiologische Diagnostik, Universitätsklinikum Aachen, RWTH Aachen. ruhl@rad.rwth-aachen.de
Langebartels
G
G
Autschbach
R
R
Katoh
M
M
Günther
R W
RW
Krombach
G A
GA
D000368:Aged; D001021:Aortic Valve; D001024:Aortic Valve Stenosis / Q000601:surgery*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009203:Myocardial Infarction / Q000473:pathology; D009206:Myocardium / Q000473:pathology*; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling