ACCELERATION MAPPING BY FOURIER ACCELERATION-ENCODING - IN-VITRO STUDY AND INITIAL RESULTS IN THE GREAT THORACIC VESSELS

Acceleration mapping can be conducted by replacing the bipolar gradien t pulse of a velocity mapping sequence by a tripolar pulse, However, s ince the acceleration encoding pulse is longer, the image quality is a ltered by the requirement of a long echo time, Since Fourier encoding velocity imaging has been shown to be robust, this velocity mapping me thod was transformed into an acceleration mapping method. Four steps o f the tripolar acceleration encoding gradient pulse were applied succe ssively; acceleration was then obtained by Fourier transform after zer o-filling. The accuracy of the method was assessed with a phantom givi ng a pulsatile flow, Acceleration maps of the ascending aorta and pulm onary artery were obtained in 10 healthy volunteers, The acceleration values measured were in the range of known physiologic values, The fea sibility of Fourier encoding acceleration imaging was also demonstrate d in four patients.