Joint cardiorespiratory 1D navigator triggering using left ventricular motion: improving T2w-FSE imaging for thoracic radiotherapy

Abstract

For MR-guided radiotherapy treatment planning of the thorax, cardiorespiratory triggered T2-weighted MRI images are desired. We investigate the usage of a navigator placed on the left ventricle to do cardiorespiratory triggering, and compare it to images obtained by placing the navigator on the liver-lung interface to do respiratory triggering. We scanned 5 healthy volunteers, making high-resolution scans with both navigators, and cine and 4D-MRI scans for reference. We found that cardiorespiratory triggering based on left ventricular motion is possible, and increases image quality, without increasing scan time and losing geometrical respiratory information.