3088 CODE ( COncurrent Dephasing and Excitation ) MRI of human lung at 3 T

Purpose: Lung MRI has been limited mainly due to innate characteristics of lung such as a paucity of protons in air, large field inhomogeneity (or short T2) at the interface between airspace and bronchovascular structure, and cardiopulmonary motions. Such difficulties can significantly be overcome by ultrashort echo-time (UTE) MRI techniques with radial data acquisition (1-3). However it may be challenging to standardize conventional UTE imaging on commercial MRI scanners due to demanding hardware requirements, gradient-ramp sampling, and difficulty in preserving k=0 data point (4). In contrast, CODE(Concurrent Dephasing and Excitation) imaging, which was recently developed, is based on a 3D radial gradient-echo sequence and avoids most of the challenges of conventional UTE, acquiring an asymmetric gradient-echo and still offering TE≥ ~0.14ms on a clinical scanner (5). The aim of our study was to investigate the technical feasibility of CODE sequence for lung MRI in human.