Pulmonary MR angiography : a comparison of 2D and 3D time-of-flight

Objective: To compare two-dimensional (2D) time-of-flight (TOF) MR angiography and three-dimensional (3D) TOF MR angiography for visualization of pulmonary arteries and to determine whether pulmonary veins can be viewed selectively. Materials and Methods: Imaging was performed using a 1.5 T superconducting MR system with a body coil. Three kinds of 2D TOF MR angiography were compared in four normal volunteers: using a 2D fast low angle shot (FLASH) without cardiac gating and both with and without breath-holding and using a T2-weighted TurboFLASH with cardiac gating and breath-holding