Respiratory-Gated 3D Fast Spin-Echo for Oxygen-Enhanced MR Imaging of Mice Lungs
Watt K, Nieman B, Bishop J, Chen J, Henkelman R
Mouse Imaging Centre (MICe), Hospital for Sick Children, University of Toronto
Oxygen-enhanced MR imaging enables evaluation of regional lung ventilation by using inhaled molecular oxygen as a paramagnetic contrast agent. Oxygen-induced increases in signal intensity of lung parenchyma are often obscured by motion artifacts arising from cardiopulmonary physiology. Addressing this limitation, this study presents a cardiac-triggered respiratory-gated 3D fast spin-echo sequence suitable for small animal oxygen-enhanced imaging. Ghosting artifacts due to variations in cardiac and respiratory rates were reduced with a gating scheme that maintained steady-state magnetization. It is demonstrated in oxygen-enhanced imaging of a normal free-breathing mouse and shows potential for future application to studies of experimental mouse models.