Assessment of MR imaging during one-lung flooding in a large animal model

摘要

Objective Magnetic resonance imaging (MRI) of the lung remains challenging due to the low tissue density, susceptibility artefacts, unfavourable relaxation times and motion. Previously, we demonstrated in vivo that one-lung flooding (OLF) with saline is a viable and safe approach. This study investigates the feasibility of OLF in an MRI environment and evaluates the flooding process on MR images. Methods OLF of the left lung was performed on five animals using a porcine model. Before, during and after OLF, standard T_2w and T_1w spin-echo (SE) and gradient-echo (GRE) sequences were applied at 3 T. Results The procedure was successfully performed in all animals. On T_1w MRI, the flooded lung appeared homogenous and isointense with muscle tissue. On T_2w images, vascular structures were highly hypointense, while the bronchi were clearly demarcated with hypointense wall and hyperintense lumen. The anatomical demarcation of the flooded lung from the surrounding organs was superior on T_2w images. No outflow effects were seen, and no respiration triggering was required. Discussion OLF can be safely performed in an MR scanner with highly detailed visualization of the pulmonary structures on T_2w images. The method provides new approaches to MRI-based image-guided pulmonary interventions using the presented experimental model.