Chest-MRI under non invasive high frequency ventilation: a new promising technique

Introduction: Respiratory movements cause motion artefacts during image acquisition of the thorax, limiting the clinical use of magnetic resonance imaging (MRI) in the visualization of lung parenchyma and thoracic vascular structures Aims and Objectives: The aim of this pilot study was to perform chest MRI under an adapted non invasive High Frequency Ventilation (HFV) system allowing 10 to 15 times longer breath hold durations than other existing systems Methods: Four healthy volunteers underwent a chest MRI under non invasive HFV. Dedicated chest imaging sequences were performed under free breathing with respiratory triggering and during HFV-supported apnoeas, using acquisition sets of 6 minutes Results: Chest-MRI under HFV was well tolerated in all cases. The median duration of the HFV-supported apnoeas was 6 min (interquartile range 3.6-6). An overall increased image quality was seen under HFV, according to predefined objective and subjective evaluation criteria, with a better delineation of the pulmonary vascular structures, of the airways and of the lung parenchyma-liver interface Conclusions: Non invasive High Frequency Ventilation is feasible and increases spatial resolution of chest MRI by allowing acquisition at full inspiration in a prolonged apnoea. This new technique could be of benefit to numerous thoracic disorders Figure: steady state free precession (SSFP) coronal chest MRI sequence without gadolinium injection