A double echo ultra short echo time (UTE) acquisition for respiratory motion‐suppressed high resolution imaging of the lung

• Published in: Magnetic resonance in medicine Vol. 79; no. 4; pp. 2297 - 2305
• Main Authors: Delacoste, Jean, Chaptinel, Jerome, Beigelman‐Aubry, Catherine, Piccini, Davide, Sauty, Alain, Stuber, Matthias
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.04.2018
• Subjects: Breathing; Computation; Computed tomography; Cystic fibrosis; Datasets; Gating; Image detection; Image processing; Image quality; Image reconstruction; Image resolution; Liver; lung; Lungs; Magnetic resonance imaging; Medical imaging; Motion detection; Motion perception; Patients; Respiration; self‐navigation; Sharpness; Signal to noise ratio; UTE; lung; self-navigation; UTE
• ISSN: 0740-3194; 1522-2594; 1522-2594
• DOI: 10.1002/mrm.26891

Purpose Magnetic resonance imaging is a promising alternative to computed tomography for lung imaging. However, organ motion and poor signal‐to‐noise ratio, arising from short T2*, impair image quality. To alleviate these issues, a new retrospective gating method was implemented and tested with an ultra‐short echo time sequence. Methods A 3D double‐echo ultra‐short echo time sequence was used to acquire data during free breathing in ten healthy adult subjects. A self‐gating method was used to reconstruct respiratory motion suppressed expiratory and inspiratory images. These images were objectively compared to uncorrected data sets using quantitative end‐points (pulmonary vessel sharpness, lung–liver interface definition, signal‐to‐noise ratio). The method was preliminarily tested in two cystic fibrosis patients who underwent computed tomography. Results Vessel sharpness in expiratory ultra‐short echo time data sets with second echo motion detection was significantly higher (13% relative increase) than in uncorrected images while the opposite was observed in inspiratory images. The method was successfully applied in patients and some findings (e.g., hypointense areas) were similar to those from computed tomography. Conclusion Free breathing ultra‐short echo time was successfully implemented, allowing flexible image reconstruction of two different respiratory states. Objective improvements in image quality were obtained with the new method and initial feasibility in a clinical setting was demonstrated. Magn Reson Med 79:2297–2305, 2018. © 2017 International Society for Magnetic Resonance in Medicine.