title: Pulmonary relaxometry with inversion recovery ultra-fast steady-state free precession at 1.5T.
abstract: To present a technique for simultaneous mapping of T1, T2, and relative spin density (M0) in human lung using inversion recovery ultra-fast steady-state free precession (IR-ufSSFP) imaging.
  
  
  
  Pulmonary relaxometry with IR-ufSSFP is based on an interleaved time series acquisition of 2D images acquired at 1.5T. The technique was tested in a phantom and in four healthy volunteers using breath-hold and electrocardiogram triggering. Typically, 30 transient state images were acquired in a single breath-hold within < 10 s. From the signal time course, voxel-wise nonlinear fitting yielded T1, T2, and M0parameter maps. Furthermore, off-resonance and B1 effects were investigated in a phantom.
  
  
  
  In the phantom, the observed T1of 829 ± 2 ms and T2of 105 ± 4 ms were in agreement with the reference T1of 858 ± 1 ms and T2of 104 ± 1 ms using spin echo methods. In volunteers, the average T1of 1375 ± 102 ms and T2of 66 ± 26 ms of lung tissue were in good agreement with the literature and were observed to be independent of the respiratory phase. Overall, high reproducibility was shown in a volunteer, yielding coefficient of variations of 0.03 for M0, 0.004 for T1, and 0.04 for T2measurements.
  
  
  
  IR-ufSSFP allows for fast and simultaneous quantitative mapping of the human lung. Magn Reson Med 77:74-82, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland.|Deparment of Biomedical Engineering, University of Basel, Basel, Switzerland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Bauman
authors.affiliation: Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland.|Deparment of Biomedical Engineering, University of Basel, Basel, Switzerland.
authors.forename: Francesco
authors.initials: F
authors.lastname: Santini
authors.affiliation: Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland.|Deparment of Biomedical Engineering, University of Basel, Basel, Switzerland.
authors.forename: Orso
authors.initials: O
authors.lastname: Pusterla
authors.affiliation: Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland.|Deparment of Biomedical Engineering, University of Basel, Basel, Switzerland.
authors.forename: Oliver
authors.initials: O
authors.lastname: Bieri
mesh_terms: D000465:Algorithms; D062485:Breath Holding; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008168:Lung / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results
keywords: inversion recovery; lung MRI; pulmonary relaxometry; ultra-fast steady-state free precession