title: A model-based reconstruction technique for fast dynamic T1 mapping.
abstract: OBJECTIVE
  To present a technique for dynamic T1 mapping.
  
  
  METHODS
  A recently proposed model-based reconstruction entitled IR-MAP allows T1 mapping of a single slice from a single radial inversion recovery Look-Locker FLASH acquisition. To enable dynamic T1 mapping, multiple of these acquisitions are consecutively performed, each followed by a waiting period of 3s for relaxation. Next, IR-MAP is used to reconstruct an individual T1 map for each of these acquisitions. Finally, T1 errors caused by insufficient relaxation between subsequent IR pulses are iteratively corrected.
  
  
  RESULTS
  The functionality of the proposed setup was validated in a phantom and in seven healthy volunteers. Systematic deviations between subsequent T1 maps originating from insufficient relaxation periods were effectively corrected. Additionally, the approach was successfully applied to monitor the T1 dynamic in a patient with primary lymphoma after the intravenous injection of contrast agent.
  
  
  CONCLUSIONS
  The proposed setup enables dynamic T1 mapping of a single slice with a spatial resolution of 1.6 mm × 1.6 mm × 3 mm and a temporal resolution of one parameter map every 9 s. It therefore represents a new opportunity to track changes in T1 over time, as it is desirable in many applications such as dynamic contrast-enhanced MRI.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany; Department of Nuclear Medicine, University of Würzburg, Würzburg, Germany. Electronic address: Tran_J@ukw.de.
authors.forename: Johannes
authors.initials: J
authors.lastname: Tran-Gia
authors.affiliation: Department of Diagnostic and Interventional Neuroradiology, Eberhard Karls University, Tübingen, Germany; Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, University College London Hospitals, London, United Kingdom.
authors.forename: Sotirios
authors.initials: S
authors.lastname: Bisdas
authors.affiliation: Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany.
authors.forename: Herbert
authors.initials: H
authors.lastname: Köstler
authors.affiliation: Department of Diagnostic and Interventional Neuroradiology, Eberhard Karls University, Tübingen, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Klose
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D002138:Calibration; D003287:Contrast Media / Q000737:chemistry; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007275:Injections, Intravenous; D008223:Lymphoma / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D009942:Organometallic Compounds / Q000737:chemistry; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D013997:Time Factors; D051598:Whole Body Imaging; D055815:Young Adult
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol
keywords: Dynamic T(1) mapping; Dynamic contrast-enhanced MRI; Dynamic parameter mapping; Inversion recovery Look-Locker T(1) mapping; Model-based reconstruction