title: In vivo proton electron double resonance imaging of mice with fast spin echo pulse sequence.
abstract: OBJECTIVE
  To develop and evaluate a two-dimensional (2D) fast spin echo (FSE) pulse sequence for enhancing temporal resolution and reducing tissue heating for in vivo proton electron double resonance imaging (PEDRI) of mice.
  
  
  METHODS
  A four-compartment phantom containing 2 mM TEMPONE was imaged at 20.1 mT using 2D FSE-PEDRI and regular gradient echo (GRE)-PEDRI pulse sequences. Control mice were infused with TEMPONE over ~1 min followed by time-course imaging using the 2D FSE-PEDRI sequence at intervals of 10-30 s between image acquisitions. The average signal intensity from the time-course images was analyzed using a first-order kinetics model.
  
  
  RESULTS
  Phantom experiments demonstrated that EPR power deposition can be greatly reduced using the FSE-PEDRI pulse sequence compared with the conventional gradient echo pulse sequence. High temporal resolution was achieved at ~4 s per image acquisition using the FSE-PEDRI sequence with a good image SNR in the range of 233-266 in the phantom study. The TEMPONE half-life measured in vivo was ~72 s.
  
  
  CONCLUSIONS
  Thus, the FSE-PEDRI pulse sequence enables fast in vivo functional imaging of free radical probes in small animals greatly reducing EPR irradiation time with decreased power deposition and provides increased temporal resolution.
authors.affiliation: Davis Heart and Lung Research Institute and Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Ziqi
authors.initials: Z
authors.lastname: Sun
authors.forename: Haihong
authors.initials: H
authors.lastname: Li
authors.forename: Sergey
authors.initials: S
authors.lastname: Petryakov
authors.forename: Alex
authors.initials: A
authors.lastname: Samouilov
authors.forename: Jay L
authors.initials: JL
authors.lastname: Zweier
mesh_terms: D000818:Animals; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D051379:Mice; D019047:Phantoms, Imaging; D011522:Protons; D051598:Whole Body Imaging / Q000295:instrumentation / Q000379:methods
chemical_list: D011522:Protons