title: DQF-MT MRI of connective tissues: application to tendon and muscle.
abstract: OBJECTIVE
  The sequence combining DQF (double quantum filtering) with magnetisation transfer (DQF-MT) was tested as an alternative to the DQF sequence for characterising tendon and muscle by MR imaging.
  
  
  METHODS
  DQF-MT images of tendon-muscle phantoms were obtained at 4.7 T using ultra-short time to echo (UTE) methods in order to alleviate the loss of SNR due to the short T2 of the tissues. Two different sampling schemes of the k-space, Cartesian or radial, were employed. In vivo images of the human ankle on a clinical 1.5 T scanner are also presented. Parameters providing optimal tendon signal as well as optimal contrast between this tissue and muscle were determined.
  
  
  RESULTS
  Two sets of parameters resulting in different contrasts between the tissues were found. For the first set (short creation time τ = 10 μs and magnetisation exchange time t LM = 100 ms), DQF-MT signals in muscle and tendon were detected, with that of the tendon being the larger one. For the second set (long creation time τ = 750 μs and magnetisation exchange time 10 μs < t LM < 100 ms), the DQF-MT signal was detected only in the tendon, and the decay of the double quantum coherence was slower than that observed for the first one, which allowed us to acquire DQF-MT MR images on a clinical 1.5 T MR scanner with minimal software interventions. In favourable conditions, the DQF-MT signal in the tendon could represent up to 10 % of the single-quantum signal.
  
  
  CONCLUSIONS
  Dipolar interaction within macromolecules such as collagen and myosin is at the origin of the DQF-MT signal observed in the first parameter set. This should enable the detection of muscle fibrosis.
authors.affiliation: IR4M UMR8081 CNRS Univ Paris-Sud, CIERM-Hôp Bicetre, 94275, Le Kremlin Bicetre, France.
authors.forename: Slawomir
authors.initials: S
authors.lastname: Kusmia
authors.forename: Uzi
authors.initials: U
authors.lastname: Eliav
authors.forename: Gil
authors.initials: G
authors.lastname: Navon
authors.forename: Geneviève
authors.initials: G
authors.lastname: Guillot
mesh_terms: D000818:Animals; D002417:Cattle; D003094:Collagen / Q000378:metabolism; D003238:Connective Tissue / Q000033:anatomy & histology / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000378:metabolism; D019047:Phantoms, Imaging; D034421:Sus scrofa; D013710:Tendons / Q000033:anatomy & histology* / Q000378:metabolism
chemical_list: D003094:Collagen