title: Diffusion tensor imaging (DTI) of desmoid tumours in familial adenomatous polyposis: initial experience.
abstract: OBJECTIVE
  To assess the feasibility of diffusion tensor imaging (DTI) of desmoid tumours in familial adenomatous polyposis (FAP).
  
  
  METHODS
  Following ethical approval and informed consent, FAP patients with desmoids underwent DTI. Fractional anisotropy (FA), relative anisotropy (RA) and apparent diffusion coefficient (ADC) were compared to control muscle using Mann-Whitney test; and to tumour site and signal intensity using one way analysis of variance (ANOVA). Imaging was repeated after 1 year.
  
  
  RESULTS
  15 desmoids (6 intra-abdominal; 6 abdominal wall, 3 extra-abdominal; size range: 1.6-22.9 cm) were evaluated in 9 patients. DTI was successful in 12/15 desmoid tumours. Median (range) of RA, FA and ADC were 0.23×10(-3) mm2/s (0.17-0.26); 0.27×10(-3) mm2/s (0.21-0.31); and 1.65×10(-3) mm2/s (1.39-1.91) for desmoids, significantly different from muscle: 0.27×10(-3) mm2/s (0.23-0.40), 0.32×10(-3) mm2/s (0.28-0.46), and 1.45×10(-3) mm2/s (0.92-1.63) (p=0.0001, p=0.0001, p=0.0016, respectively). There was no difference in RA, FA or ADC between tumour sites, or signal intensity (p>0.05). One year later, 2 patients had died. Tumour increased in size in 1 patient (+61%). DTI quantification was possible in only 8/13 tumours. FA, RA and ADC were not significantly different from baseline (p=0.77, 0.71 and 0.34, respectively).
  
  
  CONCLUSIONS
  Assessment of water diffusion has the potential to provide insight into tumour microstructure and is feasible in desmoids. Desmoid tumours demonstrate anisotropy but diffusion is less restricted and less directional than in muscle.
authors: Polyposis Registry, St. Mark's Hospital, Watford Road, Harrow, Middlesex HA1 3UJ, UK. s.bhandari10@imperial.ac.uk
authors: Santosh
authors: S
authors: Bhandari
authors: Ashish
authors: A
authors: Sinha
authors: Emily
authors: E
authors: Tam
authors: J James
authors: JJ
authors: Stirling
authors: Ian
authors: I
authors: Simcock
authors: Sue
authors: S
authors: Clark
authors: Vicky
authors: V
authors: Goh
mesh_terms: D000008:Abdominal Neoplasms / Q000150:complications* / Q000473:pathology*; D011125:Adenomatous Polyposis Coli / Q000150:complications* / Q000473:pathology*; D000328:Adult; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D018222:Desmoid Tumors / Q000150:complications* / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult