title: Achilles tendon (TA) size and power Doppler ultrasound (PD) changes compared to MRI: a preliminary observational study.
abstract: OBJECTIVE
  To assess whether abnormal Achilles tendon (TA) magnetic resonance imaging (MRI) and spectral ultrasound (US) features have associated development of microvascular power Doppler (PD) flow.
  
  
  METHODS
  In a prospective, controlled and blinded study six patients with TA symptoms were compared to five with other ankle abnormalities. Two radiologists independently measured the mean maximal anteroposterior diameter on MRI and conventional US (categorized as normal <6 mm, mild 6.1-10 mm, moderate 1.1-1.5 cm and severely enlarged > 1.6 cm), assessed morphology and studied the vessels using power Doppler. They formed a consensus over discrepancies. Sonography of the contralateral side within 24 h was used as a control.
  
  
  RESULTS
  Twenty-one tendons in six women and five men, aged 45-77 years (mean 57.6 years), were examined, 12 tendons were of normal US morphology and size (< 6 mm), and did not exhibit PD's flow (interobserver agreement K > 0.74). Of the 12 tendons studied by MRI five were normal, seven tendons were enlarged, five of which had a proportionate increase in PD flow at the margin on the deep surface and four also had vessels in the centre of the tendon. All five of these tendons had high signal on T2-weighting (T2W). Of the two mildly enlarged tendons of intermediate signal on T1 and T2W, one showed PD flow and the other did not.
  
  
  CONCLUSIONS
  In patients with TA disease power Doppler ultrasound shows proliferation of vessels in enlarged, abnormal tendons demonstrated on MRI and standard ultrasound, in the absence of definite tears.
authors.affiliation: North Staffordshire NHS Trust, Royal Infirmary, Hartshill, Stoke-on-Trent, UK. doctor-pj-richards@hotmail.com
authors.forename: P J
authors.initials: PJ
authors.lastname: Richards
authors.forename: A K
authors.initials: AK
authors.lastname: Dheer
authors.forename: I M
authors.initials: IM
authors.lastname: McCall
mesh_terms: D000125:Achilles Tendon / Q000098:blood supply / Q000000981:diagnostic imaging / Q000293:injuries / Q000473:pathology*; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000175:diagnosis; D015588:Observer Variation; D011446:Prospective Studies; D016037:Single-Blind Method; D052256:Tendinopathy / Q000175:diagnosis / Q000000981:diagnostic imaging; D013708:Tendon Injuries / Q000175:diagnosis* / Q000000981:diagnostic imaging; D018608:Ultrasonography, Doppler