title: Sonographic elasticity imaging of acute and chronic deep venous thrombosis in humans.
abstract: OBJECTIVE
  The purpose of this study was to assess the ability of sonographic elasticity imaging to distinguish acute from chronic deep venous thrombosis (DVT).
  
  
  METHODS
  Fifty-four patients, 26 with acute DVT and 28 with chronic DVT, were studied, and we analyzed the data in 46 patients, 23 with acute (mean age, 5.7 days) and 23 with chronic (>8 months) DVT. Scanning was performed with a 5-MHz linear array transducer during continuous freehand external deformation of each thrombus using the ultrasound scan head. The strains in the thrombi were normalized to the average strain between the skin surface and the back wall of the vein. Relative thrombus echogenicity was measured by comparing the echogenicity of the thrombus with that of the adjacent arterial lumen. Statistical analyses were performed with the Mann-Whitney U test and receiver operating characteristic analysis.
  
  
  RESULTS
  The median normalized strain magnitude for the acute cases was 2.75, with an interquartile range of 2.4 to 3.71, whereas the median normalized strain magnitude for the chronic cases was 0.94, with interquartile range of 0.48 to 1.36. The difference was highly significant (P < 10(-7)). The area under the receiver operating characteristic curve (A(z)) was 0.97 +/- 0.02 (SE). The echogenicity difference between the populations was highly significant (P < 10(-5)), with A(z) of 0.92 +/- 0.04. The difference between the A(z) values was not significant (P > .05).
  
  
  CONCLUSIONS
  In this population, sonographic elasticity imaging performs at least as well as thrombus echogenicity. Thrombus aging using elasticity imaging would be particularly helpful in evaluating symptoms in patients with post-thrombotic syndrome.
authors.affiliation: Department of Radiology, University of Michigan Hospitals, 1500 E Medical Center Dr, Ann Arbor, 48109, USA. jrubin@umich.edu
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Rubin
authors.forename: Hua
authors.initials: H
authors.lastname: Xie
authors.forename: Kang
authors.initials: K
authors.lastname: Kim
authors.forename: William F
authors.initials: WF
authors.lastname: Weitzel
authors.forename: Stanislav Y
authors.initials: SY
authors.lastname: Emelianov
authors.forename: Salavat R
authors.initials: SR
authors.lastname: Aglyamov
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Wakefield
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Urquhart
authors.forename: Matthew
authors.initials: M
authors.lastname: O'Donnell
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D004548:Elasticity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012815:Signal Processing, Computer-Assisted; D018709:Statistics, Nonparametric; D014463:Ultrasonography; D020246:Venous Thrombosis / Q000000981:diagnostic imaging*