title: How echographic image analysis of venous oedema reveals the benefits of leg elevation.
abstract: OBJECTIVE
  Venous insufficiency, leading to venous oedema, is a key pathogenic factor for the non-healing of venous leg ulcers. This study aimed to evaluate the effects of leg elevation on venous oedema.
  
  
  METHODS
  Ten patients aged 44-89 years (median: 61) with leg oedema had high-frequency B-mode ultrasound scanning and digital image analysis before and after three to four hours of leg elevation. The echographic image analysis system was used, where oedema is represented by the hypoechogenic part of the image--that is, the total number or density of low echogenic pixels (LEPs) in a particular area.
  
  
  RESULTS
  Compared with pre-elevation, the volume of the lower leg decreased by 2.9% +/- 0.6 (138 cm3 +/- 39) after three to four hours' elevation (p < 0.05). After elevation, the LEPs in the upper, middle and lower sites of the limb decreased by 8.8%, 15.6% and 17.3% respectively, reaching statistical significance (p < 0.05) in the lower site. The ratio of LEPs in the upper and lower dermis in the upper, middle and lower sites decreased by 30.3%, 45.8% and 22.5% respectively. This was significant in both the middle and lower sites (p < 0.01). After elevation dermal thickness increased by 0.047 mm, 0.194 mm and 0.232 mm respectively. This change was statistically significant in the middle (p < 0.05) and lower sites of the limb (p < 0.01).
  
  
  CONCLUSIONS
  LEPs are a sensitive marker of dermal oedema and its effects. Leg elevation is extremely effective in reducing oedema, even if only for three to four hours.
authors.affiliation: Oxford Wound Healing Institute, Oxford, UK.
authors.forename: Z D
authors.initials: ZD
authors.lastname: Xia
authors.forename: D
authors.initials: D
authors.lastname: Hu
authors.forename: J M
authors.initials: JM
authors.lastname: Wilson
authors.forename: G W
authors.initials: GW
authors.lastname: Cherry
authors.forename: T J
authors.initials: TJ
authors.lastname: Ryan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020405:Dermis / Q000000981:diagnostic imaging; D004487:Edema / Q000000981:diagnostic imaging* / Q000209:etiology / Q000451:nursing*; D005260:Female; D006801:Humans; D007866:Leg; D007871:Leg Ulcer / Q000150:complications / Q000451:nursing; D008297:Male; D008875:Middle Aged; D011187:Posture; D016896:Treatment Outcome; D014463:Ultrasonography; D014689:Venous Insufficiency / Q000150:complications / Q000451:nursing*