Duplex ultrasound in the diagnosis of acute leg-swelling

It is quite common in phlebological practice to examine a patient in order to make a differential diagnosis of a leg oedema. The present article presents a review of acute leg swelling according to clinical criteria, and then describes the typical external appearance and the corresponding duplex images with their characteristics. Possible causes for (generally unilateral) acute leg swelling requiring same-day treatment include: thrombosis, which should be diagnosed and treated as quickly as possible; ruptured Baker's cyst; haematoma, e.g. after a contusion or torn muscle. In the case of a post-operative lymphoedema (especially after revascularisation surgery), swelling may occur within a few days. Oedemas after radiation or tumour surgery on the other hand, may not appear until months to years after treatment, but then present an acute state. Oedemas associated with fractures may form gradually. Erysipela develops over a few days with hyperthermia and reddening in the leg. Acute bilateral oedemas are generally caused by secondary effects of medication (especially antihypertensives) or by the exacerbation of an internal disease which is generally already known (cardiac insufficiency, ascites with liver insufficiency, renal insufficiency) and therefore seldom have a phlebological explanation.