Incremental value of compression ultrasound sonography in the emergency department

Table 1 Wells’ score

Features	Score, points
Active cancer (in treatment or treated in the last 6 mo or under palliative care)	1
Paralysis, paresis, or recent plaster immobilization of the lower extremity	1
Bedridden recently > 3 d or major surgery within 12 wk	1
Localized tenderness along the deep venous system	1
Entire leg swollen	1
Calf swelling > 3 cm compared to the other leg	1
Pitting edema, confined to symptomatic leg	1
Collateral (nonvaricose) superficial veins present	1
Previously documented DVT	1
Alternative diagnosis to DVT as likely or more likely	-2

DVT: Deep venous thrombosis.

Table 2 Lesion types

Lesion definition	Characteristics
Acute thrombus	Noncompressible; deformable under probe push; regular profile; dilated vein
Subacute thrombus	Change in acute thrombus aspect few weeks apart, not includable in chronic post-thrombotic change definition (no later than 6 mo after clot formation)
Chronic post-thrombotic change	Noncompressible; resists to pressure deformation; non-uniform profile; reduced/normal vein caliber