The clinical Deep-Vein Thrombosis diagnosis is very unreliable. A patient with the “classic signs” of a hot, swollen, and tender calf or a positive Homans’ sign (calf pain on dorsiflexion of the ankle) will have a Deep-vein thrombosis only 20–50% of the time ¹⁾. 50–60% of patients with Deep-vein thrombosis will not have these findings.