Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 41 3 2003 09 15 180 182 H. Sharifian F. Gharekhanloo 2015 09 28 The goal of this study was to define the normal range of diameter in the deep vein of the lower limb and to compare this range with diameter of the veins with acute thrombosis and of veins with chronic thrombosis by using color doppler sonography. The study was cross sectional. The vein diameter and vein to artery ratio in different levels were measured and the following results were obtained. In patients with acute thrombosis the vein diameter and vein to artery ratio were more than normal range and this difference had statistical significance so we can reliably predict acute thrombosis if the vein diameter is upper than a suggested level. In chronic thrombosis, however, the vein diameter is not a good diagnostic factor and so we can not rely on it. https://acta.tums.ac.ir/index.php/acta/article/view/2660 https://acta.tums.ac.ir/index.php/acta/article/download/2660/2642