The definition of Takayasu arteritis (TAK) remission and disease activity is still unclear. Vascular imaging is an essential tool for following-up patients. Herein, we aimed to compare the evolution of vascular lesions (ie vessel wall thickening and stenosis) under conventional disease-modifying anti-rheumatic drugs (cDMARDs) relatively to biological DMARDs (bDMARDs) in TAK patients followed with the same CT angiography modalities. We compared 75 lines of therapy in TAK patients who received cDMARDs (n = 40 lines) and bDMARDs (n = 35 lines) using CT angiography. We established 1-3 main target vessels with vessel wall thickening and/or stenosis. Every targeted vessel had its thickness and its lumen diameter measured at the initiation of immunosuppressive treatment and at 12 months. We observed an overall reduction of arterial wall thickness in 73% of cases and 31% had >25% of wall thickness relative decrease. Using a linear mixed effects model, first line immunosuppressive therapy (p= 0.012) and bDMARDs relatively to cDMARDs (p= 0.026) were independently associated with vessel wall thickness reduction in TAK. Thirty-eight percent of the stenotic vessels had a > 25% relative increase in lumen diameter under immunosuppressive therapy. The relative increase >25% in lumen diameter was noted in 56% vs 17% with bDMARDs compared with cDMARDs. Immunosuppressive treatments can reduce arterial wall thickness and widen lumen diameter in TAK. bDMARDs seems to be more effective than cDMARDs to improve arterial lesions in TAK.