BACKGROUND: We studied whether 2 MHz transcranial color-coded duplex ultrasound (TCCD), combined with a second generation ECA, accelerate IV rtPA-thrombolysis in the acute phase of MCA stroke more than TCCD monitoring alone. METHODS: Non-randomized acute MCA stroke patients undergoing IV rtPA-thrombolysis and 2 MHZ-TCCD monitoring over 60 min, with (N = 11) or without (N = 15) additional continuous ECA (5 ml, SonoVue perfusion, were compared. Recanalization of the MCA was measured pre- and post-thrombolysis with the thrombolysis in brain ischemia (TIBI) grading system, clinical outcome was assessed at admission and 24 h after treatment using the NIH stroke scale (NIHSS). RESULTS: Patients who received ECA improved their NIHSS significantly more than those who were only TCCD monitored (Mann-Whitney U = 48.0; P = 0.050), and their flow signal improved more (Mann-Whitney U = 40.0; P < 0.03). CONCLUSIONS: The results of this pilot study show that in IV-thrombolysis the use of ECA in addition to TCCD monitoring lead to a greater immediate clinical improvement and to a better flow signal.