Systems for nerve and tissue modulation are disclosed. An illustrative system may include an intravascular nerve modulation system including a catheter shaft, a first flexible mount, and a cylindrical ablation transducer. The ablation transducer may be affixed to the catheter shaft through the flexible mount to allow an infusion fluid to pass through a lumen of the transducer. Another illustrative system may include an intravascular nerve modulation system including an expandable basket for centering an ablation tra7nsducer within a lumen.