A catheter is disclosed, which is capable of delivering embolization beads for treating uterine fibroids. The elongate catheter shaft includes a radially expandable portion at its distal end, which can expand radially locally when an embolization bead passes through it. In some cases, the catheter shaft includes a non-expandable portion, with an inner diameter comparable to the bead diameter, between the handle and the radially expandable portion. In some cases, the radially expandable portion is made from a tubular braid, stretched longitudinally over a mandrel, and encased in a lubricious soft polymer while still stretched. In other cases, the radially expandable portion is made from a slotted nitinol tube, encased in a lubricious soft polymer below the nitinol transition temperature. The polymer is thick enough to prevent the encased element from returning to its unstretched diameter or a larger size above the transition temperature.