A catheter (102), comprising: an elongate tubular body (114) having proximal and distal ends (114P, 114D) and a fluid lumen extending therethrough； and a plurality of flow-indicating projections (130) extending radially inward from an interior surface of the fluid lumen, each of the projections having an imageable portion (138)； wherein at least the imageable portions of the projections are configured to move relative to the fluid lumen when fluid is flowing through the fluid lumen and to remain stationary relative to the fluid lumen when fluid is not flowing through the fluid lumen.
