A medical device (100) comprising an elongate manipulation member； a thrombectomy device (102) connected to the elongate manipulation member, the thrombectomy device (102) having a first configuration and a second configuration, the thrombectomy device (102) being expandable from the first configuration to the second configuration, the thrombectomy device (102) comprising a plurality of arcuate marker-mounting projections (148) each attached to a portion of the thrombectomy device (102) configured to contact a thrombus, wherein at least some of the marker-mounting projections (148) are laterally aligned in the absence of external forces on the thrombectomy device (102), and wherein at least some of the laterally aligned marker-mounting projections (148) are arranged such that they are disposed laterally farther from each other when the thrombectomy device (102) is in the second configuration than they are when the thrombectomy device (102) is in the first configuration； and a plurality of markers (150), each of the markers (150) being attached to a respective one of the marker-mounting projections (148), wherein each of the marker-mounting projections (148) comprises a concave surface (160) and a convex surface (162) opposite the concave surface (160), and wherein each of the markers (150) contact a corresponding one of the marker-mounting projections (148) at (i) one location on the convex surface (162), and (ii) two locations on the concave surface (160).
