[0049] In some examples, catheter 12 is configured to access relatively distal locations in a patient including, for example, the middle cerebral artery (MCA), internal carotid artery (ICA), the Circle of Willis, and tissue sites more distal than the MCA, ICA, and the Circle of Willis. The MCA, as well as other vasculature in the brain or other relatively distal tissue sites (e.g., relative to the vascular access point), may be relatively difficult to reach with a catheter, due at least in part to the tortuous pathway (e.g., comprising relatively sharp twists or turns) through the vasculature to reach these tissue sites. The elongated body of catheter 12 may be structurally configured to be relatively flexible, pushable, and relatively kink- and buckle- resistant, so that it may resist buckling when a pushing force is applied to a relatively proximal section of catheter 2 to advance the elongated body distally through vasculature, and so that it may resist kinking when traversing around a tight turn in the vasculature. In some examples, the elongated body is configured to substantially conform to the curvature of the vasculature. In addition, in some examples, the elongated body has a column strength and flexibility that allows at least the distal portion of the elongated body to be navigated from a femoral artery, through the aorta of the patient, and into the intracranial vascular system of the patient, e.g., to reach a relatively distal treatment site. Alternatively, the elongated body can have a column strength (and/or be otherwise configured) to enable the distal portion of the elongated body to be navigated from a radial artery, through the aorta of the patient or otherwise to a common carotid or vertebral artery, and into the intracranial vascular system of the patient, e.g., to reach a relatively distal treatment site. [0050] Although primarily described as being used to reach relatively distal vasculature sites, catheter 12 may also be configured to be used with other target tissue sites. For example, catheter 12 may be used to access tissue sites throughout the coronary and peripheral vasculature, the gastrointestinal tract, the urethra, ureters, fallopian tubes, veins and other body lumens. [0051] In some examples, catheter 12 may be described in terms of the working length of the elongated body. The working length of catheter 12 may depend on the location of the target tissue site within the body of a patient or may depend on the medical procedure for which catheter 12 is used. For example, if catheter 12 is a distal access catheter used to access vasculature in a brain of a patient from a femoral artery access point at the groin of the patient, the elongated body may have a working length of about 115 centimeters (cm) to about 145 cm or more, such as about 130 cm, although other lengths may be used. The distal portion may be about 5 cm to about 35 cm in length.