Medical devices are disclosed having improved visualization of a portion of the medical device insertable into a patient's body while minimizing obstruction of fluid flow through a lumen of the device and while minimizing an increase in the outer diameter of the device attributable to the feature providing improved visualization. The device can include, for example, an imaging marker distal to lumen openings (exit ports), or, where the device comprises a tube, such as a metallic tube, an imaging marker embedded into a wall of the tube. Another embodiment includes attaching a marker to the surface on the inside of a lumen of a medical device without embedding the marker. Various alternative embodiments, methods and applications of using such devices are disclosed as well.
