A system for increasing rates at which fluids may be manually forced through injection/aspiration elements, such as catheters and needles, includes the injection/aspiration elements, as well as a syringe including a pair of crossed handles, one associated with the barrel of the syringe, the other associated with the plunger of the syringe, to provide a mechanical advantage. The system may include and injection/aspiration element of small (e.g., 0.052 inch or smaller) inner diameter. Such systems enable the use of a single hand to hold and operate a syringe in a variety or procedures, including angiography, angioplasty, discography, glue/cement injection, and a variety of aspiration procedures (e.g., biopsy, sampling, media removal, etc.).