Patent Number: 
Section: claims

1. A method of operating a radioisotope elution system, the method comprising:aligning a radiation shield lid with a radioisotope generator such that a first aperture in the radiation shield lid is disposed over and vertically aligned with an input of the radioisotope generator and such that a second aperture in the radiation shield lid is disposed over and vertically aligned with an output of the radioisotope generator;mating the radiation shield lid with the radioisotope generator, wherein the mating can only occur while the radiation shield lid is aligned with the radioisotope generator, and wherein each of the radiation shield lid and the radioisotope generator independently comprises at least one radiation shielding material selected from depleted uranium, tungsten, tungsten impregnated plastic, or lead; anddisposing the radiation shield lid and the radioisotope generator within an auxiliary radiation shield, wherein the auxiliary radiation shield includes a first complementary alignment structure that is keyed to an alignment structure disposed on the radiation shield lid and a second complementary alignment structure that is keyed to another alignment structure on the radioisotope generator. 2. The method of claim 1 further comprising aligning a source of eluant to the radiation shield lid. 3. The method of claim 2 further comprising aligning an elution tool to the radiation shield lid. 4. The method of claim 1 wherein the aligning comprises resting the radiation shield lid on the radioisotope generator. 5. The method of claim 1 wherein the mating comprises substantially constraining the radiation shield lid and the radioisotope generator to a single degree of relative freedom. 6. The method of claim 1 further comprising inserting an elution tool, an eluant source, or both through the radiation shield lid. 7. The method of claim 1 wherein the mating comprises directly interfacing a first alignment structure on the radiation shield lid with a second alignment structure on the radioisotope generator. 8. The method of claim 7 wherein sidewalls of the radiation shield lid are substantially parallel to sidewalls of the first alignment structure. 9. The method of claim 7 wherein the first alignment structure extends from a bottom surface of the radiation shield lid. 10. The method of claim 7 wherein the first alignment structure is disposed on a bottom surface of the radiation shield lid. 11. The method of claim 1 further comprising inserting the radiation shield lid in a receptacle defined in the auxiliary radiation shield. 12. The method of claim 11 wherein inserting the radiation shield lid comprises inserting the radiation shield lid such that a top surface of the radiation shield lid is recessed below a top plane of the auxiliary radiation shield. 13. The method of claim 1, wherein aligning a radiation shield lid with a radioisotope generator comprises aligning the radiation shield lid with a radioisotope generator that includes a cap having a recess defined therein, wherein the recess is in the form of a cylinder having both a base and walls that are generally perpendicular to the base, and wherein both an input needle and an output needle are located within the same recess defined in the cap.