Patent Number: 059862750
Section: summary

FIELD OF THE INVENTION This invention pertains to markers for nuclear medicine imaging. Specifically, an apparatus which permits the quick, safe, localized marking of structures on images of patients generated by nuclear imaging as provided. The radioactive material is inserted in the device immediately before imaging, and may be retained in the device until exhausted (decayed). The invention pertains to the device, as well as the method of using that device. DESCRIPTION OF THE INVENTION Nuclear medicine is a rapidly expanding diagnostic clinical field. Nuclear imaging permits the preparation of images of soft tissues and bone, making selective diagnosis on the basis of the nuclear medical imaging alone, or in conjunction with other conventional techniques, a more certain process. In the practice of nuclear imaging, it is conventional to use a "marker source" to localize structures on images of patients generated through this technology. Thus, where a particular structure in the image is to be studied, a localized radioactive source is used to "mark" that structure, or identify it for further study. Localized, portable markers are also used to orient the image, that is, mark the right or left side of the patient, height indications, front and back, etc. Currently available technologies, while focusing on the development of the image itself, have not provided effective, safe marker sources. Commercially available localized markers do not provide shielding to protect the medical technician and the patient from exposure to the radiation source, or radionuclide. Currently available sources have a constant radiation output. The radiation cannot be stopped, or interrupted, while positioning the marker/patient for imaging. Additionally, the sources currently available do not provide a sharply localized, defined image. Marking small structures for study is particularly difficult. Further, currently available source markers come provided with the nuclide or radioactive material. When the nuclide has decayed, the source marker is no longer usable. Accordingly an object of the art is to provide, an improved source marker which provides shielding for the diagnostician and the patient from the radiation source, provides a radiation source which can be interrupted when the source is positioned for imaging, provides sharply defined, localized marking and is refillable and reusable. SUMMARY OF THE INVENTION The invention comprises a radiation shielding chamber provided with a bottom, walls and a top, which top is either open, or, in a preferred embodiment, the chamber is provided with a radiation-shielding top, which top is provided with an aperture. The chamber is affixed to a spring, at the opposite end of which, provided proximal to the chamber, is a shutter. The shutter extends over the top of the chamber, and is provided with an aperture which, when aligned with the open top or aperture provided in the top of the chamber, permits emission of radiation through the shutter. The shutter and the chamber are moved into alignment by applying pressure the spring, to which both are attached. Releasing the spring closes the shutter, shutting off the radiation. The source of radiation, the radionuclide, is customarily provided on a felt or other absorbent in the chamber. The felt or absorbent may be loaded through the top, or through the aperture. When exhausted, the radionuclide is removed, and another source provided when the device is to be next used.