Scintillation camera radiation shielding

A gamma camera for producing images representative of the spatial distribution of administered radiation emanating from a patient comprising:

• (a) a detector including a radiation responsive receptor;
• (b) a fixed, apertured, disc ring attenuator connected to the detector in alignment with the receptor;
• (c) the attenuator being formed of a radiation absorbent material adapted to screen and block the transmission of radiation to the receptor except through the attenuator aperture;
• (d) a movable apertured disc attenuator slidably positioned adjacent the fixed attenuator for selectively aligning the movable attenuator aperture with a portion of the fixed attenuator aperture by movement across the camera field whereby to delineate a portion of the receptor which will produce an image of a field of interest;
• (e) the movable attenuator being formed of an endless quantity of material surrounding the aperture and having radiation absorbent characteristics ample to screen and block the transmission of radiation coming from regions without a field of interest under investigation;
• and,
• (f) an attenuator support secured to the detector in predetermined spaced relationship with the fixed attenuator to define a movable attenuator supporting slot therebetween with the support being positioned sufficiently close to the fixed attenuator to retain the movable attenuator in an adjusted position but sufficiently spaced to permit its adjustment.

A process of operating a scintillation camera which includes a detector to increase the quantum of energy processed by the camera which emanates from a given field of interest and thereby improve the quality of an image of that field of interest comprising the steps of:

• (a) positioning a camera to conduct a study of a field of interest;
• (b) positioning a movable attenuator shaped to screen and block radiation between a portion of the detector and the field of interest;
• (c) adjusting at least a selected one of the attenuator and detector positions across the field of interest until the field of interest is substantially aligned with an unblocked portion of the detector and the attenuator is positioned to block the transmission of radiation emanating from without the field of interest to the detector;
• and,
• (d) thereafter developing an enhanced image of the field of interest.

A process of operating a scintillation camera which includes a detector to increase the quantum of energy processed by the camera which emanates from a given field of interest and thereby improve the quality of an image of that field of interest comprising the steps of:

• (a) positioning a camera to conduct a study of a field of interest;
• (b) positioning an apertured movable attenuator between a portion of the detector and the field of interest;
• (c) moving the attenuator relative to the detector across the field of interest until the field is substantially aligned with the attenuator aperture and the attenuator is positioned to block the transmission of radiation emanating from without the field of interest to the detector;
• and,
• (d) thereafter developing an enhanced image of the field of interest.

For use with a gamma camera adapted for making cardiac and other medical studies, an improved beam delineating attenuator assembly comprising:

• (a) a fixed apertured disc of a material adapted to block the transmission of gamma radiation emitted by a patient during a diagnostic study, the fixed disc being adapted to be fixedly connected to a gamma camera detector across the camera field of view and transverse to a path along which patient emitted radiation will travel during a study;
• (b) a movable attenuator support connected to the fixed attenuator in spaced relationship to define a movable attenuator supporting space therebetween;
• and,
• (c) a movable apertured disc slidably positionable in the space and movable transversely relative to the fixed disc to adjust a camera's field of view to include a region of interest the movable disc being formed of a material adapted to screen and block radiation emitted by a patient during a diagnostic examination.