A gamma camera has a plurality of exchangeable collimators, one of which is replaceably mounted in the ray inlet opening of the camera, while the others are placed on separate supports. The invention is particularly characterized in that the supports are swingably mounted upon a column one above the other. In the illustrated embodiment, the camera is swingable through about 90.degree. to a collimator exchange position, and each of the separate supports is swingable to a vertically aligned position, with resilient limiting of the swinging movement and resilient positioning of the support at the desired exchange position. Further, the collimators are carried on the supports by means of a series of vertically disposed coil springs, projections on the camera being relatively movable from above into grooves of the collimator at the exchange position, whereupon the collimator is so turned that it is securely prevented from falling out of the camera head.
CROSS REFERENCES TO RELATED APPLICATIONS
The present application is a continuation of copending application Ser. No. 479,425, filed June 14, 1974, which in turn is a continuation of application Ser. No. 324,063 filed Jan. 16, 1973, now abandoned.
A device for attaching a collimator to a radiation detector. A number of cleats are mounted at the radiation detector for cleating the collimator to the radiation detector and a latch means serves for latching the cleated collimator against rotation. Also a collimator cleating detection means is associated with the cleat means for detecting incorrect cleating of the collimator and a collimator latch detection means is associated with the latch means for detecting incorrect latching of the collimator.
An automatic collimator exchanger for a gamma camera system for simultaneous exchange of pairs of collimators (or a single collimator) for a dual detector head system. The present invention includes an exchange assembly having an elevator, a carriage and a bridge. The elevator includes a rack of multiple parallel and stacked trays for holding various pairs of collimators. A draw bridge unit is attached to one side of the elevator (which side faces a gantry structure) and may extend into the gantry structure. The carriage is able to support two collimators and moves from within the elevator unit onto the bridge and into the gantry structure, when the bridge is lowered, to position between two aligned detector heads of the dual head gamma camera system. When the detector heads are positioned near the aligned carriage, latch pins are released and collimators may be transferred to the carriage, if empty, or hastened to the detector heads from the carriage when installing a pair of collimators. Sliding lock plates (each having hooks and a safety latch pin) are mounted on both sides of each of the detector heads and are used to transfer the collimators between the carriage and the detector heads during the exchange (for removal and installation) and are used to secure the collimators to the detector heads during an imaging session. One collimator or a pair may be simultaneously exchanged using the present invention without operator intervention.
A scintillation camera includes a plurality of detectors mounted on the camera and arranged to provide an opening for allowing the insertion of an object for examination such as a human being and for radiographing a tomographic image, a plurality of collimators each of which is attached to the front of the corresponding detectors for collimating X-rays radiating from the object for examination, and an exchanger for the collimators, the exchanger including a carrier and a holding device for holding the collimators in a swingable manner in any direction within a certain range by use of a mechanism such as a spherical bearing.
An apparatus and method for the automated positioning of a collimator exchange assembly with a gamma camera system is described. A collimator exchange assembly is coupled to a base. During operation of the gamma camera system, the exchange assembly is positioned to the side of the gamma camera system. Prior to transferring collimators between the exchange assembly and the detector heads of the gamma camera system, the exchange assembly rotates into close proximity with the gamma camera system to allow the transfer of collimators between the exchange assembly and the gamma camera system. Once the collimators have been transferred, the exchange assembly then rotates back to the side of the gamma camera system such that the exchange assembly does not interfere with the gamma camera system during the gamma camera study.
4528453 - Dual collimator - Owned by Albert Einstein College of Medicine of Yeshiva University (Bronx, NY)
A dual collimator designed for an Anger camera (gamma camera), to permit measurement of cardiac performance on a beat-to-beat basis. Special all-purpose (SAP) and special high-sensitivity (SHS) collimator sections can be interchanged without movement of the gamma camera or patient. Thus, left-ventricular regions of interest delineated on SAP multigated images can be transferred to SHS high sensitivity images to generate beat-to-beat volume curves. Preliminary balloon studies demonstrated an excellent correlation between ejection fractions calculated with the two collimators: 5>0.99, n=17, p<0.001. Varying the volume of an adjacent "right ventricle" balloon failed to alter significantly the count rate from the "left ventricle" balloon's region of interest. Preliminary results on 12 patients, comparing standard-camera ejection fractions with average beat-to-beat ejection fractions, showed that it is possible to measure cardiac function on a beat-to-beat basis with a single-crystal gamma camera. There was minimal difference between the ejection fractions calculated by the dual-collimator method and a standard gated technique (r=0.98, n=12, p<0.001).
