Abstract: A scintillation crystal module of the type having a crystal housed in a backcap which is closed off by a glass window and sealed by an internal seal located between the window and the backcap is modified to include an external seal. The external seal is of moisture-impervious material and is attached to the outer surface of the backcap and the window and bridges over the boundary therebetween. The external seal may be made of an epoxy polyamid or a blocked urethane epoxy copolymer. The outer surface of the module may be sandblasted before the external seal is attached to the module, as by casting the adhesive in a suitable mold.

Abstract: A gantry for a multi-head scintillation camera including a pair of vertically disposed annular plates between which are mounted the scintillation camera heads. The plates are supported on their peripheral edges by rollers which both provide load bearing support and allow plate rotation. A pulley is mounted on one of the plates and is belt-driven by a motor.

Abstract: The gantry of a scintillation camera is automatically counterbalanced about two parallel axes. One axis passes through the detector. The other axis is a tilt axis about which a gantry structure which supports the detector may be tilted. The gantry is also counterbalanced about an axis of rotation. A collimator may be detachably secured to the detector and automatically identified. The gantry is automatically adjusted to counterbalance it in accordance with the collimator which has been attached to the detector. In the preferred embodiment, the gantry is counterbalanced even when no collimator is secured to the detector.