Adac Laboratories, Inc.

Matthew J Murphy

Horace H Hines

Donald R Wellnitz

Peter Nellemann

Hugo Bertelsen

Gerd Muehllehner

Robert L Kay

Paul M Hug

David A Chan

Steven M Jones

Edward M Goldberg

Kenneth G Bayer

A scintillation camera detector head comprises a scintillation crystal, a plurality of photomultiplier tubes (PMTs) optically coupled to the scintillation crystal, and a diffractive surface, such as a holographic optical element (HOE), optically coupled to the scintillation crystal. The diffractive surface preferentially reflects or redirects light from a scintillation event which impinges upon the surface toward one or more predetermined PMTs as a function of the angle of incidence or the location of the event. Light emitted under a peak PMT can be preferentially reflected or transmitted away from the peak PMT and toward the surrounding PMTs to reduce spatial resolution modulation. Alternatively, light impinging on the surface from an event can be directed toward the peak PMT and away from surrounding PMTs to achieve greater isolation of events.

Tailored optical interface for scintillation camera detector

A dual head nuclear camera system automatically switchable (and optimized) to perform either SPECT imaging or PET imaging that utilizes attenuation correction for nonuniform attenuation in SPECT or PET modes. The dual head detectors contain switchable triggering circuitry so that coincidence detection for PET imaging and non-coincidence detection for SPECT imaging is available. The system uses a variable integration technique with programmable integration interval; variable sized clusters for centroiding, use of dual integrators per PMT channel, the event detection and acquisition circuitry of the camera system is switchable for PET and SPECT imaging. In such a switchable SPECT/Pet dual head camera system, a mechanism and method is shown to perform transmission and emission scanning sessions with two line sources and two detectors wherein two sliding transmission detection windows are employed to differentiate between transmission and emission photons. Transmission and emission data can be collected simultaneously. This system provides that the dual transmission detection windows are each associated with a particular line source and move in synchronization. Further, the two line sources and the two detector windows all move in synchronization in the direction of the long axis of the object being scanned. In this configuration, the system can effectively reduce the amount of cross-talk detected by a detector.

Multi-head nuclear medicine camera for dual SPECT and PET imaging with

A gamma camera for a Positron Emission Tomography (PET) system comprises a single, continvous scintillation crystal having an imaging surface, and a first layer of septa disposed along the imaging surface between the object and the imaging surface. A gap is provided between the imaging surface and the first layer of septa to allow non stray radiation to reach the imaging surface. The septa may be arranged to have a long axis disposed at an acute angle away from perpendicular to an axis of rotation or made to move in relation to the imaging surface of the scintillation crystal to reduce cold spots on the image. Multiple layers of septa may be provided.

Gamma camera having partial septas and moving septas for positron

A multi-detector head nuclear camera system automatically switchable (and optimized) to perform either SPECT imaging or PET imaging. The camera system employs, in one embodiment, multi-detector configuration having dual head scintillation detectors but can be implemented with more than two detector heads. The detectors contain switchable triggering circuitry so that coincidence detection for PET imaging and non-coincidence detection for SPECT imaging is available. Using a variable integration technique with programmable integration interval, the event detection and acquisition circuitry of the camera system is switchable to detect events of different energy distribution and count rate which are optimized for PET and SPECT imaging. The system also includes dual integrators on each scintillation detector channel for collecting more than one event per detector at a time for PET or SPECT mode. In PET or SPECT mode, the system also employs variable PMT cluster sizing having smaller cluster sizes for PET imaging and relatively larger cluster sizes for SPECT. In PET or SPECT mode, the system also employs variable centroid shape and zonal triggering. Utilizing the above programmable settings, the camera system can be automatically configured to operate in either SPECT or PET imaging modes.

Multi-head nuclear medicine camera for dual SPECT and PET imaging

A system including circuitry within a gamma camera system for generating spatially variant photomultiplier cluster based on a peak photomultiplier and for generating spatially variant weights for photomultipliers of the cluster depending on a cluster type signal. The system includes a first memory circuit addressed by a peak photomultiplier address signal and responsive thereto which generates (1) a unique photomultiplier cluster in geometry and size for the peak photomultiplier and (2) a cluster type. A resolution input signal (high/low) changes the size of the cluster. The first memory is programmable. A second memory responsive to photomultiplier addresses of the cluster and the cluster type, generates weight values for each photomultiplier. The second memory is programmable. The second memory allows weights for individual photomultipliers to be altered based on the geometry and size (e.g., type) of the cluster generated by the first memory. The system can effectively operate within a digital gamma camera system.

Spatially variant PMT cluster constitution and spatially variant PMT

A direct measurement system for proximity detection of a body profile for use within nuclear medicine. The measurement system includes two or three proximity detector units mounted on a gantry structure of a nuclear medicine camera which each emit an energy beam which is swept across a portion of a target body. Each detector is capable of directly measuring the distance from the proximity detector unit to the target body with a beam sample. The detectors then create a body profile of the target body which is used to minimize the distance between the collimator of a scanning camera and the target body surface thus improving image quality of the scanning camera. There is relative motion between the object and the gantry along a cranial-caudal axis of a target body for scanning successive body profiles. Successive body profiles are combined together to achieve a complete body contour of the target body. The proximity detector units are stationary with respect to movement of the scanning camera toward said target body. Body contour data is also used for attentuation correction.

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Los Altos, CA, United States of America

Matthew J Murphy