ECAT III: A new PET system for heart and whole body dynamic imaging

Conference · Wed May 01 04:00:00 EDT 1985 · J. Nucl. Med.; (United States)

OSTI ID:6855595

Hoffman, E J; Phelps, M E; Huang, S C; Collard, P E; Bidaut, L M; Schwab, R L; Schwaiger, M; Schelbert, H R

A new whole body PET system has been developed and is being evaluated. The ECAT III consists of 1 to 4 rings of 512-5.6 x 29 x 30 mm BGO detectors per 100 cm diameter ring. The system has a unique data collection scheme in which all events are buffered in a 512 by 32 data matrix. The 512 dimension corresponds to detector number and the 32 dimension corresponds to 8 nsec time bins. A dedicated microprocessor searches the array (1) to determine which detectors had events simultaneously +- 8 nsec to establish coincidences, (2) to determine accidentals by determining the probability of off-time events, which can be determined with a statistical accuracy improvement of a factor of 10 by using a larger ''software'' time window, and (3) to determine and distinguish between adjacent detector crosstalk and random triple events. System can process 500 K coincident events/sec/per image plane. Data are collected in list mode and scan parameter information, such as time, wobble position and occurrence of gating signals are inserted in data. Wobble position is divided in 1000 parts per rotation, minimizing positioning error in binning events, timing information allows retrospective choice of time frame for dynamic studies and cardiac gate data allows retrospective choice of framing. ECAT III has an image resolution of 4.5 mm when system is wobbled and 7.2 mm when system is stationary. Loss of efficiency due to nearest neighbor cross talk is 8 to 12%. Axial resolution is selectable with remotely driven side shielding, and interchangeable interplane sept allow different configurations to accomodate a variety of imaging conditions.

• Research Organization: UCLA School of Medicine, Los Angeles
• OSTI ID: 6855595
• Report Number(s): CONF-850611-
• Conference Information: Journal Name: J. Nucl. Med.; (United States) Journal Volume: 26:5
• Country of Publication: United States
• Language: English

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COMPUTERIZED TOMOGRAPHY
DATA ACQUISITION
DATA ACQUISITION SYSTEMS
DESIGN
DIAGNOSTIC TECHNIQUES
EMISSION COMPUTED TOMOGRAPHY
EVALUATION
IMAGE SCANNERS
MEASURING INSTRUMENTS
PERFORMANCE
POSITRON COMPUTED TOMOGRAPHY
RADIATION DETECTORS
RESOLUTION
SEMICONDUCTOR DETECTORS
TOMOGRAPHY