Adac Laboratories, Inc.

University of California

Thomas F Lang

Steven M Jones

Xiaohan Wang

John R Liebig

Michael J Janicki

J Keenan Brown

Christopher E Cann

Bruce H Hasegawa

Joseph A Heanue

Robert G Gould

A scan speed procedure and method wherein a minimum radiation exposure period is determined on an object by object basis for a transmission study. Two transmission scans are performed including a prescan followed by a second transmission scan phase. The first transmission prescan is performed using a radiation source over the object. This prescan is of a rapid and predetermined duration (Tp). A resultant count density associated with the object is then generated and examined. The portion having the smallest count density (Cm) is determined and a value (Co) representing the minimum required number of counts for transmission study is given. From the above, a transmission period (Ts) is determined by the system and the second transmission scan phase is performed for the duration Ts using a multi-pass scan phase. The computed duration Ts represents the minimum exposure duration required to collect transmission data to ensure that the count density distribution associated with the object will contain at least Cm count density over each portion of the object.

Scan speed for transmission exposure reduction in a nuclear medicine

A method and apparatus for collecting transmission information utilizing a large field of view of a detector and for collecting emission data using a small field of view window of the same detector. The system employs the large field of view of a scintillation detector in order to collect transmission data for the entire body being scanned. Such a technique improves the quantitative capability of emission data by acquiring non-truncated attenuation factors. The emission data of a small field of view window is collected so that high resolution image pixels are used for processing the emission data (e.g., of a particular body organ). Since a large field of view is used for collecting the transmission data, the imaging pixels for transmission data are of lower resolution than the emission data. The emission data can be collected using a roving zoom technique during an ECT scan. A computation adjusts the transmission data to account for the known location of the emission zoom window on the crystal and for the different pixel sizes between the full field of view transmission scan of the body and the smaller roving electronic field of view emission scan of the body organ.

Large field of view transmission and small field of view emission scan

A mechanism and method for performing 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 with the associated line source. 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 and at any given position all are within a given spatial plane that is transverse to the long axis of the object. In this configuration, the system can effectively reduce the amount of cross-talk detected by a detector (e.g., cross-talk being scattered photon radiation detected by a given detector but not originating from the detector's associated line source). The configuration of this system also effectively operates in conjunction with systems employing tracking zoom regions across detector surfaces (e.g., used for cardiac studies).

Dual synchronized sliding transmission detection windows for dual

Radionuclide emission imaging is improved by correcting emission-transmission data for attenuation along calculated path lengths and through calculated basis material. X-ray transmission data are used to develop an attenuation map through an object which is then used in reconstructing an image based on emission data, Radiation detection circuitry is provided which has different operating modes in detecting the x-ray and emission photons passing through the object. An iterative process is used to reconstruct the radionuclide distribution using the radionuclide projection data and the attenuation map based on physical characteristics of the object being imaged. Subsets of the complete radionuclide projection data are used to reconstruct image subsets of the radionuclide distribution. The image subsets can be generated concurrently with the acquisition of the radionuclide projection data or following acquisition of all data.

Emission-transmission imaging system using single energy and dual energy

Growing community of inventors

Fremont, CA, United States of America

Thomas F Lang