摘要:
Normalization coefficients in are computed for positron emission tomography (PET) continuous bed motion acquisition (CBM). The normalization coefficients for the lines-of-response in CBM account for the change in decay of the injected isotope over time and/or changes in velocity of the bed motion.
摘要:
Apparatuses and methods are provided that minimize the effects of dark-current pulses. For example, in one embodiment of the invention, a method is provided where a first pixel is struck (i.e., a primary pixel). Pixels struck within a fixed time frame after the primary pixel is struck are referred to as secondary pixels. After a short fixed time frame has expired, the number of primary and secondary pixels is added. If the count exceeds a threshold, the primary pixel was activated by the first (or early) photon from a true gamma event. If the threshold is not met then it is likely the primary pixel generated a dark pulse that should be ignored.
摘要:
Using complementary reconstruction, images from short time frames may be generated for positron emission tomography. Detected events are gathered over a long period, such as three minutes. The detected events from a short period, such as one or two seconds, are removed. Reconstruction is performed on the detected events from the long period and another reconstruction is performed on the detected events from the long period without the detected events from the short period. The second reconstruction is subtracted from the first, providing data representing the short period. The data may result in better image quality than merely reconstructing an individual frame for the short period.
摘要:
A system identifies when received packets are lost at a node in a multi-node processing chain. The system processing chain may include a gantry interface module for receiving coincident event data from a PET (Positron Emission Tomography) detector array, a DMA (direct memory access) rebinner card, and a transmission line coupled between the gantry interface module and the DMA card. FPGA and FIFO elements in each processing portion receive packets that may be lost if there is insufficient FIFO capacity. Lost packets are marked, discarded, and counted. At specified intervals, set in accordance with a threshold number of packets received a lost tally data packet is generated that includes count information for lost packets. The lost tally data packet is forwarded downstream when sufficient storage capacity exists.
摘要:
A representative positron emission tomography (PET) calibration system includes a PET scanner having a ring detector, a phantom that is placed at approximately the center of the ring detector, and a time alignment calibration manager that is coupled to the PET scanner. The time alignment calibration manager detects coincidence events from the phantom, calculates position of time of flight events from the ring detector based on the detected coincidence events, and calculates time offsets for the ring detector using a mean value calculation based on the calculated position of the time of flight events.
摘要:
A method for correcting PET emission data for prompt gamma emission background components present in non-pure positron-emitting isotopes uses a two component fit of modeled scatter and modeled prompt gamma emission in the area of scatter tails in a normalized emission sinogram. The method allows a PET scan using non-standard PET isotopes to be quantitative and thus more clinically useful.
摘要:
A method for determining quality of sinograms produced by a medical imaging device. The method may include placing a uniform phantom object in the field of view of the medical imaging device; acquiring one or more phantom sinograms of the uniform phantom object; establish a set of parameters for the acquired one or more phantom sinograms; and determine, based on pre-set ranges of the parameters, the quality of sinograms produced by the medical imaging device. The parameters may be one or more parameters of a group of parameters consisting of block uniformity, block efficiency, randoms rate, scanner efficiency, and scatter ratio.
摘要:
A method for improving clinical data quality in Positron Emission Tomography (PET). The method provides for the processing of PET data to accurately and efficiently determine a data single-to-noise ratio (SNR) corresponding to each individual clinical patient scan, as a function of a singles rate in a PET scanner. The method relates an injected dose to the singles rate to determine SNR(Dinj), and provides an accurate estimate of a quantity proportional to SNR, similar in function to the SNR(Dinj). Knowledge of SNR(Dinj) permits determination of peak SNR, optimal dose, SNR deficit, dose deficit, and differential dose benefit. The patient dose is fractionated, with a small calibration dose given initially. After a short uptake, the patient is pre-scanned to determine T, S, and R. An optimal does is then determined and the remainder injected.
摘要:
A constant fraction discriminating circuit outputs timing information corresponding to an event corresponding to a detected photon for providing nuclear medicine imaging. The constant fraction discriminating circuit includes a stripline or microstrip delay element.
摘要:
A method for improving clinical data quality in Positron Emission Tomography (PET). The method provides for the processing of PET data to accurately and efficiently determine a data signal-to-noise ratio (SNR) corresponding to each individual clinical patient scan, as a function of a singles rate in a PET scanner. The method relates an injected dose to the singles rate to determine SNR(Dinj), and provides an accurate estimate of a quantity proportional to SNR, similar in function to the SNR(Dinj). Knowledge of SNR(Dinj) permits determination of peak SNR, optimal dose, SNR deficit, dose deficit, and differential dose benefit. The patient dose is fractionated, with a small calibration dose given initially. After a short uptake, the patient is pre-scanned to determine T, S, and R. An optimal dose is then determined and the remainder injected.