Timer-based amplitude correction method for photon counting computed tomography
AssigneeAnalog Devices, Inc.
InventorsSunrita Poddar, Patrick S. Riehl, Matthew A. Woodruff
Life of this patent
Estimating the term…
Abstract
One embodiment is a method of deconvolving overlapping first and second pulses in a photon-counting CT scanning system, the method comprising detecting a first pulse event having a first detected level; detecting a second pulse event having a second detected level; determining an amount of time that elapses between the detected first pulse event and the detected second pulse event; and reconstructing the first pulse and the second pulse using the first and second detected levels, the duration of time between the first and second pulse events, and a known pulse shape.
Claims20
A method of deconvolving overlapping pulses in a photon-counting computed tomography (CT) scanning system, the method comprising:
- detecting, in a pixel of the photon-counting CT scanning system, a number of events in a sequence of discriminator codes corresponding to respective increasing voltage thresholds;
- determining amounts of time that elapsed between successive ones of the detected events;
- and
- reconstructing a most likely sequence of events that caused a measured pattern of discriminator codes based on measured code values associated with each of the detected events, the amounts of time that elapsed between successive ones of the detected events, and a known basis pulse shape.
A method of deconvolving overlapping first pulse and second pulse in a photon-counting computed tomography (CT) scanning system, the method comprising:
- detecting a first pulse event having a first detected level;
- detecting a second pulse event having a second detected level;
- determining an amount of time that elapsed between the detected first pulse event and the detected second pulse event;
- and
- reconstructing the first pulse and the second pulse using the first detected level and the second detected level, the amount of time that elapsed between the first pulse event and the second pulse event, and a known basis pulse shape.
A method for amplitude correction in a photon-counting computed tomography (PCCT) scanning system, the method including:
- detecting a pulse at a pixel of the PCCT scanning system;
- for each change of voltage level detected in connection with the pulse, incrementing a counter;
- for each voltage level detected in connection with the pulse, determining whether an amount of time the pulse remains at the voltage level exceeds a threshold amount of time corresponding to a time-over-threshold (TOT) event;
- tracking a number of voltage level changes encountered between detection of the pulse and detection of a second pulse at the pixel of the PCCT scanning system;
- in response to a TOT event in connection with a voltage level, approximating a voltage level change as a time elapse of the threshold amount of time;
- otherwise, approximating the voltage level change as a time elapse of half the threshold amount of time;
- and
- upon detection of the second pulse, using the approximated time elapse from the pulse to compensate for contributions to the second pulse from the pulse and resetting the counter to zero.
Dependencies are inferred from the claim text.