Adaptive Frame Scanning for Pulsed X-Ray Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current X-ray imaging systems face challenges with frame synchronization, particularly when the X-ray pulsing frequency exceeds the frame scan rate, leading to increased frame integration time, dark current shot noise, and artifacts in reconstructed images, especially in pulsed X-ray applications like Cone Beam CT, due to jittering radiation pulses.
Innovation Solution
An adaptive frame scanning method is implemented, where line scanning on the image detector is suspended until the end of a calculated delay after receiving an indication that radiation has begun and resumed after radiation has stopped, with additional delays to accommodate jitter in radiation-on times, ensuring a fixed frame rate and optimizing gain calibration and Cine imaging processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If frame synchronization is used with pulsed X-ray imaging, then radiation delivery can be controlled for each specific angle, but frame integration time increases and dark current shot noise increases
Solution Approach 1:
The patent implements dynamic frame scanning where the detector frame scan rate is adaptively adjusted to match the X-ray pulse frequency. The system transitions from static synchronization to dynamic scanning that can respond to varying pulse frequencies, allowing the frame scan to be suspended during radiation delivery and resumed afterward, thereby optimizing integration time while maintaining image quality
Solution Approach 2:
The system performs preliminary suspension of frame scanning before radiation delivery begins by detecting the pre-radiation signal and calculating an appropriate delay period. This preliminary action ensures that the detector is ready to capture the next frame immediately after radiation stops, minimizing unnecessary integration time while avoiding artifacts from pulse jitter
2Reliability
If frame scan rate is synchronized with X-ray pulse frequency, then artifacts from pulse jittering are reduced, but the system cannot handle varying pulsing frequencies
Solution Approach 1:
The patent employs dynamic frequency adaptation where the frame scan control system continuously monitors X-ray pulse frequency and adjusts the frame scan rate accordingly. This dynamic approach allows the system to maintain reliable artifact-free imaging while adapting to varying pulsing frequencies that may occur during different imaging protocols or gantry angle configurations
Solution Approach 2:
The system implements feedback control by detecting the actual X-ray pulse timing and using this information to adjust subsequent frame scan timing. The frame scan control generator receives feedback about pulse frequency variations and modifies the scan rate to maintain synchronization, ensuring both artifact reduction and adaptability to frequency changes
3Measurement precision
If external frame synchronization control is used, then radiation delivery can be precisely controlled, but the system becomes complex and difficult to implement
Solution Approach 1:
The patent implements self-service control where the detector frame scan control generator autonomously detects X-ray pulse signals and automatically adjusts frame scanning without requiring external synchronization inputs. The system uses its own detection capabilities to generate the appropriate control signals, eliminating the need for complex external synchronization hardware and simplifying the overall control architecture while maintaining precise radiation delivery control
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces frame integration time, minimizes dark current shot noise, and improves image quality by synchronizing frame scanning with X-ray pulses, enabling more accurate low-dose applications and reducing artifacts in CT images.
Implementation Method 1
Photosensitive element arrays for converting incident radiant energy into an electrical signal are commonly used in imaging applications
Data Source
AI summary
A method for adaptive frame scanning for pulsed x-ray imaging comprising the steps of: scanning lines on an image detector sequentially; receiving an indication that radiation is about to begin; waiting a fixed delay after the indication is received; suspending scanning after the fixed delay has lapsed; and resuming scanning of lines on the detector upon receiving an indication that radiation has stopped. By monitoring for completion of a frame a predetermined frame delay can be added before commencing the next line scan to accommodate jitter in the radiation pulse timing.