COMPUTED TOMOGRAPHY STREAK SUPPRESSION FILTER

摘要

A CT streak suppression filter, SSF (70), receives projection data signals (PDS:1-PDS:N) generated in a CT system. The SSF (70) includes spatial filter (110) for receiving projection data signals (PDS:1-PDS:N) and generating low (PDSLF:1-PDSLF:N) and high frequency signals (PDSHF:1-PDSHF:N), and further includes a non-linear filter for generating filtered signals from the high frequency signals (PDSHF:1-PDSHF:N). The SSF (70) further includes a device for combining (130:1-130:N) the low frequency (PDSLF:1-PDSLF:N) and filtered signals to generate streak corrected signals (SCS:1-SCS:N). The SSF (70) forms low frequency signals (PDSLF:1-PDSLF:N) by low pass filtering (210:1-210:N) raw density signals (PDS:1-PDS:N), and high frequency signal (PDSHF:1-PDSHF:N) by subtracting (220:1-220:N) low frequency signal (PDSLF:1-PDSLF:N) from raw density signals (PDS:1-PDS:N). The SSF (70) forms filtered signals (SCS:1-SCS:N) by thresholding (120:1-120:N) high frequency signal (PDSHF:1-PDSHF:N).