with the arrival of increasingly higher resolution pet systems, small amounts of motion can cause significant blurring in the images, compared to the intrinsic resolutions of the scanners. in this work, we have reviewed advanced correction methods for the three cases of (i) unwanted patient motion, as well as motions due to (ii) cardiac and (iii) respiratory cycles. for the first type of motion...

the liquid metal flow and the solidification behaviours in a multi-cavity casting mould of two automotive cast parts were simulated in three dimensions. the commercial code, flow-3d® was used because it can track the front of the molten metal by a volume of fluid (vof) method and allows complicated parts to be modeled by the fractional area/volume obstacle representation (favor) method. the gre...

Estimates of transfer functions from measurements contain undesired information – noise – whose effect can partly be taken away by applying different smoothing techniques. One such smoothing technique suggests to remove the noise by gating the impulse response in the time domain, hence the name time-gating. This paper shows that time-gating is a special case of a more general smoothing techniqu...

The Varian Real-time Position Management (RPM) system allows respiratory gating based on either the phase or displacement (amplitude) of the breathing waveform. A problem in clinical application is that phase-based gating, required for respiration-correlated (4D-CT) simulation, is not robust to irregular breathing patterns during treatment, and a widely used system version (1.6) does not provid...

(a,e) Images reconstructed using 55 spokes/time frame without any constraints. (b,f) Corresponding STCR reconstructions without respiratory self-gating and (c,g) with respiratory self-gating. The arrows indicate the locations of the lesions. (d,h) Comparison of mean intensity time curves for the tumor ROIs. Constrained Reconstruction of Dynamic Contrast Enhanced Tumor MR Data with Respiratory S...