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Cone-beam computed tomography (CBCT) with a tangentially offset flat-panel detector is used for target imaging in image-guided radiotherapy and for localization and attenuation correction in SPECT/CT imaging. The offset-detector geometry offers a large field-of-view for a given detector size. Data are acquired on a circular trajectory over 360 degrees, with gantry rotation times ranging from 12 s to 60 s and longer on commercially available systems. These acquisition times, much longer than in conventional CT, make flat-panel CBCT more susceptible to motion artifacts from voluntary or involuntary patient motion. Here, we present phantom studies on motion artifacts in flat-panel CBCT, with the goal to facilitate better artifact assessment on clinical cases and to provide a basis for future investigations into artifact mitigation methods. Software phantoms for five typically observed motion types were simulated; phantom reconstructions are presented and compared to clinical cases. In addition, three analytic and iterative reconstruction methods were evaluated with respect to their performance on motion-affected data. [ABSTRACT FROM PUBLISHER]

Coil Misalignment in wireless power transfer links that use inductive coupling has limited the wireless power transfer efficiency considerably. Motion artifacts leading to coil misalignments also results in intermittent power outage at the receiving coil. In this paper, we address these issues using the concept of flux sharing between three coils. By using magnetic fields of induced currents in an intermediate coil, the flux linkage between a traditional two coil inductive power links can be improved. We present the analysis of inductive power links with intermediate coils and compare their improved performance with the conventional wireless power links. The mitigation of detrimental effects of motion artifacts is also discussed. All the theoretical results augur well with the measured results. [ABSTRACT FROM PUBLISHER]