Cone beam CT (CBCT) systems mounted on robotic C-arms enable the implementation of arbitrary scan trajectories. These can be exploited to actuate the source and detector around interfering equipment during interventions. Non-conventional acquisition orbits can provide comparable and in some cases even locally enhanced image quality while simultaneously increasing the flexibility of the interventional equipment and even reduce the exposure for patients and personnel. The inherent image quality alteration is heavily dependent on the utilized orbit geometry and may limit the performance of radiologists during...

We consider an imaging scenario of a robot-assisted liver-biopsy. In this case, the location of a metallic biopsy needle needs to be determined, which is positioned by the robot. A circular acquisition orbit is not possible in this situation due to the assistance robot effectively blocking the necessary actuation space. Alternatively, a tilted circular (20°-angle) as well as a triple-arc-orbit (180°-40°-180°) are investigated; both are depicted in Figure 2 along with a conventional circular trajectory. The tilted orbit satisfies the Tuy condition and therefore promises...

The proposed framework enables the simulation of CBCT image quality and physical dose maps depending on the acquisition orbit. Accurate MTF determinations using oversampled LSFs revealed efficient alternatives to the standard circular scan trajectory in the imaging scenario of robot-assisted surgery. In addition, the possibility to calculate deposited dose to the patient using GATE simulations was demonstrated. In future work, the major issue of insufficient photon counts in the GATE projections needs to be addressed by increasing the number of primary photons up to tenfold....

T. Russ; Mannheim/DE - nothing to disclose L. R. Schad; Mannheim/DE - nothing to disclose D. F. Bauer; Mannheim/DE - nothing to disclose S. Hatamikia; Vienna/AT - nothing to disclose A. M. Abdelrehim; Mannheim/DE - nothing to disclose F. G. Zöllner; Mannheim/DE - nothing to disclose K. Chung; Mannheim/DE - nothing to disclose

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