PMC4770620_01
The FI system interface during the phantom feasibility testing procedure: (a) active marker and target selection window, and (b) navigation window for hybrid imaging CT-EUS procedure
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F2
If additional positioning adjustments are necessary for a more accurate CT-EUS registration, the physician can lock the EUS image and navigate through the CT stack to find a similar virtual section using the rotation and translation buttons [Figure 2b].
(a) Representative screen shot of the FI system interface during an EUS-CT procedure in a patient with A - co-registration at the level of the descending aorta (red arrows), imaged from the esophagus; and (b) co-registration at the level of a small submucosal tumor (lipoma, red arrows), imaged from the terminal esophagus. Beside the vascular structures and/or target structure (tumor), there is no correspondence in between anatomical structures visible on EUS and CT windows, as the lung tissue (containing air) and bony structures (spine) are visible only on CT, while EUS has a limited field of view
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F4
The two images (CT and EUS) were co-registered and visualized in real-time using the FI system [Figure 4]. On the CT images, the physician will identify the active marker on the patient skin for initial registration [Figure 4a] and will mark the anatomical target. A 3-D volume of the patient is automatically created from CT scans and can be adjusted for a better tissue and tumor identification [Figure 4b].