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FIG 2. Diaphragm device—assisted procedure.
A, A 3-mm axial CT image with a 19° angle gantry tilt. This is the planning image for the procedure, with the goal to biopsy the L5-S1 level. An ideal vector is drawn from the target to the skin. Nonsterile skin entry-point pattern is seen as two hyperattenuating dots. The distance measured is 53 mm and defines the entry-point slice select coordinate. The second coordinate offset value is 8 mm. The skin entry-point localizer is punctured at this point and lines are drawn parallel to the slice on the patient’s skin.
B, First poststerile CT image with the multilevel device placed over the target. The sterile pattern localizer is seen as two small hyperattenuating dots on the skin. The ideal targeting vector is drawn on the monitor, and its intersection point with the upper level pattern component is measured. The slice location is 63 mm and the offset 15 mm. The diaphragm is punctured at this point, and the needle is placed at the predefined skin entry point. After one adjustment, the needle is advance the measured depth to the target.
C, CT image shows the needle entering the target along the predefined vector. The upper diaphragm was sliced, allowing the probe to pass through the diaphragm to reach the target. Despite the complex double oblique vector, the entire needle is visible, demonstrating the accuracy of the device.
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