Rationale and objectives: A new navigation system (Navi-Ball) for computed tomography (CT)-guided punctures was tested clinically.
Methods: The device consists of a transparent hemisphere with an angular scale. The hemisphere is fluid filled and contains a bubble indicating the angulation. The system works as a circular spirit level. Adapted to the handle of the needle, it allows needle adjustment according to the planned puncture path on the CT image. The system was tested in 36 patients who had 40 procedures. The needle deviation (in relation to the planned course of the needle) was measured in two rectangular planes.
Results: Without requiring preparation time, the guidance system allowed rapid and easy performance of the puncture. First-time needle placement in a double-angulated approach led to a deviation of the needle from the planned path ranging from 0.2 degrees to 4.6 degrees (mean 2.1 degrees, SD 1.4 degrees ) in the axial plane and from 0.4 degrees to 4.0 degrees (mean 2.3 degrees, SD 1.2 degrees).
Conclusions: This "low-tech" system offers easy to use guidance by a single operator and provides for adequate accuracy of first-time needle placement.