Navi-Ball: A new guidance device for CT-directed punctures

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 sc ale. The hemisphere is fluid filled and contains a bubble indicating the an gulation. The system works as a circular spirit level, Adapted to the handl e of the needle, it allows needle adjustment according to the planned punct ure path on the CT image, The system was tested in 36 patients who had 40 p rocedures. The needle deviation (in relation to the planned course of the n eedle) was measured in two rectangular planes. RESULTS. Without requiring preparation time, the guidance system allowed ra pid 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 deg rees) in the axial plane and from 0.4 degrees to 4.0 degrees (mean 2.3 degr ees, 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 .