Gyroscope-Assisted CT-Guided Puncture Improves Accuracy and Hit Rate Compared with Free-Hand Puncture: A Phantom Study

Purpose: To evaluate gyroscope-assisted CT-guided needle puncture (GAP) compared to free hand puncture (FHP) in a phantom.

Material and methods: A simple, low-cost gyroscope was equipped with a magnetic rail to attach it to common puncture needles. 18 radiologists with different levels of training and experience in CT-guided punctures first punctured three targets in free hand technique in a special biopsy phantom with different difficulty levels of the puncture path (T1: not angulated, needle path 7.3 cm, size 15 mm in diameter, T2: single angulated 41°, needle path 11.3 cm, size 9 mm in diameter, T3: double angulated 38°/26°, needle path 7 cm, size 8 mm in diameter). Without knowing the result of the puncture, a second puncture was performed directly afterwards with the aid of the gyroscope. Punctures were performed in a continuous procedure without intermediate control. The hit rate and the distance between the needle tip and the center of the lesion were evaluated. Additionally, the time needed for the procedure was measured.

Results: Thirty-three of 54 insertions (61.1%) hit the target in GAP compared to 20 of 54 (37%) in FHP (p = 0.002). The mean distance of the needle tip to the lesion center was 7.49 ± 5.31 mm in GAP compared to 13.37 ± 10.24 mm in FHP (p < 0.001). Puncture time was not significantly different between GAP (36.72 ± 20.38 s) and FHP (37.83 ± 20.53 s) (p = 0.362).

Conclusion: Needle guidance with a gyroscope enables an improved hit rate and puncture accuracy in CT-guided punctures without prolonging the puncture time. The needle guidance by gyroscope is inexpensive and easy to establish.