Improving puncture accuracy in percutaneous CT-guided needle insertion with wireless inertial measurement unit: a phantom study

ObjectivesA novel method applying inertial measurement units (IMUs) was developed to assist CT-guided puncture, which enables real-time displays of planned and actual needle trajectories. The method was compared with freehand and laser protractor-assisted methods.MethodsThe phantom study was performed by three operators with 8, 2, and 0 years of experience in CT-guided procedure conducted five consecutive needle placements for three target groups using three methods (freehand, laser protractor-assisted, or IMU-assisted method). The endpoints included mediolateral angle error and caudocranial angle error of the first pass, the procedure time, the total number of needle passes, and the radiation dose.ResultsThere was a significant difference in the number of needle passes (IMU 1.2 +/- 0.42, laser protractor 2.9 +/- 1.6, freehand 3.6 +/- 2.0 time, p < 0.001), the procedure time (IMU 3.0 +/- 1.2, laser protractor 6.4 +/- 2.9, freehand 6.2 +/- 3.1 min, p < 0.001), the mediolateral angle error of the first pass (IMU 1.4 +/- 1.2, laser protractor 1.6 +/- 1.3, freehand 3.7 +/- 2.5 degree, p < 0.001), the caudocranial angle error of the first pass (IMU 1.2 +/- 1.2, laser protractor 5.3 +/- 4.7, freehand 3.9 +/- 3.1 degree, p < 0.001), and the radiation dose (IMU 250.5 +/- 74.1, laser protractor 484.6 +/- 260.2, freehand 561.4 +/- 339.8 mGy-cm, p < 0.001) among three CT-guided needle insertion methods.ConclusionThe wireless IMU improves the angle accuracy and speed of CT-guided needle punctures as compared with laser protractor guidance and freehand techniques.