Fig. 4.

Phantom experiment 1. A Comparative box-and-whisker plot of total errors for both guidance methods. Each superimposed dot represents a total error measurement for an insertion. B Frequency plot of total errors using AR guidance and CT-guided freehand (FH). Mean errors (standard deviations) are indicated by dotted lines. C Line chart displaying each operator’s average error over eight needle insertions per guidance method. D Comparative box-and-whisker plots of the in-direction and lateral errors for both guidance methods