Figure 6.

(a) Power Doppler ultrasound image and (b) B-mode ultrasound image acquired for an 18G needle inserted in bovine muscle at 54${}^{\circ }$. In the B-mode image, the yellow arrow points to the needle shaft and the red arrow points to the needle tip. (c) The needle localization result obtained by the proposed method. (d) The needle localization result obtained by the method in [12]. (e) The needle localization result obtained by the method in [21]. In (c–e), the localized needle axis and tip are shown as a yellow line and red circle, respectively, overlaid on the B-mode ultrasound image.