Signal attenuation maps for needle enhancement and localization in 2D ultrasound

We propose a novel framework for enhancement and localization of steeply inserted hand-held needles under in-plane 2D ultrasound guidance.

Depth-dependent attenuation and non-axial specular reflection hinder visibility of steeply inserted needles. Here, we model signal transmission maps representative of the attenuation probability within the image domain. The maps are employed in a contextual regularization framework to recover needle shaft and tip information. The needle tip is automatically localized by line-fitting along the local-phase-directed trajectory, followed by statistical optimization.

The proposed method was tested on 300 ex vivo ultrasound scans collected during insertion of an epidural needle into freshly excised porcine and bovine tissue. A tip localization accuracy of [Formula: see text] was achieved.

The proposed method could be useful in challenging procedures where needle shaft and tip are inconspicuous. Improved needle localization results compared to previously proposed methods suggest that the proposed method is promising for further clinical evaluation.