Projection-Based Phase Features for Localization of a Needle Tip in 2D Curvilinear Ultrasound
Localization of a needle’s tip in ultrasound images is often a challenge during percutaneous procedures due to the inherent limitations of ultrasound imaging. A new method is proposed for tip localization with curvilinear arrays using local image statisti
- PDF / 1,532,955 Bytes
- 8 Pages / 439.363 x 666.131 pts Page_size
- 26 Downloads / 198 Views
Electrical and Computer Engineering, University of British Columbia, Canada 2 Mechanical Engineering, Universtiy of British Columbia, Canada 3 Philips Research, Bothell, Washington, United States
Abstract. Localization of a needle’s tip in ultrasound images is often a challenge during percutaneous procedures due to the inherent limitations of ultrasound imaging. A new method is proposed for tip localization with curvilinear arrays using local image statistics over a region extended from the partially visible needle shaft. First, local phase-based image projections are extracted using orientation-tuned Log-Gabor filters to coarsely estimate the needle trajectory. The trajectory estimation is then improved using a best fit iterative method. To account for the typically discontinuous needle shaft appearance, a geometric optimization is then performed that connects the extracted inliers of the point cloud. In the final stage, the enhanced needle trajectory points are passed to a feature extraction method that uses a combination of spatially distributed image statistics to enhance the needle tip. The needle tip is localized using the enhanced images and calculated trajectory. Validation results obtained from 150 ex vivo ultrasound scans show an accuracy of 0.43 ± 0.31 mm for needle tip localization. Keywords: Ultrasound, local phase, epidurals, needle enhancement.
1
Introduction
Ultrasound (US) guidance is useful for many needle insertions, including biopsy, therapy and anesthesia. The key is to observe the advancement of a needle tip towards the target. Unfortunately, needle visualization in US images is strongly dependent on the orientation of the specularly reflecting needle to the US beam and is poorest when performing blocks with a steep needle insertion angle, such as, typically femoral blocks in obese patients [1]. Medium frequency curvilinear transducers are used to achieve the necessary depth of penetration and field of view, but only a small portion or none of the needle gives a strong reflection. Needle visibility can be successfully enhanced by beam steering on linear transducers, seen on commercial machines, but only a portion of the needle is enhanced with curvilinear arrays so the tip is still indistinguishable. A solution © Springer International Publishing Switzerland 2015 N. Navab et al. (Eds.): MICCAI 2015, Part I, LNCS 9349, pp. 347–354, 2015. DOI: 10.1007/978-3-319-24553-9_43
348
I. Hacihaliloglu et al.
is needed for enhancing and localizing a needle in US images obtained using curvilinear transducers. The following papers provide a brief overview of the general history of needle enhancement in US. Methods based on Radon transform and variants of Hough transform were proposed by different groups [2, 3]. The needle tip localization error results varied between 0.45 mm and 1.92 mm for ex vivo or phantom scans. In [2], validation on clinical scans achieved a mean needle targeting error value of 0.19 mm. However, tip localization accuracy was not reported. Parallel integral projection based algorith
Data Loading...
