A Novel Method for Enhanced Needle Localization Using Ultrasound-Guidance

In this paper, we propose a novel and fast method to localize and track needles during image-guided interventions. Our proposed method is comprised of framework of needle detection and tracking in highly noisy ultrasound images via level set and PDE (partial differential equation) based methods. Major advantages of the method are: (1) efficiency, the entire numerical procedure can be finished in real-time: (2) robustness, insensitive to noise in the ultrasound images and: (3) flexibility, the motion of the needle can be arbitrary. Our method will enhance the ability of medical care-providers to track and localize needles in relation to objects of interest during image-guided interventions. 1 Medical Background Image guided interventions have become the standard of care for many surgical procedures. Optimal visualization of the object of interest and biopsy needle in ultrasound images requires the use of specialized biopsy needles and high cost, cart-based ultrasound units. The success of image guided interventions is dependent on anatomic knowledge, visualization, and precise tracking and control of the biopsy needle. A majority of medical care-providers utilize low resolution ultrasound units. In addition, many office-based or emergency department procedures are performed using generic (non-specialized) needles. Unfortunately, the quality of the imagery obtained by most ultrasound units does not allow for clear and concise visualization of a regular needle during many needle-based procedures. The inability to clearly see the tip of a needle in relation to the object of interest (e.g., a vein, artery, or mass) makes such image guided interventions less accurate. In view of the inadequacy of ultrasound technology identifying inserted needles with desired resolution, a new and improved system for tracking such needles needs to be developed. A more accurate method for localizing the distal tip of The research is supported by SN-30014, Center for Computational Biology NIH Toga; and the Telemedicine and Advanced Technology Research Center (TATRC) of the US Army Medical Research and Material Command (MRMC). 2 B. Dong, E. Savitsky, S. Osher inserted needles will greatly improve the efficacy and safety of ultrasound imageguided interventions. In this paper, we shall employ modern level set and PDE methods and fast numerical algorithms to solve the needle tracking problem for ultrasound images. The rest of the paper is organized as follows. In Section 2, we shall lay down the fundamental mathematical model which is the core of solving our problem. In Section 3 we shall describe the complete schematic procedure of needle localization. Numerical experiments on ultrasound image frames will be given in Section 4 and concluding remarks will be given in Section 5. 2 Mathematical Model We denote the video frames of ultrasound images as I(x, t) with 0 ≤ I(x, t) ≤ 1, and define the integrated difference of frames as