A preliminary evaluation of a flexible needle steering algorithm using magnetic resonance images as feedback

Abstract

Needle-based procedures are commonly performed for cancer diagnosis and treatment. Imaging modalities are used to visualize the needle tip and the target during these needle insertion procedures. Among the available imaging techniques, magnetic resonance (MR) offers the best tissue contrast, where detection of an early stage cancer is possible. MR-guided needle insertions are currently performed with rigid needles, which have limited steerability. Flexible needles have been introduced to increase the steerability during the insertion. In this paper, we present a preliminary evaluation of a steering method for flexible bevel-tipped needles using MR as an imaging modality. The steering algorithm uses a needle deflection model to predict the tip motion and calculate the optimal rotation to reach the target. The best sequence of rotations are defined by an optimization algorithm based on the Nelder-Mead technique. The needle tip and the target are manually tracked through a graphical user interface. The needle is inserted by a device fabricated with MR-compatible material. The MR-guided flexible needle steering is evaluated by a series of insertions in two phantoms with real obstacles and targets. The average targeting error with flexible needles is 4.3mm, which is 28% lower than the values reported in the literature with rigid needles. The results indicate the feasibility of MR-guided flexible needle insertions.

Review of Clinical and Technological Consideration for MRI-Guided Robotic Prostate Brachytherapy

“…2) Needle Insertion: Complexities of the surgical intervention include soft-tissue interaction, lesion targeting, and needle flexion. Manual needle insertion is achieved using rigid needles with an assumption of nearly straight insertion; however, this usually results in a lesion shift due to tissue deformation [94]. Researchers focus on thinner and flexible needles to reduce tissue damage and edema with steerability improvements in recent years.…”

“…These models need real-time imaging feedback for needle tip tracking, which is challenging under MR-imaging due to imaging update times. Moreira et al [94] presented the first MRI-guided needle tiptracking in phantom using a flexible needle steering algorithm under MRI feedback. They reported targeting errors of 4.3 , 28% lower as compared to rigid needles.…”

Endpoint Accuracy in Manual Control of a Steerable Needle

“…The majority of work within these robotic studies make use of beveled needles. The degrees of freedom in actuation of these needles (axial insertion and rotation) are considered unintuitive for the human operator (17), and lead to placement errors (18). The rotations can also lead to out-of-plane steering errors due to torsional friction (19).…”

Dispositivo robótico para guiagem de agulhas flexíveis em procedimentos minimamente invasivos

“…Neste caso, as peças do mecanismo devem ser de plástico ou de polímeros e os atuadores devem ser pneumáticos ou piezoelétricos. Em [48], Moreira et al desenvolveram um sistema de guiagem de agulhas baseado em um dispositivo compatível com MRI. Contudo, na versão publicada deste dispositivo, a inserção ainda é realizada de forma manual.…”