Manually controlled steerable needle for MRI-guided percutaneous interventions

This study aims to develop and evaluate a manually controlled steerable needle that is compatible with and visible on MRI to facilitate full intra-procedural control and accurate navigation in percutaneous interventions. The steerable needle has a working channel that provides a lumen to a cutting stylet or a therapeutic instrument. A steering mechanism based on cable-operated compliant elements is integrated in the working channel. The needle can be steered by adjusting the orientation of the needle tip through manipulation of the handle. The steering mechanism is evaluated by recording needle deflection at constant steering angles. A steering angle of 20.3° results in a deflection of 9.1-13.3 mm in gelatin and 4.6-18.9 mm in porcine liver tissue at an insertion depth of 60 mm. Additionally, the possibility to control the needle path under MRI guidance is evaluated in a gelatin phantom. The needle can be steered to targets at different locations while starting from the same initial position and orientation under MRI guidance with generally available sequences. The steerable needle offers flexibility to the physician in control and choice of the needle path when navigating the needle toward the target position, which allows for optimization of individual treatment and may increase target accuracy

Manually controlled steerable needle for MRI-guided percutaneous interventions

This study aims to develop and evaluate a manually controlled steerable needle that is compatible with and visible on MRI to facilitate full intra-procedural control and accurate navigation in percutaneous interventions. The steerable needle has a working channel that provides a lumen to a cutting stylet or a therapeutic instrument. A steering mechanism based on cable-operated compliant elements is integrated in the working channel. The needle can be steered by adjusting the orientation of the needle tip through manipulation of the handle. The steering mechanism is evaluated by recording needle deflection at constant steering angles. A steering angle of 20.3° results in a deflection of 9.1-13.3 mm in gelatin and 4.6-18.9 mm in porcine liver tissue at an insertion depth of 60 mm. Additionally, the possibility to control the needle path under MRI guidance is evaluated in a gelatin phantom. The needle can be steered to targets at different locations while starting from the same initial position and orientation under MRI guidance with generally available sequences. The steerable needle offers flexibility to the physician in control and choice of the needle path when navigating the needle toward the target position, which allows for optimization of individual treatment and may increase target accuracy

An Ex Vivo Phantom Validation Study of an MRI-Transrectal Ultrasound Fusion Device for Targeted Prostate Biopsy

Objectives: To evaluate the ex vivo accuracy of an MRI-TRUS fusion device for guiding targeted prostate biopsies, to identify the origin of errors, and to evaluate the likelihood that lesions can be accurately targeted. Materials and Methods: Three prostate phantoms were used to perform 27 biopsies using transperineal MRI-TRUS fusion. All phantoms underwent 3-T MRI. The prostate contour and nine lesions were delineated onto the MRI. A 3D-US dataset was generated and fused with the MRI. Per lesion, one needle was virtually planned. The postbiopsy needle location was virtually registered. The needle trajectory was marked using an MRI-safe guidewire. Postinterventional MRI was performed. The coordinates of the lesion on preinterventional MRI, the virtually planned needle, the virtually registered needle, and the marked needle trajectory on postinterventional MRI were documented and used to calculate the planning error (PE), targeting error (TE), and overall error (OE). Using the OE in the transversal plane, an upper one-sided tolerance interval was calculated to assess the likelihood that a biopsy needle was on target. Results: In the transversal plane, the mean PE, TE, and OE were 1.18, 0.39, and 2.33 mm, respectively. Using a single biopsy core, the likelihood that lesions with a diameter of 2 mm can be accurately targeted is 26%; lesions of 3 mm 61%; lesions of 4 mm 86%; lesions of 5 mm 96%; and lesions of 6 mm 99%. The likelihood of accurate sampling increases if more biopsy cores are used. Conclusion: MRI-TRUS fusion allows for accurate sampling of MRI-identified lesions with an OE of 2.33 mm. Lesions with a diameter of 3 mm or more can be accurately targeted. These results should be considered the lower limit of in vivo accuracy

An Ex Vivo Phantom Validation Study of an MRI-Transrectal Ultrasound Fusion Device for Targeted Prostate Biopsy

Objectives: To evaluate the ex vivo accuracy of an MRI-TRUS fusion device for guiding targeted prostate biopsies, to identify the origin of errors, and to evaluate the likelihood that lesions can be accurately targeted. Materials and Methods: Three prostate phantoms were used to perform 27 biopsies using transperineal MRI-TRUS fusion. All phantoms underwent 3-T MRI. The prostate contour and nine lesions were delineated onto the MRI. A 3D-US dataset was generated and fused with the MRI. Per lesion, one needle was virtually planned. The postbiopsy needle location was virtually registered. The needle trajectory was marked using an MRI-safe guidewire. Postinterventional MRI was performed. The coordinates of the lesion on preinterventional MRI, the virtually planned needle, the virtually registered needle, and the marked needle trajectory on postinterventional MRI were documented and used to calculate the planning error (PE), targeting error (TE), and overall error (OE). Using the OE in the transversal plane, an upper one-sided tolerance interval was calculated to assess the likelihood that a biopsy needle was on target. Results: In the transversal plane, the mean PE, TE, and OE were 1.18, 0.39, and 2.33 mm, respectively. Using a single biopsy core, the likelihood that lesions with a diameter of 2 mm can be accurately targeted is 26%; lesions of 3 mm 61%; lesions of 4 mm 86%; lesions of 5 mm 96%; and lesions of 6 mm 99%. The likelihood of accurate sampling increases if more biopsy cores are used. Conclusion: MRI-TRUS fusion allows for accurate sampling of MRI-identified lesions with an OE of 2.33 mm. Lesions with a diameter of 3 mm or more can be accurately targeted. These results should be considered the lower limit of in vivo accuracy

Implications of the law on video recording in clinical practice

Background: Technological developments allow for a variety of applications of video recording in health care, including endoscopic procedures. Although the value of video registration is recognized, medicolegal concerns regarding the privacy of patients and professionals are growing. A clear understanding of the legal framework is lacking. Therefore, this research aims to provide insight into the juridical position of patients and professionals regarding video recording in health care practice. Methods: Jurisprudence was searched to exemplify legislation on video recording in health care. In addition, legislation was translated for different applications of video in health care found in the literature. Results: Three principles in Western law are relevant for video recording in health care practice: (1) regulations on privacy regarding personal data, which apply to the gathering and processing of video data in health care settings; (2) the patient record, in which video data can be stored; and (3) professional secrecy, which protects the privacy of patients including video data. Practical implementation of these principles in video recording in health care does not exist. Conclusion: Practical regulations on video recording in health care for different specifically defined purposes are needed. Innovations in video capture technology that enable video data to be made anonymous automatically can contribute to protection for the privacy of all the people involved