Electromagnetic Navigation System Research Articles

Electromagnetic navigation system for computed tomography-guided synchronous percutaneous lung biopsy and microwave ablation of pulmonary nodules: a prospective, single-center, single-arm clinical study

Background The purpose of this study was to clinically evaluate the safety and effectiveness of the electromagnetic navigation (EMN) system designed for computed tomography (CT)-guided synchronous percutaneous lung biopsy and microwave ablation (MWA) of pulmonary nodules. Methods This prospective, single-center, single-arm clinical cohort study was conducted in Beijing Hospital from March 2023 to May 2023. Patients who underwent CT-guided synchronous percutaneous lung biopsy and MWA via the EMN system were prospectively enrolled in our study. All the interventional procedures were performed by the same interventional radiologist. The technical success rate, the technical efficacy rates of biopsy and MWA were assessed as the primary outcomes. Preoperative, intraoperative, and postoperative variables were also recorded and analyzed for each patient. Results A total of 48 patients were enrolled in the study. The technical success rate was 100%. The technical efficacy rate of biopsy was 95.8% (46/48), and the technical efficacy rate of WMA was 100% (48/48) with no recurrence during follow-up. The total and subpleural needle trajectory length and distance error were 8.3 ± 2.6 cm, 3.6 ± 1.6 cm, and 1.84 ± 1.08 mm, respectively. The median numbers of needle adjustments and CT acquisitions were 1 (range 1–3) and 3 (range 3–5), respectively. The time to reach the target and procedure time were 4.4 ± 1.7 and 19.7 ± 5.2 min, respectively. The dose length product was 748.8 ± 221.8 mGy*cm. The median postoperative hospital stay was 1 (range 1–7) days. No major complications (grade ≥3) occurred and only seven minor complications (14.6%) occurred, including six cases of pneumothorax and one case of hemoptysis. The radiologists achieved high satisfaction scores after surgery. Conclusion The EMN system is feasible, safe and effective for CT-guided synchronous percutaneous lung biopsy and MWA of pulmonary nodules.

Cryoprobe Placement Using Electromagnetic Navigation System (IMACTIS® CT-Navigation™) for Cryoablation Treatment of Upper Kidney Pole Lesions and Adrenal Metastases: Experience from a Single-Center, 4-Year Study.

The aim of this study is to evaluate the safety and efficacy of the use of the IMACTIS® CT-Navigation™-electromagnetic navigation system (EMNS) in cryoablation CT-guided procedures under local anesthesia for the treatment of upper kidney pole and adrenal lesions. We conducted a retrospective analysis of patients with upper kidney pole lesions and adrenal metastases who underwent cryoablation using the IMACTIS-CT®-EMNS between January 2019 and April 2023. The EMNS was used to guide the placement of the cryoprobes with CT guidance under local anesthesia. The primary outcome was technical success, defined as the successful placement of the cryoprobes in the target lesion. A total of 31 patients were studied, of whom, 25 patients were treated with cryoablation for upper pole kidney masses, and 6 patients underwent the cryoablation of adrenal metastases during the study period. The mean age was 60 years (range, 36-82 years), and 21 patients were male. All the upper kidney pole lesions were renal cell carcinomas, and regarding adrenal metastases, the primary cancer sites were the lungs (n = 3), breast (n = 2), and the colon (n = 1). The median size of the lesions was 3,8 cm (range, 1.5-5 cm). All procedures were technically successful, with the cryoprobes accurately placed in the target lesions under CT guidance using the EMNS, avoiding the penetration of any other organs using an oblique trajectory. No major complications were reported, and local tumor control was achieved in all cases. Our initial experience using the EMNS for cryoprobe placement during CT-guided interventional procedures under local anesthesia for the cryoablation treatment of upper pole kidney lesions and adrenal metastases showed that it is safe and effective.

Assessing the efficacy and safety of a novel, registration-free, CT-guided percutaneous transthoracic needle biopsy navigation system (RC120): A multicenter, prospective, single-arm clinical trial.

197 Background: Current optical and electromagnetic navigation systems for CT-guided percutaneous transthoracic needle biopsies (PTNB) have limitations. They require surface markers on the patient and intraoperative registration. Specific patient positioning during biopsies is required. Our team developed a new navigation system that addresses these issues. It doesn’t rely on patient surface markers or intraoperative registration, and it provides more flexibility in patient positioning during biopsies. Our research evaluates the effectiveness and safety of this system. Methods: A single-arm prospective study was conducted, including participants aged 18-80 years prepared for percutaneous lung core biopsy at two clinical centers in China. The primary endpoint was the success rate of biopsies within 2 needle adjustments. The secondary endpoint was the success rate of biopsies within a single needle adjustment. Safety endpoints were defined by the occurrence of adverse events. The number of CT scans patients underwent during the procedure was used to assess radiation dosage. Follow-up was conducted on subsequent pathological and molecular diagnoses. Results: The study included 98 patients from two sites, with a median age of 64 years. Most participants were males, accounting for 72.45% (71 out of 98). The primary endpoint was achieved with a biopsy success rate of 98.98%, requiring a maximum of two needle adjustments. The secondary endpoint was met, demonstrating a biopsy success rate of 97.96% with a maximum of one needle adjustment. The overall success rate was 98.98%, with a 95% confidence interval (CI) of 94.45% to 99.97%, significantly exceeding the target value of 85% (P < 0.0001). The median number of CT scans was 3, ranging from 3 to 12. The average duration of the procedure was 18.0 minutes. Regarding safety endpoints, the two most common adverse events were hemorrhage in the lesion (14 instances, 29.17%) and pneumothorax (8 instances, 16.67%). Other adverse events included elevated blood pressure (5 instances, 10.42%), hemoptysis (4 instances, 8.33%), and other common adverse events such as cough, constipation, anemia, and bloody sputum, each occurring twice. There were 9 other less common adverse events, each occurring once. These adverse events are common in PTNB and can be attributed to the puncture operation itself, not our navigation system. Conclusions: Our new registration-free navigation system proved to be an effective, efficient, safe, and well-utilized system for assisting percutaneous lung biopsies in clinical practice. Clinical trial information: ChiCTR2300072197 .

Fast and accurate distal locking of interlocked intramedullary nails using computer-vision and a 3D printed device

IntroductionDistal locking is a challenging and time-consuming step in interlocked intramedullary nailing of long bone fractures. Current methods have limitations in terms of simplicity, universality, accuracy, speed, and safety. We propose a novel device and software for distal locking using computer vision.Methods and materialsThe device consists of an universal ancillary clamp, a telescopic arm, a viewfinder clamp, and a radio-opaque cross. The software uses a camera photo from the C-arm intensifier and adjusts for geometric projection deformities. The software employs edge detection, Hough transform, perspective interpolation, and vector calculation algorithms to locate the distal hole center. The device and software were designed, manufactured, and tested using 3D CAD, FEM, DRR, and performance testing on phantom bones.ResultsThe device and software showed high accuracy and precision of 98.7% and 99.2% respectively in locating the distal hole center and calculating the correctional vector. The device and software also showed high success ratio in drilling the hole and inserting the screw. The device and software reduced the radiation exposure for the surgeon and the patient. The success ratio of the device and software was validated by the physical testing, which simulated the real clinical scenario of distal locking. The radiation exposure was as low as 5 s with a radiation dose of 0.2mSv, drastically reducing radiation exposure during distal locking.DiscussionOur device and software have several advantages over other distal locking methods, such as simplicity, universality, accuracy, speed, and safety. Our device and software also have some disadvantages, such as reliability and legislation. Our device and software can be compared with other distal locking methods based on these criteria. Our device and software have some limitations and challenges that need to be addressed in the future, such as clinical validation, and regulatory approval.ConclusionThe device showed promising results in terms of low-cost, reusability, low radiation exposure, high accuracy, fast distal locking, high stiffness, and adaptability. The device has several advantages over other distal locking techniques, such as free-hand technique, mechanical aiming devices, electromagnetic navigation systems, and computer-assisted systems. We believe that our device and software have the potential to revolutionize the distal locking technique and to improve the outcomes and quality of life of the patients with long bone fractures.

A Human‐Scale Clinically Ready Electromagnetic Navigation System for Magnetically Responsive Biomaterials and Medical Devices (Adv. Mater. 31/2024)

A Human‐Scale Clinically Ready Electromagnetic Navigation System for Magnetically Responsive Biomaterials and Medical Devices (Adv. Mater. 31/2024)

Magnetic Field Synthesis of Electromagnetic Navigation Systems in Current Limits

Magnetic Field Synthesis of Electromagnetic Navigation Systems in Current Limits

Bridging papermaking and hydrogel production: Nanoparticle-loaded cellulosic hollow fibers with pitted walls as skeleton materials for multifunctional electromagnetic hydrogels

Electromagnetic hydrogels have attracted significant attention due to their vast potential in soft robotics, biomedical engineering, and energy harvesting. To facilitate future commercialization via large-scale industrial processes, we present a facile concept that utilizes the specialized knowledge of papermaking to fabricate hydrogels with multifunctional electromagnetic properties. The principles of papermaking wet end chemistry, which involves the handling of interactions among cellulosic fibers, fines, polymeric additives, and other components in aqueous systems, serves as a key foundation for this concept. Notably, based on these principles, the versatile use of chemical additives in combination with cellulosic materials enables the tailored design of various products. Our methodology exploits the unique hierarchically pitted and hollow tube-like structures of papermaking grade cellulosic fibers with discernible pits, enabling the incorporation of magnetite nanoparticles through lumen loading. By combining microscale softwood-derived cellulosic fibers with additives, we achieve dynamic covalent interactions that transform the cellulosic fiber slurry into an impressive hydrogel. The cellulosic fibers act as a skeleton, providing structural support within the hydrogel framework and facilitating the dispersion of nanoparticles. In accordance with our concept, the typical hydrogel exhibits combined attributes, including electrical conductivity, self-healing properties, pH responsiveness, and dynamic rheologic behavior. Our approach not only yields hydrogels with interesting properties but also aligns with the forefront of advanced cellulosic material applications. These materials hold the promise in remote strain sensing devices, electromagnetic navigation systems, contactless toys, and flexible electronic devices. The concept and findings of the current work may shed light on materials innovation based on traditional pulp and paper processes. Furthermore, the facile processes involved in hydrogel formation can serve as valuable tools for chemistry and materials education, providing easy demonstrations of principles for university students at different levels.

A Human-Scale Clinically Ready Electromagnetic Navigation System for Magnetically Responsive Biomaterials and Medical Devices.

Magnetic navigation systems are used to precisely manipulate magnetically responsive materials enabling the realization of new minimally invasive procedures using magnetic medical devices. Their widespread applicability has been constrained by high infrastructure demands and costs. The study reports on a portable electromagnetic navigation system, the Navion, which is capable of generating a large magnetic field over a large workspace. The system is easy to install in hospital operating rooms and transportable through health care facilities, aiding in the widespread adoption of magnetically responsive medical devices. First, the design and implementation approach for the system are introduced and its performance is characterized. Next, in vitro navigation of different microrobot structures is demonstrated using magnetic field gradients and rotating magnetic fields. Spherical permanent magnets, electroplated cylindrical microrobots, microparticle swarms, and magnetic composite bacteria-inspired helical structures are investigated. The navigation of magnetic catheters is also demonstrated in two challenging endovascular tasks: 1) an angiography procedure and 2) deep navigation within the circle of Willis. Catheter navigation is demonstrated in a porcine model in vivo to perform an angiography under magnetic guidance.

Clinical application of optical and electromagnetic navigation system in CT-guided radiofrequency ablation of lung metastases

Purpose To evaluate the clinical value of CT-guided radiofrequency ablation (RFA) in the diagnosis and treatment of pulmonary metastases under optical and electromagnetic navigation. Methods Data on CT-guided radiofrequency ablation treatment of 93 metastatic lung lesions in 70 patients were retrospectively analyzed. There were 46 males and 24 females with a median age of 60.0 years (16–85 years). All lesions were ≤3cm in diameter. 57 patients were treated with 17 G radiofrequency ablation needle puncture directly ablated the lesion without biopsy, and 13 patients were treated with 16 G coaxial needle biopsy followed by radiofrequency ablation. There were 25 cases in the optical navigation group, 25 in the electromagnetic navigation group, and 20 in the non-navigation group. The navigation group was performed by primary interventionalists with less than 5 years of experience, and the non-navigation group was performed by interventionalists with more than 5 years of experience. Result All operations were successfully performed. There was no statistically significant difference in the overall distribution of follow-up results among the optical, electromagnetic, and no navigation groups. Complete ablation was achieved in 84 lesions (90.3%). 7 lesions showed incomplete ablation and were completely inactivated after repeat ablation. 2 lesions progressed locally, and one of them still had an increasing trend after repeat ablation. No serious complications occurred after the operation. Conclusions Treatment with optical and electromagnetic navigation systems by less experienced operators has similar outcomes to traditional treatments without navigational systems performed by more experienced operators.

Efficacy of navigation system-assisted distraction osteogenesis for hemifacial microsomia based on artificial intelligence for 3 to 18 years old: study protocol for a randomized controlled single-blind trial

BackgroundMandibular distraction osteogenesis (MDO) is a major part of the treatment for hemifacial microsomia patients. Due to the narrow surgical field of the intraoral approach, osteotomy accuracy is highly dependent on the surgeons’ experience. Electromagnetic (EM) tracking systems can achieve satisfying accuracy to provide helpful real-time surgical navigation. Our research team developed an EM navigation system based on artificial intelligence, which has been justified in improving the accuracy of osteotomy in the MDO in animal experiments. This study aims to clarify the effect of the EM navigation system in improving the MDO accuracy for hemifacial microsomia patients.MethodsThis study is designed as a single-centered and randomized controlled trial. Altogether, 22 hemifacial microsomia patients are randomly assigned to the experiment and control groups. All patients receive three-dimensional CT scans and preoperative surgical plans. The EM navigation system will be set up for those in the experiment group, and the control group will undergo traditional surgery. The primary outcome is the surgical precision by comparing the osteotomy position of pre- and postoperative CT scan images through the Geomagic Control software. The secondary outcomes include mandibular symmetry (occlusal plane deviation angle, mandibular ramus height, and body length), pain scale, and complications. Other indications, such as the adverse events of the system and the satisfactory score from patients and their families, will be recorded.DiscussionThis small sample randomized controlled trial intends to explore the application of an EM navigation system in MDO for patients, which has been adopted in other surgeries such as orthognathic procedures. Because of the delicate structures of children and the narrow surgical view, accurate osteotomy and protection of nearby tissue from injury are essential for successful treatment. The EM navigation system based on artificial intelligence adopted in this trial is hypothesized to provide precise real-time navigation for surgeons and optimally improve patient outcomes, including function and aesthetic results. The results of this trial will extend the application of new navigation technology in pediatric plastic surgery.Trial registrationChinese Clinical Trial Registry ChiCTR2200061565. Registered on 29 June 2022.

Ablation for Single Pulmonary Nodules, Primary or Metastatic. Εndobronchial Ablation Systems or Percutaneous.

Single pulmonary nodules are a difficult to diagnose imagining artifact. Currently novel diagnostic tools such as Radial-EBUS with or not C-ARM flouroscopy, electromagnetic navigation systems, robotic bronchoscopy and cone beam-compuer tomography (CBCT) can assist in the optimal guidance of biopsy equipment. After diagnosis of lung cancer or metastatic disease as pulmonary nodule, then surgery or ablation methods as local treatment can be applied. The percutaneous ablation systems under computed tomography guidance with radiofrequency, microwave, cryo and thermosphere have been used for several years. In the past 10 years extensive research has been made for endobronchial ablation systems and methods. We will present and comment on the two different ablation methods and present up to date data.

Intelligent electromagnetic navigation system for robot-assisted intraoral osteotomy in mandibular tumor resection: a model experiment.

Mandibular tumor surgery necessitates precise osteotomies based on tumor boundaries; however, conventional osteotomies often lack accuracy in predicting osteotomy positions and planes, potentially leading to excessive resection of normal bone tissues or residual tumors, thus compromising postoperative quality of life and clinical outcomes. Robotic-assisted surgery (RAS) augmented with artificial intelligence (AI) offers precise localization capabilities, aiding surgeons in achieving accurate osteotomy positioning. This study aimed to evaluate the feasibility and accuracy of a robotic magnetic navigation system for positioning and osteotomy in an intraoral surgical trial of a mandibular tumor model. Patient computed tomography (CT) imaging data of mandibular chin and body tumors were utilized to create 3D printed models, serving as study subjects for mandibular tumor resection. Ten pairs of models were printed for the experimental and control groups. The experimental group (EG) underwent osteotomy using a robot-assisted surgical navigation system, performing osteotomy under robotic navigation following alignment based on preoperative design. The control group (CG) underwent traditional surgery, estimating osteotomy position empirically according to preoperative design. Postoperative CT scans were conducted on both models, and actual postoperative results were compared to preoperative design. Osteotomy accuracy was evaluated by positional and angular errors between preoperatively designed and actual osteotomy planes. For ten randomly selected spots on the left and right sides, respectively, the EG group had mean distance errors of 0.338mm and 0.941mm. These values were obtained from the EG group. In the EG group, on the left side, the mean angular errors were 14.741 degrees, while on the right side, they were 13.021 degrees. For the 10 randomly selected spots on the left and right sides, respectively, the CG had mean distance errors of 1.776mm and 2.320mm. This is in contrast to the results obtained by the EG. It was determined that the left side had a mean angle error of 16.841 degrees, while the right side had an error of 18.416 degrees in the CG group. The above results indicated significantly lower point errors of bilateral osteotomy planes in the experimental group compared to the control group. This study demonstrates the feasibility of electromagnetic navigation robot-assisted intraoral osteotomy for mandibular tumors and suggests that this approach can enhance the precision of clinical surgery.

Computed Tomography-guided Percutaneous Lung Biopsy With Electromagnetic Navigation Compared With Conventional Approaches: An Open-label, Randomized Controlled Trial.

The purpose of this study was to assess the efficiency and safety of computed tomography (CT)-guided percutaneous biopsy of lung lesions with electromagnetic (EM) navigation and compare them with those of conventional approaches. Seventy-nine patients with lung or liver lesions who needed biopsies were enrolled in this trial. All patients were randomly assigned to the E group underwent CT-guided percutaneous biopsies with the EM navigation system or to the C group treated with conventional approaches. In total, 27 patients with lung lesions were assigned to the E group, and 20 patients were assigned to the C group. The diagnostic success rate was 92.6% and 95% in both groups, respectively ( P >0.9999). The median number of needle repositions in the E group was less than that in the C group (2.0 vs. 2.5, P =0.03). The positioning success rate with 1 or 2 needle repositions for the E group was significantly higher than the C group (81.5% vs. 50%, P =0.03). The median accuracy of the puncture location in the E group was better than that in the C group (2.0 vs. 6.6mm, P <0.0001). The total procedure time lengthened in the E group compared with the C group (30.5±1.6 vs. 18.3±1.7min, P <0.0001), but the number of CT acquisitions was not significantly different ( P =0.08). There was no significant difference in complication incidence between the 2 groups ( P =0.44). The EM navigation system is an effective and safe auxiliary tool for CT-guided percutaneous lung biopsy, but lengthen the procedure time. ChiCTR2100043361, registered February 9, 2021-retrospectively registered ( http://www.medresman.org.cn/uc/project/projectedit.aspx?proj=7591 ).

Augmented Reality Improves Learning Curve of Endovascular Navigation

Intra-Operative Positioning System (IOPS) (Centerline Biomedical, Cleveland, OH) is a 3D electromagnetic (EM) endovascular navigation system approved by the US Food and Drug Administration and developed as an adjunct to fluoroscopy. It provides real-time 3D display of sensorized material on an anatomical map on a flat screen. An investigational prototype based on IOPS incorporates the ability to map implanted stent grafts and visualize the stents and anatomy using augmented reality headset. The aim of this study was to compare the completion of bifurcated stent graft gate cannulation performed by participants of varying experience using fluoroscopy or different variations of IOPS. The task was cannulation of the gate of a bifurcated aortic endograft deployed into a 3D printed abdominal aortic aneurysm model connected to flow pump reproducing physiological conditions, performed in a hybrid operating room (GE Allia IGS 7). Each participant performed the tasks with fluoroscopy, EM guidance with flat screen display (EM-FS), and EM guidance with augmented reality headset (EM-AR) (Fig 1), in randomized order. All participants used the same sensorized guidewire and steerable sensorized 6F catheter for the three runs. Participants were classified in three groups of experience. Primary end points included cannulation time and technical success, defined as the advancement of the catheter over the guidewire within the graft main body. Fifteen minutes was the cutoff time for each trial. There were 26 participants including 13 endovascular naïve trainees (group 1), 12 in training surgeons (group 2) and one advanced level vascular surgeon. In group 1, mean cannulation time was lower using EM-AR versus fluoroscopy (4.3 ± 4.4 vs 7.1 ± 4.9 minutes; P = .04), with no difference between EM-FS and fluoroscopy (6.3 ± 4.5 vs 7.1 ± 4.9 minutes; P = .63). In group 1, technical success was 77% with fluoroscopy and 92% with both EM modalities (P = .59). In group 2, there was a trend toward shorter times with EM-FS or EM-AR as compared to fluoroscopy (mean of 2.5 ± 0.9, 4.4 ± 4.0 and 5.2 ± 4.5 minutes, respectively). In group 2, technical success was 92% with fluoroscopy and 100% with IOPS (P > .99). The advanced level vascular surgeon repeated the cannulation task four times for each endovascular approach, with 100% technical success and no difference in mean time (P = .89) (Fig 2). Augmented reality allows for reducing the gate cannulation time as compared to fluoroscopy in participants with no previous experience in endovascular navigation. This auspicious finding suggests that augmented reality can be beneficial for individuals early in their career and can mitigate the learning curve.Fig 2Mean cannulation times of bifurcated stent graft gate cannulation using electromagnetic (EM) guidance with flat screen display or augmented reality compared to fluoroscopy, performed by operators of varying experience.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Abstract No. 534 Percutaneous Abdominal and Pelvic Biopsies: Comparison of an Electromagnetic Navigation System and CT Fluoroscopy

Abstract No. 534 Percutaneous Abdominal and Pelvic Biopsies: Comparison of an Electromagnetic Navigation System and CT Fluoroscopy

On the Workspace of Electromagnetic Navigation Systems

In remote magnetic navigation, a magnetic navigation system is used to generate magnetic fields to apply mechanical wrenches to steer a magnetic object. This technique can be applied to navigate untethered micro- and nanorobots, as well as tethered magnetic surgical tools for minimally invasive medicine. The design and characterization of these systems have been extensively investigated over the past decade. The determination of the region in space in which these systems can operate has yet to be formalized within the research community. This region is commonly referred to as the “workspace” and constitutes a central concept for any class of robotic system. We focus on magnetic navigation systems comprised of electromagnets and propose a first set of definitions for a magnetic workspace, a methodology to determine it, and evaluation metrics to analyze its characteristics. Our methodology and tools are illustrated with several examples of planar and spatial electromagnetic magnetic navigation systems for both didactic and realistic navigation scenarios.

Percutaneous CT-Guided Abdominal and Pelvic Biopsies: Comparison of an Electromagnetic Navigation System and CT Fluoroscopy

PurposeTo compare electromagnetic navigation (EMN) with computed tomography (CT) fluoroscopy for guiding percutaneous biopsies in the abdomen and pelvis. Materials and MethodsA retrospective matched-cohort design was used to compare biopsies in the abdomen and pelvis performed with EMN (consecutive cases, n = 50; CT-Navigation; Imactis, Saint-Martin-d’Hères, France) with those performed with CT fluoroscopy (n = 100). Cases were matched 1:2 (EMN:CT fluoroscopy) for target organ and lesion size (±10 mm). ResultsThe population was well-matched (age, 65 vs 65 years; target size, 2.0 vs 2.1 cm; skin-to-target distance, 11.4 vs 10.7 cm; P > .05, EMN vs CT fluoroscopy, respectively). Technical success (98% vs 100%), diagnostic yield (98% vs 95%), adverse events (2% vs 5%), and procedure time (33 minutes vs 31 minutes) were not statistically different (P > .05). Operator radiation dose was less with EMN than with CT fluoroscopy (0.04 vs 1.2 μGy; P < .001), but patient dose was greater (30.1 vs 9.6 mSv; P < .001) owing to more helical scans during EMN guidance (3.9 vs 2.1; P < .001). CT fluoroscopy was performed with a mean of 29.7 tap scans per case. In 3 (3%) cases, CT fluoroscopy was performed with gantry tilt, and the mean angle out of plane for EMN cases was 13.4°. ConclusionsPercutaneous biopsies guided by EMN and CT fluoroscopy were closely matched for technical success, diagnostic yield, procedure time, and adverse events in a matched cohort of patients. EMN cases were more likely to be performed outside of the gantry plane. Radiation dose to the operator was higher with CT fluoroscopy, and patient radiation dose was higher with EMN. Further study with a wider array of procedures and anatomic locations is warranted.

A NEW LESS INVASIVE HIP APPROACH

This technique is a novel superior based muscle sparing approach. Acetabular reaming in all hip approaches requires femoral retraction. This technique is performed through a hole in the lateral femoral cortex without the need to retract the femur.A 5 mm hole is drilled in the lateral femur using a jig attached to the broach handle, similar to a femoral nail. Specialised instruments have been developed, including a broach with a hole going through it at the angle of the neck of the prosthesis, to allow the rotation of the reaming rod whilst protecting the femur. A special C-arm is used to push on the reaming basket. The angle of the acetabulum is directly related to the position of the broach inside the femoral canal and the position of the leg. A specialised instrument allows changing of offset and length without dislocating the hip during trialling.Some instrumentation has been used in surgery but ongoing cadaver work is being performed for proof of concept. The ability to ream through the femur has been proven during surgery. The potential risk to the bone has been assessed using finite analysis as minimal. The stress levels for any diameter maintained within a safety factor &gt;4 compared to the ultimate tensile strength of cortical bone.The described technique allows for transfemoral acetabular reaming without retraction of the femur. It is minimally invasive and simple, requiring minimal assistance. We are incorporating use with a universal robot system as well as developing an electromagnetic navigation system. Assessment of the accuracy of these significantly cheaper systems is ongoing but promising.This approach is as minimally invasive as is possible, safe, requires minimal assistance and has a number of other potential advantages with addition of other new navigation and simple robotic attachments.

Initial experience, feasibility, and technical development with an electromagnetic navigation assistance in percutaneous pelvic bone cementoplasty: retrospective analysis.

To assess the feasibility and technical outcomes of pelvic bone cementoplasty using an electromagnetic navigation system (EMNS) in standard practice. Monocentric retrospective study of all consecutive patients treated with cementoplasty or reinforced cementoplasty of the pelvic bone with EMNS-assisted procedures. The endpoints were periprocedural adverse events, needle repositioning rates, procedure duration, and radiation exposure. A detailed description of the technical steps is provided. Thirty-three patients (68 years ± 10) were treated between February 2016 and February 2020. Needle repositioning was required for 1/33 patients (3%). The main minor technical adverse event was soft tissue PMMA cement leaks. No major adverse event was noted. The median number of CT acquisitions throughout the procedures was 4 (range: 2 to 8). Radiation exposure and mean procedure duration are provided. Electromagnetic navigation system-assisted percutaneous interventions for the pelvic bone are feasible and lead to low rates of minor technical adverse events and needle repositioning. Procedure duration and radiation exposure were low. • Initial experience for 33 patients treated with an electromagnetic navigation assistance for pelvic cementoplasty shows feasibility and safety. • The use of an electromagnetic navigation system does not expose to high procedure duration or radiation exposure. • The system is efficient in assisting the radiologist for extra-axial planes in challenging approaches.

Anatomical and Technical Preparations of the Human Brain for White Matter Fibers Dissection with Electromagnetic Neuronavigation Assistance Technical Nuances for Application

Klinger's fiber dissection technique is widely used for studying the anatomy of white matter. Herein, we present a technical description of Klinger's proposed fiber dissection algorithm with neuronavigation assistance which allows for a more accurate determination of the projection of association fibers. An anatomical study was conducted on 8 hemispheres of the human brain, prepared according to the Klingler fiber dissection technique. In all the cases, a frameless electromagnetic navigation system was used. For each anatomical specimen, an individualized support device was three-dimensional -printed and placed it into the magnetic resonance imaging (MRI) gantry. MRI study of each anatomical specimen was performed using a specific protocol that enabled a subsequent three-dimensional visualization of the anatomical structures as follows: FSPGR (Fast SPoiled Gradient Recalled echo) BRAVO (BRAin VOlume Imaging), T2 CUBE, FLAIR (FLuid Attenuated Inversion Recovery) CUBE, CUBE DIR (double inversion recovery) WHITE MATTER, and CUBE DIR GRAY MATTER. The average time required to register an anatomical specimen in the navigation system was 7minutes 28seconds. In all of the 8 cases, the anatomical structures were correctly identified using neuronavigation. Moreover, the choice of MRI mode depends on the purpose of the study and the region of interest in the brain. Electromagnetic navigation is an accurate and useful technique. It allows the researcher the ability to virtually project the association fibers and their cortico-cortical terminations to the surface of the brain, even at the final stages of dissection when the superficial structures are removed. To obtain accurate targeting, it is important to use the appropriate neuronavigation protocol.