Accuracy of instrument tip position using fiber optic shape sensing for navigated bronchoscopy.

The purpose of this study was to evaluate the accuracy of a method for estimating the tip position of a fiber optic shape-sensing (FOSS) integrated instrument being inserted through a bronchoscope. A modified guidewire with a multicore optical fiber was inserted into the working channel of a custom-made catheter with three electromagnetic (EM) sensors. The displacement between the instruments was manually set, and a point-based method was applied to match the position of the EM sensors to corresponding points on the shape.

Endovascular navigation in patients: vessel-based registration of electromagnetic tracking to preoperative images.

Electromagnetic tracking of instruments combined with preoperative images can supplement fluoroscopy for guiding endovascular aortic repair (EVAR). The aim of this study was to evaluate the in-vivo accuracy of a vessel-based registration algorithm for matching electromagnetically tracked positions of an endovascular instrument to preoperative computed tomography angiography. Five patients undergoing elective EVAR were included, and a clinically available semi-automatic 3D-3D registration algorithm, based on similarity measures computed over the entire image, was used for reference.

A Steerable and Electromagnetically Tracked Catheter: Navigation Performance Compared With Image Fusion in a Swine Model.

Purpose: Cannulation of visceral vessels is necessary during fenestrated and branched endovascular aortic repair. In an attempt to reduce the associated radiation and contrast dose, an electromagnetically (EM) trackable and manually steerable catheter has been developed. The purpose of this preclinical swine study was to evaluate the cannulation performance and compare the cannulation performance using either EM tracking or image fusion as navigation tools.

Vessel-based rigid registration for endovascular therapy of the abdominal aorta.

Background: Combining electromagnetic tracking of instruments with preoperatively acquired images can provide detailed visualization for intraoperative guidance and reduce the need for fluoroscopy and contrast. In this study, we investigated the accuracy of a vessel-based registration method designed for matching preoperative image and electromagnetically tracked positions for endovascular therapy.

Material And Methods: An open-source registration method was used to match the centerline extracted from computed tomography (CT) to electromagnetically tracked positions within a vascular phantom representing the abdominal aorta with bifurcations.

Using the CustusX toolkit to create an image guided bronchoscopy application: Fraxinus.

Purpose: The aim of this paper is to show how a specialized planning and guidance application called Fraxinus, can be built on top of the CustusX platform (www.custusx.org), which is an open source image-guided intervention software platform.

Laboratory test of Single Landmark registration method for ultrasound-based navigation in laparoscopy using an open-source platform.

Purpose: Test the feasibility of the novel Single Landmark image-to-patient registration method for use in the operating room for future clinical trials. The algorithm is implemented in the open-source platform CustusX, a computer-aided intervention research platform dedicated to intraoperative navigation and ultrasound, with an interface for laparoscopic ultrasound probes.

Methods: The Single Landmark method is compared to fiducial landmark on an IOUSFAN (Kyoto Kagaku Co.

Pulmonologist evaluation on new CT visualization for guidance to lung lesions during bronchoscopy.

Objective: Endoluminal visualization in virtual and video bronchoscopy lacks information about the surrounding structures, and the traditional 2 D axial, coronal and sagittal CT views can be difficult to interpret. To address this challenge, we previously introduced a novel visualization technique, Anchored to Centerline Curved Surface, for navigated bronchoscopy. The current study compares the ACCuSurf to the standard ACS CT views as planning and guiding tools in a phantom study.

Manually Steerable Catheter With Improved Agility.

Purpose: A prototype steerable catheter was designed for endovascular procedures. This technical pilot study reports the initial experience using the catheter for cannulation of visceral arteries.

Technique: The 7F catheter was manually steerable with operator control handle for bending and rotation of the tip.

Electromagnetic navigation versus fluoroscopy in aortic endovascular procedures: a phantom study.

Purpose: To explore the possible benefits of electromagnetic (EM) navigation versus conventional fluoroscopy during abdominal aortic endovascular procedures.

Methods: The study was performed on a phantom representing the abdominal aorta. Intraoperative cone beam computed tomography (CBCT) of the phantom was acquired and merged with a preoperative multidetector CT (MDCT).

Registration of Real-Time 3-D Ultrasound to Tomographic Images of the Abdominal Aorta.

The purpose of this study was to develop an image-based method for registration of real-time 3-D ultrasound to computed tomography (CT) of the abdominal aorta, targeting future use in ultrasound-guided endovascular intervention. We proposed a method in which a surface model of the aortic wall was segmented from CT, and the approximate initial location of this model relative to the ultrasound volume was manually indicated. The model was iteratively transformed to automatically optimize correspondence to the ultrasound data.

CustusX: an open-source research platform for image-guided therapy.

Purpose: CustusX is an image-guided therapy (IGT) research platform dedicated to intraoperative navigation and ultrasound imaging. In this paper, we present CustusX as a robust, accurate, and extensible platform with full access to data and algorithms and show examples of application in technological and clinical IGT research.

Methods: CustusX has been developed continuously for more than 15 years based on requirements from clinical and technological researchers within the framework of a well-defined software quality process.

Three-dimensional electromagnetic navigation vs. fluoroscopy for endovascular aneurysm repair: a prospective feasibility study in patients.

Purpose: To evaluate the in vivo feasibility of a 3-dimensional (3D) electromagnetic (EM) navigation system with electromagnetically-tracked catheters in endovascular aneurysm repair (EVAR).

Methods: The pilot study included 17 patients undergoing EVAR with a bifurcated stent-graft. Ten patients were assigned to the control group, in which a standard EVAR procedure was used.

Accuracy of electromagnetic tracking with a prototype field generator in an interventional OR setting.

Purpose: The authors have studied the accuracy and robustness of a prototype electromagnetic window field generator (WFG) in an interventional radiology suite with a robotic C-arm. The overall purpose is the development of guidance systems combining real-time imaging with tracking of flexible instruments for bronchoscopy, laparoscopic ultrasound, endoluminal surgery, endovascular therapy, and spinal surgery.

Methods: The WFG has a torus shape, which facilitates x-ray imaging through its centre.

Three-dimensional endovascular navigation with electromagnetic tracking: ex vivo and in vivo accuracy.

Purpose: To evaluate the accuracy of a 3-dimensional (3D) navigation system using electromagnetically tracked tools to explore its potential in patients.

Methods: The 3D navigation accuracy was quantified on a phantom and in a porcine model using the same setup and vascular interventional suite. A box-shaped phantom with 16 markers was scanned in 5 different positions using computed tomography (CT).

3D ultrasound reconstruction algorithms from analog and digital data.

Freehand 3D ultrasound is increasingly being introduced in the clinic for diagnostics and image-assisted interventions. Various algorithms exist for combining 2D images of regular ultrasound probes to 3D volumes, being either voxel-, pixel- or function-based. Previously, the most commonly used input to 3D ultrasound reconstruction has been digitized analog video.

Endovascular image-guided navigation: validation of two volume-volume registration algorithms.

The limited volume covered by intraoperatively acquired CT scans makes the use of navigation systems difficult. Preoperative images cover a larger volume of interest. Hence, reliable registration of high quality preoperative to intraoperative CT will provide the necessary image information required for navigation.

A novel research platform for electromagnetic navigated bronchoscopy using cone beam CT imaging and an animal model.

Electromagnetic guided bronchoscopy is a new field of research, essential for the development of advanced investigation of the airways and lung tissue. Consecutive problem-based solutions and refinements are urgent requisites to achieve improvements. For that purpose, our intention is to build a complete research platform for electromagnetic guided bronchoscopy.

Efficiency of ultrasound training simulators: method for assessing image realism.

Although ultrasound has become an important imaging modality within several medical professions, the benefit of ultrasound depends to some degree on the skills of the person operating the probe and interpreting the image. For some applications, the possibility to educate operators in a clinical setting is limited, and the use of training simulators is considered an alternative approach for learning basic skills. To ensure the quality of simulator-based training, it is important to produce simulated ultrasound images that resemble true images to a sufficient degree.

Computer-assisted 3D ultrasound-guided neurosurgery: technological contributions, including multimodal registration and advanced display, demonstrating future perspectives.

Background: Navigation systems are now frequently being used for guiding surgical procedures. Existing neuronavigation systems suffer from the lack of updated images when tissue changes during surgery as well as from user-friendly displays of all essential images for accurate and safe surgery guidance.

Methods: We have developed various new technologies for improved neuronavigation.

[3-D navigation in laparoscopic surgery].

Background: The main drawback with the laparoscopic approach is that the surgeon lacks the possibility to palpate vessels, tumours and organs during surgery. Furthermore, the laparoscope only provides a surface view of organs. There is a need for more advanced visualization that enhances the view to include information below the surface of the organs when the procedure is planned and for control and guidance during treatment.

Probe calibration for freehand 3-D ultrasound.

Ultrasound (US) probe calibration establishes the rigid body transformation between the US image and a tracking device attached to the probe. This is an important requirement for correct 3-D reconstruction of freehand US images and, thus, for accurate surgical navigation based on US. In this study, we evaluated three methods for probe calibration, based on a single-point phantom, a wire-cross phantom requiring 2-D alignment and a wire phantom for freehand scanning.