A Safe Framework for Quantitative In Vivo Human Evaluation of Image Guidance.

We present a new framework for in vivo image guidance evaluation and provide a case study on robotic partial nephrectomy. This framework (called the "bystander protocol") involves two surgeons, one who solely performs the therapeutic process without image guidance, and another who solely periodically collects data to evaluate image guidance. This isolates the evaluation from the therapy, so that in-development image guidance systems can be tested without risk of negatively impacting the standard of care.

Assessment of Orbital Computed Tomography (CT) Imaging Biomarkers in Patients with Thyroid Eye Disease.

To understand potential orbital biomarkers generated from computed tomography (CT) imaging in patients with thyroid eye disease. This is a retrospective cohort study. From a database of an ongoing thyroid eye disease research study at our institution, we identified 85 subjects who had both clinical examination and laboratory records supporting the diagnosis of thyroid eye disease and concurrent imaging prior to any medical or surgical intervention.

A novel method for texture-mapping conoscopic surfaces for minimally invasive image-guided kidney surgery.

Purpose: Organ-level registration is critical to image-guided therapy in soft tissue. This is especially important in organs such as the kidney which can freely move. We have developed a method for registration that combines three-dimensional locations from a holographic conoscope with an endoscopically obtained textured surface.

Robust optic nerve segmentation on clinically acquired computed tomography.

The optic nerve (ON) plays a critical role in many devastating pathological conditions. Segmentation of the ON has the ability to provide understanding of anatomical development and progression of diseases of the ON. Recently, methods have been proposed to segment the ON but progress toward full automation has been limited.

Constructing a statistical atlas of the radii of the optic nerve and cerebrospinal fluid sheath in young healthy adults.

Optic neuritis is a sudden inflammation of the optic nerve (ON) and is marked by pain on eye movement, and visual symptoms such as a decrease in visual acuity, color vision, contrast and visual field defects. The ON is closely linked with multiple sclerosis (MS) and patients have a 50% chance of developing MS within 15 years. Recent advances in multi-atlas segmentation methods have omitted volumetric assessment.

Disambiguating the optic nerve from the surrounding cerebrospinal fluid: Application to MS-related atrophy.

Purpose: Our goal is to develop an accurate, automated tool to characterize the optic nerve (ON) and cerebrospinal fluid (CSF) to better understand ON changes in disease.

Methods: Multi-atlas segmentation is used to localize the ON and sheath on T2-weighted MRI (0.6 mm(3) resolution).

A new paradigm for treatment of glaucoma.

Glaucoma is the leading irreversible cause of blindness in the world. We are developing a new image-guidance system to deliver a neuroprotective drug in a controlled release nanosponge. The system consists of a magnetically tracked image-guidance system, the nanosponge material and the drug.

Transorbital target localization with augmented ophthalmologic surgical endoscopy.

Purpose: Access to the space behind the eyeball is limited by the position of the globe anteriorly, the neurovascular structures embedded in fat posteriorly, and the tight bony confine of the orbit. These anatomical relationships have impeded application of minimally invasive procedures to the region, such as foreign body removal, tumor biopsy, or the administration of medical therapy directly to the optic nerve. An image-guided system was developed using a magnetically tracked flexible endoscope to navigate behind the eye, with the aim of enabling accurate transorbital surgery to user-specified target locations.

Image-guided transorbital procedures with endoscopic video augmentation.

Purpose: Surgical interventions to the orbital space behind the eyeball are limited to highly invasive procedures due to the confined nature of the region along with the presence of several intricate soft tissue structures. A minimally invasive approach to orbital surgery would enable several therapeutic options, particularly new treatment protocols for optic neuropathies such as glaucoma. The authors have developed an image-guided system for the purpose of navigating a thin flexible endoscope to a specified target region behind the eyeball.

Robust Optic Nerve Segmentation on Clinically Acquired CT.

The optic nerve is a sensitive central nervous system structure, which plays a critical role in many devastating pathological conditions. Several methods have been proposed in recent years to segment the optic nerve automatically, but progress toward full automation has been limited. Multi-atlas methods have been successful for brain segmentation, but their application to smaller anatomies remains relatively unexplored.

Robust Non-Local Multi-Atlas Segmentation of the Optic Nerve.

Labeling or segmentation of structures of interest on medical images plays an essential role in both clinical and scientific understanding of the biological etiology, progression, and recurrence of pathological disorders. Here, we focus on the optic nerve, a structure that plays a critical role in many devastating pathological conditions - including glaucoma, ischemic neuropathy, optic neuritis and multiple-sclerosis. Ideally, existing fully automated procedures would result in accurate and robust segmentation of the optic nerve anatomy.

Trans-meningeal drug delivery to optic nerve ganglion cell axons using a nanoparticle drug delivery system.

The purpose of this study was to investigate if neuroprotective drugs can cross the optic nerve sheath in vitro. Four optic nerves were used for this study. Two porcine nerves were harvested at the time of euthanasia and two human nerves were obtained at the time of therapeutic globe enucleation.

Image-Guided Abdominal Surgery and Therapy Delivery.

Image-Guided Surgery has become the standard of care in intracranial neurosurgery providing more exact resections while minimizing damage to healthy tissue. Moving that process to abdominal organs presents additional challenges in the form of image segmentation, image to physical space registration, organ motion and deformation. In this paper, we present methodologies and results for addressing these challenges in two specific organs: the liver and the kidney.

Image-guided robotic surgery: update on research and potential applications in urologic surgery.

Purpose Of Review: New methods of imaging and image-guidance technology have the potential to provide surgeons with spatially accurate three-dimensional information about the location and anatomical relationships of critical subsurface structures and instrument position updated and displayed during the performance of surgery. Robotic platforms and technology in various forms continues to revolutionize surgery and will soon incorporate image guidance.

Recent Research: Image-guided surgery (IGS) for abdominal and urologic interventions presents complex engineering and surgical challenges along with potential benefits to surgeons and patients.

Comparison and assessment of semi-automatic image segmentation in computed tomography scans for image-guided kidney surgery.

Purpose: Image segmentation is integral to implementing intraoperative guidance for kidney tumor resection. Results seen in computed tomography (CT) data are affected by target organ physiology as well as by the segmentation algorithm used. This work studies variables involved in using level set methods found in the Insight Toolkit to segment kidneys from CT scans and applies the results to an image guidance setting.

Organ surface deformation measurement and analysis in open hepatic surgery: method and preliminary results from 12 clinical cases.

The incidence of soft tissue deformation has been well documented in neurosurgical procedures and is known to compromise the spatial accuracy of image-guided surgery systems.Within the context of image-guided liver surgery (IGLS), no detailed method to study and analyze the observed organ shape change between preoperative imaging and the intra-operative presentation has been developed. Contrary to the studies of deformation in neurosurgical procedures, the majority of deformation in IGLS is imposed prior to resection and due to laparotomy and mobilization.

Kidney deformation and intraprocedural registration: a study of elements of image-guided kidney surgery.

Introduction: Central to any image-guided surgical procedure is the alignment of image and physical coordinate spaces, or registration. We explored the task of registration in the kidney through in vivo and ex vivo porcine animal models and a human study of minimally invasive kidney surgery.

Methods: A set of (n = 6) ex vivo porcine kidney models was utilized to study the effect of perfusion and loss of turgor caused by incision.

Towards image guided robotic surgery: multi-arm tracking through hybrid localization.

Objective: Use of the robotic assisted surgery has been increasing in recent years, due both the continuous increase in the number of applications and the clinical benefits that surgical robots can provide. Currently robotic assisted surgery relies on endoscopic video for navigation, providing only surface visualization, thus limiting subsurface vision. To be able to visualize and identify subsurface information, techniques in image-guidance can be used.

Optimizing electrode placement using finite-element models in radiofrequency ablation treatment planning.

Conventional radiofrequency ablation (RFA) planning methods for identifying suitable electrode placements typically use geometric shapes to model ablation outcomes. A method is presented for searching electrode placements that couples finite-element models (FEMs) of RFA together with a novel optimization strategy. The method was designed to reduce the need for model solutions per local search step.

Determining the presence of bias error using statistical methods.

Current techniques in image-guided surgery rely on the use of localizers for the measurement of position in physical space. These measurements are prone to error due to intrinsic properties of the localizer used. The error and thus accuracy of a localizer can be determined using various techniques, many of which assume that the error is isotropic and free of bias.

Toward image guided robotic surgery: system validation.

Purpose: Navigation for current robotic assisted surgical techniques is primarily accomplished through a stereo pair of laparoscopic camera images. These images provide standard optical visualization of the surface but provide no subsurface information. Image guidance methods allow the visualization of subsurface information to determine the current position in relationship to that of tracked tools.

Feasibility study for image-guided kidney surgery: assessment of required intraoperative surface for accurate physical to image space registrations.

A notable complication of applying current image-guided surgery techniques of soft tissue to kidney resections (nephrectomies) is the limited field of view of the intraoperative kidney surface. This limited view constrains the ability to obtain a sufficiently geometrically descriptive surface for accurate surface-based registrations. The authors examined the effects of the limited view by using two orientations of a kidney phantom to model typical laparoscopic and open partial nephrectomy views.

Robust surface registration using salient anatomical features for image-guided liver surgery: algorithm and validation.

A successful surface-based image-to-physical space registration in image-guided liver surgery (IGLS) is critical to provide reliable guidance information to surgeons and pertinent surface displacement data for use in deformation correction algorithms. The current protocol used to perform the image-to-physical space registration involves an initial pose estimation provided by a point based registration of anatomical landmarks identifiable in both the preoperative tomograms and the intraoperative presentation. The surface based registration is then performed via a traditional iterative closest point (ICP) algorithm between the preoperative liver surface, segmented from the tomographic image set, and an intraoperatively acquired point cloud of the liver surface provided by a laser range scanner.

Found in translation; from the laboratory to the operating room to the market.

Translation is a term, of late, frequently used in medical research. It means different things to different people. For some it is moving from conception to science and engineering to application; for others it means moving technological development into the treatment of patients; and for still others it means moving a research development into a commercial system.

Characterization of tracked radiofrequency ablation in phantom.

In radiofrequency ablation (RFA), successful therapy requires accurate, image-guided placement of the ablation device in a location selected by a predictive treatment plan. Current planning methods rely on geometric models of ablations that are not sensitive to underlying physical processes in RFA. Implementing plans based on computational models of RFA with image-guided techniques, however, has not been well characterized.