This research was supported by the National Institutes of Health (NIH) under grant numbers S10 RR026565, R21 AR063844, F32 AR067075, R01 R077636, R56 AR074416, R01 GM083925. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

The authors have no conflicts of interest.

Dual fluoroscopy is a powerful tool for the investigation of in vivo kinematics, especially for the hip, which is difficult to accurately measure using traditional optical motion capture. However, fluoroscopy equipment is specialized, wherein a unique system setup may be required when imaging other joints of the human body. For example, several modifications were made to the mounting of the image intensifiers, positioning of the system, and settings of the beam energy in the application of dual fluoroscopy to th...

The number of total hip arthroplasty (THA) procedures performed on adults aged 45-64 years suffering from hip osteoarthritis (OA) more than doubled between 2000 and 20101. Based on the increases in THA procedures from 2000 to 2014, a recent study predicted that the overall number of yearly procedures may triple over the next twenty years2. These large increases in THA procedures are alarming considering that current treatment costs exceed $18 billion annually in the United States alone3.
Developmental dysplasia of the hip (DDH) and femoroacetabular impingement syndrome (FAIS), which describe an under- or over-constrained hip, respectively, are believed to be the primary etiology of hip OA4. The high prevalence of these structural hip deformities in individuals undergoing THA was initially described more than three decades ago5. Still, the relationship between abnormal hip anatomy and osteoarthritis is not well understood. One challenge to improving the working understanding of the role of deformities in the development of hip OA is that abnormal hip morphology is very common amongst asymptomatic adults. Notably, studies have observed morphology associated with cam-type FAIS in approximately 35% of the general population6, 83% of senior athletes7, and more than 95% of collegiate male athletes8. In another study of female collegiate athletes, 60% of participants had radiographic evidence of cam FAIS, and 30% had evidence of DDH9.
Studies demonstrating a high prevalence of deformities amongst individuals without hip pain point to the possibility that morphology commonly associated with FAIS and DDH may be a natural variant that only becomes symptomatic under certain conditions. However, the interaction between hip anatomy and hip biomechanics is not well understood. Notably, there are known difficulties with measuring hip joint motion using traditional optical motion capture technology. First, the joint is relatively deep within the body, such that the location of the hip joint center is difficult to both identify and track dynamically using optical skin marker motion capture, with errors on the same order of magnitude as the radius of the femoral head10,11. Second, the hip joint is surrounded by large soft tissue bulk, including subcutaneous fat and muscle, that moves relative to the underlying bone, resulting in soft tissue artifact12,13,14. Finally, using optical tracking of skin markers, kinematics are evaluated relative to generalized anatomy and thus do not provide insight into how subtle morphological differences might affect the biomechanics of the joint.
To address the lack of accurate kinematics in combination with subject-specific bone morphology, both single and dual fluoroscopy systems have been developed for analyzing other natural joint systems15,16,17. However, this technology has only recently been applied to the native hip joint, likely due to the difficulty in acquiring high-quality images through the soft tissue surrounding the hip. The methodology to accurately measure in vivo hip joint motion and display this motion relative to subject-specific bone anatomy is described herein. The resulting arthrokinematics provide an unparalleled ability to investigate the subtle interplay between bone morphology and biomechanics.
Herein, the procedures for acquiring and processing dual fluoroscopy images of the hip during activities of daily living have been described. Owing to the desire to capture whole-body kinematics with optical marker tracking simultaneously with dual fluoroscopy images, the data collection protocol requires coordination between several sources of data. Calibration of the dual fluoroscopy system utilizes plexiglass structures implanted with metallic beads that can be directly identified and tracked as markers. In contrast, dynamic bone motion is tracked using markerless tracking, which utilizes only the CT-based radiographic density of the bones to define orientation. Dynamic motion is then tracked simultaneously using dual fluoroscopy and motion capture data that are spatially and temporally synced.
The systems are synced spatially during calibration through concurrent imaging of a cube with both reflective markers and implanted metal beads and the generation of a common coordinate system. The systems are synced temporally for each activity or capture through the use of a split electronic trigger, which sends a signal to end the recording of the dual fluoroscopy cameras and interrupts a constant 5 V input to the motion capture system. This coordinated protocol enables the quantification of the position of body segments that fall outside the combined field of view of the dual fluoroscopy system, expression of kinematic results relative to gait-normalized events, and characterization of the soft tissue deformation around the femur and pelvis.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Amira Software</td>
			<td>ThermoFisher Scientific</td>
			<td>Version 6.0</td>
			<td></td>
		</tr>
		<tr>
			<td>Calibration Cube</td>
			<td></td>
			<td>Custom</td>
			<td>36 steel beads (3 mm diameter, spacing 6.35 cm, uncertainty 0.0036 mm)</td>
		</tr>
		<tr>
			<td>Calibration Wand</td>
			<td>Vicon</td>
			<td>Active Wand</td>
			<td></td>
		</tr>
		<tr>
			<td>CT Scanner</td>
			<td>Siemens AG</td>
			<td colspan="2">SOMATOM Definition 128 CT</td>
		</tr>
		<tr>
			<td>Distortion Correction Grid</td>
			<td></td>
			<td>Custom</td>
			<td>Acrylic plate with a grid of steel beads spaced 10 mm and 31 beads across the diameter (2 mm diameter)</td>
		</tr>
		<tr>
			<td>Dynamic Calibration Plate</td>
			<td></td>
			<td>Custom</td>
			<td>Acrylic plate with 3 steel beads spaced 30 mm (2 mm diameter, uncertainty 0.0013 mm)</td>
		</tr>
		<tr>
			<td>Emitter (2)</td>
			<td>Varian Interay; remanufactured by Radiological Imaging Services</td>
			<td>Housing B-100/Tube A-142</td>
			<td></td>
		</tr>
		<tr>
			<td>Epinephrine</td>
			<td>Hospira</td>
			<td>Injection, USP 10 mg/mL</td>
			<td></td>
		</tr>
		<tr>
			<td>FEBioStudio Software</td>
			<td>FEBio.org</td>
			<td>Version 1.3</td>
			<td>Mesh processing and kinematic visualization</td>
		</tr>
		<tr>
			<td>Graphical Processing Unit</td>
			<td>Nvidia</td>
			<td>Tesla</td>
			<td></td>
		</tr>
		<tr>
			<td>Hare Traction Splint</td>
			<td>DynaMed</td>
			<td>Trac-III, Model No. 95201</td>
			<td></td>
		</tr>
		<tr>
			<td>High-speed Camera (2)</td>
			<td>Vision Research, Inc.</td>
			<td>Phantom Micro 3</td>
			<td></td>
		</tr>
		<tr>
			<td>Image Intensifier (2)</td>
			<td>Dunlee, Inc.; remanufactured by Radiological Imaging Services</td>
			<td>T12964P/S</td>
			<td></td>
		</tr>
		<tr>
			<td>Iohexol injection</td>
			<td>GE Healthcare</td>
			<td>Omnipaque 240 mgI/mL</td>
			<td>517.7 mg iohexol, 1.21 mg tromethamine, 0.1 mg edetate calcium disodium per mL</td>
		</tr>
		<tr>
			<td>ImageJ</td>
			<td>National Institutes of Health and Laboratory for Optical and Computational Instrumentation</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Lidocaine HCl</td>
			<td>Hospira</td>
			<td>Injection, USP 10 mg/mL</td>
			<td></td>
		</tr>
		<tr>
			<td>Laser and Mirror Alignment System</td>
			<td></td>
			<td>Custom</td>
			<td>Three lasers adhered to acrylic plate that attaches to emitter, mirror attaches to face of image intensifier</td>
		</tr>
		<tr>
			<td>Markless Tracking Workbench</td>
			<td>Henry Ford Hospital, Custom Software</td>
			<td>Custom</td>
			<td></td>
		</tr>
		<tr>
			<td>MATLAB Software</td>
			<td>Mathworks, Inc.</td>
			<td>Version R2017b</td>
			<td></td>
		</tr>
		<tr>
			<td>Motion Capture Camera (10)</td>
			<td>Vicon</td>
			<td>Vantage</td>
			<td></td>
		</tr>
		<tr>
			<td>Nexus Software</td>
			<td>Vicon</td>
			<td>Version 2.8</td>
			<td>Motion capture</td>
		</tr>
		<tr>
			<td>Phantom Camera Control (PCC) Software</td>
			<td>Vision Research, Inc.</td>
			<td>Version 1.3</td>
			<td></td>
		</tr>
		<tr>
			<td>Pre-tape Spray Glue</td>
			<td>Mueller Sport Care</td>
			<td>Tuffner</td>
			<td></td>
		</tr>
		<tr>
			<td>Retroreflective Spherical Skin Markers</td>
			<td></td>
			<td></td>
			<td>14 mm</td>
		</tr>
		<tr>
			<td>Split Belt Fully Instrumented Treadmill</td>
			<td>Bertec Corporation</td>
			<td>Custom</td>
			<td></td>
		</tr>
		<tr>
			<td>Visual3D Software</td>
			<td>C-Motion Inc.</td>
			<td>Version 6.01</td>
			<td>Kinematic processing</td>
		</tr>
	</tbody>
</table>

in vivo quantification of hip arthrokinematics during dynamic weight-bearing activities using dual fluoroscopy

Several hip pathologies have been attributed to abnormal morphology with an underlying assumption of aberrant biomechanics. However, structure-function relationships at the joint level remain challenging to quantify due to difficulties in accurately measuring dynamic joint motion. The soft tissue artifact errors inherent in optical skin marker motion capture are exacerbated by the depth of the hip joint within the body and the large mass of soft tissue surrounding the joint. Thus, the complex relationship between bone shape and hip joint kinematics is more difficult to study accurately than in other joints. Herein, a protocol incorporating computed tomography (CT) arthrography, three-dimensional (3D) reconstruction of volumetric images, dual fluoroscopy, and optical motion capture to accurately measure the dynamic motion of the hip joint is presented. The technical and clinical studies that have applied dual fluoroscopy to study form-function relationships of the hip using this protocol are summarized, and the specific steps and future considerations for data acquisition, processing, and analysis are described.

Using dual fluoroscopy as a reference standard, the accuracy of skin-marker-based estimates of the hip joint center and the effect of soft-tissue artifact on kinematic and kinetic measurements were quantified22,23,24. The superior accuracy of dual fluoroscopy was then used to identify subtle differences in pelvic and hip joint kinematics between patients with FAIS and asymptomatic control participants25. ...

Watch this Scientific Journal Video about In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy at JoVE.com

In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy

Dual fluoroscopy accurately captures in vivo dynamic motion of human joints, which can be visualized relative to reconstructed anatomy (e.g., arthrokinematics). Herein, a detailed protocol to quantify hip arthrokinematics during weight-bearing activities of daily living is presented, including the integration of dual fluoroscopy with traditional skin marker motion capture.

In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy

Several hip pathologies have been attributed to abnormal morphology with an underlying assumption of aberrant biomechanics. However, structure-function ...

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2.9K Views.  University of Utah. Dual fluoroscopy accurately captures in vivo dynamic motion of human joints, which can be visualized relative to reconstructed anatomy (e.g., arthrokinematics). Herein, a detailed protocol to quantify hip arthrokinematics during weight-bearing activities of daily living is presented, including the integration of dual fluoroscopy with traditional skin marker motion capture. 

Video: In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy

In vivo Dual Substrate Bioluminescent Imaging

Our understanding of how and when breast cancer cells transit from established primary tumors to metastatic sites has increased at an exceptional rate since the advent of in vivo bioluminescent imaging technologies 1-3. Indeed, the ability to locate and quantify tumor growth longitudinally in a single cohort of animals to completion of the study as opposed to sacrificing individual groups of animals at specific assay times has revolutionized how researchers investigate breast cancer metastasis. Unfortunately, current methodologies preclude the real-time assessment of critical changes that transpire in cell signaling systems as breast cancer cells (i) evolve within primary tumors, (ii) disseminate throughout the body, and (iii) reinitiate proliferative programs at sites of a metastatic lesion. However, recent advancements in bioluminescent imaging now make it possible to simultaneously quantify specific spatiotemporal changes in gene expression as a function of tumor development and metastatic progression via the use of dual substrate luminescence reactions. To do so, researchers take advantage for two light-producing luciferase enzymes isolated from the firefly (Photinus pyralis) and sea pansy (Renilla reniformis), both of which react to mutually exclusive substrates that previously facilitated their wide-spread use in in vitro cell-based reporter gene assays 4. Here we demonstrate the in vivo utility of these two enzymes such that one luminescence reaction specifically marks the size and location of a developing tumor, while the second luminescent reaction serves as a means to visualize the activation status of specific signaling systems during distinct stages of tumor and metastasis development. Thus, the objectives of this study are two-fold. First, we will describe the steps necessary to construct dual bioluminescent reporter cell lines, as well as those needed to facilitate their use in visualizing the spatiotemporal regulation of gene expression during specific steps of the metastatic cascade. Using the 4T1 model of breast cancer metastasis, we show that the in vivo activity of a synthetic Smad Binding Element (SBE) promoter was decreased dramatically in pulmonary metastasis as compared to that measured in the primary tumor 4-6. Recently, breast cancer metastasis was shown to be regulated by changes within the primary tumor microenvironment and reactive stroma, including those occurring in fibroblasts and infiltrating immune cells 7-9. Thus, our second objective will be to demonstrate the utility of dual bioluminescent techniques in monitoring the growth and localization of two unique cell populations harbored within a single animal during breast cancer growth and metastasis.

In vivo Dual Substrate Bioluminescent Imaging

Herein we describe the methods to construct, visualize, and quantify the bioluminescent reactions of both firefly and renilla luciferase enzymes expressed in metastatic breast cancer cells during their growth and metastasis in vivo.

Our understanding of how and when breast cancer cells transit from established primary tumors to metastatic sites has increased at an exceptional rate ...

3D-Neuronavigation In Vivo Through a Patient's Brain During a Spontaneous Migraine Headache

A growing body of research, generated primarily from MRI-based studies, shows that migraine appears to occur, and possibly endure, due to the alteration of specific neural processes in the central nervous system. However, information is lacking on the molecular impact of these changes, especially on the endogenous opioid system during migraine headaches, and neuronavigation through these changes has never been done. This study aimed to investigate, using a novel 3D immersive and interactive neuronavigation (3D-IIN) approach, the endogenous &#181;-opioid transmission in the brain during a migraine headache attack in vivo. This is arguably one of the most central neuromechanisms associated with pain regulation, affecting multiple elements of the pain experience and analgesia. A 36 year-old female, who has been suffering with migraine for 10 years, was scanned in the typical headache (ictal) and nonheadache (interictal) migraine phases using Positron Emission Tomography (PET) with the selective radiotracer [11C]carfentanil, which allowed us to measure &#181;-opioid receptor availability in the brain (non-displaceable binding potential - &#181;OR BPND). The short-life radiotracer was produced by a cyclotron and chemical synthesis apparatus on campus located in close proximity to the imaging facility. Both PET scans, interictal and ictal, were scheduled during separate mid-late follicular phases of the patient's menstrual cycle. During the ictal PET session her spontaneous headache attack reached severe intensity levels; progressing to nausea and vomiting at the end of the scan session. There were reductions in &#181;OR BPND in the pain-modulatory regions of the endogenous &#181;-opioid system during the ictal phase, including the cingulate cortex, nucleus accumbens (NAcc), thalamus (Thal), and periaqueductal gray matter (PAG); indicating that &#181;ORs were already occupied by endogenous opioids released in response to the ongoing pain. To our knowledge, this is the first time that changes in &#181;OR BPND during a migraine headache attack have been neuronavigated using a novel 3D approach. This method allows for interactive research and educational exploration of a migraine attack in an actual patient's neuroimaging dataset.

3D-Neuronavigation In Vivo Through a Patient's Brain During a Spontaneous Migraine Headache

In this study, the authors report for the first time a novel 3D-Immersive &#38; Interactive Neuronavigation (3D-IIN) through the impact of a spontaneous migraine headache attack in the &#956;-opioid system of a patient's brain in vivo.

A growing body of research, generated primarily from MRI-based studies, shows that migraine appears to occur, and possibly endure, due to the alteration ...

In vivo 19F MRI for Cell Tracking

In vivo 19F MRI allows quantitative cell tracking without the use of ionizing radiation. It is a noninvasive technique that can be applied to humans. Here, we describe a general protocol for cell labeling, imaging, and image processing. The technique is applicable to various cell types and animal models, although here we focus on a typical mouse model for tracking murine immune cells. The most important issues for cell labeling are described, as these are relevant to all models. Similarly, key imaging parameters are listed, although the details will vary depending on the MRI system and the individual setup. Finally, we include an image processing protocol for quantification. Variations for this, and other parts of the protocol, are assessed in the Discussion section. Based on the detailed procedure described here, the user will need to adapt the protocol for each specific cell type, cell label, animal model, and imaging setup. Note that the protocol can also be adapted for human use, as long as clinical restrictions are met.

In vivo 19F MRI for Cell Tracking

We describe a general protocol for in vivo cell tracking using MRI in a mouse model with ex vivo labeled cells. A typical protocol for cell labeling, image acquisition processing and quantification is included.

In vivo 19F MRI allows quantitative cell tracking without the use of ionizing radiation. It is a noninvasive technique that can be applied to humans. ...

Sequential In vivo Imaging of Osteogenic Stem/Progenitor Cells During Fracture Repair

Bone turns over continuously and is highly regenerative following injury. Osteogenic stem/progenitor cells have long been hypothesized to exist, but in vivo demonstration of such cells has only recently been attained. Here, in vivo imaging techniques to investigate the role of endogenous osteogenic stem/progenitor cells (OSPCs) and their progeny in bone repair are provided. Using osteo-lineage cell tracing models and intravital imaging of induced microfractures in calvarial bone, OSPCs can be directly observed during the first few days after injury, in which critical events in the early repair process occur. Injury sites can be sequentially imaged revealing that OSPCs relocate to the injury, increase in number and differentiate into bone forming osteoblasts. These methods offer a means of investigating the role of stem cell-intrinsic and extrinsic molecular regulators for bone regeneration and repair.

Sequential In vivo Imaging of Osteogenic Stem/Progenitor Cells During Fracture Repair

Quantitative measurement of bone progenitor function in fracture healing requires high resolution serial imaging technology. Here, protocols are provided for using intravital microscopy and osteo-lineage tracking to sequentially image and quantify the migration, proliferation and differentiation of endogenous osteogenic stem/progenitor cells in the process of repairing bone fracture.

Bone turns over continuously and is highly regenerative following injury. Osteogenic stem/progenitor cells have long been hypothesized to exist, but in ...

Non-fluoroscopic Catheter Tracking for Fluoroscopy Reduction in Interventional Electrophysiology

A technological platform (MediGuide) has been recently introduced for non-fluoroscopic catheter tracking. In several studies, we have demonstrated that the application of this non-fluoroscopic catheter visualization system (NFCV) reduces fluoroscopy time and dose by 90-95% in a variety of electrophysiology (EP) procedures. This can be of relevance not only to the patients, but also to the nurses and physicians working in the EP lab. Furthermore, in a subset of indications such as supraventricular tachycardias, NFCV enables a fully non-fluoroscopic procedure and allows the lab staff to work without wearing lead aprons. With this protocol, we demonstrate that even complex procedures such as ablations of atrial fibrillation, that are typically associated with fluoroscopy times of &#62;30 min in conventional settings, can safely be performed with a reduction of &#62;90% in fluoroscopy exposure by the additional use of NFCV.

Radiation exposure is an underestimated risk in complex ablation procedures. Here, we describe a protocol to significantly decrease fluoroscopy time and dosage for both the patient and the lab staff by using a novel non-fluoroscopic catheter visualization system.

A technological platform (MediGuide) has been recently introduced for non-fluoroscopic catheter tracking. In several studies, we have demonstrated that ...

Depletion of Mouse Cells from Human Tumor Xenografts Significantly Improves Downstream Analysis of Target Cells

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic patient tumors in different assays1. Human tumor xenografts represent the gold standard with respect to tumor biology, drug discovery, and metastasis research 2-4. Tumor xenografts can be derived from different types of material like tumor cell lines, tumor tissue from primary patient tumors4 or serially transplanted tumors. When propagated in vivo, xenografted tissue is infiltrated and vascularized by cells of mouse origin. Multiple factors such as the tumor entity, the origin of xenografted material, growth rate and region of transplantation influence the composition and the amount of mouse cells present in tumor xenografts. However, even when these factors are kept constant, the degree of mouse cell contamination is highly variable.
Contaminating mouse cells significantly impair downstream analyses of human tumor xenografts. As mouse fibroblasts show high plating efficacies and proliferation rates, they tend to overgrow cultures of human tumor cells, especially slowly proliferating subpopulations. Mouse cell derived DNA, mRNA, and protein components can bias downstream gene expression analysis, next-generation sequencing, as well as proteome analysis 5. To overcome these limitations, we have developed a fast and easy method to isolate untouched human tumor cells from xenografted tumor tissue. This procedure is based on the comprehensive depletion of cells of mouse origin by combining automated tissue dissociation with the benchtop tissue dissociator and magnetic cell sorting. Here, we demonstrate that human target cells can be can be obtained with purities higher than 96% within less than 20 min independent of the tumor type.

Human tumor xenografts are vascularized and infiltrated by cells of mouse origin during the growth phase in vivo. To circumvent the bias caused by these contaminating cells during downstream analysis, we developed a method allowing for comprehensive depletion of all mouse cells by magnetic cell sorting.

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic ...

In Vivo Evaluation of Fracture Callus Development During Bone Healing in Mice Using an MRI-compatible Osteosynthesis Device for the Mouse Femur

Endochondral fracture healing is a complex process involving the development of fibrous, cartilaginous, and osseous tissue in the fracture callus. The amount of the different tissues in the callus provides important information on the fracture healing progress. Available in vivo techniques to longitudinally monitor the callus tissue development in preclinical fracture-healing studies using small animals include digital radiography and &#181;CT imaging. However, both techniques are only able to distinguish between mineralized and non-mineralized tissue. Consequently, it is impossible to discriminate cartilage from fibrous tissue. In contrast, magnetic resonance imaging (MRI) visualizes anatomical structures based on their water content and might therefore be able to noninvasively identify soft tissue and cartilage in the fracture callus. Here, we report the use of an MRI-compatible external fixator for the mouse femur to allow MRI scans during bone regeneration in mice. The experiments demonstrated that the fixator and a custom-made mounting device allow repetitive MRI scans, thus enabling longitudinal analysis of fracture-callus tissue development.

In Vivo Evaluation of Fracture Callus Development During Bone Healing in Mice Using an MRI-compatible Osteosynthesis Device for the Mouse Femur

The evaluation of tissue development in the fracture callus during endochondral bone healing is essential to monitor the healing process. Here, we report the use of a magnetic resonance imaging (MRI)-compatible external fixator for the mouse femur to allow MRI scans during bone regeneration in mice.

Endochondral fracture healing is a complex process involving the development of fibrous, cartilaginous, and osseous tissue in the fracture callus. The ...

Individualized Stem-positioning in Calcar-guided Short-stem Total Hip Arthroplasty

Bone- and soft-tissue sparing short stems are increasingly used in total hip arthroplasty (THA). However, there are a large variety of models of short stems, differing in design and function. Calcar-guided short stems provide an anatomical curvature in the medial calcar region, thus, positioning is done individually alongside the calcar in the "round-the-corner" technique. Depending on the level of the neck's osteotomy, stems can be aligned individually in a large bandwidth of varus- and valgus anatomies. This differs from conventional total hip arthroplasty and potentially includes a severe learning curve. Given that a great variety of caput-collum-diaphyseal (CCD)-angles can be retained, the reconstruction of femoro-acetabular offsets can be achieved precisely. However, particularly extensive varus- and valgus positioning has raised concerns in regard to stability and bone remodeling. The purpose of the present manuscript is to showcase the implantation technique in calcar-guided short-stem THA and to summarize short-term clinical and radiological results.

This protocol describes the round-the-corner technique and the individualized stem-positioning of calcar-guided short stems alongside the medial calcar, depending on the level of the osteotomy. This differs from conventional total hip arthroplasty and includes a learning curve.

Bone- and soft-tissue sparing short stems are increasingly used in total hip arthroplasty (THA). However, there are a large variety of models of short ...

Improved Registration of 3D CT Angiography with X-ray Fluoroscopy for Image Fusion During Transcatheter Aortic Valve Implantation

The fusion of 3D anatomical models derived from high-fidelity pre-interventional computed tomography angiography (CTA), and x-ray (XR) fluoroscopy to facilitate anatomical guidance is of huge interest for complex cardiac interventions like TAVI procedures with cerebral protection. Co-registration of CTA and XR has been introduced either based on additional intraoperative non-/contrast-enhanced cone-beam computed tomography (CBCT) or two separate aortograms. With the related increase of radiation exposure and/or contrast agent (CA) dose, a potential additional risk for the patient is introduced. Here, we propose a modified co-registration approach making use of arteriograms of the iliofemoral arteries, routinely performed during the femoral puncture and sheath introduction. On-the-fly refinement of the co-registration during the on-going procedure enables accurate co-registration without any additional angiograms, thus reducing CA, XR dose and procedure time, while simultaneously improving operator confidence and procedure safety.

The aim of this study was to improve the co-registration for image fusion (IF) of pre-interventional CT data with real-time x-ray (XR) fluoroscopy during transfemoral transcatheter aortic valve implantation (TAVI).

The fusion of 3D anatomical models derived from high-fidelity pre-interventional computed tomography angiography (CTA), and x-ray (XR) fluoroscopy to ...

An In Vivo Mouse Model of Total Intravenous Anesthesia During Cancer Resection Surgery

Anesthesia is a routine component of cancer care that is used for diagnostic and therapeutic procedures. The anesthetic technique has recently been implicated in impacting long-term cancer outcomes, possibly through modulation of adrenergic-inflammatory responses that impact cancer cell behavior and immune cell function. Emerging evidence suggests that propofol-based total intravenous anesthesia (TIVA) may be beneficial for long-term cancer outcomes when compared to inhaled volatile anesthesia. However, the available clinical findings are inconsistent. Preclinical studies that identify the underlying mechanisms involved are critically needed to guide the design of clinical studies that will expedite insight. Most preclinical models of anesthesia have been extrapolated from the use of anesthesia in in vivo research and are not optimally designed to study the impact of anesthesia itself as the primary endpoint. This paper describes a method for delivering propofol-TIVA anesthesia in a mouse model of breast cancer resection that replicates key aspects of clinical delivery in cancer patients. The model can be used to study mechanisms of action of anesthesia on cancer outcomes in diverse cancer types and can be extrapolated to other non-cancer areas of preclinical anesthesia research.

An In Vivo Mouse Model of Total Intravenous Anesthesia During Cancer Resection Surgery

This paper describes a method for modeling total intravenous anesthesia (TIVA) during cancer resection surgery in mice. The goal is to replicate key features of anesthesia delivery to patients with cancer. The method allows investigation of how anesthetic technique affects cancer recurrence after resection surgery.

Anesthesia is a routine component of cancer care that is used for diagnostic and therapeutic procedures. The anesthetic technique has recently been ...

In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy

Summary

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Chapters in this video

In vivo Dual Substrate Bioluminescent Imaging

3D-Neuronavigation In Vivo Through a Patient's Brain During a Spontaneous Migraine Headache

In vivo ¹⁹F MRI for Cell Tracking

Sequential In vivo Imaging of Osteogenic Stem/Progenitor Cells During Fracture Repair

Non-fluoroscopic Catheter Tracking for Fluoroscopy Reduction in Interventional Electrophysiology

Depletion of Mouse Cells from Human Tumor Xenografts Significantly Improves Downstream Analysis of Target Cells

In Vivo Evaluation of Fracture Callus Development During Bone Healing in Mice Using an MRI-compatible Osteosynthesis Device for the Mouse Femur

Individualized Stem-positioning in Calcar-guided Short-stem Total Hip Arthroplasty

Improved Registration of 3D CT Angiography with X-ray Fluoroscopy for Image Fusion During Transcatheter Aortic Valve Implantation

An In Vivo Mouse Model of Total Intravenous Anesthesia During Cancer Resection Surgery