In-vivo three-dimensional optoacoustic molecular imaging of the synovial vasculature in a mouse model of knee joint osteoarthritis (Conference Presentation)

Author(s):  
Zhongyu LIU ◽  
Xuan Wang ◽  
Manting Au ◽  
Duojia Li ◽  
Yongping Zheng ◽  
...  
1999 ◽  
Vol 121 (6) ◽  
pp. 650-656 ◽  
Author(s):  
F. T. Sheehan ◽  
F. E. Zajac ◽  
J. E. Drace

Improper patellar tracking is often considered to be the cause of patellar-femoral pain. Unfortunately, our knowledge of patellar-femoral-tibial (knee) joint kinematics is severely limited due to a lack of three-dimensional, noninvasive, in vivo measurement techniques. This study presents the first large-scale, dynamic, three-dimensional, noninvasive, in vivo study of nonimpaired knee joint kinematics during volitional leg extensions. Cine-phase contrast magnetic resonance imaging was used to measure the velocity profiles of the patella, femur, and tibia in 18 unimpaired knees during leg extensions, resisted by a 34 N weight. Bone displacements were calculated through integration and then converted into three-dimensional orientation angles. We found that the patella displaced laterally, superiorly, and anteriorly as the knee extended. Further, patellar flexion lagged knee flexion, patellar tilt was variable, and patellar rotation was fairly constant throughout extension.


Author(s):  
Hannah J. Lundberg ◽  
Markus A. Wimmer

Detailed knowledge of in vivo knee contact forces and the contribution from muscles, ligaments, and other soft-tissues to knee joint function are essential for evaluating total knee replacement (TKR) designs. We have recently developed a mathematical model for calculating knee joint contact forces using parametric methodology (Lundberg et al., 2009). The numerical model calculates a “solution space” of three-dimensional contact forces for both the medial and lateral compartments of the tibial plateau. The solution spaces are physiologically meaningful, and represent the result of balancing the external moments and forces by different strategies.


2019 ◽  
Author(s):  
Siyi Du ◽  
Thomas S.C. Ng ◽  
Adrian House ◽  
Tang Tang ◽  
Lin Zheng ◽  
...  

AbstractDespite advances in diagnosis and management, cardiovascular diseases (CVDs) remain the leading cause of death in the US. Atherosclerosis is the most common form of CVD and the vulnerability of atherosclerotic plaques to rupture is a primary determinant for risk of catastrophic ischemic events. Current imaging of atherosclerotic disease focuses on assessing plaque size and the degree of luminal stenosis, which are not good predictors of plaque stability. Functional methods to identify biomarkers of inflammation in plaques could facilitate assessment of plaque instability to allow early intervention. In this study, we validate the use of a purpose-built, magnetic resonance imaging (MRI)-compatible positron emission tomography (PET) insert for multimodal, molecular imaging of vulnerable plaques in mice. We illustrate the application of PET to screen for inflamed regions to guide the application of MRI. Molecular MRI visualizes regions of vascular inflammation and is coupled with anatomical MRI to generate detailed maps of the inflammatory marker within the context of an individual vessel. As a testbed for this imaging methodology, we developed a multimodal, iron oxide nanoparticle (NP) targeting vascular cell adhesion molecule-1 (VCAM-1) for simultaneous PET/MRI of vascular inflammation performed on a mouse carotid ligation model. In vitro cell studies confirmed that the NPs are not cytotoxic to liver cells. In vivo simultaneous PET/MRI imaging identified regions of inflammation. Three-dimensional rendering of the MRI data facilitated high-resolution visualization of patterns of inflammation along the injured vessel. Histology validated the co-localization of the NPs with VCAM-1 expression at sites of induced inflammation. The results of this work validate the utility of the simultaneous PET/MR insert as a research tool for small animals and lays groundwork to further advance the potential clinical utility of integrated imaging systems.


2019 ◽  
Vol 28 (13) ◽  
pp. 2174-2188 ◽  
Author(s):  
Samuel Chiquita ◽  
Mário Ribeiro ◽  
João Castelhano ◽  
Francisco Oliveira ◽  
José Sereno ◽  
...  

Author(s):  
Jiang Yao ◽  
Art D. Salo ◽  
Monica Barbu-McInnis ◽  
Amy L. Lerner

A finite element model of the knee joint could be helpful in providing insight on mechanisms of injury, effects of treatment, and the role of mechanical factors in degenerative conditions. However, preparation of such a model involves many geometric simplifications and input of material properties, some of which are poorly understood. Therefore, a method to compare model predictions to actual behaviors under controlled conditions could provide confidence in the model before exploration of other loading scenarios. Our laboratory has developed a method to apply axial loads to the in vivo human knee during magnetic resonance imaging, resembling weightbearing conditions. Image processing algorithms may then be used to assess the three-dimensional kinematics of the tibia and femur during loading. A three-dimensional model of the tibio-menisco-femoral contact has been generated and the image-based kinematic boundary conditions were applied to investigate the distribution of stresses and strains in the articular cartilage and menisci throughout the loading period. In this study, our goal is to investigate the contact patterns during long term loading of up to twenty minutes in the healthy knee. Specifically, we assess the use of both elastic and poroelastic material properties in the cartilage, and compare model predictions to known loading conditions and images of tissue deformations.


2008 ◽  
Vol 01 (01) ◽  
pp. 17-28 ◽  
Author(s):  
MARCO RUGGERI ◽  
HASSAN WEHBE ◽  
GAVRIIL TSECHPENAKIS ◽  
SHULIANG JIAO ◽  
MARIA ELENA JOCKOVICH ◽  
...  

An ultra high resolution spectral-domain optical coherence tomography (SD-OCT) together with an advanced animal restraint and positioning system was built for noninvasive non-contact in vivo three-dimensional imaging of rodent models of ocular diseases. The animal positioning system allowed the operator to rapidly locate and switch the areas of interest on the retina. This function together with the capability of precise spatial registration provided by the generated OCT fundus image allows the system to locate and compare the same lesion (retinal tumor in the current study) at different time point throughout the entire course of the disease progression. An algorithm for fully automatic segmentation of the tumor boundaries and calculation of tumor volume was developed. The system and algorithm were successfully applied to monitoring retinal tumor growth quantitatively over time in the LHBETATAG mouse model of retinoblastoma.


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