PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 12630742

A new approach to elastography using mutual information and finite elements.

Michael I Miga
View original source ↗Export metadata ↓

Abstract

Historically, increased mechanical stiffness during tissue palpation exams has been associated with assessing organ health as well as with detecting the growth of a potentially life-threatening cell mass. As such, techniques to image elasticity parameters (i.e., elastography) have recently become of great interest to scientists. In this work, a new method of elastography will be introduced within the context of mammographic imaging. The elastography method proposed represents a non-rigid iterative image registration algorithm that varies material properties within a finite element model to improve registration. More specifically, regional measures of image similarity are used within an objective function minimization framework to reconstruct elasticity images of tissue stiffness. Numerical simulations illustrate: (1) the encoding of stiffness information within the context of a regional image similarity criterion, (2) the methodology for an iterative elastographic imaging framework and (3) elasticity reconstruction simulations. The real strength in this approach is that images from any modality (e.g., magnetic resonance, computed tomography, ultrasound. etc) that have sufficient anatomically-based intensity heterogeneity and remain consistent from a pre- to a post-deformed state could be used in this paradigm.

Explore related subjects

Adipose TissueAlgorithmsBreastBreast NeoplasmsCarcinoma, Ductal, BreastComputer SimulationConnective TissueElasticityFinite Element AnalysisHumansImage Interpretation, Computer-AssistedMagnetic Resonance ImagingModels, BiologicalMotionReproducibility of ResultsSensitivity and SpecificityStress, MechanicalSubtraction TechniqueTomographyEvaluation StudyJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Michael I Miga. 2003-02-21. A new approach to elastography using mutual information and finite elements.. https://doi.org/10.1088/0031-9155%2F48%2F4%2F304

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2025

Rapidly decellularized adipose tissue induces soft tissue vascularization in potential anatomical spaces.

Decellularized tissues provide biological cues owing to the wealth of structural and regulatory factors that promote angiogenesis, adipogenesis, and myogenesis and facilitate neurite outgrowth. Here, we demonstrated the advantages of decellularized adipose tissue (adipoECM) over defined collagen-based biomaterials for host tissue integration. Three batches of human adipose tissue were decellularized using a rapid decellularization protocol and analyzed using mass spectrometry. To assess the biological activity of the decellularized materials, adipoECM and a reference standard of care biomaterial (Integra®DRT, also containing collagen I and glycosaminoglycans) were implanted subcutaneously, but far from the wound bed (in anatomical potential spaces) of immunocompetent BALB/c mice. The mice were euthanized in the acute (1 day) and chronic (day 60) inflammatory reaction phases, followed by biomaterial excision and Masson’s trichrome immunohistofluorescence imaging of the paraffin-embedded specimens. Each batch of processed tissue passed a quality control check, showing a low level of donor genomic DNA, lack of nuclei, lipids, endotoxins, and bacterial contamination. Mass spectrometry revealed that all batches of decellularized tissue mainly contained collagen I and, to a lesser degree, collagen III, collagen IV, collagen V, laminin, fibrillin, fibronectin, tenascin, and elastin. No acute inflammatory reaction was observed in either material one day post-transplantation. At 60 days post-implantation, different cell types were detected in adipoECM specimens, whereas Integra®DRT remained acellular. Additional immunohistochemical staining of adipoECM revealed CD31-positive cells in the blood vessels. Mesenchymal (CD90 positive) and myeloid (CD14 positive) cells were also detected. Primary cell types involved in soft tissue healing and remodeling were found in the adipoECM-treated group. The ingrowth of blood vessels and mesenchymal cells confirmed the effective integration of adipoECM with host tissues. Our results demonstrate that decellularized adipose tissue implanted away from the wound bed possesses contextual biological activities that promote efficient integration with host tissues.

Adipose Tissue↗
PubMed2007

The correlation of extranodal invasion with other prognostic parameters in lymph node positive breast cancer.

BACKGROUND: The presence of extranodal invasion (ENI) in the metastatic lymph nodes is reported to increase the risk of locoregional recurrence while shortening disease-free and overall survival in patients with breast cancer. In this study the relationship between ENI and other prognostic parameters and survival is investigated. METHODS: Of 650 patients with breast cancer who were treated in Ankara Oncology Teaching and Research Hospital from 1996 to 2003, 368 (56.6%) had lymph node metastasis. The patients with axillary metastasis were separated into two groups as with and without invasion to lymph node capsule and the surrounding adipose tissue. Clinicopathologic features were analyzed by univariate and multivariate logistic regression. RESULTS: Of 368 patients with axillary metastasis, 135 (36.7%) had ENI. Based on multivariate analysis; the number of metastatic lymph nodes, lymphatic invasion, and tumor necrosis were found to be related with ENI. In the group with ENI, 5-year overall survival rate was 74.8%, compared to 82.3% for patients without ENI which was significantly lower (P = 0.04). CONCLUSIONS: In lymph node positive breast cancer with presence of ENI, adverse prognostic parameters are more frequently encountered and has a worse overall survival compared to group without ENI.

Adipose Tissue↗
PubMed2007

Pulmonary vein encircling ablation alters the atrial electrophysiologic response to autonomic stimulation.

OBJECTIVE: Pulmonary vein encircling ablation is often effective in the treatment of atrial fibrillation (AF). The success of the procedure does not depend upon creation of continuous lines of block. Thus mechanisms by which pulmonary vein encircling can cure AF remain unclear. Stimulation of cardiac autonomic ganglia alters atrial refractoriness and potentiates AF. We hypothesized that pulmonary vein encircling alters atrial autonomic function and that these alterations account in part for prevention of AF recurrences following ablation. METHODS: Atrial effective refractory periods (ERP) and AF inducibility were quantified in ten dogs before and during central autonomic nerve stimulation. Pulmonary vein encircling ablation was then performed and electrophysiologic testing repeated. In two dogs subjected to sham procedures measurements were repeated without performance of ablation. Hearts were examined histologically. RESULTS: Autonomic nerve stimulation led to decreased atrial refractoriness and increased AF inducibility and duration. Each of these effects were attenuated following pulmonary vein encircling (e.g., mean ERP decreased before (-23.7 +/- 1.8, p < 0.001) but not after ablation (-2.3 +/- 1.9, p = 0.25); AF inducibility increased by 26% before vs. 5% after ablation). No attenuation was seen in the sham operated animals. Histologic analysis following pulmonary vein encircling demonstrated destruction of some but not all autonomic ganglia. CONCLUSION: Autonomic stimulation shortens atrial refractory periods and potentiates AF. Pulmonary vein encircling ablation partially destroys atrial autonomic inputs, attenuates the refractory period shortening effect of autonomic stimulation and decreases AF inducibility. Destruction of autonomic ganglia may contribute to the anti-fibrillatory effects of pulmonary vein encircling and warrants further investigation.

Adipose Tissue↗