Publications by authors named "Rachel K Surowiec"
Quasi-brittle fracture mechanics is used to evaluate fracture of human cortical bone in aging. The approach is demonstrated using cortical bone bars extracted from one 92-year-old human male cadaver. In-situ fracture mechanics experiments in a 3D X-ray microscope are conducted.
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- Female distance runners often experience bone stress injuries, especially in the leg and foot long bones, which may be prevented through participation in multidirectional sports during youth.
- A study comparing college athletes in cross-country running and soccer found that soccer players had larger and stronger tibias, fibulas, and second metatarsals, indicating better bone adaptation due to their diverse movement patterns.
- The results suggest that young female athletes should avoid early specialization in running and engage in sports like soccer to develop stronger and more resilient skeletal structures, potentially reducing the risk of bone stress injuries.
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- Postmenopausal osteoporosis, driven by estrogen deficiency, significantly increases fracture risk, making early fracture prediction crucial yet difficult.
- A study on ovariectomized rats aimed to investigate changes in inflammation, oxidative stress, and bone properties post-surgery, testing new imaging techniques for early detection of bone alterations.
- Results indicated that while OVX rats showed increased inflammation and oxidative stress, changes in bone hydration measured by ultrashort echo time MRI were noticeable as early as 2 weeks after surgery, although these did not correlate with bone turnover rates in the assessed time frame.
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- Type 2 diabetes (T2D) is linked to higher rates of fractures and related mortality, with effective mouse models for studying its impact on bone health being limited.
- The KK/A mouse model, with a mutation in the agouti gene, reliably induces T2D with persistent hyperglycemia in both male and female subjects, making it suitable for bone studies.
- Findings indicate that KK/A mice represent the early stages of T2D characterized by high blood glucose and insulin levels, though the presence of diabetic male control mice presents some limitations for comparison.
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- Patients with chronic kidney disease (CKD) have a significantly higher risk of fractures due to changes in bone structure, specifically increased cortical porosity and diminished matrix hydration.
- The study involved inducing CKD in mice and testing the effects of mechanical loading and a drug, raloxifene, on bone properties over ten weeks.
- Results showed that combining mechanical loading with raloxifene treatment improved bone characteristics in CKD mice, leading to lower porosity and enhanced hydration, which could help reduce fracture risk.
Introduction: Conventional bone imaging methods primarily use X-ray techniques to assess bone mineral density (BMD), focusing exclusively on the mineral phase. This approach lacks information about the organic phase and bone water content, resulting in an incomplete evaluation of bone health. Recent research highlights the potential of ultrashort echo time magnetic resonance imaging (UTE MRI) to measure cortical porosity and estimate BMD based on signal intensity.
View Article and Find Full Text PDFPurpose Of Review: This review summarizes recent advances in the assessment of bone quality using non-X-ray techniques.
Recent Findings: Quantitative ultrasound (QUS) provides multiple measurements of bone characteristics based on the propagation of sound through bone, the attenuation of that sound, and different processing techniques. QUS parameters and model predictions based on backscattered signals can discriminate non-fracture from fracture cases with accuracy comparable to standard bone mineral density (BMD).
Changes in Bone Quality after Treatment with Etelcalcetide.
Clin J Am Soc Nephrol
November 2023
Article Synopsis
- - The study investigates the effects of etelcalcetide, a treatment for secondary hyperparathyroidism in dialysis patients, on bone health, specifically aiming to improve bone quality and strength without harming bone tissue.
- - Conducted over 36 weeks with 22 participants, the results showed significant reductions in parathyroid hormone levels and increases in bone mineral density and trabecular quality, suggesting positive impacts on bone health.
- - However, bone biopsies indicated a decrease in bone formation rate, highlighting a complex interaction between treatment and bone remodeling processes.
Article Synopsis
- Chronic kidney disease (CKD) can lead to increased cortical porosity and a higher chance of hip fractures due to secondary hyperparathyroidism.
- This study aimed to determine if ultrashort echo time magnetic resonance imaging (UTE-MRI) could effectively measure changes in bone porosity in a rat model of CKD.
- Results showed that while UTE-MRI correlates with microCT imaging at some skeletal sites, inconsistencies in findings suggest it may need further refinement before being used clinically, but it could still be a useful tool for assessing fracture risk without radiation exposure.
Raloxifene (RAL) reduces clinical fracture risk despite modest effects on bone mass and density. This reduction in fracture risk may be due to improved material level-mechanical properties through a non-cell mediated increase in bone hydration. Synthetic salmon calcitonin (CAL) has also demonstrated efficacy in reducing fracture risk with only modest bone mass and density improvements.
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- High-resolution peripheral quantitative computed tomography (HR-pQCT) enables detailed 3D assessments of bone microarchitecture, but traditionally relies on static evaluations of cortical porosity at a single time point.
- This study introduced a method to assess the dynamics of individual cortical pores in aging women over one year, observing activities like development, contraction, and expansion of pores using HR-pQCT imaging.
- Findings revealed that more pores developed and expanded than were infilled or contracted, leading to an overall increase in pore area, particularly with dynamic changes occurring in closed pores at the tibia.
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- The study investigates how participating in multidirectional sports (MDS) during youth may help female runners strengthen their bones to reduce the risk of bone stress injuries (BSIs) such as fractures.
- Female collegiate cross-country runners were divided into two groups, those who only ran (RUN) and those who also played MDS like soccer or basketball (RUN + MDS), with various bone strength measurements taken via advanced imaging.
- Results showed that the RUN + MDS group had significantly stronger bones, with increased cortical and trabecular measures, indicating that engaging in diverse sports can lead to better skeletal health and potentially lower the risk of BSIs in future runners.
Water constitutes roughly a quarter of the cortical bone by volume yet can greatly influence mechanical properties and tissue quality. There is a growing appreciation for how water can dynamically change due to age, disease, and treatment. A key emerging area related to bone mechanical and tissue properties lies in differentiating the role of water in its four different compartments, including free/pore water, water loosely bound at the collagen/mineral interfaces, water tightly bound within collagen triple helices, and structural water within the mineral.
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- Understanding the cancer stem cell (CSC) characteristics in diffuse intrinsic pontine glioma (DIPG) is crucial for overcoming treatment resistance and finding new therapies.
- Patient-derived DIPG cells showed varying levels of aldehyde dehydrogenase (ALDH) and CD133, indicating a stem-like phenotype associated with increased cell growth and survival challenges.
- Targeting the MAPK/PI3K/mTOR signaling pathway can inhibit tumor growth and metabolism in ALDH-positive tumors, suggesting potential for targeted therapy against the CSC traits in DIPG.
Bone is a composite biomaterial of mineral crystals, organic matrix, and water. Each contributes to bone quality and strength and may change independently, or together, with disease progression and treatment. Even so, there is a near ubiquitous reliance on ionizing x-ray-based approaches to measure bone mineral density (BMD) which is unable to fully characterize bone strength and may not adequately predict fracture risk.
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- Sclerostin antibody (SclAb) therapy is being explored as a potential treatment for osteogenesis imperfecta (OI), but most research has been conducted on mouse models, leading to a lack of data on the human response to the therapy.* -
- In this study, bone tissue from pediatric OI patients was treated with different doses of SclAb in vitro and implanted into mice to analyze cellular responses and gene expression related to osteoblasts.* -
- Results showed that SclAb treatment increased markers for osteoblasts in OI bone, with varying responses based on the baseline gene expression levels; the therapy also led to positive bone formation in the implanted OI bone observed through imaging techniques.*
Stereotactic Transcranial Focused Ultrasound Targeting System for Murine Brain Models.
IEEE Trans Ultrason Ferroelectr Freq Control
January 2021
An inexpensive, accurate focused ultrasound stereotactic targeting method guided by pretreatment magnetic resonance imaging (MRI) images for murine brain models is presented. An uncertainty of each sub-component of the stereotactic system was analyzed. The entire system was calibrated using clot phantoms.
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- Osteogenesis imperfecta (OI) is a rare condition that leads to fragile bones, primarily affecting children and making it hard to conduct clinical trials; thus, researchers often use genetically modified mice to study potential treatments.
- A new treatment, sclerostin antibody (SclAb), shows promise for improving bone density, but its effects on pediatric patients with OI have not yet been tested.
- The study employs a novel method by implanting patient-derived bone samples into mice to assess the effectiveness of SclAb over different time frames, using various techniques to evaluate bone cell survival, activity, and overall treatment response.
Article Synopsis
- This study investigates if magnetic resonance (MR) imaging can replace computed tomography (CT) for creating 3D bone models.
- MR images were taken from a cadaver's knee and compared to CT images to measure how similar the bone models generated from each method were.
- Results showed that MR models were very close in accuracy to CT models, particularly with the VIBE sequence, suggesting MR could be a safer and more comprehensive option for joint evaluations without the harmful radiation from CT scans.
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- The study aimed to assess how different sitting surfaces (flat, air-filled cushion, and stability ball) impact muscle activation and energy expenditure among 11 young adult females.
- Results showed that both the stability ball and cushion significantly increased energy expenditure compared to the flat surface, with the stability ball also enhancing muscle activation in the calves.
- The findings highlight the potential benefits of using active sitting options to promote muscle engagement and caloric burn, which is particularly relevant in today's sedentary lifestyle.
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- Current MRI techniques struggle to evaluate peroneal tendons due to their complex path, making it challenging to assess tendon health and track recovery.
- This study aimed to establish normative T2* values for the peroneal tendons using MRI scans of asymptomatic volunteers to create a baseline for identifying tendon issues.
- Results showed that T2* values were higher in areas distal to the lateral malleolus compared to proximal areas, suggesting anatomical variations that could impact tendon health assessments.
Rationale And Objectives: This study aimed to evaluate the accuracy of an automated method for segmentation and T2 mapping of the medial meniscus (MM) and lateral meniscus (LM) in clinical magnetic resonance images from patients with acute knee injury.
Materials And Methods: Eighty patients scheduled for surgery of an anterior cruciate ligament or meniscal injury underwent magnetic resonance imaging of the knee (multiplanar two-dimensional [2D] turbo spin echo [TSE] or three-dimensional [3D]-TSE examinations, T2 mapping). Each meniscus was automatically segmented from the 2D-TSE (composite volume) or 3D-TSE images, auto-partitioned into anterior, mid, and posterior regions, and co-registered onto the T2 maps.
Article Synopsis
- The study aimed to analyze T2 mapping values in both damaged and healthy articular cartilage specimens from patients undergoing treatment for femoroacetabular impingement (FAI), in relation to International Cartilage Repair Society (ICRS) grading.
- A total of 24 patients, aged 18 and older, were involved, with 44 specimens (22 healthy and 22 damaged) collected for analysis, using various methods including T2 mapping, histology, and immunohistochemistry.
- Results indicated that damaged specimens had significantly higher median T2 values compared to healthy ones, especially in mild defects, and a notable correlation was found between T2 values and collagen fiber orientation in healthy-appearing specimens.
Background: Quantitative magnetic resonance imaging (MRI) techniques, such as T2 and T2 star (T2*) mapping, have been used to evaluate ligamentous tissue in vitro and to identify significant changes in structural integrity of a healing ligament. These studies lay the foundation for a clinical study that uses quantitative mapping to evaluate ligaments in vivo, particularly the posterior cruciate ligament (PCL). To establish quantitative mapping as a clinical tool for identifying and evaluating chronic or acute PCL injuries, T2 and T2* values first must be determined for an asymptomatic population.
View Article and Find Full Text PDFObjective: A standardized definition of normative T2 values across the articular surface of the hip must be defined in order to fully understand T2 values for detecting early degeneration. Therefore, in this article, we seek to lay foundational methodology for reproducible quantitative evaluation of hip cartilage damage using T2 mapping to determine the normative T2 values in asymptomatic individuals.
Design: Nineteen prospectively enrolled asymptomatic volunteers (age 18-35 years, males 10, females 9, alpha angle 49.