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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 361 records · Page 20
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Local Ultrasound-Facilitated Thrombolysis in High-Risk Pulmonary Embolism: First Dutch Experience

Purpose: To provide insight into the current use and results of ultrasound-facilitated catheter-directed thrombolysis (USAT) in patients with high-risk pulmonary embolism (PE). Introduction: Systemic thrombolysis is an effective treatment for hemodynamically unstable, high-risk PE, but is associated with bleeding complications. USAT is thought to reduce bleeding and is therefore advocated in patients with high-risk PE and contraindications for systemic thrombolysis. Methods: We conducted a retrospective cohort study of all patients who underwent USAT for high-risk PE in the Netherlands from 2010 to 2017. Characteristics and outcomes were analyzed. Primary outcomes were major (including intracranial and fatal) bleeding and all-cause mortality after 1 month. Secondary outcomes were all-cause mortality and recurrent venous thromboembolism within 3 months. Results: 33 patients underwent USAT for high-risk PE. Major bleeding occurred in 12 patients (36%, 95% CI 22–53), including 1 intracranial and 3 fatal bleeding. All-cause mortality after 1 month was 48% (16/33, 95% CI 31–66). All-cause mortality after 3 months was 50% (16/32, 95% CI 34–66), recurrent venous thromboembolism occurred in 1 patient (1/32, 3%, 95% CI 1–16). Conclusions: This study was the first to describe characteristics and outcomes after USAT in a study population of patients with high-risk PE only, an understudied population. Although USAT is considered a relatively safe treatment option, our results illustrate that at least caution is needed in critically ill patients with high-risk PE. Further research in patients with high-risk PE is warranted to guide patient selection.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Effects of Prostatic Artery Embolization on the Dynamic Component of Benign Prostate Hyperplasia as Assessed by Ultrasound Elastography: A Pilot Series

Purpose: To determine the effects of prostatic artery embolization (PAE) on prostatic elasticity as assessed by Ultrasound Elastography (US-E), as well as to describe the feasibility and role of US-E as a novel tool in both pre- and post-PAE evaluation. Materials and Methods: This is a prospective, single-center investigation that included eight patients undergoing PAE for treatment of lower urinary tract symptoms (LUTS) attributed to benign prostate hyperplasia (BPH). Baseline and 3-month follow-up evaluations were performed and included prostate-specific antigen (PSA), uroflowmetry, pelvic magnetic resonance imaging and clinical assessment using the International Prostate Symptom Score (IPSS) questionnaire and the IPSS-Quality of life (QoL) item. US-E with measurement of the prostatic Elastic Modulus (EM) was performed before PAE and at 1-month follow-up. Results: After PAE, US-E showed a significant reduction of prostatic EM as assessed in kPa (33.14 vs. 47.24, − 29.8%, p = 0.002) and in m/s (3.75 vs. 4.63, − 19.0%, p < 0.001). Also, the transitional/peripheral zone ratio was significantly reduced by 45.36% (0.53 vs. 0.97, p < 0.05). All eight patients presented with significant LUTS improvement after PAE (p < 0.05 for IPSS, QoL, prostate volume, peak urinary flow rate and PSA). Conclusions: Findings described in this study suggest that PAE significantly reduces prostatic EM, leading to a positive effect on BPH dynamic component related to prostatic elasticity. Also, it features US-E as an additional tool for pre- and post-PAE evaluation, describing a novel indication for this technology.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2017

Simplified Readability Metric Drives Improvement of Radiology Reports: an Experiment on Ultrasound Reports at a Pediatric Hospital

Highly complex medical documents, including ultrasound reports, are greatly mismatched with patient literacy levels. While improving radiology reports for readability is a longstanding concern, few articles objectively measure the effectiveness of physician training for readability improvement. We hypothesized that writing styles may be evaluated using an objective two-dimensional measure and writing training could improve the writing styles of radiologists. To test it, a simplified “grade vs. length” readability metric is developed based on results from factor analysis of ten readability metrics applied to more than 500,000 radiology reports. To test the short-term effectiveness of a writing workshop, we measured the writing style improvement before and after the training. Statistically significant writing style improvement occurred as a result of the training. Although the degree of improvement varied for different measures, it is evident that targeted training could provide potential benefits to improve readability due to our statistically significant results. The simplified grade vs. length metric enables future clinical decision support systems to quantitatively guide physicians to improve writing styles through writing workshops.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Double Bragg Diffraction of Bessel Light Beams on Ultrasound in Uniaxial Gyrotropic Crystals

Noncollinear double acousto-optical diffraction of Bessel light beams on ultrasound in uniaxial gyrotropic crystals is studied theoretically and experimentally. It is found that when a Bessel light beam propagates along the optic axis of a crystal, the diffracted light beams of the ±1 order are symmetric relative to the incident beam and have roughly the same intensity. Double Bragg diffraction is also observed when a Bessel light beam is incident at the Bragg angle and near the optic axis, but the intensities of the +1 and +2 order diffracted beams are significantly different.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2021

Determining elastic anisotropy of textured polycrystals using resonant ultrasound spectroscopy

Abstract Polycrystalline materials can have complex anisotropic properties depending on their crystallographic texture and crystal structure. In this study, we use resonant ultrasound spectroscopy (RUS) to nondestructively quantify the elastic anisotropy in extruded aluminum alloy 1100-O, an inherently low-anisotropy material. Further, we show that RUS can be used to indirectly provide a description of the material’s texture, which in the present case is found to be transversely isotropic. By determining the entire elastic tensor, we can identify the level and orientation of the anisotropy originated during extrusion. The relative anisotropy of the compressive (c 11 /c 33 ) and shear (c 44 /c 66 ) elastic constants is 1.5% ± 0.5% and 5.7% ± 0.5%, respectively, where the elastic constants (five independent elastic constants for transversely isotropic) are those associated with the extrusion axis that defines the symmetry of the texture. These results indicate that the texture is expected to have transversely isotropic symmetry. This finding is confirmed by two additional approaches. First, we confirm elastic constants and the degree of elastic anisotropy by direct sound velocity measurements using ultrasonic pulse echo. Second, neutron diffraction (ND) data confirm the symmetry of the bulk texture consistent with extrusion-induced anisotropy, and polycrystal elasticity simulations using the elastic self-consistent model with input from ND textures and aluminum single-crystal elastic constants render similar levels of polycrystal elastic anisotropy to those measured by RUS. We demonstrate the ability of RUS to detect texture-induced anisotropy in inherently low-anisotropy materials. Therefore, as many other common materials have intrinsically higher elastic anisotropy, this technique should be applicable for similar levels of texture, providing an efficient general diagnostic and characterization tool.

36 MATERIALS SCIENCE↗
DOE OSTI2014

In Situ Synchrotron X-ray Study of Ultrasound Cavitation and Its Effect on Solidification Microstructures

Considerable progress has been made in studying the mechanism and effectiveness of using ultrasound waves to manipulate the solidification microstructures of metallic alloys. However, uncertainties remain in both the underlying physics of how microstructures evolve under ultrasonic waves, and the best technological approach to control the final microstructures and properties. We used the ultrafast synchrotron X-ray phase contrast imaging facility housed at the Advanced Photon Source, Argonne National Laboratory, US to study in situ the highly transient and dynamic interactions between the liquid metal and ultrasonic waves/bubbles. The dynamics of ultrasonic bubbles in liquid metal and their interactions with the solidifying phases in a transparent alloy were captured in situ. The experiments were complemented by the simulations of the acoustic pressure field, the pulsing of the bubbles, and the associated forces acting onto the solidifying dendrites. The study provides more quantitative understanding on how ultrasonic waves/bubbles influence the growth of dendritic grains and promote the grain multiplication effect for grain refinement.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Impact Damage Investigation on Glass Fiber-Reinforced Plate Laminates at Room and Lower Temperatures through Ultrasound Testing and Electronic Speckle Pattern Interferometry

In this work, the evaluation of damage area due to low-velocity impact tests at different impact energy values and different temperatures on glass fiber-reinforced plate laminates was investigated by two nondestructive evaluation (NDE) techniques, electronic speckle pattern interferometry (ESPI) and ultrasound testing (UT). Composites are characterized by several interacting failure modes such as matrix breakage, fiber failure and delaminations, which can be simultaneously induced by low-velocity impacts and can be different depending on the temperature. It can be complicated to detect by visual inspections of the structures for such phenomena. This paper aims to investigate the dependence of the damaged area with respect to temperature variation on glass fiber composite laminates. GF composite laminates were impacted with three energy levels (5, 10, 20 J) and at different temperatures (room temperature, − 25, − 50 °C) by a drop weight impact machine. The results show that at decreasing temperature, a decrease in the damage extension was observed, which is more evident at increasing impact energy. Moreover, as expected, the results confirm UT and ESPI techniques are able to identify the barely visible low-velocity impact damage. However, some limitations for detection were found in ESPI. Nonetheless, the ESPI technique can be considered as one of the useful NDE methods if the calibration and the post-processing methods are improved.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Static and Dynamic Ultrasound Imaging of the Iliotibial Band/Fascia Lata: Brief Review of Current Literature and Gaps in Knowledge

Purpose of the Review: The physiopathology of iliotibial band syndrome (ITBS) remains obscure and ultrasound (US) imaging could be a low-cost modality improving our understanding of this condition as well as its diagnosis and management. This brief review synthesizes the up-to-date knowledge on static and dynamic US imaging measurements of the fascia lata and iliotibial band (ITB) in both asymptomatic individuals and patients with ITBS. Recent Findings: Mean ITB thickness values for asymptomatic individuals ranged from 1.10 to 1.95 mm. Only three studies with very small sample size focused on ITBS patients and no quantitative data were reported. All dynamic US imaging studies involved asymptomatic participants. One study demonstrated a lateral movement of the ITB relative to the femoral condyle and a group of investigators showed 3D displacement of the fascia lata. No study could be found on ITB loose connective tissue measurements. Summary: This review clearly indicates a paucity of research in the field of static and dynamic US measures. Measuring the loose connective tissue that lies between the deep fascia layers could be an interesting target to help our understanding of ITBS and improve care for the patients.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Low-intensity pulsed ultrasound regulates proliferation and differentiation of osteoblasts through osteocytes

Highlights: Black-Right-Pointing-Pointer CM from LIPUS-stimulated osteocytes inhibits proliferation of osteoblasts. Black-Right-Pointing-Pointer CM from LIPUS-stimulated osteocytes enhances differentiation of osteoblasts. Black-Right-Pointing-Pointer LIPUS stimulates MLO-Y4 cells to secrete PGE{sub 2} and NO. -- Abstract: Low-intensity pulsed ultrasound (LIPUS) has been used as a safe and effective modality to enhance fracture healing. As the most abundant cells in bone, osteocytes orchestrate biological activities of effector cells via direct cell-to-cell contacts and by soluble factors. In this study, we have used the osteocytic MLO-Y4 cells to study the effects of conditioned medium from LIPUS-stimulated MLO-Y4 cells on proliferation and differentiation of osteoblastic MC3T3-E1 cells. Conditioned media from LIPUS-stimulated MLO-Y4 cells (LIPUS-Osteocyte-CM) were collected and added on MC3T3-E1 cell cultures. MC3T3-E1 cells cultured in LIPUS-Osteocyte-CM demonstrated a significant inhibition of proliferation and an increased alkaline phosphatase activity. The results of PGE{sub 2} and NO assay showed that LIPUS could enhance PGE{sub 2} and NO secretion from MLO-Y4 cells at all time points within 24 h after LIPUS stimulation. We conclude that LIPUS regulates proliferation and differentiation of osteoblasts through osteocytes in vitro. Increased secretion of PGE{sub 2} from osteocytes may play a role in this effect.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Myocardial regeneration in adriamycin cardiomyopathy by nuclear expression of GLP1 using ultrasound targeted microbubble destruction

Recently GLP-1 was found to have cardioprotective effects independent of those attributable to tight glycemic control. Methods and results: We employed ultrasound targeted microbubble destruction (UTMD) to deliver piggybac transposon plasmids encoding the GLP-1 gene with a nuclear localizing signal to rat hearts with adriamycin cardiomyopathy. After a single UTMD treatment, overexpression of transgenic GLP-1 was found in nuclei of rat heart cells with evidence that transfected cardiac cells had undergone proliferation. UTMD-GLP-1 gene therapy restored LV mass, fractional shortening index, and LV posterior wall diameter to nearly normal. Nuclear overexpression of GLP-1 by inducing phosphorylation of FoxO1-S256 and translocation of FoxO1 from the nucleus to the cytoplasm significantly inactivated FoxO1 and activated the expression of cyclin D1 in nuclei of cardiac muscle cells. Reversal of adriamycin cardiomyopathy appeared to be mediated by dedifferentiation and proliferation of nuclear FoxO1-positive cardiac muscle cells with evidence of embryonic stem cell markers (OCT4, Nanog, SOX2 and c-kit), cardiac early differentiation markers (NKX2.5 and ISL-1) and cellular proliferation markers (BrdU and PHH3) after UTMD with GLP-1 gene therapy. Conclusions: Intranuclear myocardial delivery of the GLP-1gene can reverse established adriamycin cardiomyopathy by stimulating myocardial regeneration. - Highlights: • The activation of nuclear FoxO1 in cardiac muscle cells associated with adriamycin cardiomyopathy. • Myocardial nuclear GLP-1 stimulates myocardial regeneration and reverses adriamycin cardiomyopathy. • The process of myocardial regeneration associated with dedifferentiation and proliferation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Low-intensity pulsed ultrasound induces cartilage matrix synthesis and reduced MMP13 expression in chondrocytes

Highlights: • LIPUS induces collagen synthesis. • LIPUS suppresses MMP13 expression. • LIPUS induces aggrecan remodeling. Low-intensity pulsed ultrasound (LIPUS) is used for bone healing in orthopedics. In previous in vivo and in vitro studies, LIPUS has been shown to have promising effects on cellular elements in articular cartilage, particularly chondrocytes in patients with osteoarthritis. However, the effects of LIPUS on the cellular mechanisms through which LIPUS alters extracellular matrix (ECM) synthesis in chondrocytes are unclear. In this study, we investigated the effects of the optimal intensity and cellular mechanisms of LIPUS on the regeneration of cartilage matrix in chondrocytes. LIPUS induced collagen synthesis and the remodeling of aggrecan via the activation of ERK1/2. In contrast, MMP13 expression was decreased in chondrocytes. Additionally, chondrocytes responded optimally to LIPUS at an intensity higher than the clinical setting for bone fracture healing. These results suggested that LIPUS induced ECM regeneration via increases in hypertrophic chondrocytes and delayed endochondral ossification in chondrocytes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2012

Simultaneous study of mechanical property development and early hydration chemistry in Portland cement slurries using X-ray diffraction and ultrasound reflection

A sample cell for the simultaneous measurement of synchrotron X-ray powder diffraction and ultrasound shear-wave reflection data from cement slurries is described. White cement slurries at 25 and 50 C with 0-3% bwoc CaCl{sub 2} were studied to illustrate the potential of the apparatus. The decrease in reflected S-wave amplitude, in dB, showed a linear correlation with C{sub 3}S hydration. CaCl{sub 2} retarded the development of G{prime} and G{double_prime} relative to the extent of C{sub 3}S hydration. At short times, there was a correlation between the time evolution of both G{prime} and G{double_prime}, and the amount of precipitated CH seen by diffraction, which was almost independent of CaCl{sub 2} concentration and temperature. CaCl{sub 2} addition resulted in a decrease in the amount of CH visible to X-rays, relative the degree of C{sub 3}S hydration. This may indicate a change in C-S-H gel C:S ratio or the presence of nanoscale CH that could not be seen by diffraction.

36 MATERIALS SCIENCE↗
DOE OSTI2011

Patterns of Response After Preoperative Intensity-Modulated Radiation Therapy and Capecitabine/Oxaliplatin in Rectal Cancer: Is There Still a Place for Ecoendoscopic Ultrasound?

Purpose: The main goals of preoperative chemoradiotherapy (CHRT) in rectal cancer are to achieve pathological response and to ensure tumor control with functional surgery when possible. Assessment of the concordance between clinical and pathological responses is necessary to make decisions regarding alternative conservative procedures. The present study evaluates the patterns of response after a preoperative CHRT regimen, and the value of endoscopic ultrasound (EUS) in assessing response. Methods and Materials: A total of 51 EUS-staged T3 to T4 and/or N0 to N+ rectal cancer patients received preoperative CHRT (intensity-modulated radiation therapy and capecitabine/oxaliplatin (XELOX) followed by radical resection. Clinical response was assesed by EUS. Rates of pathological tumor regression grade (TRG) and lymph node (LN) involvement were determined in the surgical specimen. Clinical and pathological responses were compared, and the accuracy of EUS in assessing response was calculated. Results: Twenty-four patients (45%) achieved a major pathological response (complete or >95% pathological response (TRG 3+/4)). Sensitivity, specificity, negative predictive value, and positive predictive value of EUS in predicting pathological T response after preoperative CHRT were 77.8%, 37.5%, 60%, and 58%, respectively. The EUS sensitivity, specificity, negative predictive value, and positive predictive value for nodal staging were 44%, 88%, 88%, and 44%, respectively. Furthermore, EUS after CHRT accurately predicted the absence of LN involvement in 7 of 7 patients (100%) with major pathological response of the primary tumor. Conclusion: Preoperative IMRT with concomitant XELOX induces favorable rates of major pathological response. EUS has a limited ability to predict primary tumor response after preoperative CHRT, but it is useful for accurately determining LN status. EUS may have a potential value in identifying patients with a very low risk of LN involvement in association with a good pathological response as potential candidates for conservative local surgical protocols.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Active Breathing Control in Combination With Ultrasound Imaging: A Feasibility Study of Image Guidance in Stereotactic Body Radiation Therapy of Liver Lesions

Purpose: Accurate tumor positioning in stereotactic body radiation therapy (SBRT) of liver lesions is often hampered by motion and setup errors. We combined 3-dimensional ultrasound imaging (3DUS) and active breathing control (ABC) as an image guidance tool. Methods and Materials: We tested 3DUS image guidance in the SBRT treatment of liver lesions for 11 patients with 88 treatment fractions. In 5 patients, 3DUS imaging was combined with ABC. The uncertainties of US scanning and US image segmentation in liver lesions were determined with and without ABC. Results: In free breathing, the intraobserver variations were 1.4 mm in left-right (L-R), 1.6 mm in superior-inferior (S-I), and 1.3 mm anterior-posterior (A-P). and the interobserver variations were 1.6 mm (L-R), 2.8 mm (S-I), and 1.2 mm (A-P). The combined uncertainty of US scanning and matching (inter- and intraobserver) was 4 mm (1 SD). The combined uncertainty when ABC was used reduced by 1.7 mm in the S-I direction. For the L-R and A-P directions, no significant difference was observed. Conclusion: 3DUS imaging for IGRT of liver lesions is feasible, although using anatomic surrogates in the close vicinity of the lesion may be needed. ABC-based breath-hold in midventilation during 3DUS imaging can reduce the uncertainty of US-based 3D table shift correction.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Proton Therapy as Salvage Treatment for Local Relapse of Prostate Cancer Following Cryosurgery or High-Intensity Focused Ultrasound

Purpose: Local recurrence of prostate cancer after cryosurgery (CS) and high-intensity focused ultrasound (HIFU) is an emerging problem for which optimal management is unknown. Proton therapy (PT) may offer advantages over other local therapeutic options. This article reviews a single institution's experience using PT for salvage of local recurrent disease after HIFU or CS. Methods and Materials: We reviewed the medical records of 21 consecutive patients treated with salvage PT following a local recurrence of prostate cancer after CS (n=12) or HIFU (n=9) between January 2007 and July 2014. Patients were treated to a median dose of 74 Gy(relative biological effectiveness [RBE]; range: 74-82 Gy[RBE]) and 8 patients received androgen deprivation therapy with radiation therapy. Patients were evaluated for quality of life (QOL) by using the Expanded Prostate Index Composite questionnaire and toxicity by using Common Terminology Criteria for Adverse Events, version 3.0, weekly during treatment, every 6 months for 2 years after treatment, and then annually. Results: Median follow-up was 37 months (range: 6-95 months). The 3-year biochemical progression-free survival (bPFS) rate was 77%. The 3-year grade 3 toxicity rate was 17%; however, 2 of these patients had pre-existing grade 3 GU toxicities from their HIFU/CRYO prior to PT. At 1 year, bowel summary, urinary incontinence, and urinary obstructive QOL scores declined, but only the bowel QOL score at 12 months met the minimally important difference threshold. Conclusions: PT achieved a high rate of bPFS with acceptable toxicity and minimal changes in QOL scores compared with baseline pre-PT functions. Although most patients have done fairly well, the study size is small, follow-up is short, and early results suggest that outcomes with PT for salvage after HIFU or CS failure are inferior to outcomes with PT given in the de novo setting with respect to disease control, toxicity, and QOL.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Magnetic Resonance–Guided High-Intensity Focused Ultrasound Hyperthermia for Recurrent Rectal Cancer: MR Thermometry Evaluation and Preclinical Validation

Purpose: To evaluate the feasibility of magnetic resonance–guided high-intensity focused ultrasound (MR-HIFU) mild hyperthermia in deep tissue targets for enhancing radiation therapy and chemotherapy in the context of recurrent rectal cancer. A preclinical study was performed to evaluate the safety and performance of MR-HIFU mild hyperthermia. A prospective imaging study was performed in volunteers with rectal cancer to evaluate MR thermometry quality near the rectum and accessibility of rectal tumors using MR-HIFU. Methods and Materials: Mild hyperthermia was performed in pig thigh (9 sonications, 6 pigs) using a clinical MR-HIFU system. Targets near the rectal wall and deep thigh were evaluated. Thermal maps obtained in 6 planes every 3.2 seconds were used to control sonications in 18-mm diameter treatment regions at temperatures of 42°C to 42.5°C for 10 to 60 minutes. Volunteer imaging-only studies to assess the quality of MR thermometry (without heating) were approved by the institutional research ethics board. Anatomic and MR thermometry images were acquired in consenting volunteers with rectal cancer. In 3 of 6 study participants, rectal filling with saline was used to reduce motion-related MR thermometry artifacts near the tumor. Results: In pigs, mean target temperature matched the desired hyperthermia temperature within 0.2°C; temporal standard deviation ≤0.5°C. With optimized control thresholds, no undesired tissue damage was observed. In human volunteers, MR temperature measurements had adequate precision and stability, especially when rectal filling was used to reduce bowel motion. Conclusions: In pigs, MR-HIFU can safely deliver mild hyperthermia (41°C-43°C) to a targeted volume for 30 minutes. In humans, careful patient selection and preparation will enable adequate targeting for recurrent rectal cancers and sufficient MR temperature mapping stability to control mild hyperthermia. These results enable human trials of MR-HIFU hyperthermia.

62 RADIOLOGY AND NUCLEAR MEDICINE↗