Ultrasound in Medicine and Biology最新文献

{"title":"Effects of Different Gas Cores on the Ambient Pressure Sensitivity of the Subharmonic Response of SonoVue","authors":"Roozbeh H. Azami ,&nbsp;Mehmet Yapar ,&nbsp;Saikat Halder ,&nbsp;Flemming Forsberg ,&nbsp;John R. Eisenbrey ,&nbsp;Kausik Sarkar","doi":"10.1016/j.ultrasmedbio.2024.11.006","DOIUrl":"10.1016/j.ultrasmedbio.2024.11.006","url":null,"abstract":"<div><h3>Objective</h3><div>Subharmonic Aided Pressure Estimation (SHAPE) is a noninvasive technique for estimating organ-level blood pressure using the strong correlation between the subharmonic signal and ambient pressure. The compressible gas core of microbubbles enables them to generate linear and nonlinear acoustic responses when exposed to ultrasound. Here, the sulfur hexafluoride (SF₆) gas core of SonoVue (known as Lumason in the United States), a clinical contrast agent, was exchanged with a perfluorobutane (PFB) core to investigate its effect on the SHAPE response.</div></div><div><h3>Methods</h3><div>Excitations of 25–700 kPa peak negative pressure (PNP) and 3 MHz transmission frequency were used to study <em>in vitro</em> the effects of overpressure changes ranging from 5 to 25 kPa (37–186 mm Hg).</div></div><div><h3>Results</h3><div>Unlike SonoVue with SF₆, at low PNPs (&lt;400 kPa), SonoVue with a PFB gas core exhibited no subharmonic at the atmospheric pressure, but during pressurization, a stable subharmonic response (maximum of 25 dB at 100 kPa PNP and 20 kPa Overpressure) appeared. SonoVue with a PFB gas core showed an increase in subharmonics with overpressure at high PNPs (&gt;400 kPa), which was not observed before in normal SonoVue or other lipid microbubbles. With negligible size distribution difference between these two microbubbles, these effects on subharmonic generation are likely due to the gas core, casting new light on the mechanism by which ambient overpressure affects subharmonic.</div></div><div><h3>Conclusion</h3><div>This study may inform future SHAPE technique developments.</div></div>","PeriodicalId":49399,"journal":{"name":"Ultrasound in Medicine and Biology","volume":"51 2","pages":"Pages 373-380"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142711668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Review on Ultrasound-based Methods to Image the Distribution of Magnetic Nanoparticles in Biomedical Applications","authors":"Christian Marinus Huber ,&nbsp;Theo Z. Pavan ,&nbsp;Ingrid Ullmann ,&nbsp;Christian Heim ,&nbsp;Stefan J. Rupitsch ,&nbsp;Martin Vossiek ,&nbsp;Christoph Alexiou ,&nbsp;Helmut Ermert ,&nbsp;Stefan Lyer","doi":"10.1016/j.ultrasmedbio.2024.10.007","DOIUrl":"10.1016/j.ultrasmedbio.2024.10.007","url":null,"abstract":"<div><div>Magnetic nanoparticles (MNPs) have gained significant attention in biomedical engineering and imaging applications due to their unique magnetic and mechanical properties. With their high magnetization and small size, MNPs serve as excitation sources for magnetically heating to destroy tumors (magnetic hyperthermia) and magnetically controlled drug carriers in magnetic drug targeting. However, effectively visualizing the distribution of MNPs during research or potential clinical use with low-cost modalities remains a critical challenge. Although magnetic resonance imaging provides pre- and post-procedural imaging, it is considered to be high cost, and real-time imaging during clinical procedures is limited. In contrast, ultrasound-based imaging methods offer the advantage of providing the potential for immediate feedback during clinical use and are considered to be a low-cost modality. Ultrasound-based imaging techniques, including magnetomotive ultrasound, magnetoacoustic tomography, and thermoacoustic imaging, emerged as promising approaches for imaging the distribution of MNPs. These techniques offer the potential for real-time imaging, facilitating precise therapy monitoring. By exploring the strengths and limitations of various ultrasound-based imaging techniques for MNPs, this review seeks to provide comprehensive insights that can guide researchers in selecting suitable ultrasound-based modalities and inspire further advancements in this exciting field.</div></div>","PeriodicalId":49399,"journal":{"name":"Ultrasound in Medicine and Biology","volume":"51 2","pages":"Pages 210-234"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142631386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative Ultrasound for Periodontal Soft Tissue Characterization","authors":"Daria Poul ,&nbsp;Ankita Samal ,&nbsp;Amanda Rodriguez Betancourt ,&nbsp;Carole Quesada ,&nbsp;Hsun-Liang Chan ,&nbsp;Oliver D. Kripfgans","doi":"10.1016/j.ultrasmedbio.2024.10.003","DOIUrl":"10.1016/j.ultrasmedbio.2024.10.003","url":null,"abstract":"<div><h3>Objective</h3><div>Periodontal diseases are a spectrum of inflammatory diseases that affect 45.9% of adults aged ≥30 years in the United States Current standard of care in clinics for the assessment of oral soft tissue inflammation is bleeding on probing,which is invasive, subjective and semi-qualitative. Quantitative ultrasound (QUS) has shown promising results in the non-invasive quantitative characterization of various soft tissues; however, it has not been used in clinical periodontics.</div></div><div><h3>Methods</h3><div>Here, we investigated the QUS analysis of two periodontal soft tissues (alveolar mucosa and gingiva) <em>in vivo</em>. The study cohort included 10 swine scanned at four oral quadrants, resulting in 40 scans. Two-parameter Burr and Nakagami models were employed for QUS-based speckle modeling. Parametric imaging of these parameters was also created using an optimal window size estimated in a separate phantom study.</div></div><div><h3>Results</h3><div>Phantom results suggested a window size of 10 wavelengths as the reasonable estimation kernel. The Burr power-law parameter and Nakagami shape factor were higher in gingiva than alveolar mucosa, while Burr and Nakagami scale factors were both lower in the gingiva. The difference between the two tissue types was statistically significant (<em>p</em> &lt; 0.0001). Linear classifications of these two tissue types using a 2-D parameter space of the Burr and Nakagami models resulted in a segmentation accuracy of 93.51% and 90.91%, respectively. Findings from histology-stained images showed that gingiva and alveolar mucosa had distinct underlying structures, with the gingiva showing a denser stain.</div></div><div><h3>Conclusion</h3><div>QUS results suggest that gingiva and alveolar mucosa can be differentiated using Burr and Nakagami parameters. We propose that QUS holds promising potential for the characterization of periodontal soft tissues and could become an objective and quantitative diagnostic tool for periodontology and implant dentistry to improve dental health care.</div></div>","PeriodicalId":49399,"journal":{"name":"Ultrasound in Medicine and Biology","volume":"51 2","pages":"Pages 288-301"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142711680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of In Vivo Human Carotid Artery Elasticity Using Arterial Dispersion Ultrasound Vibrometry","authors":"Tuhin Roy ,&nbsp;Hyoung-Ki Lee ,&nbsp;Charles B. Capron ,&nbsp;Francisco Lopez-Jimenez ,&nbsp;Gina K. Hesley ,&nbsp;James F. Greenleaf ,&nbsp;Matthew W. Urban ,&nbsp;Murthy N. Guddati","doi":"10.1016/j.ultrasmedbio.2024.09.023","DOIUrl":"10.1016/j.ultrasmedbio.2024.09.023","url":null,"abstract":"<div><h3>Objective</h3><div>Arterial stiffening serves as an early indicator for a variety of cardiovascular diseases. Arterial Dispersion Ultrasound Vibrometry (ADUV) is a method that leverages acoustic radiation force to stimulate arterial wall motion, assess wave propagation characteristics, and subsequently calculate the arterial shear modulus. Previously, we introduced an inversion technique based on a guided cylindrical wave model, which proved effective in rubber tube phantom experiments. In this study, we broaden the scope of our investigation from phantom experiments to <em>in vivo</em> examination of common carotid arteries in human subjects, identify the challenges, and provide solutions, leading to a systematic protocol for ADUV application and robust estimation of the elastic modulus of common carotid arteries.</div></div><div><h3>Methods</h3><div>We achieve this by analyzing ADUV data from 59 subjects categorized as (a) confirmed atherosclerotic cardiovascular disease (<em>n</em> = 27), (b) with cardiovascular risk factors (<em>n</em> = 20), and (c) healthy (<em>n</em> = 12). A crucial aspect of this work is the development of metrics to differentiate high-quality ADUV data from unusable data.</div></div><div><h3>Results and Conclusions</h3><div>With the proposed metrics, in our cohort, we observed 82% of diameter data and 78% of motion data as usable data. Future work will involve applying this protocol to a larger cohort with subsequent statistical analysis to assess and validate the resulting biomarkers.</div></div>","PeriodicalId":49399,"journal":{"name":"Ultrasound in Medicine and Biology","volume":"51 2","pages":"Pages 250-261"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142548555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of a Deep Learning Model for Classification of Hepatic Steatosis from Clinical Standard Ultrasound","authors":"Ahmed El Kaffas ,&nbsp;Krishna Chaitanya Bhatraju ,&nbsp;Jenny M. Vo-Phamhi ,&nbsp;Thodsawit Tiyarattanachai ,&nbsp;Neha Antil ,&nbsp;Lindsey M. Negrete ,&nbsp;Aya Kamaya ,&nbsp;Luyao Shen","doi":"10.1016/j.ultrasmedbio.2024.09.020","DOIUrl":"10.1016/j.ultrasmedbio.2024.09.020","url":null,"abstract":"<div><h3>Objective</h3><div>Early detection and monitoring of hepatic steatosis can help establish appropriate preventative measures against progression to more advanced disease. We aimed to develop a deep learning (DL) program for classification of hepatic steatosis from standard-of-care grayscale ultrasound (US) images.</div></div><div><h3>Methods</h3><div>In this single-center retrospective study, we utilized grayscale US images from January 1, 2010, to October 23, 2022, labeled with magnetic resonance imaging (MRI) proton density fat fraction (MRI-PDFF) to develop a DL multi-instance program for differentiating normal (S0) from steatotic liver (S1/2/3) and normal/mild steatosis (S0/1) from moderate/severe steatosis (S2/3). Diagnostic performances were assessed with area under the receiver operating characteristic curves (AUC), sensitivity, specificity and balanced accuracy with 95% confidence interval (CI).</div></div><div><h3>Results</h3><div>A total of 403 patients with 403 US exams were included: 171 (42%) were normal (S0: MRI-PDFF &lt;5%), 154 (38%) had mild steatosis (S1: MRI-PDFF 5–17.4%), 29 (7%) had moderate steatosis (S2: MRI-PDFF &gt;17.4%–22.1%) and 49 (12%) had severe steatosis (S3: MRI-PDFF &gt;22.1%). The dataset was split to include 322 patients in train/validation and 81 patients in a holdout test set (kept blind). The S0 versus S1/2/3 model achieved 81.3% (95% CI 72.1–90.5) AUC, 81.1% (70.6–91.6) sensitivity, 71.4% (54.7–88.2) specificity and 76.3% (66.4–86.2) balanced accuracy. The S0/1 versus S2/3 model achieved 95.9% (89–100) AUC, 87.5% (71.3–100) sensitivity, 96.9% (92.7–100) specificity and 92.2% (83.8–100) balanced accuracy. A multi-class model achieved a sensitivity of 71.4% (54.7–88.2) for S0, 67.6% (52.5–82.7) for S1 and 87.5% (71.3–100) for S2/3; specificity for the same model was 81.1% (70.6–91.6) for S0, 77.3% (64.9–89.7) for S1 and 96.9% (92.7–100) for S2/3.</div></div><div><h3>Conclusion</h3><div>Our DL program offered high sensitivity and accuracy in detecting and categorizing hepatic steatosis from standard-of-care ultrasound.</div></div>","PeriodicalId":49399,"journal":{"name":"Ultrasound in Medicine and Biology","volume":"51 2","pages":"Pages 242-249"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142631397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sonopermeation With Size-sorted Microbubbles Synergistically Increases Survival and Enhances Tumor Apoptosis With L-DOX by Increasing Vascular Permeability and Perfusion in Neuroblastoma Xenografts","authors":"Rachael M. Sundland ,&nbsp;Donia Ballan ,&nbsp;Kylie M. Callier ,&nbsp;Joy Ayemoba ,&nbsp;Aditi Bellary ,&nbsp;Isabella J. Iwanicki ,&nbsp;Lydia L. Wu ,&nbsp;Tylar Larkins ,&nbsp;Fernando Flores-Guzman ,&nbsp;Jacky Gomez-Villa ,&nbsp;Gracey Wyles ,&nbsp;Jameel Feshitan ,&nbsp;Jessica J. Kandel ,&nbsp;Shashank R. Sirsi ,&nbsp;Sonia L. Hernandez","doi":"10.1016/j.ultrasmedbio.2024.10.014","DOIUrl":"10.1016/j.ultrasmedbio.2024.10.014","url":null,"abstract":"<div><h3>Objective</h3><div>Despite aggressive therapy, approximately 50% of patients with neuroblastoma (NB) fail to respond, and survivors endure lifelong toxicities. Sonopermeation increases drug uptake via cell bilayer disruption through focused ultrasound and microbubbles (MBs)—gas-filled, sound sensitive lipid spheres. MB response to a given ultrasound pulse (cavitation) varies according to MB size. We asked whether size-sorted MBs (SSMB) 4 to 5 µm in diameter will more consistently and predictably enhance doxorubicin uptake, compared with polydisperse MBs (PMB, 0.5–10 µm in diameter), thereby increasing drug delivery to NB xenografts.</div></div><div><h3>Methods</h3><div>Human NB cells were implanted into the left kidney of nude mice and grown for 5 to 6 wk. Mice received sonopermeation alongside either PMB or SSMB at low (0.6 MPa) or high (2 MPa) negative pressures. Some mice also received different chemotherapy agents (doxorubicin, etoposide or cyclophosphamide). Circulating tumor cells were assessed by flow cytometry 1 h after treatment. Survival was assessed for up to 21 d, a subset of mice was euthanized 24 h after treatment for histological assessment of apoptosis, vascular lumen size and tight junctions.</div></div><div><h3>Results</h3><div>Tumors treated with SSMB and high pressure showed synergy with liposomal doxorubicin (L-DOX) owing to increased vascular lumen and disruption of tight junctions, resulting in drug uptake, apoptosis, lack of tumor growth and increased survival. We found no difference in the numbers of circulating tumor cells.</div></div><div><h3>Conclusion</h3><div>Sonopermeation with SSMB at 2 MPa synergizes with L-DOX delivery, increasing apoptosis, perfusion and vascular permeability, suggesting that SSMB sonopermeation at high pressure is promising for NB-targeted treatment, especially in combination with L-DOX.</div></div>","PeriodicalId":49399,"journal":{"name":"Ultrasound in Medicine and Biology","volume":"51 2","pages":"Pages 348-357"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11677626/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142711694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial Advisory Board","authors":"","doi":"10.1016/S0301-5629(24)00451-4","DOIUrl":"10.1016/S0301-5629(24)00451-4","url":null,"abstract":"","PeriodicalId":49399,"journal":{"name":"Ultrasound in Medicine and Biology","volume":"51 2","pages":"Page i"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143135239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Boiling Histotripsy in Ex Vivo Human Brain: Proof-of-concept","authors":"Ekaterina Ponomarchuk ,&nbsp;Sergey Tsysar ,&nbsp;Alexey Kadrev ,&nbsp;Anastasia Kvashennikova ,&nbsp;Daria Chupova ,&nbsp;Polina Pestova ,&nbsp;Liliya Papikyan ,&nbsp;Maria Karzova ,&nbsp;Natalia Danilova ,&nbsp;Pavel Malkov ,&nbsp;Andrey Chernyaev ,&nbsp;Sergey Buravkov ,&nbsp;Oleg Sapozhnikov ,&nbsp;Vera Khokhlova","doi":"10.1016/j.ultrasmedbio.2024.10.006","DOIUrl":"10.1016/j.ultrasmedbio.2024.10.006","url":null,"abstract":"<div><h3>Objective</h3><div>Non-invasive surgical approaches, including boiling histotripsy (BH), are currently being developed for the treatment of brain disorders aiming to avoid craniotomy and exposure of intervening tissues, and, thus, minimize associated complications. This work aimed to demonstrate the feasibility of BH for mechanical fractionation of human brain tissues <em>ex vivo</em> under B-mode guidance, with preliminary measurements of tissue stiffness <em>via</em> shear wave elastography.</div></div><div><h3>Methods</h3><div>Young's moduli of 25 human autopsy brain samples obtained from de-identified patients of 51–91 y old (median 77 y old) were measured <em>via</em> shear wave elastography prior to BH sonication. Seventeen volumetric BH lesions (1–4 layers of 5 × 5 points with a 1- mm step) were produced near brain surface (<em>n</em> = 10), in white matter (<em>n</em> = 3), in thalamus (<em>n</em> = 2), and globus pallidus (<em>n</em> = 2) using 12 element 1.5 MHz sector transducer under B-mode guidance with 10 ms or 2 ms pulses delivered 10 or 15 times per sonication point with 1% duty cycle. After treatment, the lesions were evaluated grossly through bisection, histologically with hematoxylin and eosin staining, and ultrastructurally <em>via</em> scanning and transmission electron microscopy.</div></div><div><h3>Results</h3><div>Young's moduli of autopsy brain samples were lower in older patients (from 32.9 ± 6.6 kPa in 51 y olds to 10 ± 2 kPa in 91 y olds) and at higher temperature (6%–50% lower at 37°С <em>vs</em> 23°С), and were within the range observed clinically. All tested BH treatments performed near the brain surface (i.e., mostly in gray matter) resulted in formation of well-demarcated rectangular lesions with homogenized content and sharp boundaries, with majority of residual fragments below 100 microns. The use of shorter pulses (2 ms <em>vs</em> 10 ms) accelerated the treatment at least threefold, and the highest liquefaction rate was 568 mm³/min. White matter was more resistant to BH <em>vs</em> gray matter: at least 15 pulses of 2 ms duration were required per each sonication point, and the liquefaction rate was three times lower. The ability of BH to produce lesions in thalamus and globus pallidus was also confirmed.</div></div><div><h3>Conclusion</h3><div>This work presents the first demonstration of BH proof-of-concept in human brain tissues <em>ex vivo</em> under B-mode guidance with clinically relevant treatment rates.</div></div>","PeriodicalId":49399,"journal":{"name":"Ultrasound in Medicine and Biology","volume":"51 2","pages":"Pages 312-320"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142559213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrasound Speckle Tracking Method Based on Gradient Optical Flow to Quantify Small Longitudinal Displacement, Shear and Longitudinal Strain in Peripheral Nerves","authors":"Žiga Snoj ,&nbsp;Gregor Omejec ,&nbsp;Jaka Javh ,&nbsp;Nejc Umek","doi":"10.1016/j.ultrasmedbio.2024.10.002","DOIUrl":"10.1016/j.ultrasmedbio.2024.10.002","url":null,"abstract":"<div><h3>Objective</h3><div>This study aimed to develop, validate and test the clinical feasibility of ultrasound (US) speckle tracking method based on gradient optical flow for quantifying small longitudinal displacements, shear and strain in peripheral nerves.</div></div><div><h3>Methods</h3><div>The speckle tracking method was validated using seven thawed, fresh-frozen isolated cadaveric forearms. Longitudinal motion of the median nerve was captured using a high-frequency 22 MHz linear probe. An air bubble marker was inserted as a reference point for manual measurement comparison. The precision and accuracy of the method were assessed by comparing manual and automatic measurements. Clinical feasibility was tested on eight healthy subjects, measuring the longitudinal displacement of the median nerve during elbow extension and shoulder anteflexion.</div></div><div><h3>Results</h3><div>The method demonstrated linearity, high precision and accuracy, particularly with a backtrace of five frames, reducing the displacement underestimation to 4%. In cadaveric models, the highest shear strain was observed at the nerve-tissue interfaces. In healthy subjects, the mean displacement of the median nerve was 3.3 ± 1.0 mm, with good inter-rater reliability (intraclass correlation coefficient = 0.87).</div></div><div><h3>Conclusion</h3><div>The US speckle tracking method based on gradient optical flow effectively quantifies small longitudinal displacements and shear strain in peripheral nerves, with high precision and accuracy. However, the method could not detect longitudinal strain in nerves within the range of tested displacements. Future studies should investigate its applicability to smaller and deeper nerves and its usefulness in different pathological conditions.</div></div>","PeriodicalId":49399,"journal":{"name":"Ultrasound in Medicine and Biology","volume":"51 2","pages":"Pages 280-287"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142548556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ischemia/Reperfusion Injury Enhances Accumulation of Perfluoropropane Droplets","authors":"Cheng Chen ,&nbsp;Shouqiang Li ,&nbsp;Terry O. Matsunaga ,&nbsp;John J. Pacella ,&nbsp;E. Carr Everbach ,&nbsp;Feng Xie ,&nbsp;Thomas R. Porter ,&nbsp;Flordeliza S. Villanueva ,&nbsp;Xucai Chen","doi":"10.1016/j.ultrasmedbio.2024.10.012","DOIUrl":"10.1016/j.ultrasmedbio.2024.10.012","url":null,"abstract":"<div><h3>Objective</h3><div>Perfluoropropane droplets (PD) are nanometer-sized particles that can be formulated from commercially available contrast agents. The preferential retention of PDs in diseased microvascular beds can be detected by ultrasound imaging techniques after acoustic activation and offers an opportunity for the detection of such processes as scar formation or inflammation. We hypothesized that in the presence of ischemia/reperfusion (I/R) injury, retention of intravenously injected PDs would be enhanced.</div></div><div><h3>Methods</h3><div>Using an established intravital microscopy model of rat cremaster microcirculation, we determined the retention and subsequent acoustic activation behavior of PDs in exteriorized rat cremaster tissue. DiI-labeled droplets (200 µL) were administered intravenously. Acoustic activation was achieved with a clinical ultrasound system at two ultrasound frequencies (1.5 and 7 MHz).</div></div><div><h3>Results</h3><div>Fluorescent microbubbles could be detected in the microvasculature after intravenous injection of PDs and subsequent acoustic activation. Increased retention of PDs was observed in the I/R group compared with control group with both ultrasound frequencies (<em>p</em> &lt; 0.05). Using higher-resolution microscopy, we found evidence that some droplets extravasate to the outside of the endothelial border or are potentially engulfed by leukocytes.</div></div><div><h3>Conclusion</h3><div>Our data indicate that targeted imaging of the developing scar zones might be possible with ultrasound activation of intravenously injected PDs, and a method of targeting therapies to these same regions could be developed.</div></div>","PeriodicalId":49399,"journal":{"name":"Ultrasound in Medicine and Biology","volume":"51 2","pages":"Pages 336-340"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11744877/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142631399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}