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PHYSICS (576 journals)

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Journal Cover Ultrasound in Medicine & Biology
  [SJR: 0.885]   [H-I: 106]   [8 followers]  Follow
    
   Full-text available via subscription Subscription journal
   ISSN (Print) 0301-5629
   Published by Elsevier Homepage  [3123 journals]
  • Automated Visualization and Quantification of Spiral Artery Blood Flow
           
    • Authors: Gordon N. Stevenson; J. Alison Noble; Alec W. Welsh; Lawrence Impey; Sally L. Collins
      Pages: 522 - 531
      Abstract: Publication date: Available online 2 January 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Gordon N. Stevenson, J. Alison Noble, Alec W. Welsh, Lawrence Impey, Sally L. Collins
      The goal of our research was to quantify the placental vascularity in 3-D at 11–13 + 6 wk of pregnancy at precise distances from the utero-placental interface (UPI) using 3-D power Doppler ultrasound. With this automated image analysis technique, differences in vascularity between normal and pathologic pregnancies may be observed. The algorithm was validated using a computer-generated image phantom and applied retrospectively in 143 patients. The following features from the PD data were recorded: The number of spiral artery jets into the inter-villous space, total geometric and PD area. These were automatically measured at discrete millimeter distances from the UPI. Differences in features were compared with pregnancy outcomes: Pre-eclamptic versus normal, all small-for-gestational age (SGA) to appropriate-for-gestational age (AGA) patients and AGA versus SGA in normotensives (Mann-Whitney). The Benjamini-Hochberg procedure was used (false discovery rate 10%) for multiple comparison testing. Features decreased with increasing distance from the UPI (Kruskal-Wallis test; p < 0.001). At 2– 3 mm from the UPI, all features were smaller in pre-eclamptic compared with normal patients and for some in SGA compared with AGA patients (p < 0.05). For AGA versus SGA in normotensive patients, no significant differences were found. Number of jets measured at 2–5 mm from the UPI did not vary because of the position of the placenta in the uterus (ANOVA; p > 0.05). This method provides a new in-vivo imaging tool for examining spiral artery development through pregnancy. Size and number of entrances of blood flow into the UPI could potentially be used to identify high-risk pregnancies and may provide a new imaging biomarker for placental insufficiency.

      PubDate: 2018-01-10T06:27:41Z
      DOI: 10.1016/j.ultrasmedbio.2017.11.018
      Issue No: Vol. 44, No. 3 (2018)
       
  • Motorizing and Optimizing Ultrasound Strain Elastography for Detection of
           Intrauterine Growth Restriction Pregnancies
    • Authors: Shier Nee Saw; Jess Yi Ru Low; Citra Nurfarah Zaini Mattar; Arijit Biswas; Lujie Chen; Choon Hwai Yap
      Pages: 532 - 543
      Abstract: Publication date: Available online 9 January 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Shier Nee Saw, Jess Yi Ru Low, Citra Nurfarah Zaini Mattar, Arijit Biswas, Lujie Chen, Choon Hwai Yap
      Intrauterine growth restriction is a prevalent disease in pregnancy in which placental insufficiency leads to 5 to 10 times higher mortality and lifelong morbidities. The current detection rate is poor, and recently, ultrasound strain elastography (USEL) was proposed as a new diagnostic technique. Currently, placental USEL uses maternal subcutaneous fat as the reference layer, but this is not ideal as fat tissue stiffness can vary widely between subjects. Current USEL also uses manual palpation, and under different compression depths and rates, viscoelastic tissues such as placenta can yield different stiffness results. In the study described here, we strove to improve placental USEL by (i) using an external polymeric pad of known stiffness as the reference layer and (ii) adopting motorized control of the transducer during USEL to standardize palpation motion. Results indicated that motorized USEL reduced measurement variability by 67% compared with freehand USEL. Satisfactory and statistically significant correlations between USEL measurements and mechanical testing validation results were obtained for our new USEL protocol. Placental tissues were found to be non-linear and viscoelastic in nature and, thus, differed in stiffness at different compression rates and depths. Our study also revealed that there was a specific compression depth and rate during USEL that provided better correlation to mechanical testing, and should be considered in clinical placental USEL.

      PubDate: 2018-01-10T06:27:41Z
      DOI: 10.1016/j.ultrasmedbio.2017.12.007
      Issue No: Vol. 44, No. 3 (2018)
       
  • New Definition Criteria of Myocardial Dysfunction in Patients with Liver
           Cirrhosis: A Speckle Tracking and Tissue Doppler Imaging Study
    • Authors: Roxana Cristina Rimbaş; Sorina Mihăilă Baldea; Ruxandra Drăgoi Galrinho Antunes Guerra; Simona Ionela Visoiu; Mihai Rimbaş; Corina Silvia Pop; Dragoş Vinereanu
      Pages: 562 - 574
      Abstract: Publication date: Available online 3 January 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Roxana Cristina Rimbaş, Sorina Mihăilă Baldea, Ruxandra Drăgoi Galrinho Antunes Guerra, Simona Ionela Visoiu, Mihai Rimbaş, Corina Silvia Pop, Dragoş Vinereanu
      There are no clear recommendations regarding cirrhotic cardiomyopathy (CC) evaluation in patients with pre-transplant liver cirrhosis. The roles of new methods, tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE) in the diagnosis and prognosis of cirrhotic cardiomyopathy remain controversial. We investigated the utility of TDI/STE parameters in cirrhotic cardiomyopathy diagnosis and also in predicting mortality in patients with liver cirrhosis. Left/right ventricular function was studied using conventional TDI (velocities) and STE (strain/strain rate). We assessed left ventricular diastolic dysfunction, graded into four new classes (I/Ia/II/III). Serum NTproBNP (N-terminal prohormone of brain natriuretic peptide), troponin I, β-crosslaps, QTc interval, arterial compliance and endothelial function were measured. Liver-specific scores (Child–Pugh, MELD, MELDNa) were computed. There was a 1-y follow-up visit to determine mortality. We observed resting biventricular diastolic myocardial dysfunction, not presently included in the definition of cirrhotic cardiomyopathy. We provided an improved characterization of cardiac dysfunction in patients with liver cirrhosis. This might change the current definition. However, the utility of STE/TDI parameters in predicting long-term mortality in patients with liver cirrhosis remains controversial.

      PubDate: 2018-01-10T06:27:41Z
      DOI: 10.1016/j.ultrasmedbio.2017.11.013
      Issue No: Vol. 44, No. 3 (2018)
       
  • Combination of Sonoelastography and TIRADS for the Diagnostic Assessment
           of Thyroid Nodules
    • Authors: Simone Schenke; Michael Zimny
      Pages: 575 - 583
      Abstract: Publication date: Available online 2 January 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Simone Schenke, Michael Zimny
      To evaluate the diagnostic performance of elastography alone and combined with Thyroid Imaging Reporting And Data System (TIRADS) for the assessment of non-autonomous thyroid nodules. We included 244 thyroid nodules and analyzed the visual elasticity scores, strain value (SV) and TIRADS classification. Histologic examination revealed 38 malignant (16%) and 206 benign nodules. The SV was lower in malignant nodules than in benign with an optimal cutoff ≤0.225. The visual elasticity scores showed a better diagnostic performance than the SV measurement. The risk for malignancy increased with higher TIRADS category. The sensitivity, specificity, positive predictive value and negative predictive value of TIRADS were superior to sonoelastography. The combination of TIRADS ≥4C and SV ≤0.225 showed the highest odds ratio to predict malignancy. Kwak-TIRADS classification is superior to elastography for the differentiation of benign and malignant thyroid nodules. Our data demonstrate that a high TIRADS class alone is predictive for thyroid carcinoma and the clinical relevance of sonoelastography is negligible.

      PubDate: 2018-01-10T06:27:41Z
      DOI: 10.1016/j.ultrasmedbio.2017.11.017
      Issue No: Vol. 44, No. 3 (2018)
       
  • Bubble-Induced Color Doppler Feedback Correlates with Histotripsy-Induced
           Destruction of Structural Components in Liver Tissue
    • Authors: Jonathan J. Macoskey; Xi Zhang; Timothy L. Hall; Jiaqi Shi; Shahaboddin Alahyari Beig; Eric Johnsen; Fred T. Lee; Charles A. Cain; Zhen Xu
      Pages: 602 - 612
      Abstract: Publication date: Available online 9 January 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Jonathan J. Macoskey, Xi Zhang, Timothy L. Hall, Jiaqi Shi, Shahaboddin Alahyari Beig, Eric Johnsen, Fred T. Lee, Charles A. Cain, Zhen Xu
      Bubble-induced color Doppler (BCD) is a histotripsy-therapy monitoring technique that uses Doppler ultrasound to track the motion of residual cavitation nuclei that persist after the collapse of the histotripsy bubble cloud. In this study, BCD is used to monitor tissue fractionation during histotripsy tissue therapy, and the BCD signal is correlated with the destruction of structural and non-structural components identified histologically to further understand how BCD monitors the extent of treatment. A 500-kHz, 112-element phased histotripsy array is used to generate approximately 6- × 6- × 7-mm lesions within ex vivo bovine liver tissue by scanning more than 219 locations with 30–1000 pulses per location. A 128-element L7-4 imaging probe is used to acquire BCD signals during all treatments. The BCD signal is then quantitatively analyzed using the time-to-peak rebound velocity (tprv) metric. Using the Pearson correlation coefficient, the tprv is compared with histologic analytics of lesions generated by various numbers of pulses using a significance level of 0.001. Histologic analytics in this study include viable cell count, reticulin-stained type III collagen area and trichrome-stained type I collagen area. It is found that the tprv metric has a statistically significant correlation with the change in reticulin-stained type III collagen area with a Pearson correlation coefficient of −0.94 (p < 0.001), indicating that changes in BCD are more likely because of destruction of the structural components of tissue.

      PubDate: 2018-01-10T06:27:41Z
      DOI: 10.1016/j.ultrasmedbio.2017.11.012
      Issue No: Vol. 44, No. 3 (2018)
       
  • Low-Intensity Ultrasound Reduces High Glucose-Induced Nitric Oxide
           Generation in Retinal Pigment Epithelial Cells
    • Authors: Mrigendra Bir Karmacharya; Binika Hada; So Ra Park; Byung Hyune Choi
      Pages: 647 - 656
      Abstract: Publication date: Available online 4 January 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Mrigendra Bir Karmacharya, Binika Hada, So Ra Park, Byung Hyune Choi
      Diabetic retinopathy (DR) is a severe micro-vascular complication of diabetes. High glucose (HG)-evoked nitric oxide (NO) production mediated by increased oxidative stress is a key factor in DR pathogenesis. In this study, we examined whether low-intensity ultrasound (LIUS) stimulation can reduce HG-induced NO generation. We determined that LIUS stimulation decreased the HG-induced NO generation possibly via inhibition of reactive oxygen species (ROS) and subsequently diminished the associated pro-inflammatory pathway involving the induced expression of inducible nitric oxide synthase, cyclooxygenase-2 and vascular endothelial growth factor. In addition, we determined that LIUS stimulation reduced the quantity of NO produced by N-acetylcysteine, which was not mediated by ROS. These results indicate that LIUS can inhibit both ROS-dependent and -independent NO generation processes in ARPE-19 cells. We envision LIUS as a potential therapeutic alternative to treat DR. Further studies are required to understand the underlying mechanism of the LIUS-induced reduction of NO generation for DR therapy.

      PubDate: 2018-01-10T06:27:41Z
      DOI: 10.1016/j.ultrasmedbio.2017.12.004
      Issue No: Vol. 44, No. 3 (2018)
       
  • Preliminary Clinical Experience with a Combined Automated Breast
           Ultrasound and Digital Breast Tomosynthesis System
    • Authors: Eric D. Larson; Won-Mean Lee; Marilyn A. Roubidoux; Mitchell M. Goodsitt; Chris Lashbrook; Cynthia E. Davis; Oliver D. Kripfgans; Paul L. Carson
      Pages: 734 - 742
      Abstract: Publication date: Available online 5 January 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Eric D. Larson, Won-Mean Lee, Marilyn A. Roubidoux, Mitchell M. Goodsitt, Chris Lashbrook, Cynthia E. Davis, Oliver D. Kripfgans, Paul L. Carson
      We analyzed the performance of a mammographically configured, automated breast ultrasound (McABUS) scanner combined with a digital breast tomosynthesis (DBT) system. The GE Invenia ultrasound system was modified for integration with GE DBT systems. Ultrasound and DBT imaging were performed in the same mammographic compression. Our small preliminary study included 13 cases, six of whom had contained invasive cancers. From analysis of these cases, current limitations and corresponding potential improvements of the system were determined. A registration analysis was performed to compare the ease of McABUS to DBT registration for this system with that of two systems designed previously. It was observed that in comparison to data from an earlier study, the McABUS-to-DBT registration alignment errors for both this system and a previously built combined system were smaller than those for a previously built standalone McABUS system.

      PubDate: 2018-01-10T06:27:41Z
      DOI: 10.1016/j.ultrasmedbio.2017.12.003
      Issue No: Vol. 44, No. 3 (2018)
       
  • Bowel Sonoelastography in Patients with Crohn's Disease: A Systematic
           Review
    • Authors: Lorenzo Carlo Pescatori; Giovanni Mauri; Edoardo Savarino; Luca Pastorelli; Maurizio Vecchi; Luca Maria Sconfienza
      Pages: 297 - 302
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Lorenzo Carlo Pescatori, Giovanni Mauri, Edoardo Savarino, Luca Pastorelli, Maurizio Vecchi, Luca Maria Sconfienza
      Sonoelastography is an ultrasound-based method for evaluating the biological properties of a target tissue. It is commonly used in the diagnosis of liver and thyroid disease, but recently its use for monitoring the characteristics of bowel wall in patients affected by Crohn's disease (CD) has been proposed. Our aim was a systematic review of the use of sonoelastography in patients with CD. An initial database search retrieved 32 possible articles. On initial screening, 7 articles, concerning a total of 129 patients and 154 lesions of the small and large bowel, were finally included in the review. The age range varied between 6 and 53 y, and disease duration ranged between 1 and 623 mo. We collected data on the examinations performed (type and time), bowel area considered and parameters evaluated. All authors found that elastography correlates well with the degree of fibrosis, as wall strain significantly decreases in segments affected by fibrotic stenosis. Even though the endpoints proposed in the various articles are relatively inhomogeneous and scarcely comparable, we found that sonoelastography is a promising tool in the evaluation of patients with CD as it can differentiate inflammatory and fibrotic strictures in small case series.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.10.004
       
  • Evaluating the Benefit of Elevated Acoustic Output in Harmonic Motion
           Estimation in Ultrasonic Shear Wave Elasticity Imaging
    • Authors: Yufeng Deng; Mark L. Palmeri; Ned C. Rouze; Clare M. Haystead; Kathryn R. Nightingale
      Pages: 303 - 310
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Yufeng Deng, Mark L. Palmeri, Ned C. Rouze, Clare M. Haystead, Kathryn R. Nightingale
      Harmonic imaging techniques have been applied in ultrasonic elasticity imaging to obtain higher-quality tissue motion tracking data. However, harmonic tracking can be signal-to-noise ratio and penetration depth limited during clinical imaging, resulting in decreased yield of successful shear wave speed measurements. A logical approach is to increase the source pressure, but the in situ pressures used in diagnostic ultrasound have been subject to a de facto upper limit based on the Food and Drug Administration guideline for the mechanical index (MI <1.9). A recent American Institute of Ultrasound in Medicine report concluded that an in situ MI up to 4.0 could be warranted without concern for increased risk of cavitation in non-fetal tissues without gas bodies if there were a concurrent clinical benefit. This work evaluates the impact of using an elevated MI in harmonic motion tracking for hepatic shear wave elasticity imaging. The studies indicate that high-MI harmonic tracking increased shear wave speed estimation yield by 27% at a focal depth of 5 cm, with larger yield increase in more difficult-to-image patients. High-MI tracking improved harmonic tracking data quality by increasing the signal-to-noise ratio and decreasing jitter in the tissue motion data. We conclude that there is clinical benefit to use of elevated acoustic output in shear wave tracking, particularly in difficult-to-image patients.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.10.003
       
  • Comprehensively Assessing the Acute Femoral Cartilage Response and
           Recovery after Walking and Drop-Landing: An Ultrasonographic Study
    • Authors: Matthew S. Harkey; J. Troy Blackburn; Anthony C. Hackney; Michael D. Lewek; Randy J. Schmitz; Daniel Nissman; Brian Pietrosimone
      Pages: 311 - 320
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Matthew S. Harkey, J. Troy Blackburn, Anthony C. Hackney, Michael D. Lewek, Randy J. Schmitz, Daniel Nissman, Brian Pietrosimone
      We compared the acute response and recovery of ultrasonography (US) cartilage outcomes (i.e., thickness, cross-sectional area, and echo intensity) between walking, drop-landing and control conditions in 43 young adults with no history of lower extremity injury. A femoral cartilage US assessment was performed before and after each condition to determine the acute cartilage response and recovery at 15, 30 and 45 min. Percentage change scores from pre- to all post-time points were used for analysis. Acute cartilage response and recovery were analyzed with a 3 × 4 (condition × time) repeated-measures analysis of variance. Greater deformation of the medial and lateral femoral cartilage was observed immediately after both the walking and drop-landing conditions compared with the control condition. Cartilage deformation after the drop-landing condition required longer time to recover compared with the walking condition. The femoral cartilage deformation was not accompanied by concurrent alterations in cartilage echo intensity.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.10.009
       
  • An Ultrasound Surface Wave Technique for Assessing Skin and Lung Diseases
    • Authors: Xiaoming Zhang; Boran Zhou; Sanjay Kalra; Brian Bartholmai; James Greenleaf; Thomas Osborn
      Pages: 321 - 331
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Xiaoming Zhang, Boran Zhou, Sanjay Kalra, Brian Bartholmai, James Greenleaf, Thomas Osborn
      Systemic sclerosis (SSc) is a multi-organ connective tissue disease characterized by immune dysregulation and organ fibrosis. Severe organ involvement, especially of the skin and lung, is the cause of morbidity and mortality in SSc. Interstitial lung disease (ILD) includes multiple lung disorders in which the lung tissue is fibrotic and stiffened. The purpose of this study was to translate ultrasound surface wave elastography (USWE) for assessing patients with SSc and/or ILD via measuring surface wave speeds of both skin and superficial lung tissue. Forty-one patients with both SSc and ILD and 30 healthy patients were enrolled in this study. An external harmonic vibration was used to generate the wave propagation on the skin or lung. Three excitation frequencies of 100, 150 and 200 Hz were used. An ultrasound probe was used to measure the wave propagation in the tissue non-invasively. Surface wave speeds were measured on the forearm and upper arm of both left and right arm, as well as the upper and lower lungs, through six intercostal spaces of patients and healthy patients. Viscoelasticity of the skin was calculated by the wave speed dispersion with frequency using the Voigt model. The magnitudes of surface wave speed and viscoelasticity of patients' skin were significantly higher than those of healthy patients (p < 0.0001) for each location and each frequency. The surface wave speeds of patients' lung were significantly higher than those of healthy patients (p < 0.0001) for each location and each frequency. USWE is a non-invasive and non-ionizing technique for measuring both skin and lung surface wave speed and may be useful for quantitative assessment of SSc and/or ILD.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.10.010
       
  • Assessing Liver Stiffness by 2-D Shear Wave Elastography in a Healthy
           Cohort
    • Authors: Felix Bende; Anesa Mulabecirovic; Ioan Sporea; Alina Popescu; Roxana Sirli; Odd Helge Gilja; Mette Vesterhus; Roald Flesland Havre
      Pages: 332 - 341
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Felix Bende, Anesa Mulabecirovic, Ioan Sporea, Alina Popescu, Roxana Sirli, Odd Helge Gilja, Mette Vesterhus, Roald Flesland Havre
      The aim of this study was to assess the normal ranges of liver stiffness measurements (LSMs) in participants with healthy livers, using General Electric 2-D shear wave elastography (2-D-SWE-GE) compared with transient elastography (TE). We included 80 participants with healthy livers and without known liver disease, in whom liver stiffness was evaluated in the same session using two elastographic methods, TE and 2-D-SWE-GE. Reliable LSMs were defined for TE as the median of 10 measurements with a success rate of ≥60% and an interquartile range (IQR) < 30%, and for 2-D-SWE-GE, as the median of 10 measurements acquired in a homogenous area and an IQR < 30%. Participants with LSMs > 6.5 kPa by TE were excluded. Reliable LSMs were obtained in 79 participants (98.7%) by means of 2-D-SWE-GE and in 80 participants (100%) by means of TE (p = 0.9). The mean LSM obtained by 2-D-SWE-GE in our cohort of participants with healthy livers was 5.1 ± 1.3 kPa, which was significantly higher than the LSM assessed by TE (4.3 ± 0.9 kPa, p < 0.0001). In 2-D SWE-GE, mean LSMs were significantly higher for men than for women, 5.9 ± 1.2 kPa versus 4.7 ± 1.2 kPa (p = 0.0005). In conclusion, 2-D-SWE-GE has very good feasibility (98.7%) in healthy persons. The mean LSM determined by 2-D-SWE-GE in healthy participants was 5.1 ± 1.3 kPa. LSMs obtained by means of 2-D-SWE-GE were higher than those obtained by TE in participants with healthy livers.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.10.013
       
  • Correlation between Ultrasound Appearance of Small Breast Cancer and
           Axillary Lymph Node Metastasis
    • Authors: Xiaoqin Yu; Xiaoyan Hao; Jing Wan; Yingying Wang; Lan Yu; Binyue Liu
      Pages: 342 - 349
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Xiaoqin Yu, Xiaoyan Hao, Jing Wan, Yingying Wang, Lan Yu, Binyue Liu
      To study the correlation of ultrasonographic signs of small breast cancer (maximum diameter ≤2.0 cm) with axillary lymph node metastasis, pre-operative ultrasonographic images of 153 small breast malignant neoplasms in 143 breast cancer patients were analyzed according to their pathologic features. Of the small breast tumors included, 47 showed axillary lymph node metastasis. Diagnosis of all patients was obtained with radical axillary surgery or a sentinel lymph node biopsy procedure. Ultrasonographic signs included irregular shape, microlobulated contour, spiculation, microcalcification, posterior echo attenuation, blood-flow grade, perforating vessels, changes in fascia or cooper's ligament and maximum cortical thickness of lymph nodes. The relationship between ultrasonographic features and axillary lymph node metastasis was analyzed using a chi-square test for univariate distributions and logistic regression for multivariate analysis. A logistic regression model was established by taking the pathologic diagnosis of lymph node metastasis as the dependent variable and the ultrasonographic signs of each small breast cancer as independent variables. In small breast cancer, characteristics such as perforating vessels and maximum cortical thickness of lymph nodes >3.0 mm correlated well with axillary lymph node metastasis as determined by univariate analysis (χ2 = 13.945, 51.276, respectively, p < 0.05) and multivariate analysis (OR = 48.783, 46.754, respectively, p < 0.05).

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.09.020
       
  • Optimal Ultrasound Criteria for Grading Stenosis of the Superficial
           Femoral Artery
    • Authors: Mingjie Gao; Yang Hua; Xinyu Zhao; Lingyun Jia; Jie Yang; Beibei Liu
      Pages: 350 - 358
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Mingjie Gao, Yang Hua, Xinyu Zhao, Lingyun Jia, Jie Yang, Beibei Liu
      This retrospective study determined the duplex ultrasound scanning criteria for detecting 50%–69% and 70%–99% stenosis of the superficial femoral artery (SFA). Examinations of 278 limbs in 185 patients with peripheral arterial disease were performed. Duplex ultrasound scanning was used to measure the diameter of the vascular lumen, the peak systolic velocity (PSV) at the stenotic segment of the SFA (PSVst), the segment proximal to the stenosis (PSVpro) and the popliteal artery (PSVpop, distal to the stenosis). The ratios PSVst/PSVpro and PSVst/PSVpop were calculated. Receiver operator characteristic curves were plotted, with digital subtraction angiography as the reference. PSVst and PSVst/PSVpop had the highest diagnostic value for stenosis. Cut-off thresholds were: for 50%–69% stenosis, PSVst ≥ 210 cm/s, PSVst/PSVpop ≥ 2.5, with PSVst the better parameter; for 70%–99% stenosis, PSVst ≥ 275 cm/s, PSVst/PSVpop ≥ 4.0, with PSVst/PSVpop superior. PSVst/PSVpop may be a better parameter than PSVst/PSVpro for diagnosing SFA stenosis.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.10.001
       
  • Effect of Pulsed Therapeutic Ultrasound and Diosmin on Skeletal Muscle
           Oxidative Parameters
    • Authors: Luis Fernando Sousa Filho; Paula P. Menezes; Dayanne Valéria Soares Santana; Bruno S. Lima; Shanmugan Saravanan; Grace Kelly M. Almeida; José Evaldo R. Menezes Filho; Marta M.B. Santos; Adriano Antunes S. Araújo; Evaleide Diniz de Oliveira
      Pages: 359 - 367
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Luis Fernando Sousa Filho, Paula P. Menezes, Dayanne Valéria Soares Santana, Bruno S. Lima, Shanmugan Saravanan, Grace Kelly M. Almeida, José Evaldo R. Menezes Filho, Marta M.B. Santos, Adriano Antunes S. Araújo, Evaleide Diniz de Oliveira
      Cyclodextrins (CDs) have been widely used as a promising alternative in the formation of inclusion complexes with poorly soluble molecules. From this perspective, the present study aimed to study the inclusion complexes of diosmin in β-cyclodextrin, chemically quantify the diosmin-in-gel preparation and analyze the stability of the gels. Furthermore, we evaluated the effect of therapeutic pulsed ultrasound (TPU) in association with the gel–diosmin complex on the parameters of muscle damage and oxidative stress in rats. Serum creatine kinase (CK) levels were used as an indicator of skeletal muscle injury. Lipid peroxidation (thiobarbituric acid-reactive substances [TBARS]) and superoxide dismutase and catalase activities were used as indicators of oxidative stress. The results obtained indicated that the inclusion complex obtained by co-evaporation had the highest complexation efficiency and stability; there was no change in the features of diosmin on incorporation into the Carbopol gel. Additionally, a significant (p < 0.05) decrease was observed in CK levels (TPU plus gel-diosmin: 178.4 ± 85.3 U/L) relative to the untreated group (527.8 ± 46.1 U/L). Levels of TBARS were lower in the TPU plus gel-diosmin group (0.008 ± 0.0004 nmol malondialdehyde/mg protein, p < 0.05) compared with the untreated group (0.081 ± 0.011 nmol malondialdehyde/mg protein, p < 0.05, n = 6). Catalase activity did not statistically significantly differ between the treatment groups, and superoxide dismutase activity was lower in the diosmin-treated group (0.320 ± 0.11 U/mg protein) compared with the untreated group (0.983 ± 0.40 U/mg protein). These results suggest that TPU in association with the diosmin–gel complex is effective in reducing muscle damage and oxidative stress after mechanical trauma.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.09.009
       
  • Determination of Acoustic Cavitation Probabilities and Thresholds Using a
           Single Focusing Transducer to Induce and Detect Acoustic Cavitation
           Events: I. Method and Terminology
    • Authors: Julian Haller; Volker Wilkens; Adam Shaw
      Pages: 377 - 396
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Julian Haller, Volker Wilkens, Adam Shaw
      A method to determine acoustic cavitation probabilities in tissue-mimicking materials (TMMs) is described that uses a high-intensity focused ultrasound (HIFU) transducer for both inducing and detecting the acoustic cavitation events. The method was evaluated by studying acoustic cavitation probabilities in agar-based TMMs with and without scatterers and for different sonication modes like continuous wave, single pulses (microseconds to milliseconds) and repeated burst signals. Acoustic cavitation thresholds (defined here as the peak rarefactional in situ pressure at which the acoustic cavitation probability reaches 50%) at a frequency of 1.06 MHz were observed between 1.1 MPa (for 1 s of continuous wave sonication) and 4.6 MPa (for 1 s of a repeated burst signal with 25-cycle burst length and 10-ms burst period) in a 3% (by weight) agar phantom without scatterers. The method and its evaluation are described, and general terminology useful for standardizing the description of insonation conditions and comparing results is provided. In the accompanying second part, the presented method is used to systematically study the acoustic cavitation thresholds in the same material for a range of sonication modes.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.08.1946
       
  • Determination of Acoustic Cavitation Probabilities and Thresholds Using a
           Single Focusing Transducer to Induce and Detect Acoustic Cavitation
           Events: II. Systematic Investigation in an Agar Material
    • Authors: Julian Haller; Volker Wilkens; Adam Shaw
      Pages: 377 - 396
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Julian Haller, Volker Wilkens
      In the accompanying article (Part I), a method is described to determine acoustic cavitation probabilities in tissue-mimicking materials (TMMs) using a high-intensity focused ultrasound (HIFU) transducer for both inducing and detecting the acoustic cavitation events, and its suitability for different sonication modes like continuous wave, single pulses (with pulse lengths from microseconds to milliseconds) and repeated burst signals is discussed. In Part II, the use of the method for a systematic study of the dependence of the acoustic cavitation thresholds in 3% (by weight) agar phantoms on the temporal sonication parameters is discussed. The values obtained at a frequency of 1.06 MHz, ranging from (0.58 ± 0.12) MPa for a 3-s continuous wave mode sonication to (5.2 ± 1.0) MPa for single shots with a length of 10 wave cycles, are discussed and interpreted on the basis of literature values and their self-consistency.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.08.1946
       
  • Lipid Microbubbles as Ultrasound-Stimulated Oxygen Carriers for
           Controllable Oxygen Release for Tumor Reoxygenation
    • Authors: Chunjiang Yang; Huan Xiao; Yang Sun; Lirong Zhu; Yang Gao; Sunny Kwok; Zhigang Wang; Yi Tang
      Pages: 416 - 425
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Chunjiang Yang, Huan Xiao, Yang Sun, Lirong Zhu, Yang Gao, Sunny Kwok, Zhigang Wang, Yi Tang
      Microbubbles are proposed as a potentially novel method for oxygen delivery in vivo in initial studies. The lack of commercial microbubbles for oxygen delivery in preclinical research prompted us to fabricate an oxygen-loaded lipid microbubble. We aimed to extend the innovative strategy to modulate the tumor hypoxic microenvironment, using microbubbles intravenously as an oxygen carrier for the controllable tumor-specific delivery of oxygen by ultrasound (US). In our experiment, an oxygen-loaded lipid-coated microbubble (OLM) with mixed gas (O2/C3 F8, 5:1 v/v) was fabricated and exhibited a higher rate of oxygen release to a desaturated solution through burst by US than that in the absence of US. Although in in vivo studies, OLMs could be imaged and triggered by US to elevate the pO2 level in the breast VX2 tumor dramatically within a matter of minutes. The added presence of US-activated OLMs elicited a nearly six-fold increase in pO2 levels within 1 min compared with that of the pre-injection. Owing to the high oxygen payload, great acoustic stability and acoustic properties, OLMs may be proposed as an ideal radio-sensitizer. We conclude that oxygen release mediated by ultrasound-targeted microbubble destruction is feasible and shows potential in image-guided, site-specific cancer radiotherapy.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.08.1883
       
  • Repeatability of Contrast-Enhanced Ultrasonography of the Kidneys in
           Healthy Cats
    • Authors: Emmelie Stock; Luc Duchateau; Jimmy H. Saunders; Veerle Volckaert; Ingeborgh Polis; Katrien Vanderperren
      Pages: 426 - 433
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Emmelie Stock, Luc Duchateau, Jimmy H. Saunders, Veerle Volckaert, Ingeborgh Polis, Katrien Vanderperren
      Contrast-enhanced ultrasound can be used to image and quantify tissue perfusion. It holds great potential for the use in the diagnosis of various diffuse renal diseases in both human and veterinary medicine. Nevertheless, the technique is known to have an inherent relatively high variability, related to various factors associated with the patient, the contrast agent and machine settings. Therefore, the aim of this study was to assess week-to-week intra- and inter-cat variation of several perfusion parameters obtained with CEUS of both kidneys of 12 healthy cats. Repeatability was determined by calculating the coefficient of variation (CV). The contrast-enhanced ultrasound parameters with the lowest variation for the renal cortex were time-to-peak (CV 6.0%), rise time (CV 13%), fall time (CV 19%) and mean transit time (24%). Intensity-related parameters and parameters related to the slope of the time-intensity curve had a CV of >35%. Lower repeatability was present for perfusion parameters derived from the renal medulla compared with the renal cortex. Normalization to the inter-lobar artery does not cause a reduction in variation. In conclusion, time-related parameters for the cortex show a reasonable repeatability; whereas poor repeatability is present for intensity-related parameters and parameters related to in- and outflow of contrast agent. Poor repeatability is also present for all perfusion parameters for the renal medulla, except for time to peak, which has a good repeatability.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.09.019
       
  • Effect of Temperature on the Size Distribution, Shell Properties, and
           Stability of Definity®
    • Authors: Himanshu Shekhar; Nathaniel J. Smith; Jason L. Raymond; Christy K. Holland
      Pages: 434 - 446
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Himanshu Shekhar, Nathaniel J. Smith, Jason L. Raymond, Christy K. Holland
      Physical characterization of an ultrasound contrast agent (UCA) aids in its safe and effective use in diagnostic and therapeutic applications. The goal of this study was to investigate the impact of temperature on the size distribution, shell properties, and stability of Definity®, a U.S. Food and Drug Administration-approved UCA used for left ventricular opacification. A Coulter counter was modified to enable particle size measurements at physiologic temperatures. The broadband acoustic attenuation spectrum and size distribution of Definity® were measured at room temperature (25 °C) and physiologic temperature (37 °C) and were used to estimate the viscoelastic shell properties of the agent at both temperatures. Attenuation and size distribution was measured over time to assess the effect of temperature on the temporal stability of Definity®. The attenuation coefficient of Definity® at 37 °C was as much as 5 dB higher than the attenuation coefficient measured at 25 °C. However, the size distributions of Definity® at 25 °C and 37 °C were similar. The estimated shell stiffness and viscosity decreased from 1.76 ± 0.18 N/m and 0.21 × 10–6 ± 0.07 × 10–6 kg/s at 25 °C to 1.01 ± 0.07 N/m and 0.04 × 10–6 ± 0.04 × 10–6 kg/s at 37 °C, respectively. Size-dependent differences in dissolution rates were observed within the UCA population at both 25 °C and 37 °C. Additionally, cooling the diluted UCA suspension from 37 °C to 25 °C accelerated the dissolution rate. These results indicate that although temperature affects the shell properties of Definity® and can influence the stability of Definity®, the size distribution of this agent is not affected by a temperature increase from 25 °C to 37 °C.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.09.021
       
  • Quantitative Evaluation of Denervated Muscle Atrophy with Shear Wave
           Ultrasound Elastography and a Comparison with the Histopathologic
           Parameters in an Animal Model
    • Authors: Jing Wen; Yuexiang Wang; Wenli Jiang; Yukun Luo; Jiang Peng; Mingxue Chen; Xiaoguang Jing
      Pages: 458 - 466
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Jing Wen, Yuexiang Wang, Wenli Jiang, Yukun Luo, Jiang Peng, Mingxue Chen, Xiaoguang Jing
      This study explored the efficacy of shear wave ultrasound elastography (SWUE) for quantitative evaluation of denervated muscle atrophy in a rabbit model. The elastic modulus of the triceps surae muscle was measured with SWUE and compared with histopathologic parameters at baseline and at various post-denervation times (2, 4 and 8 wk) with 10 animals in each group. Our results revealed that the elastic modulus of denervated muscle was significantly lower at 2 wk but higher at 8 wk compared with that at the baseline (p < 0.05), and no significant difference was found between the elastic modulus at 4 wk and that at the baseline (p > 0.05). The wet-weight ratio and the muscle fiber cross-sectional area of the denervated muscle decreased gradually during the 8 wk post-denervation together with a gradual increase of the collagen fiber area (p < 0.05). In conclusion, SWUE was useful for quantitative evaluation of muscle denervation. The decreased elastic modulus might be an early sign of denervated muscle atrophy.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.08.1887
       
  • Histologic and Hemodynamic Correlates of Right Ventricular Function in a
           Pressure Overload Model: a Study Using Three-Dimensional Speckle Tracking
           Echocardiography
    • Authors: Yuman Li; Lei Li; Junwei Liu; Mengmei Li; Qing Lv; Jing Wang; Lin He; Mingxing Xie
      Pages: 467 - 476
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Yuman Li, Lei Li, Junwei Liu, Mengmei Li, Qing Lv, Jing Wang, Lin He, Mingxing Xie
      The aim of our study was to assess the characterization of right ventricular (RV) deformation using three-dimensional (3D) speckle tracking echocardiography (STE) and association of 3D-STE indices with histologic and hemodynamic parameters in a chronic RV pressure overload animal model. Pulmonary artery banding (PAB) was used to induce RV pressure overload in seven beagles. 3D-STE, histologic and hemodynamic measurements were performed in PAB and sham-operated beagles 3 mo after PAB. RV longitudinal, radial and circumferential strain was measured from 3D-STE. Three mo after PAB, RV longitudinal strain was decreased; whereas radial and circumferential strain remained unchanged in PAB group. RV longitudinal strain was associated with interstitial fibrosis (r = −0.733) in the endocardial layer of the RV free wall. RV circumferential strain was related to dp/dtmax (r = 0.718). The significant correlations of RV 3D-STE indices with histologic and hemodynamic parameters indicate that 3D-STE may be a valuable tool for assessment of ventricular function in RV pressure overload.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.09.022
       
  • Development and Validation of a Phase-Filtered Moving Ensemble Correlation
           for Echocardiographic Particle Image Velocimetry
    • Authors: Brett A. Meyers; Craig J. Goergen; Pavlos P. Vlachos
      Pages: 477 - 488
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Brett A. Meyers, Craig J. Goergen, Pavlos P. Vlachos
      A new processing method for echocardiographic particle image velocimetry (EchoPIV) using moving ensemble (ME) correlation with dynamic phase correlation filtering was developed to improve velocity measurement accuracy for routine clinical evaluation of cardiac function. The proposed method was tested using computationally generated echocardiogram images. Error analysis indicated that ME EchoPIV yields a twofold improvement in bias and random error over the current standard correlation method (βPairwise = −0.15 vs. βME = −0.06; σPairwise = 1.00 vs. σME = 0.49). Subsequently a cohort of eight patients with impaired diastolic filling underwent similar evaluation. Comparison of patient EchoPIV velocity time series with corresponding color M-mode velocity time series revealed better agreement for ME EchoPIV compared with standard PIV processing (R ME = 0.90 vs. R Pairwise = 0.70). Further time series analysis was performed to measure filling propagation velocity and 1-D intraventricular pressure gradients. Comparison against CMM values indicated that both measurements are completely decorrelated for pairwise processing (R 2 Vp = 0.15, R 2 IVPD = 0.07), whereas ME processing correlates decently (R 2 Vp = 0.69, R 2 IVPD = 0.69). This new approach enables more robust processing of routine clinical scans and can increase the utility of EchoPIV for the assessment of left ventricular function.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.10.008
       
  • A Novel Method of Synovitis Stratification in Ultrasound Using Machine
           Learning Algorithms: Results From Clinical Validation of the MEDUSA
           Project
    • Authors: Pawel Mielnik; Marcin Fojcik; Jakub Segen; Marek Kulbacki
      Pages: 489 - 494
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Pawel Mielnik, Marcin Fojcik, Jakub Segen, Marek Kulbacki
      Ultrasound is widely used in the diagnosis and follow-up of chronic arthritis. We present an evaluation of a novel automatic ultrasound diagnostic tool based on image recognition technology. Methods used in developing the algorithm are described elsewhere. For the purpose of evaluation, we collected 140 ultrasound images of metacarpophalangeal and proximal interphalangeal joints from patients with chronic arthritis. They were classified, according to hypertrophy size, into four stages (0–3) by three independent human observers and the algorithm. An agreement ratio was calculated between all observers and the standard derived from results of human staging using κ statistics. Results was significant in all pairs, with the highest p value of 3.9 × 10–6. κ coefficients were lower in algorithm/human pairs than between human assessors. The algorithm is effective in staging synovitis hypertrophy. It is, however, not mature enough to use in a daily practice because of limited accuracy and lack of color Doppler recognition. These limitations will be addressed in the future.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.10.005
       
  • Ultrasound Determination of the Femoral Head-Neck Alpha Angle
    • Authors: D.J. Robinson; S. Lee; P. Marks; M.E. Schneider
      Pages: 495 - 501
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): D.J. Robinson, S. Lee, P. Marks, M.E. Schneider
      The femoral head-neck alpha angle is used to quantify the degree of femoral head asphericity in patients suspected of cam-type femoroacetabular impingement. The measurement was first performed using magnetic resonance imaging and, more recently, three-dimensional computed tomography (CT). We set out to determine whether the alpha angle could be reliably measured using ultrasound. Patients were recruited from a cohort presenting for CT of the hip. Alpha angles were calculated following the departmental protocol by institutionally accredited radiographers. After the CT, patients were imaged with ultrasound and the alpha angle calculated from the ultrasound image by a sonographer blinded to the CT result. Statistical comparison of the two methods was performed with the Bland-Altman test using SPSS (version 21.0, Chicago, USA), and a p < 0.05 afforded significance. Twenty-eight patients were recruited. Eleven patients were bilateral examinations, providing 39 hips for analysis. There were 15 females and 13 males, with 21 right and 18 left hips examined. Average patient age (±standard deviation) was 40 y (±13.9 y). Mean (±standard deviation) measurements for CT and ultrasound were 62.5° (±14.2°) and 64.5° (±12.6°), respectively. The mean absolute difference between the two methods was 10.5° (95% confidence interval 6.9°–14.0°). Sensitivity of each individual ultrasound measurement was 91.3%. The specificity of ultrasound was 43.75%. The positive predictive value was 0.7, and the negative predictive value was 0.78. Overall accuracy of the ultrasound-derived alpha angle was calculated at 0.718. Ultrasound demonstrates good sensitivity and good negative predictive value in calculation of the femoral head-neck alpha angle compared with CT; however, specificity is low. Ultrasound measurement of the alpha angle can provide objective evidence of cam-type femoroacetabular impingement in symptomatic patients and can direct patients to more established imaging techniques where appropriate.

      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.10.006
       
  • Transbulbar B-Mode Sonography in Multiple Sclerosis: Clinical and
           Biological Relevance
    • Authors: Maddalena De Bernardo; Nicola Rosa
      First page: 508
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Maddalena De Bernardo, Nicola Rosa


      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.10.002
       
  • Response to the Letter to the Editor-in-Chief on Manuscript Entitled:
           Transbulbar B-Mode Sonography in Multiple Sclerosis: Clinical and
           Biological Relevance
    • Authors: Roberto De Masi; Stefania Orlando
      Pages: 508 - 509
      Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2
      Author(s): Roberto De Masi, Stefania Orlando


      PubDate: 2017-12-27T04:27:39Z
      DOI: 10.1016/j.ultrasmedbio.2017.09.023
       
  • Transtemporal Investigation of Brain Parenchyma Elasticity Using 2-D Shear
           Wave Elastography: Definition of Age-Matched Normal Values
    • Authors: Michael Ertl; Nele Raasch; Gertrud Hammel; Katharina Harter; Christopher Lang
      Pages: 78 - 84
      Abstract: Publication date: January 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 1
      Author(s): Michael Ertl, Nele Raasch, Gertrud Hammel, Katharina Harter, Christopher Lang
      The goal of our research was to assess the possibility of reliable investigation of brain tissue stiffness using ultrasonographic brain parenchyma elastography with an intact temporal bone. We enrolled 108 patients after exclusion of intracranial pathology or healthy volunteers. All patients were subdivided by age into groups: 20–40, 40–60 and >60 y. For statistical analysis, the χ2 test and t-test were used. The mean values, regardless of age and other parameters, were 3.34 kPa (SD = 0.59) on the left side and 3.33 kPa (SD = 0.58) on the right side. We found no correlation between the values, body mass index (r = 0.07, p = 0.48) and sex (t = −0.11, p = 0.91), but we observed a highly significant correlation between the values and age (r = 0.43, p < 0.0001). We found ultrasonographic brain parenchyma elastography to be a valid, reproducible and investigator-independent method that reliably determines brain parenchyma stiffness. Normal values should serve as a reference for studies on various intracranial lesions.

      PubDate: 2017-12-12T03:42:33Z
      DOI: 10.1016/j.ultrasmedbio.2017.08.1885
       
  • High-Frequency Ultrasound Imaging of Tidemark In Vitro in Advanced Knee
           Osteoarthritis
    • Authors: Yan-Ping Huang; Jin Zhong; Jie Chen; Chun-Hoi Yan; Yong-Ping Zheng; Chun-Yi Wen
      Pages: 94 - 101
      Abstract: Publication date: January 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 1
      Author(s): Yan-Ping Huang, Jin Zhong, Jie Chen, Chun-Hoi Yan, Yong-Ping Zheng, Chun-Yi Wen
      High-frequency ultrasound imaging has been widely adopted for assessment of the degenerative changes of articular cartilage in osteoarthritis (OA). Yet, there are few reports on investigating its capability to evaluate subchondral bone. Here, we employed high-frequency ultrasound imaging (25 MHz) to examine in vitro the tidemark in cylindrical osteochondral disks (n = 33) harvested from advanced OA knees of humans. We found good correspondence in morphology observed by ultrasound imaging and micro-computed tomography. Ultrasound roughness index (URI) of tidemark was derived from the raw radiofrequency signals to compare with bone quality factors, including bone volume fraction (BV/TV) and bone mineral density (BMD) measured by micro-computed tomography, using the Spearman correlation (ρ). URI of the tidemark was negatively associated with the subchondral plate BV/TV (ρ = −0.73, p < 0.001), BMD (ρ = −0.40, p = 0.020), as well as the underneath trabecular bone BV/TV (ρ = −0.39, p = 0.025) and BMD (ρ = −0.43, p = 0.012). In conclusion, this preliminary study demonstrated that morphology measured by high-frequency ultrasound imaging could reflect the quality of the subchondral bone. High-frequency ultrasound is a promising imaging tool to evaluate the changes of the subchondral bone in addition to those of the overlying cartilage in OA.

      PubDate: 2017-12-12T03:42:33Z
      DOI: 10.1016/j.ultrasmedbio.2017.08.1884
       
  • Spatio-Temporal Flow and Wall Shear Stress Mapping Based on Incoherent
           Ensemble-Correlation of Ultrafast Contrast Enhanced Ultrasound Images
    • Authors: Chee Hau Leow; Meng-Xing Tang
      Pages: 134 - 152
      Abstract: Publication date: January 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 1
      Author(s): Chee Hau Leow, Meng-Xing Tang
      In this study, a technique for high-frame-rate ultrasound imaging velocimetry (UIV) is extended first to provide more robust quantitative flow velocity mapping using ensemble correlation of images without coherent compounding, and second to generate spatio-temporal wall shear stress (WSS) distribution. A simulation model, which couples the ultrasound simulator with analytical flow solution, was implemented to evaluate its accuracy. It is shown that the proposed approach can reduce errors in velocity estimation by up to 10-fold in comparison with the coherent correlation approach. Mean errors (ME) of 3.2% and 8.6% were estimated under a steady flow condition, while 3.0% and 10.6% were found under a pulsatile condition for the velocity and wall shear rate (WSR) measurement, respectively. Appropriate filter parameters were selected to constrain the velocity profiles before WSR estimations and the effects of incorrect wall tracking were quantified under a controlled environment. Although accurate wall tracking is found to be critical in WSR measurement (as a 200 µm deviation from the wall may yield up to a 60% error), this can be mitigated by HFR imaging (of up to 10 kHz) with contrast agents, which allow for improved differentiation of the wall-fluid boundaries. In vitro investigations on two carotid bifurcation phantoms, normal and diseased, were conducted, and their relative differences in terms of the flow patterns and WSR distribution were demonstrated. It is shown that high-frame-rate UIV technique can be a non-invasive tool to measure quantitatively the spatio-temporal velocity and WSS distribution.

      PubDate: 2017-12-12T03:42:33Z
      DOI: 10.1016/j.ultrasmedbio.2017.08.930
       
  • Analysis of Carotid Artery Transverse Sections in Long Ultrasound Video
           Sequences
    • Authors: Kamil Říha; Martin Zukal; Franz Hlawatsch
      Pages: 153 - 167
      Abstract: Publication date: January 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 1
      Author(s): Kamil Říha, Martin Zukal, Franz Hlawatsch
      Examination of the common carotid artery (CCA) based on an ultrasound video sequence is an effective method for detecting cardiovascular diseases. Here, we propose a video processing method for the automated geometric analysis of CCA transverse sections. By explicitly compensating the parasitic phenomena of global movement and feature drift, our method enables a reliable and accurate estimation of the movement of the arterial wall based on ultrasound sequences of arbitrary length and in situations where state-of-the-art methods fail or are very inaccurate. The method uses a modified Viola–Jones detector and the Hough transform to localize the artery in the image. Then it identifies dominant scatterers, also known as interest points (IPs), whose positions are tracked by means of the pyramidal Lucas–Kanade method. Robustness to global movement and feature drift is achieved by a detection of global movement and subsequent IP re-initialization, as well as an adaptive removal and addition of IPs. The performance of the proposed method is evaluated using simulated and real ultrasound video sequences. Using the Harris detector for IP detection, we obtained an overall root-mean-square error, averaged over all the simulated sequences, of 2.16 ± 1.18 px. The computational complexity of our method is compatible with real-time operation; the runtime is about 30–70 ms/frame for sequences with a spatial resolution of up to 490 × 490 px. We expect that in future clinical practice, our method will be instrumental for non-invasive early-stage diagnosis of atherosclerosis and other cardiovascular diseases.

      PubDate: 2017-12-12T03:42:33Z
      DOI: 10.1016/j.ultrasmedbio.2017.08.933
       
  • Editorial Advisory Board
    • Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2


      PubDate: 2017-12-27T04:27:39Z
       
  • Calendar
    • Abstract: Publication date: February 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 2


      PubDate: 2017-12-27T04:27:39Z
       
  • In Vivo Assessment of the Potential for Renal Bio-Effects from the
           Vaporization of Perfluorocarbon Phase-Change Contrast Agents
    • Authors: A. Gloria Nyankima; Juan D. Rojas; Rachel Cianciolo; Kennita A. Johnson; Paul A. Dayton
      Abstract: Publication date: Available online 15 December 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): A. Gloria Nyankima, Juan D. Rojas, Rachel Cianciolo, Kennita A. Johnson, Paul A. Dayton
      Low-boiling-point perfluorocarbon phase-change contrast agents (PCCAs) provide an alternative to microbubble contrast agents. Although parameter ranges related to in vivo bio-effects of microbubbles are fairly well characterized, few studies have been done to evaluate the potential of bio-effects related to PCCAs. To bridge this gap, we present an assessment of biological effects (e.g., hemorrhage) related to acoustically excited PCCAs in the rodent kidney. The presence or absence of bio-effects was observed after sonication with various perfluorocarbon core PCCAs (decafluorobutane, octafluoropropane or a 1:1 mixture) and as a function of activation pulse mechanical index (MI; minimum activation threshold, which was a moderate MI of 0.81–1.35 vs. a clinical maximum of 1.9). Bio-effects on renal tissue were assessed through hematology and histology including measurement of blood creatinine levels and the quantity of red blood cell (RBC) casts present in hematoxylin and eosin-stained kidney tissue sections after sonication. Short-term (24 h) and long-term (2 and 4 wk) analyses were performed after treatment. Results indicated that bio-effects from PCCA vaporization were not observed at lower mechanical indices. At higher mechanical indices, bio-effects were observed at 24 h, although these were not observable 2 wk after treatment.

      PubDate: 2017-12-17T18:42:18Z
      DOI: 10.1016/j.ultrasmedbio.2017.10.016
       
  • Editorial Advisory Board
    • Abstract: Publication date: January 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 1


      PubDate: 2017-12-12T03:42:33Z
       
  • Acoustic Characterization of Echogenic Polymersomes Prepared From
           Amphiphilic Block Copolymers
    • Authors: Lang Xia; Fataneh Karandish; Krishna Nandan Kumar; James Froberg; Prajakta Kulkarni; Kara N. Gange; Yongki Choi; Sanku Mallik; Kausik Sarkar
      Abstract: Publication date: Available online 8 December 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Lang Xia, Fataneh Karandish, Krishna Nandan Kumar, James Froberg, Prajakta Kulkarni, Kara N. Gange, Yongki Choi, Sanku Mallik, Kausik Sarkar
      Polymersomes are a class of artificial vesicles prepared from amphiphilic polymers. Like lipid vesicles (liposomes), they too can encapsulate hydrophilic and hydrophobic drug molecules in the aqueous core and the hydrophobic bilayer respectively, but are more stable than liposomes. Although echogenic liposomes have been widely investigated for simultaneous ultrasound imaging and controlled drug delivery, the potential of the polymersomes remains unexplored. We prepared two different echogenic polymersomes from the amphiphilic copolymers polyethylene glycol–poly-DL-lactic acid (PEG-PLA) and polyethylene glycol–poly-L-lactic acid (PEG-PLLA), incorporating multiple freeze-dry cycles in the synthesis protocol to ensure their echogenicity. We investigated acoustic behavior with potential applications in biomedical imaging. We characterized the polymeric vesicles acoustically with three different excitation frequencies of 2.25, 5 and 10 MHz at 500 kPa. The polymersomes exhibited strong echogenicity at all three excitation frequencies (about 50- and 25-dB enhancements in fundamental and subharmonic, respectively, at 5-MHz excitation from 20 µg/mL polymers in solution). Unlike echogenic liposomes, they emitted strong subharmonic responses. The scattering results indicated their potential as contrast agents, which was also confirmed by clinical ultrasound imaging.

      PubDate: 2017-12-12T03:42:33Z
      DOI: 10.1016/j.ultrasmedbio.2017.10.011
       
  • Statement and Recommendations on Interventional Ultrasound as a Thyroid
           Diagnostic and Treatment Procedure
    • Authors: Christoph F. Dietrich; Thomas Müller; Jörg Bojunga; Yi Dong; Giovanni Mauri; Maija Radzina; Manjiri Dighe; Xin-Wu Cui; Frank Grünwald; Andreas Schuler; Andre Ignee; Huedayi Korkusuz
      Abstract: Publication date: Available online 7 November 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Christoph F. Dietrich, Thomas Müller, Jörg Bojunga, Yi Dong, Giovanni Mauri, Maija Radzina, Manjiri Dighe, Xin-Wu Cui, Frank Grünwald, Andreas Schuler, Andre Ignee, Huedayi Korkusuz
      The recently published guidelines of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) on interventional ultrasound (INVUS)-guided procedures summarize the intended interdisciplinary and multiprofessional approach. Herewith, we report on recommendations for interventional procedures for diagnosis and treatment of the thyroid gland.

      PubDate: 2017-11-11T18:39:01Z
      DOI: 10.1016/j.ultrasmedbio.2017.08.1889
       
  • Usefulness of Contrast-Enhanced Ultrasound in Differentiating Inflammatory
           Bowel Disease From Colon Cancer
    • Authors: Fan Zhang; Li-ying Miao; Hui-yu Ge; Shi Tan; Zhi-Qiang Li; Bo Zhao
      Abstract: Publication date: Available online 7 November 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Fan Zhang, Li-ying Miao, Hui-yu Ge, Shi Tan, Zhi-Qiang Li, Bo Zhao
      To evaluate the diagnostic performance of contrast-enhanced ultrasound (CEUS) in differential diagnosis of inflammatory bowel disease (IBD) and colon cancer, we enrolled 51 patients with thickened bowel walls (13 with IBD and 38 with colon cancer). Ultrasound and CEUS were performed and both qualitative and quantitative features were analyzed. The intestinal wall stratification was preserved in 63.6% of the IBD group but in only 2.6% of the colon cancer group (p < 0.01). On CEUS, disordered enhancement and heterogeneous enhancement were shown in only 9.1% and 0%, respectively, of the IBD group while in 94.7% and 78.9%, respectively, of the colon cancer group (p < 0.01). For quantitative analysis, compared to IBD, colon cancer showed later enhancement and slower wash-out with less speed to reach peak intensity (p < 0.05). In conclusion, CEUS may prove useful for the differential diagnosis of IBD and colon cancer, but more studies are required.

      PubDate: 2017-11-11T18:39:01Z
      DOI: 10.1016/j.ultrasmedbio.2017.09.016
       
  • Diagnostic Accuracy of 2-D Shear Wave Elastography for the Non-Invasive
           Staging of Liver Fibrosis in Patients with Elevated Alanine
           Aminotransferase Levels
    • Authors: Jie Zeng; Zeping Huang; Jieyang Jin; Jian Zheng; Tao Wu; Rongqin Zheng
      Abstract: Publication date: Available online 6 November 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Jie Zeng, Zeping Huang, Jieyang Jin, Jian Zheng, Tao Wu, Rongqin Zheng
      This study assessed the diagnostic accuracy of 2-D shear wave elastography (2-D-SWE) for the non-invasive staging of liver fibrosis and compared the findings with those for biochemical markers (the aspartate aminotransferase-to-platelet index and fibrosis-4 index) of liver fibrosis in patients with elevated alanine aminotransferase (ALT) levels (>5 × the upper limit of normal). Patients with chronic liver diseases and elevated ALT levels who underwent liver biopsy were consecutively included. Receiver operating characteristic (ROC) curves were constructed to assess overall accuracy and to identify optimal cutoff values. After exclusions, data from 105 patients were analyzed. The areas under the ROC curves (AUROCs) for significant fibrosis, severe fibrosis and cirrhosis were 0.83, 0.86 and 0.91, respectively. The optimal cutoff values for predicting significant fibrosis, severe fibrosis and cirrhosis were 10.6, 13.2 and 17.6 kPa, respectively. The AUROCs of 2-D-SWE were significantly higher than those of biochemical markers for predicting significant fibrosis, severe fibrosis and cirrhosis (all p values < 0.05). Therefore, the diagnostic performance of 2-D-SWE in assessing liver fibrosis stages in patients with elevated ALT levels was promising. The optimal cutoff values were increased but appropriate for this cohort because the baseline levels of liver stiffness measurements were increased in these patients, even in the absence of fibrosis.

      PubDate: 2017-11-11T18:39:01Z
      DOI: 10.1016/j.ultrasmedbio.2017.09.011
       
  • Sonographic and Anatomic Description of the Subtalar Joint
    • Authors: Peter Mandl; David Bong; Peter V. Balint; Hilde Berner Hammer; Maribel Miguel; Esperanza Naredo; Lene Terslev; Ingrid Möller
      Abstract: Publication date: Available online 6 November 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Peter Mandl, David Bong, Peter V. Balint, Hilde Berner Hammer, Maribel Miguel, Esperanza Naredo, Lene Terslev, Ingrid Möller
      Our study provides a detailed anatomic and sonographic description of the subtalar joint, a single joint that, anatomically, is divided into the anterior subtalar joint (ASTJ) and the posterior subtalar joint (PSTJ). Cadaver specimens of the ankle and foot were examined in detail by ultrasound (US), and the subtalar joints of all the specimens were injected with colored latex of a contrasting color under US guidance. Compatible with other studies, examination of the sections revealed lack of communication between the ASTJ and the PSTJ and communication between the PSTJ and the posterior recess of the tibiotalar joint. A recommended list of standardized ultrasound scans was developed using a Delphi consensus process, which allows sonographers to evaluate both the ASTJ and PSTJ from the medial, lateral and posterior aspects. The recommended ultrasound scans were found to be applicable based on a test of agreement between images acquired in cadaver specimens and images acquired in four centers using healthy patients.

      PubDate: 2017-11-11T18:39:01Z
      DOI: 10.1016/j.ultrasmedbio.2017.09.017
       
  • Can in Vivo Medial Gastrocnemius Muscle–Tendon Unit Lengths be Reliably
           Estimated by Two Ultrasonography Methods' A Within-Session Analysis
    • Authors: Francesco Cenni; Simon-Henri Schless; Lynn Bar-On; Guy Molenaers; Anja Van Campenhout; Erwin Aertbeliën; Herman Bruyninckx; Britta Hanssen; Kaat Desloovere
      Abstract: Publication date: Available online 6 November 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Francesco Cenni, Simon-Henri Schless, Lynn Bar-On, Guy Molenaers, Anja Van Campenhout, Erwin Aertbeliën, Herman Bruyninckx, Britta Hanssen, Kaat Desloovere
      A clinically feasible method to reliably estimate muscle–tendon unit (MTU) lengths could provide essential diagnostic and treatment planning information. A 3-D freehand ultrasound (3-DfUS) method was previously validated for extracting in vivo medial gastrocnemius (MG) lengths, although the processing time can be considered substantial for the clinical environment. This investigation analyzed a quicker and simpler method using the US transducer as a spatial pointer (US-PaP), where the within-session reliability of extracting the muscle–tendon unit (MTU) and tendon lengths are estimated. MG MTU lengths were extracted in a group of 14 healthy adults using both 3-DfUS and US-PaP. Two consecutive acquisitions were performed per participant, and the data processed by two researchers independently. The intra-class correlation coefficients were above 0.97, and the standard error of measurements below 3.6 mm (1.5%). This investigation proposes that the simplified US-PaP method is a viable alternative for estimating MG MTU lengths.

      PubDate: 2017-11-11T18:39:01Z
      DOI: 10.1016/j.ultrasmedbio.2017.09.018
       
  • Assessing the Reliability of Ultrasound Imaging to Examine Peripheral
           Nerve Excursion: A Systematic Literature Review
    • Authors: Ben Kasehagen; Richard Ellis; Rodney Pope; Nicholas Russell; Wayne Hing
      Abstract: Publication date: Available online 31 October 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Ben Kasehagen, Richard Ellis, Rodney Pope, Nicholas Russell, Wayne Hing
      Ultrasound imaging (USI) is gaining popularity as a tool for assessing nerve excursion and is becoming an important tool for the assessment and management of entrapment neuropathies. This systematic review aimed to identify current methods and report on the reliability of using USI to examine nerve excursion and identify the level of evidence supporting the reliability of this technique. A systematic search of five electronic databases identified studies assessing the reliability of using USI to examine nerve excursion. Two independent reviewers critically appraised and assessed the methodological quality of the identified articles. Eighteen studies met the eligibility criteria. The majority of studies were of “moderate” or “high” methodological quality. The overall analysis indicated a “strong” level of evidence of moderate to high reliability of using USI to assess nerve excursion. Further reliability studies with consistency of reporting are required to further strengthen the level of evidence.

      PubDate: 2017-11-05T16:20:03Z
      DOI: 10.1016/j.ultrasmedbio.2017.08.1886
       
  • Monitoring Progression of Amyotrophic Lateral Sclerosis Using Ultrasound
           Morpho-Textural Muscle Biomarkers: A Pilot Study
    • Authors: Jacinto J. Martínez-Payá; José Ríos-Díaz; Francesc Medina-Mirapeix; Juan F. Vázquez-Costa; María Elena del Baño-Aledo
      Abstract: Publication date: Available online 31 October 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Jacinto J. Martínez-Payá, José Ríos-Díaz, Francesc Medina-Mirapeix, Juan F. Vázquez-Costa, María Elena del Baño-Aledo
      The need is increasing for progression biomarkers that allow the loss of motor neurons in amyotrophic lateral sclerosis (ALS) to be monitored in clinical trials. In this prospective longitudinal study, muscle thickness, echointensity, echovariation and gray level co-occurrence matrix textural features are examined as possible progression ultrasound biomarkers in ALS patients during a 5-mo follow-up period. We subjected 13 patients to 3 measurements for 20 wk. They showed a significant loss of muscle, an evident tendency to loss of thickness and increased echointensity and echovariation. In regard to textural parameters, muscle heterogeneity tended to increase as a result of the neoformation of non-contractile tissue through denervation. Considering some limitations of the study, the quantitative muscle ultrasound biomarkers evaluated showed a promising ability to monitor patients affected by ALS.

      PubDate: 2017-11-05T16:20:03Z
      DOI: 10.1016/j.ultrasmedbio.2017.09.013
       
  • Ultrasound Imaging Technologies for Breast Cancer Detection and
           Management: A Review
    • Authors: Rongrong Guo; Guolan Lu; Binjie Qin; Baowei Fei
      Abstract: Publication date: Available online 26 October 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Rongrong Guo, Guolan Lu, Binjie Qin, Baowei Fei
      Ultrasound imaging is a commonly used modality for breast cancer detection and diagnosis. In this review, we summarize ultrasound imaging technologies and their clinical applications for the management of breast cancer patients. The technologies include ultrasound elastography, contrast-enhanced ultrasound, 3-D ultrasound, automatic breast ultrasound and computer-aided detection of breast ultrasound. We summarize the study results seen in the literature and discuss their future directions. We also provide a review of ultrasound-guided, breast biopsy and the fusion of ultrasound with other imaging modalities, especially magnetic resonance imaging (MRI). For comparison, we also discuss the diagnostic performance of mammography, MRI, positron emission tomography and computed tomography for breast cancer diagnosis at the end of this review. New ultrasound imaging techniques, ultrasound-guided biopsy and the fusion of ultrasound with other modalities provide important tools for the management of breast patients.

      PubDate: 2017-11-05T16:20:03Z
      DOI: 10.1016/j.ultrasmedbio.2017.09.012
       
 
 
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