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PHYSICS (578 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  (Not entitled to full-text)
   ISSN (Print) 0301-5629
   Published by Elsevier Homepage  [3030 journals]
  • Role of Bowel Ultrasound in the Diagnosis and Follow-up of Patients with
           Crohn's Disease
    • Authors: Clara Benedetta Conti; Mariangela Giunta; Daniele Gridavilla; Dario Conte; Mirella Fraquelli
      Pages: 725 - 734
      Abstract: Publication date: Available online 6 February 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Clara Benedetta Conti, Mariangela Giunta, Daniele Gridavilla, Dario Conte, Mirella Fraquelli
      Crohn's disease (CD) is an inflammatory chronic bowel disorder; it can involve the whole gastrointestinal tract, but its localization in the ileum or colon is most common. The reference standard for the diagnosis of CD is ileocolonoscopy with histologic assessment. The reference standard for the detection of any complications is surgery. However, imaging techniques have an important role both in the detection/localization of CD and in the follow-up of CD patients. In the last few years, the technical development of ultrasound equipment, the advent of new technologies such as elastography and mostly the increased expertise of sonographers have boosted the role of bowel ultrasound in assessment of the gastrointestinal tract. In fact, bowel ultrasound is particularly attractive thanks to its widespread availability, non-invasiveness, low cost and good reproducibility, as it can be easily repeated during follow-up. The aim of this article is to provide an extensive overview of the actual role of bowel ultrasound in the detection and follow-up of patients with CD.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.12.014
      Issue No: Vol. 43, No. 4 (2017)
       
  • Diagnostic Accuracy of Transabdominal Ultrasound in Chronic Pancreatitis
    • Authors: Trond Engjom; Dag A. Sangnes; Roald F. Havre; Friedemann Erchinger; Khanh Do-Cong Pham; Ingfrid S. Haldorsen; Odd H. Gilja; Georg Dimcevski
      Pages: 735 - 743
      Abstract: Publication date: April 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 4
      Author(s): Trond Engjom, Dag A. Sangnes, Roald F. Havre, Friedemann Erchinger, Khanh Do-Cong Pham, Ingfrid S. Haldorsen, Odd H. Gilja, Georg Dimcevski
      The performance of transabdominal ultrasound (US) in chronic pancreatitis (CP) following the advances in US technology made during recent decades has not been explored. Our aim in this prospective study was to evaluate the diagnostic accuracy of modern abdominal US compared with the Mayo score in CP. One hundred thirty-four patients referred for suspected CP were included in the study. Fifty-four patients were assigned the diagnosis CP. After inclusion, transabdominal US was performed. Ductal features (calculi, dilations and caliber variations, side-branch dilations and hyper-echoic duct wall margins) and parenchymal features (calcifications, cysts, hyper-echoic foci, stranding, lobulation and honeycombing) were recorded. Features were counted and scored according to a weighting system defined at the international consensus meeting in Rosemont, Illinois (Rosemont score). Diagnostic performance indices (95% confidence interval) of US were calculated: The unweighted count of features had a sensitivity of 0.69 (0.54–0.80) and specificity of 0.97 (0.90–1). The Rosemont score had a sensitivity of 0.81 (0.69–0.91) and specificity of 0.97 (0.90–1). Exocrine pancreatic failure was most pronounced in Rosemont groups I and II (p < 0.001). We conclude that using both unweighted and weighted scores, the diagnostic accuracy of modern transabdominal US is good. The extent of pancreatic changes detected by the method is correlated with exocrine pancreatic function.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.020
       
  • Integrative Cardiopulmonary Ultrasound for Interstitial Lung Disease
           Assessment: Correlation between Lung Ultrasound Performance and Cardiac
           Involvement
    • Authors: Wei-Wei Zhu; Yi-Dan Li; Hong Li; Xiu-Zhang Lu; Ling-Yun Kong; Xiao-Guang Ye; Qi-Zhe Cai; Lan-Lan Sun; Wei Jiang; Li Wang
      Pages: 744 - 752
      Abstract: Publication date: April 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 4
      Author(s): Wei-Wei Zhu, Yi-Dan Li, Hong Li, Xiu-Zhang Lu, Ling-Yun Kong, Xiao-Guang Ye, Qi-Zhe Cai, Lan-Lan Sun, Wei Jiang, Li Wang
      The aims of this study were to apply integrative cardiopulmonary ultrasound (thoracic ultrasound) to the evaluation of patients with interstitial lung disease (ILD) and to determine the relationship between lung ultrasound signs and echocardiographic parameters such as systolic pulmonary artery pressure (SPAP) and various right ventricular parameters. ILD patients and healthy controls underwent lung ultrasound (LUS) and echocardiographic tests. In addition to traditional echocardiographic parameters, right ventricular free wall longitudinal strain (RVLS_FW) was measured using 2-D speckle-tracking echocardiography. The degree of pulmonary fibrosis or the disease severity of each ILD patient was scored with a semiquantitative scoring method, taking into account multiple LUS signs. Statistical analyses were performed to compare various parameters between ILD patients with and those without pulmonary hypertension. Correlations between the different parameters were then evaluated, and the LUS scores were used to predict pulmonary hypertension using a receiver operating characteristic curve analysis. Among the 90 patients who qualified for entry into this study, 30% (n = 27) had pulmonary hypertension. The patients with pulmonary hypertension had larger right ventricular dimensions, lower RVLS_FW and higher LUS scores. An effective correlation was found between ILD LUS scores and echocardiographic parameters, especially SPAP (r = 0.735, p < 0.001). The groups were comparable with respect to most echocardiographic parameters, with mild, moderate and severe pulmonary fibrosis, whereas SPAP was significantly higher in the moderate and severe groups. RVLS_FW was obviously reduced in the group with severe pulmonary fibrosis. Although RVLS_FW in the mild pulmonary fibrosis group was in the normal range, it was slightly reduced compared with that of the controls. A cutoff of more than 16 LUS points had 85.2% sensitivity and 80.3% specificity in predicting elevated SPAP (>36 mm Hg). Thoracic ultrasound is useful in the assessment of ILD. As ILD progresses, the structure or function of the right ventricle gradually deteriorates. LUS not only detects lung conditions in ILD, but also indirectly reflects SPAP and right ventricular function. Integrated use of LUS and echocardiography will provide an invaluable point-of-care imaging modality to facilitate the diagnosis, management and treatment of patients with ILD.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.004
       
  • Cardiac Shear Wave Velocity Detection in the Porcine Heart
    • Authors: Hendrik J. Vos; Bas M. van Dalen; Ilkka Heinonen; Johan G. Bosch; Oana Sorop; Dirk J. Duncker; Antonius F.W. van der Steen; Nico de Jong
      Pages: 753 - 764
      Abstract: Publication date: April 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 4
      Author(s): Hendrik J. Vos, Bas M. van Dalen, Ilkka Heinonen, Johan G. Bosch, Oana Sorop, Dirk J. Duncker, Antonius F.W. van der Steen, Nico de Jong
      Cardiac muscle stiffness can potentially be estimated non-invasively with shear wave elastography. Shear waves are present on the septal wall after mitral and aortic valve closure, thus providing an opportunity to assess stiffness in early systole and early diastole. We report on the shear wave recordings of 22 minipigs with high-frame-rate echocardiography. The waves were captured with 4000 frames/s using a programmable commercial ultrasound machine. The wave pattern was extracted from the data through a local tissue velocity estimator based on one-lag autocorrelation. The wave propagation velocity was determined with a normalized Radon transform, resulting in median wave propagation velocities of 2.2 m/s after mitral valve closure and 4.2 m/s after aortic valve closure. Overall the velocities ranged between 0.8 and 6.3 m/s in a 95% confidence interval. By dispersion analysis we found that the propagation velocity only mildly increased with shear wave frequency.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.015
       
  • Atlas-Based Mosaicing of Left Atrial 3-D Transesophageal Echocardiography
           Images
    • Authors: Harriët W. Mulder; Marijn van Stralen; Ben Ren; Alexander Haak; Max A. Viergever; Johan G. Bosch; Josien P.W. Pluim
      Pages: 765 - 774
      Abstract: Publication date: April 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 4
      Author(s): Harriët W. Mulder, Marijn van Stralen, Ben Ren, Alexander Haak, Max A. Viergever, Johan G. Bosch, Josien P.W. Pluim
      Transesophageal echocardiography (TEE) is a promising imaging modality used to guide cardiac interventions, such as catheter ablation for the treatment of cardiac arrhythmias. These procedures rely on good visualization of the left atrium and pulmonary veins. To visualize these structures in a single volume, the acquisition, registration and fusion of multiple TEE views of the left atrium are required. We introduce atlas-based mosaicing as a method for the registration of images that are acquired according to a standardized protocol. Inspired by atlas-based segmentation approaches, compounded data of other patients serve as atlases for the registration of new data. The performance of atlas-based mosaicing is studied on 3-D TEE data of the left atrium and compared with that of regular pairwise registration. This study indicates that improved registration robustness and smaller registration errors are achieved with atlas-based mosaicing compared with regular pairwise registration. This is an important step toward the use of TEE for interventional guidance of ablation procedures.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.017
       
  • 2-D and 3-D Ultrasound for Tumor Volume Analysis:
           A Prospective Study
    • Authors: Segundo J. González; Blaise Mooney; Hui-Yi Lin; Xiuhua Zhao; John V. Kiluk; Nazanin Khakpour; Christine Laronga; M. Catherine Lee
      Pages: 775 - 781
      Abstract: Publication date: Available online 7 February 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Segundo J. González, Blaise Mooney, Hui-Yi Lin, Xiuhua Zhao, John V. Kiluk, Nazanin Khakpour, Christine Laronga, M. Catherine Lee
      Ultrasound (US) allows real-time tumor assessment. We evaluated the volumetric limits of 2-D and 3-D US, compared with magnetic resonance imaging (MRI), with a prospective institutional review board–approved clinical evaluation of US-to-MRI volumetric correlation. US images of pre- and post-neoadjuvant breast cancers were obtained. Volume discrepancy was evaluated with the non-parametric Wilcoxon signed-rank test. Expected inter-observer variability <14% was evaluated as relative paired difference (RPD); clinical relevance was gauged with the volumetric standard error of the mean (SEM). For 42 patients, 133 of 170 US examinations were evaluable. For tumors ≤20 cm3, both highly correlated to MRI with RPD within inter-observer variability and Pearson's correlation up to 0.86 (0.80 before and 0.86 after neoadjuvant chemotherapy, respectively). Lesions 20–40 cm3 had US-to-MRI discrepancy within inter-observer variability for 2-D (RPD: 13%), but not 3-D (RPD: 27%) US (SEM: 1.47 cm3 for 2-D, SEM: 2.28 cm3 for 3-D), suggesting clinical utility. Tumors >40 cm3 correlated poorly. Tumor volumes ≤20 cm3 exhibited a good correlation to MRI. Studies of clinical applications are warranted.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.12.009
       
  • Testicular Shear Wave Elastography in Normal and Infertile Men: A
           Prospective Study on 601 Patients
    • Authors: Laurence Rocher; Aline Criton; Jean-Luc Gennisson; Vincent Izard; Sophie Ferlicot; Mickael Tanter; Gerard Benoit; Marie France Bellin; Jean-Michel Correas
      Pages: 782 - 789
      Abstract: Publication date: April 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 4
      Author(s): Laurence Rocher, Aline Criton, Jean-Luc Gennisson, Vincent Izard, Sophie Ferlicot, Mickael Tanter, Gerard Benoit, Marie France Bellin, Jean-Michel Correas
      Our aim in the study described here was to prospectively establish the feasibility of using and reproducibility of testicular shear-wave elastography in the assessment of testicular stiffness in 62 normal patients and 539 infertile men with obstructive azoospermia (OA), non-Klinefelter syndrome non-obstructive azoospermia (non-KS NOA), Klinefelter syndrome NOA (KS NOA), oligoasthenoteratozoospermia (OAT) or a left varicocele. The feasibility rate was 96.9%, with an intra-class correlation coefficient of 0.85 (95% confidence interval: 0.83–0.88). Median stiffness (interquartile range) values were 2.4 kPa (2.0, 2.9), 2.1 kPa (1.8, 2.5), 2.4 kPa (2.0, 2.7), 2.0 kPa (1.7, 2.4), 2.6 kPa (2, 3.2) and 2.2 kPa (1.8, 2.6) for men with a normal testis (n = 108), OAT (n = 689), OA (n = 119), non-KS NOA (n = 183), KS NOA (n = 70) and varicocele (n = 132), respectively. Testicular shear wave elastography is a feasible and reproducible technique. A significant positive association was found between stiffness and testis volume (p = 0.001). Testicular stiffness was higher in OA than in non-KS NOA populations (p = 1.e−10) and in KS NOA than in NOA populations (p = 2.0e−8), but the substantial number of overlapping values limited the clinical impact.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.016
       
  • Assessment of Structural Heterogeneity and Viscosity in the Cervix Using
           Shear Wave Elasticity Imaging: Initial Results from a Rhesus Macaque Model
           
    • Authors: Ivan M. Rosado-Mendez; Mark L. Palmeri; Lindsey C. Drehfal; Quinton W. Guerrero; Heather Simmons; Helen Feltovich; Timothy J. Hall
      Pages: 790 - 803
      Abstract: Publication date: Available online 8 February 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Ivan M. Rosado-Mendez, Mark L. Palmeri, Lindsey C. Drehfal, Quinton W. Guerrero, Heather Simmons, Helen Feltovich, Timothy J. Hall
      Shear wave elasticity imaging has shown promise in evaluation of the pregnant cervix. Changes in shear wave group velocity have been attributed exclusively to changes in stiffness. This assumes homogeneity within the region of interest and purely elastic tissue behavior. However, the cervix is structurally/microstructurally heterogeneous and viscoelastic. We therefore developed strategies to investigate these complex tissue properties. Shear wave elasticity imaging was performed ex vivo on 14 unripened and 13 misoprostol-ripened cervix specimens from rhesus macaques. After tests of significant and uniform shear wave displacement, as well as reliability of estimates, group velocity decreased significantly from the distal (vaginal) to proximal (uterine) end of unripened, but not ripened, specimens. Viscosity was quantified by the slope of the phase velocity versus frequency. Dispersion was observed in both groups (median: 5.5 m/s/kHz, interquartile range: 1.5–12.0 m/s/kHz), also decreasing toward the proximal cervix. This work suggests that comprehensive assessment of complex tissues such as cervix requires consideration of structural heterogeneity and viscosity.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.12.006
       
  • Implementation of Elastography Score and Strain Ratio in Combination with
           B-Mode Ultrasound Avoids Unnecessary Biopsies of Breast Lesions
    • Authors: Kristina Bojanic; Natasa Katavic; Martina Smolic; Marija Peric; Kristina Kralik; Miroslav Sikora; Kristina Vidačić; Mirta Pacovski; Damir Stimac; Gordana Ivanac
      Pages: 804 - 816
      Abstract: Publication date: April 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 4
      Author(s): Kristina Bojanic, Natasa Katavic, Martina Smolic, Marija Peric, Kristina Kralik, Miroslav Sikora, Kristina Vidačić, Mirta Pacovski, Damir Stimac, Gordana Ivanac
      The aim of this study was to evaluate whether the combination of B-mode ultrasound, elastography score (ES) and strain ratio (SR) improves diagnostic performance with respect to breast lesions. One hundred thirty lesions were prospectively evaluated by B-mode ultrasound and strain elastography, followed by fine-needle aspiration cytology/biopsy in 117 woman who were scheduled for regular breast BUS. The median ES (4.5 vs. 2.9, p < 0.001) and SR (4.9 vs. 2.3, p < 0.001) were significantly higher for malignant than for benign lesions. A sensitivity of 90.5% and specificity of 93.2% for the ES (cutoff point = 3.8) and a sensitivity of 87.5% and specificity of 87.6% for the SR (cutoff point = 3.5) were obtained. Elastography combined with B-mode ultrasound improved the specificity, accuracy and positive predictive value. Receiver operating characteristic curves yielded a higher value for the combined technique for diagnosis of breast lesions. Routine use of such a diagnostic algorithm could reduce the number of unnecessary biopsies.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.019
       
  • Non-Invasive Identification of Vulnerable Atherosclerotic Plaques Using
           Texture Analysis in Ultrasound Carotid Elastography: An In Vivo
           Feasibility Study Validated by Magnetic Resonance Imaging
    • Authors: Chengwu Huang; Qiong He; Manwei Huang; Lingyun Huang; Xihai Zhao; Chun Yuan; Jianwen Luo
      Pages: 817 - 830
      Abstract: Publication date: April 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 4
      Author(s): Chengwu Huang, Qiong He, Manwei Huang, Lingyun Huang, Xihai Zhao, Chun Yuan, Jianwen Luo
      The aims of this study were to quantify the textural information of strain rate images in ultrasound carotid elastography and evaluate the feasibility of using the textural features in discriminating stable and vulnerable plaques with magnetic resonance imaging as an in vivo reference. Ultrasound radiofrequency data were acquired in 80 carotid plaques from 52 patients, mainly in the longitudinal imaging view, and axial strain rate images were estimated with an ultrasound carotid elastography technique based on an optical flow algorithm. Four textural features of strain rate images—contrast, homogeneity, correlation and angular second moment—were derived based on the gray-level co-occurrence matrix in plaque regions to quantify the deformation distribution pattern. Conventional elastographic indices based on the magnitude of the absolute strain rate, such as the maximum, mean, median, standard deviation and 99th percentile of the axial strain rate, were also obtained for comparison. Composition measurement with magnetic resonance imaging identified 30 plaques as vulnerable and the other 50 as stable. The four textural features, as well as the magnitude of strain rate images, significantly differed between the two groups of plaques. The best performing features for plaque classification were found to be the contrast and 99th percentile of the absolute strain rate, with a comparative area under the receiver operating characteristic curve of 0.81; a slightly higher maximum accuracy of plaque classification can be achieved by the textural feature of contrast (83.8% vs. 81.3%). The results indicate that the use of texture analysis in plaque classification is feasible and that larger local deformations and higher level of complexity in deformation patterns (associated with the elastic or stiffness heterogeneity of plaque tissues) are more likely to occur in vulnerable plaques.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2016.12.003
       
  • Differential Intensity Projection for Visualisation and Quantification of
           Plaque Neovascularisation in Contrast-Enhanced Ultrasound Images of
           Carotid Arteries
    • Authors: Wing Keung Cheung; Benoy N. Shah; Antonio Stanziola; Dorothy M. Gujral; Navtej S. Chahal; David O. Cosgrove; Roxy Senior; Meng-Xing Tang
      Pages: 831 - 837
      Abstract: Publication date: April 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 4
      Author(s): Wing Keung Cheung, Benoy N. Shah, Antonio Stanziola, Dorothy M. Gujral, Navtej S. Chahal, David O. Cosgrove, Roxy Senior, Meng-Xing Tang
      Studies have reported that intraplaque neovascularisation (IPN) is closely correlated with plaque vulnerability. In this study, a new image processing approach, differential intensity projection (DIP), was developed to visualise and quantify IPN in contrast-enhanced non-linear ultrasound image sequences of carotid arteries. DIP used the difference between the local temporal maximum and the local temporal average signals to identify bubbles against tissue non-linear artefact and noise. The total absolute and relative areas occupied by bubbles within each plaque were calculated to quantify IPN. In vitro measurements on a laboratory phantom were made, followed by in vivo measurements in which 24 contrast-enhanced non-linear ultrasound image sequences of carotid arteries from 48 patients were selected and motion corrected. The results using DIP were compared with those obtained by maximum intensity projection (MIP) and visual assessment. The results indicated that DIP can significantly reduce non-linear propagation tissue artefacts and is much more specific in detecting bubble signals than MIP, being able to reveal microbubble signals that are buried in tissue artefacts in the corresponding MIP image. A good correlation was found between microvascular area (MVA) (r = 0.83, p < 0.001)/microvascular density (r = 0.77, p < 0.001) obtained using DIP and the corresponding expert visual grades, comparing favourably to r = 0.26 and 0.23 obtained using MIP on the same data. In conclusion, the proposed method exhibits great potential in quantification of IPN in contrast-enhanced ultrasound images of carotid arteries.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.018
       
  • Microbubble-Assisted Ultrasound-Induced Transient Phosphatidylserine
           Translocation
    • Authors: Jean-Michel Escoffre; Marc Derieppe; Bart Lammertink; Clemens Bos; Chrit Moonen
      Pages: 838 - 851
      Abstract: Publication date: April 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 4
      Author(s): Jean-Michel Escoffre, Marc Derieppe, Bart Lammertink, Clemens Bos, Chrit Moonen
      Microbubble-assisted ultrasound (sonopermeabilization) results in reversible permeabilization of the plasma membrane of cells. This method is increasingly used in vivo because of its potential to deliver therapeutic molecules with limited cell damage. Nevertheless, the effects of sonopermeabilization on the plasma membrane remain not fully understood. We investigated the influence of sonopermeabilization on the transverse mobility of phospholipids, especially on phosphatidylserine (PS) externalization. We performed studies using optical imaging with Annexin V and FM1-43 probes to monitor PS externalization of rat glioma C6 cells. Sonopermeabilization induced transient membrane permeabilization, which is positively correlated with reversible PS externalization. This membrane disorganization was temporary and not associated with loss of cell viability. Sonopermeabilization did not induce PS externalization via activation of the scramblase. We hypothesize that acoustically induced membrane pores may provide a new pathway for PS migration between both membrane leaflets. During the membrane-resealing phase, PS asymmetry may be re-established by amino-phospholipid flippase activity and/or endocytosis, along with exocytosis processes.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2016.12.002
       
  • Single-Beam Acoustic Trapping of Red Blood Cells and Polystyrene
           Microspheres in Flowing Red Blood Cell Saline and Plasma Suspensions
    • Authors: Hsiao-Chuan Liu; Ying Li; Ruimin Chen; Hayong Jung; K. Kirk Shung
      Pages: 852 - 859
      Abstract: Publication date: Available online 22 February 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Hsiao-Chuan Liu, Ying Li, Ruimin Chen, Hayong Jung, K. Kirk Shung
      Single-beam acoustic tweezers (SBATs) represent a new technology for particle and cell trapping. The advantages of SBATs are their deep penetration into tissues, reduction of tissue damage and ease of application to in vivo studies. The use of these tools for applications in drug delivery in vivo must meet the following conditions: large penetration depth, strong trapping force and tissue safety. A reasonable penetration depth for SBATs in the development of in vivo applications was established in a previous study conducted in water with zero velocity. However, capturing objects in flowing fluid can provide more meaningful results. In this study, we investigated the capability of SBATs to trap red blood cells (RBCs) and polystyrene microspheres in flowing RBC suspensions. Two different types of RBC suspension were prepared in this work: an RBC phosphate-buffered saline (PBS) suspension and an RBC plasma suspension. The results indicated that SBATs successfully trapped RBCs and polystyrene microspheres in a flowing RBC PBS suspension with an average steady velocity of 1.6 cm/s in a 2-mm-diameter polyimide. Furthermore, SBATs were found able to trap RBCs in a flowing RBC PBS suspension at speeds as high as 7.9 cm/s in a polyimide tube, which is higher than the velocity in capillaries (0.03 cm/s) and approaches the velocity in arterioles and venules. Moreover, the results also indicated that polystyrene microspheres can be trapped in an RBC plasma suspension, where aggregation is observed. This work represents a step forward in using this tool in actual in vivo experimentation.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.12.005
       
  • Nodular Fasciitis: Sonographic–Pathologic Correlation
    • Authors: Ho-Hsian Yen; Hong-Jen Chiou; Yi-Hong Chou; Chih-Hsueh Chen; Wan-Yuo Guo
      Pages: 860 - 867
      Abstract: Publication date: April 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 4
      Author(s): Ho-Hsian Yen, Hong-Jen Chiou, Yi-Hong Chou, Chih-Hsueh Chen, Wan-Yuo Guo
      We evaluated nodular fasciitis (NF) in 19 patients, focusing on the correlation between its sonographic and histopathologic features. Sonograms were retrospectively reviewed, and the location, shape, margin, echogenicity, echogenic rim, peripheral hyper-echoic nodules, posterior enhancement and vascularity of the lesions were recorded. In the histopathologic analysis, three patterns—infiltrating, pushing border and well circumscribed—were identified, and culture-like tissue centers were classified according to the distribution of focal keloid-like collagen bundles: uneven or even. For the sonographic–pathologic correlation, most NF cases were inhomogeneously hypo-echoic and had an echogenic rim, with an infiltrating or pushing border pattern. In addition, all NF cases with the infiltrating pattern were observed to have peripheral hyper-echoic nodules in sonograms. Thus, echogenic rims may be associated with the peripheral adipose tissues in infiltrating pattern, and the degree of infiltration may be associated with specific sonographic features of NF.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2016.12.001
       
  • Strain Elastography as a New Method for Assessing Pelvic Floor
           Biomechanics
    • Authors: Jana Marie Kreutzkamp; Sebastian Daniel Schäfer; Susanne Amler; Felix Strube; Ludwig Kiesel; Ralf Schmitz
      Pages: 868 - 872
      Abstract: Publication date: April 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 4
      Author(s): Jana Marie Kreutzkamp, Sebastian Daniel Schäfer, Susanne Amler, Felix Strube, Ludwig Kiesel, Ralf Schmitz
      Strain elastography (SE) is a new technique of parametric imaging that allows quantification of the elasticity of tissue. The aim of our study was to determine if the elasticity of para-urethral tissue correlates with urethral mobility and urinary incontinence (UI). Ninety-nine unselected women were investigated with SE. They were given a standardized interview about UI, and SE raw data for the para-urethral tissue were acquired in a sagittal standard urethra-symphysis view while being stimulated by a coughing fit. We placed one region of interest (ROI A) in the tissue between the urethra and vagina at midlevel of the urethra bordering the urethral wall. The second ROI (ROI B) was set at the level of the os urethra internum in the tissue of the bladder neck in one line to ROI A. We measured elasticity in both ROIs with TDI-Q (Tissue Doppler Imaging-Quantification Software) and calculated the ratio between ROI A and ROI B (A/B). Mobility of the urethra was quantified by measuring the angle between a line parallel to the urethra and a line parallel to the bladder neck during stress and rest. SE analysis was feasible in all cases. A/B was found to be correlated with the incidence of urethral mobility (p < 0.001). The incidence of UI was associated with an increase in urethral mobility (p = 0.04). No correlation between UI and A/B could be shown (p = 0.24). We observed a correlation between urethral mobility and elasticity of the para-urethral tissue. In case of increasing urethral mobility, the para-urethral tissue close to the bladder neck seems to be more elastic, and the patients reported about more symptoms of UI. No noticeable correlation between UI and urethral elasticity was shown. SE may be a useful technique for direct quantification of tissue elasticity and assessment of pelvic floor biomechanics.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2016.12.004
       
  • Neonatal Cranial Ultrasound: Are Current Safety Guidelines
           Appropriate?
    • Authors: Assema Lalzad; Flora Wong; Michal Schneider
      Pages: 553 - 560
      Abstract: Publication date: March 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 3
      Author(s): Assema Lalzad, Flora Wong, Michal Schneider
      Ultrasound can lead to thermal and mechanical effects in interrogated tissues. We reviewed the literature to explore the evidence on ultrasound heating on fetal and neonatal neural tissue. The results of animal studies have suggested that ultrasound exposure of the fetal or neonatal brain may lead to a significant temperature elevation at the bone–brain interface above current recommended safety thresholds. Temperature increases between 4.3 and 5.6°C have been recorded. Such temperature elevations can potentially affect neuronal structure and function and may also affect behavioral and cognitive function, such as memory and learning. However, the majority of these studies were carried out more than 25 y ago using non-diagnostic equipment with power outputs much lower than those of modern machines. New studies to address the safety issues of cranial ultrasound are imperative to provide current clinical guidelines and safety recommendations.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.002
       
  • Totally Implantable Wireless Ultrasonic Doppler Blood Flowmeters: Toward
           Accurate Miniaturized Chronic Monitors
    • Authors: Michael A. Rothfuss; Jignesh V. Unadkat; Michael L. Gimbel; Marlin H. Mickle; Ervin Sejdić
      Pages: 561 - 578
      Abstract: Publication date: March 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 3
      Author(s): Michael A. Rothfuss, Jignesh V. Unadkat, Michael L. Gimbel, Marlin H. Mickle, Ervin Sejdić
      Totally implantable wireless ultrasonic blood flowmeters provide direct-access chronic vessel monitoring in hard-to-reach places without using wired bedside monitors or imaging equipment. Although wireless implantable Doppler devices are accurate for most applications, device size and implant lifetime remain vastly underdeveloped. We review past and current approaches to miniaturization and implant lifetime extension for wireless implantable Doppler devices and propose approaches to reduce device size and maximize implant lifetime for the next generation of devices. Additionally, we review current and past approaches to accurate blood flow measurements. This review points toward relying on increased levels of monolithic customization and integration to reduce size. Meanwhile, recommendations to maximize implant lifetime should include alternative sources of power, such as transcutaneous wireless power, that stand to extend lifetime indefinitely. Coupling together the results will pave the way for ultra-miniaturized totally implantable wireless blood flow monitors for truly chronic implantation.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.005
       
  • In Vivo Validation of Volume Flow Measurements of Pulsatile Flow Using a
           Clinical Ultrasound System and Matrix Array Transducer
    • Authors: John M. Hudson; Ross Williams; Laurent Milot; Qifeng Wei; James Jago; Peter N. Burns
      Pages: 579 - 585
      Abstract: Publication date: March 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 3
      Author(s): John M. Hudson, Ross Williams, Laurent Milot, Qifeng Wei, James Jago, Peter N. Burns
      The goal of this study was to evaluate the accuracy of a non-invasive C-plane Doppler estimation of pulsatile blood flow in the lower abdominal vessels of a porcine model. Doppler ultrasound measurements from a matrix array transducer system were compared with invasive volume flow measurements made on the same vessels with a surgically implanted ultrasonic transit-time flow probe. For volume flow rates ranging from 60 to 750 mL/min, agreement was very good, with a Pearson correlation coefficient of 0.97 (p < 0.0001) and a mean bias of −4.2%. The combination of 2-D matrix array technology and fast processing gives this Doppler method clinical potential, as many of the user- and system-dependent parameters of previous methods, including explicit vessel angle and diameter measurements, are eliminated.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.10.008
       
  • Ultrasound Measurements of Skeletal Muscle Architecture Are Associated
           with Strength and Functional Capacity in Older Adults
    • Authors: Isaac Selva Raj; Stephen R. Bird; Anthony J. Shield
      Pages: 586 - 594
      Abstract: Publication date: March 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 3
      Author(s): Isaac Selva Raj, Stephen R. Bird, Anthony J. Shield
      The goal of this study was to determine whether ultrasound measures of muscle architecture can be used to infer strength and functional capacity in older adults. Thirty-six healthy older adults (aged 68.2 ± 5.3 y) undertook isokinetic dynamometry for isometric and isokinetic concentric knee extensor strength, the 6-m fast walk, timed up and go, stair climb and descent and vertical jump tests. Longitudinal brightness-mode ultrasound scans (probe frequency, 10 MHz) of the vastus lateralis, vastus intermedius, rectus femoris and gastrocnemius medialis were obtained, and muscle architecture measures (thickness, fascicle pennation angle and fascicle length) were correlated with the aforementioned strength and functional measures. Quadriceps thickness was a significant (p < 0.05) independent predictor of isometric and isokinetic knee extensor strength (R 2 ≥ 0.630). Gastrocnemius medialis thickness was a significant independent predictor of 6-m fast walk test (R 2 = 0.216, p < 0.05), timed up and go test (R 2 = 0.455, p < 0.01), stair climb power (R 2 = 0.591, p < 0.01), stair descent power (R 2 = 0.608, p < 0.01) and vertical jump height (R 2 = 0.579, p < 0.01). Ultrasound is a safe, non-invasive and efficient tool for inferring the strength and functional capacity of older adults.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.013
       
  • Time-Harmonic Elastography of the Liver is Sensitive to Intrahepatic
           Pressure Gradient and Liver Decompression after Transjugular Intrahepatic
           Portosystemic Shunt (TIPS) Implantation
    • Authors: Heiko Tzschätzsch; Ingolf Sack; Stephan Rodrigo Marticorena Garcia; Selcan Ipek-Ugay; Jürgen Braun; Bernd Hamm; Christian E. Althoff
      Pages: 595 - 600
      Abstract: Publication date: March 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 3
      Author(s): Heiko Tzschätzsch, Ingolf Sack, Stephan Rodrigo Marticorena Garcia, Selcan Ipek-Ugay, Jürgen Braun, Bernd Hamm, Christian E. Althoff
      We investigated the correlation between hepatic venous pressure gradient (HVPG) and liver shear wave speed (SWS) measured by multi-frequency time-harmonic ultrasound elastography (THE) before and after transjugular intrahepatic portosystemic shunt (TIPS) implantation. Ten patients with ascites, cirrhotic liver disease and portal hypertension were prospectively examined with invasive HVPG measurement and THE before and after TIPS implantation. HVPG and SWS decreased after TIPS placement from 20.4 ± 2.2 mmHg to 9.8 ± 4.1 mmHg (mean ± standard deviation) and from 3.87 ± 0.54 m/s to 3.27 ± 0.44 m/s. Mean reduction HVPG was −10.6 ± 3.7 mmHg, p < 0.001; mean reduction SWS was −0.60 ± 0.29 m/s, p < 0.001. A linear correlation was observed between HVPG and SWS (R = 0.59, p = 0.0061). THE-measured SWS is a first potential direct ultrasound marker for liver decompression following TIPS in ascites-associated cirrhotic liver disease and therefore might be suitable to non-invasively detect portal hypertension.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.10.007
       
  • Differential Diagnosis of Breast Category 3 and 4 Nodules Through BI-RADS
           Classification in Conjunction with Shear Wave Elastography
    • Authors: Min Wang; Zhi Yang; Can Liu; Junhong Yan; Wenxiao Zhang; Jian Sun; Guanghe Cui
      Pages: 601 - 606
      Abstract: Publication date: March 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 3
      Author(s): Min Wang, Zhi Yang, Can Liu, Junhong Yan, Wenxiao Zhang, Jian Sun, Guanghe Cui
      Ultrasound (US) has become one of the important imaging methods for differentiating benign from malignant breast lesions. In 2013, the American College of Radiology published the fifth edition of the Breast Imaging-Reporting and Data System (BI-RADS). BI-RADS is a guide with recommendations for the standardization of breast imaging (US, mammography and magnetic resonance imaging) reports and for the auditing of centers employing such methods. Its objective is to standardize the nomenclature used in the reports. However, current US examinations are neither adequately sensitive nor sufficiently specific enough. The average Young's modulus was measured through shear wave elastography (SWE) to evaluate the diagnostic value of the BI-RADS classification in conjunction with SWE in differentiating BI-RADS 3 and 4 nodules. A total of 100 consecutive women with 126 breast lesions, including 65 benign and 61 malignant lesions, were included. The average Young's modulus of breast nodules and peri-nodule tissue (Emean1 and Emean2) was also determined through SWE. A receiver operating characteristic curve was drawn on the basis of pathologic results. The highest cut-off values were C1 and C2. At Emean1 > C1 or Emean2 > C2, BI-RADS 3 was increased to 4a and BI-RADS 4a was increased to 4b. At Emean1 ≤ C1 and Emean2 ≤ C2, BI-RADS 4b was decreased to 4a. Other BI-RADS classifications remained unchanged. BI-RADS 3 and 4a were considered benign. BI-RADS 4b and 4c were malignant. The area under the curve, sensitivity and specificity of the BI-RADS classification in conjunction with SWE were 0.952, 93.4% and 95.4%, respectively. The area under the curve, sensitivity and specificity of the original BI-RADS classification were 0.883, 82.0% and 87.7%, respectively. Differences were statistically significant (p = 0.028, Z-test). The diagnostic sensitivity and specificity were increased effectively. As a new method, BI-RADS classification in conjunction with SWE that combines the average Young's modulus yields a high value in terms of the differential diagnosis of breast nodules.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.10.004
       
  • Quantitative Analysis of Contrast-Enhanced Ultrasound Imaging in Invasive
           Breast Cancer: A Novel Technique to Obtain Histopathologic Information of
           Microvessel Density
    • Authors: Naoko Mori; Shunji Mugikura; Shoki Takahashi; Koichi Ito; Chiaki Takasawa; Li Li; Minoru Miyashita; Atsuko Kasajima; Yu Mori; Takanori Ishida; Tetsuya Kodama; Kei Takase
      Pages: 607 - 614
      Abstract: Publication date: March 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 3
      Author(s): Naoko Mori, Shunji Mugikura, Shoki Takahashi, Koichi Ito, Chiaki Takasawa, Li Li, Minoru Miyashita, Atsuko Kasajima, Yu Mori, Takanori Ishida, Tetsuya Kodama, Kei Takase
      We examined whether enhancement area ratios obtained by the new bubble detection method correlate with histologic microvessel density in invasive breast cancer. Forty consecutive patients with invasive breast cancer lesions underwent contrast-enhanced ultrasound. The ratio of enhanced area to manually segmented tumor area (enhancement area ratio) was obtained with the new method at peak and delayed phases (50–54, 55–59, 60–64 and 65–69 s). We also analyzed time–intensity curves to obtain peak intensity and area under curve. Enhancement area ratios in both peak and delayed phases (50–54, 55–59, 60–64 and 65–69 s) were significantly correlated with microvessel density (r = 0.57, 0.62, 0.68, 0.61 and 0.58; p = 0.0001, <0.0001, <.0001, <.0001 and 0.0001, respectively). In time–intensity curve analysis, peak intensity was significantly correlated (r = 0.43, p = 0.0073), whereas area under the curve was not (r = 0.29, p = 0.0769). Enhancement area ratios obtained by the new method were correlated with microvessel density in invasive breast cancer.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.009
       
  • A Novel Approach to Detecting Postpartum Hemorrhage Using
           Contrast-Enhanced Ultrasound
    • Authors: Kenji Imai; Tomomi Kotani; Hiroyuki Tsuda; Tomoko Nakano; Akihiro Hirakawa; Fumitaka Kikkawa
      Pages: 615 - 620
      Abstract: Publication date: March 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 3
      Author(s): Kenji Imai, Tomomi Kotani, Hiroyuki Tsuda, Tomoko Nakano, Akihiro Hirakawa, Fumitaka Kikkawa
      The aim of this study was to estimate the efficacy of contrast-enhanced ultrasound (CEUS) in detecting postpartum hemorrhage (PPH) after cesarean section. This is the first study of CEUS in obstetric hemorrhage. A total of 37 patients, operated at Nagoya University Hospital, underwent CEUS. We evaluated the findings of CEUS, which were qualitatively defined as positive when pooling or leakage of contrast agent was observed in the uterine cavity, by measuring the amount of bleeding during the first 4 h after cesarean section. The time–intensity curve patterns of leaked contrast agents were also analyzed for quantitative prediction of the amount of blood loss. Significant differences between the excessive hemorrhage (N = 7) and non-excessive hemorrhage groups (N = 30) were noted in the occurrence of positive CEUS (p = 0.011). Additionally, mean postpartum blood loss markedly increased in patients with a positive CEUS (p = 0.002). From a quantitative perspective, the time until leakage of contrast agents was detected correlated with the amount of bleeding, but the other characteristics of the time–intensity curve pattern did not provide valuable information. In conclusion, CEUS, which enables bedside assessment and rapid diagnosis, is a promising strategy for the detection of PPH.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.008
       
  • Contrast-Enhanced Ultrasound Using Perfluorobutane-Containing Microbubbles
           in the Assessment of Liver Allograft Damage: An Exploratory Prospective
           Study
    • Authors: Ijin Joo; Jae Young Lee; Dong Ho Lee; Ju Hyeon Jeon; Hyeyoung Kim; Nam-Joon Yi; Kwang-Woong Lee; Kyung-Suk Suh
      Pages: 621 - 628
      Abstract: Publication date: March 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 3
      Author(s): Ijin Joo, Jae Young Lee, Dong Ho Lee, Ju Hyeon Jeon, Hyeyoung Kim, Nam-Joon Yi, Kwang-Woong Lee, Kyung-Suk Suh
      This prospective study investigated the usefulness of contrast (perfluorobutane-containing microbubbles)-enhanced ultrasound in the non-invasive assessment of liver allograft damage. Forty-one liver recipients underwent contrast-enhanced ultrasound followed by a liver biopsy. The hepatic filling rate (time between the arrival of contrast agent in the right hepatic artery and the maximum intensity of hepatic parenchyma) and parenchymal intensity difference before and after instantaneous high-power emission in the Kupffer phase were measured. Patients with allograft damage had higher hepatic filling rates and lower parenchymal intensity differences than those without damage (42.0 ± 16.9 vs. 30.5 ± 7.7 s, p = 0.005; 6.1 ± 7.4 vs. 16.6 ± 16.1 dB, p = 0.047, respectively). In the diagnosis of liver allograft damage, hepatic filling rate and parenchymal intensity difference had sensitivities of 61.5% and 90.9% and specificities of 92.6% and 63.6% using cutoffs of >38.5 s and ≤10.3 dB, respectively. In conclusion, contrast-enhanced ultrasound may be a promising tool in the detection of liver allograft damage.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.012
       
  • Effects of Non-Focused Microbubble-Enhanced and High-Intensity Focused
           Ultrasound on Hemostasis in a Rabbit Model of Liver Trauma
    • Authors: Da-Wei Zhao; Meng Tian; Jian-Zhong Zou; Yuan-Yi Zheng; Tao Li
      Pages: 629 - 639
      Abstract: Publication date: March 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 3
      Author(s): Da-Wei Zhao, Meng Tian, Jian-Zhong Zou, Yuan-Yi Zheng, Tao Li
      Uncontrolled hemorrhage after trauma to the liver can lead to death. The present study compared the effects of non-focused microbubble-enhanced ultrasound and high-intensity focused ultrasound on hepatic hemostasis in the injured liver. Blood perfusion level, serum liver enzyme levels and the aspartate transaminase/alanine transaminase ratio differed between the two types of treatment (all p values < 0.05). Hepatic cells in the microbubble-enhanced ultrasound group exhibited edema and compressed the hepatic sinus and blood vessels in the portal area. Coagulation and necrosis, inflammatory cell infiltration, and fibrous tissue encapsulation were observed in the high-intensity focused ultrasound group at later stages. The groups also differed in degree of ultrastructural damage and recovery time. Thus, microbubble-enhanced ultrasound has less of an impact on blood reperfusion and surrounding normal tissue than high-intensity focused ultrasound and is a better choice for the treatment of liver trauma.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.014
       
  • Cesarean Scar Pregnancy: Comparing the Efficacy and Tolerability of
           Treatment with High-Intensity Focused Ultrasound and Uterine Artery
           Embolization
    • Authors: Juhua Xiao; Zhen Shi; Jinshui Zhou; Jun Ye; Jianfang Zhu; Xin Zhou; Fang Wang; Shouhua Zhang
      Pages: 640 - 647
      Abstract: Publication date: March 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 3
      Author(s): Juhua Xiao, Zhen Shi, Jinshui Zhou, Jun Ye, Jianfang Zhu, Xin Zhou, Fang Wang, Shouhua Zhang
      The aim of this study was to investigate the clinical efficacy of high-intensity focused ultrasound (HIFU) for the treatment of a cesarean scar pregnancy compared with uterine artery embolization (UAE) and intra-arterial methotrexate infusion combined with uterine curettage. In this retrospective cohort study, 31 patients were treated with HIFU (HIFU group), and 45 patients were treated with UAE (UAE group). We compared the treatment and recovery of the patients, including follow-up. After UAE treatment, serum levels of the β subunit of human chorionic gonadotropin declined significantly on the first day, and the residual lesions disappeared in 3–17 wk. One patient underwent hysterectomy; intrauterine adhesions were found by hysteroscopic examination after 6 mo in 2 patients, whose menstrual function did not return to normal. The remainder of the 42 patients recovered normal menstrual functioning during the 3- to 18-wk follow-up. In the patients who underwent HIFU treatment, serum β-HCG levels did not decline rapidly; serum β-HCG levels increased in many patients and then declined to normal steadily within 2–12 wk. Lesions detached in 3–14 wk in all patients, and menstrual functioning was recovered in 3–9 wk without uterine curettage. Compared with the UAE group, the HIFU group had less pain and fewer complications; the patients in the HIFU group were not hospitalized or anesthetized and had lower costs. HIFU is an efficient, tolerable and non-invasive treatment.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.001
       
  • Strain-Initialized Robust Bone Surface Detection in 3-D Ultrasound
    • Authors: Mohammad Arafat Hussain; Antony J. Hodgson; Rafeef Abugharbieh
      Pages: 648 - 661
      Abstract: Publication date: March 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 3
      Author(s): Mohammad Arafat Hussain, Antony J. Hodgson, Rafeef Abugharbieh
      Three-dimensional ultrasound has been increasingly considered as a safe radiation-free alternative to radiation-based fluoroscopic imaging for surgical guidance during computer-assisted orthopedic interventions, but because ultrasound images contain significant artifacts, it is challenging to automatically extract bone surfaces from these images. We propose an effective way to extract 3-D bone surfaces using a surface growing approach that is seeded from 2-D bone contours. The initial 2-D bone contours are estimated from a combination of ultrasound strain images and envelope power images. Novel features of the proposed method include: (i) improvement of a previously reported 2-D strain imaging-based bone segmentation method by incorporation of a depth-dependent cumulative power of the envelope into the elastographic data; (ii) incorporation of an echo decorrelation measure-based weight to fuse the strain and envelope maps; (iii) use of local statistics of the bone surface candidate points to detect the presence of any bone discontinuity; and (iv) an extension of our 2-D bone contour into a 3-D bone surface by use of an effective surface growing approach. Our new method produced average improvements in the mean absolute error of 18% and 23%, respectively, on 2-D and 3-D experimental phantom data, compared with those of two state-of-the-art bone segmentation methods. Validation on 2-D and 3-D clinical in vivo data also reveals, respectively, an average improvement in the mean absolute fitting error of 55% and an 18-fold improvement in the computation time.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.11.003
       
  • Diagnosis of Complex Pulley Ruptures Using Ultrasound in Cadaver
           Models
    • Authors: Isabelle Schöffl; Arnica Hugel; Volker Schöffl; Wolfgang Rascher; Jörg Jüngert
      Pages: 662 - 669
      Abstract: Publication date: March 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 3
      Author(s): Isabelle Schöffl, Arnica Hugel, Volker Schöffl, Wolfgang Rascher, Jörg Jüngert
      Pulley ruptures are common in climbing athletes. The purposes of this study were to determine the specific positioning of each pulley with regards to the joint, and to evaluate the ultrasound diagnostics of various pulley rupture combinations. For this, 34 cadaver fingers were analyzed via ultrasound, the results of which were compared to anatomic measurements. Different pulley ruptures were then simulated and evaluated using ultrasound in standardized dynamic forced flexion. Visualization of the A2 and A4 pulleys was achieved 100% of the time, while the A3 pulley was visible in 74% of cases. Similarly, injuries to the A2 and A4 pulleys were readily observable, while A3 pulley injuries were more challenging to identify (sensitivity of 0.2 for singular A3 pulley, 0.5 for A2/A4 pulley and 0.33 for A3/A4 pulley ruptures). Receiver operating characteristic analysis was used to evaluate the optimal tendon-bone distance for pulley rupture diagnosis, a threshold which was determined to be 1.9 mm for A2 pulley ruptures and 1.85 for A4 pulley ruptures. This study was the first to carry out a cadaver ultrasound examination of a wide variety of pulley ruptures. Ultrasound is a highly accurate tool for visualizing the A2 and A4 pulleys in a cadaver model. This method of pathology diagnosis was determined to be suitable for injuries to the A2 and A4 pulleys, but inadequate for A3 pulley injuries.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2016.10.005
       
  • Editorial Advisory Board
    • Abstract: Publication date: April 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 4


      PubDate: 2017-03-27T16:57:48Z
       
  • Calendar
    • Abstract: Publication date: April 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 4


      PubDate: 2017-03-27T16:57:48Z
       
  • Ultrasound Stimulation of Insulin Release from Pancreatic Beta Cells as a
           Potential Novel Treatment for Type 2 Diabetes
    • Authors: Ivan Suarez Castellanos; Aleksandar Jeremic; Joshua Cohen; Vesna Zderic
      Abstract: Publication date: Available online 25 March 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Ivan Suarez Castellanos, Aleksandar Jeremic, Joshua Cohen, Vesna Zderic
      Type 2 diabetes mellitus is a complex metabolic disease that has reached epidemic proportions in the United States and around the world. This disease is characterized by loss of insulin secretion and, eventually, destruction of insulin-producing pancreatic beta cells. Controlling type 2 diabetes is often difficult as pharmacological management routinely requires complex therapy with multiple medications, and loses its effectiveness over time. The objective of this study was to explore the effectiveness of a novel, non-pharmacological approach that uses the application of ultrasound energy to augment insulin release from rat INS 832/13 beta cells. The cells were exposed to unfocused ultrasound for 5 min at a peak intensity of 1 W/cm2 and frequencies of 400 kHz, 600 kHz, 800 kHz and 1 MHz. Insulin release was measured with enzyme-linked immunosorbent assay and cell viability was assessed via the trypan blue dye exclusion test. A marked release (approximately 150 ng/106 cells, p < 0.05) of insulin was observed when beta cells were exposed to ultrasound at 400 and 600 kHz as compared with their initial control values; however, this release was accompanied by a substantial loss in cell viability. Ultrasound application at frequencies of 800 kHz resulted in 24 ng/106 cells released insulin (p < 0.05) as compared with its unstimulated base level, while retaining cell viability. Insulin release from beta cells caused by application of 800-kHz ultrasound was comparable to that reported by the secretagogue glucose, thus operating within physiological secretory capacity of these cells. Ultrasound has potential as a novel and alternative method to current approaches aimed at correcting secretory deficiencies in patients with type 2 diabetes.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2017.01.007
       
  • Mechanical and Biological Effects of Ultrasound: A Review of Present
           Knowledge
    • Authors: Zahra Izadifar; Paul Babyn; Dean Chapman
      Abstract: Publication date: Available online 23 March 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Zahra Izadifar, Paul Babyn, Dean Chapman
      Ultrasound is widely used for medical diagnosis and increasingly for therapeutic purposes. An understanding of the bio-effects of sonography is important for clinicians and scientists working in the field because permanent damage to biological tissues can occur at high levels of exposure. Here the underlying principles of thermal mechanisms and the physical interactions of ultrasound with biological tissues are reviewed. Adverse health effects derived from cellular studies, animal studies and clinical reports are reviewed to provide insight into the in vitro and in vivo bio-effects of ultrasound.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2017.01.023
       
  • Automatic Evaluation of Scan Adequacy and Dysplasia Metrics in 2-D
           Ultrasound Images of the Neonatal Hip
    • Authors: Niamul Quader; Antony J. Hodgson; Kishore Mulpuri; Emily Schaeffer; Rafeef Abugharbieh
      Abstract: Publication date: Available online 22 March 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Niamul Quader, Antony J. Hodgson, Kishore Mulpuri, Emily Schaeffer, Rafeef Abugharbieh
      Ultrasound (US) imaging of an infant's hip joint is widely used for early detection of developmental dysplasia of the hip. In current US-based diagnosis of developmental dysplasia of the hip, trained clinicians acquire US images and, if they judge them to be adequate (i.e., to contain relevant hip joint structures), analyze them manually to extract clinically useful dysplasia metrics. However, both the scan adequacy classification and dysplasia metrics extraction steps exhibit significant variability within and between both clinicians and institutions, which can result in significant over- and undertreatment rates. To reduce the subjectivity resulting from this variability, we propose a computational image analysis technique that automatically identifies adequate images and subsequently extracts dysplasia metrics from these 2-D US images. Our automatic method uses local phase symmetry-based image measures to robustly identify intensity-invariant geometric features of bone/cartilage boundaries from the US images. Using the extracted geometric features, we trained a random forest classifier to classify images as adequate or inadequate, and in the adequate images we used a subset of the geometric features to calculate key dysplasia metrics. We validated our method on a data set of 693 US scans collected from 35 infants. Our approach produces excellent agreement with clinician adequacy classifications (area under the receiver operating characteristic curve = 0.985) and in reducing variability in the measured developmental dysplasia of the hip metrics (p < 0.05). The automatically computed dysplasia metrics appear to be slightly biased toward higher Graf categories than the manually estimated metrics, which could potentially reduce missed early diagnoses.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2017.01.012
       
  • Validation of Shear Wave Elastography Cutoff Values on the Supersonic
           Aixplorer for Practical Clinical Use in Liver Fibrosis Staging
    • Authors: Manish Dhyani; Joseph R. Grajo; Atul K. Bhan; Kathleen Corey; Raymond Chung; Anthony E. Samir
      Abstract: Publication date: Available online 22 March 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Manish Dhyani, Joseph R. Grajo, Atul K. Bhan, Kathleen Corey, Raymond Chung, Anthony E. Samir
      The purpose of this study was to determine the validity of previously established ultrasound shear wave elastography (SWE) cut-off values (≥F2 fibrosis) on an independent cohort of patients with chronic liver disease. In this cross-sectional study, approved by the institutional review board and compliant with the Health Insurance Portability and Accountability Act, 338 patients undergoing liver biopsy underwent SWE using an Aixplorer ultrasound machine (SuperSonic Imagine, Aix-en-Provence, France). Median SWE values were calculated from sets of 10 elastograms. A single blinded pathologist evaluated METAVIR fibrosis staging as the gold standard. The study analyzed 277 patients with a mean age of 48 y. On pathologic examination, 212 patients (76.5%) had F0–F1 fibrosis, whereas 65 (23.5%) had ≥F2 fibrosis. Spearman's correlation of fibrosis with SWE was 0.456 (p < 0.001). A cut-off value of 7.29 kPa yielded sensitivity of 95.4% and specificity of 50.5% for the diagnosis of METAVIR stage ≥F2 liver fibrosis in patients with liver disease using the SuperSonic Imagine Aixplorer SWE system.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2017.01.022
       
  • Point Shear Wave Elastography to Evaluate and Monitor Changing Portal
           Venous Pressure in Patients with Decompensated Cirrhosis
    • Authors: Hao Han; Jian Yang; Yu-zheng Zhuge; Ming Zhang; Min Wu
      Abstract: Publication date: Available online 21 March 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Hao Han, Jian Yang, Yu-zheng Zhuge, Ming Zhang, Min Wu
      This study evaluated whether the stiffness of the liver and spleen, measured using the point shear wave elastography (pSWE) technique, correlates with portal venous pressure (PVP) and whether the result extends to estimate the diminishing change in PVP (ΔPVP) in patients with decompensated cirrhosis. We evaluated the data of 67 prospectively enrolled patients who underwent both transjugular intrahepatic portosystemic shunt (TIPS) and pSWE. The stiffness of liver and spleen were evaluated by measuring shear wave velocity (SWV) to determine the statistical correlation with PVP. We also analyzed whether change in SWV (ΔSWV) correlates with ΔPVP. The correlations were assessed with Spearman's rank correlation coefficients. Furthermore, receiver operating characteristic (ROC) curves were constructed to evaluate diagnostic capacity of ΔSWV. Spleen stiffness (SS) was positively correlated with PVP before and after TIPS (p < 0.002), although no correlation between liver stiffness and PVP was detected. A strong relationship between ΔSWV in SS and ΔPVP change in portal hypertension (r = 0.871) was also found in the overall population. The area under the ROC curve for the diagnosis of TIPS technical success was 0.869 and at a ΔSWV cut-off value of 0.36 m/s sensitivity was 77%. Measurement of SS can be used for non-invasive assessment and monitoring of PVP in patients with decompensated cirrhosis.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2017.01.019
       
  • Model for Porosity Changes Occurring during Ultrasound-Enhanced
           Transcorneal Drug Delivery
    • Authors: Prasanna Hariharan; Marjan Nabili; Allan Guan; Vesna Zderic; Matthew Myers
      Abstract: Publication date: Available online 21 March 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Prasanna Hariharan, Marjan Nabili, Allan Guan, Vesna Zderic, Matthew Myers
      Ultrasound-enhanced drug delivery through the cornea has considerable therapeutic potential. However, our understanding of how ultrasound enhances drug transport is poor, as is our ability to predict the increased level of transport for given ultrasound parameters. Described here is a computational model for quantifying changes in corneal porosity during ultrasound exposure. The model is calibrated through experiments involving sodium fluorescein transport through rabbit cornea. Validation was performed using nylon filters, for which the properties are known. It was found that exposure to 800-kHz ultrasound at an intensity 2 W/cm2 for 5 min increased the porosity of the epithelium by a factor of 5. The model can be useful for determining the extent to which ultrasound enhances the amount of drug transported through biological barriers, and the time at which a therapeutic dose is achieved at a given location, for different drugs and exposure strategies.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2017.01.013
       
  • Multi-focus Beamforming for Thermal Strain Imaging Using a Single
           Ultrasound Linear Array Transducer
    • Authors: Man M. Nguyen; Xuan Ding; Steven A. Leers; Kang Kim
      Abstract: Publication date: Available online 18 March 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Man M. Nguyen, Xuan Ding, Steven A. Leers, Kang Kim
      Ultrasound-induced thermal strain imaging (TSI) has been used successfully to identify lipid- and water-based tissues in atherosclerotic plaques in some research settings. However, TSI faces several challenges to be realized in clinics. These challenges include motion artifacts and displacement tracking accuracy, as well as limited heating capability, which contributes to low thermal strain signal-to-noise ratio, and a limited field of view. Our goal was to address the challenge in heating tissue in TSI. Current TSI systems use separate heating and imaging transducers, which require physical alignment of the heating and imaging beams and result in a bulky setup that limits in vivo operation. We evaluated a new design for heating beams that can be implemented on a linear array imaging transducer and can provide improved heating area and efficiency as compared with previous implementations. The heating beams designed were implemented with a clinical linear array imaging transducer connected to a research ultrasound platform. In vitro experiments using tissue-mimicking phantoms with no blood flow revealed that the new design resulted in an effective heating area of approximately 0.85 cm2 and a 0.3°C temperature rise in 2 s of heating, which compared well with in silico finite-element simulations. With the new heating beams, TSI was found to be able to detect a lipid-mimicking rubber inclusion with a diameter of 1 cm from the water-based gelatin background, with a strain contrast of 2.3 (+0.14% strain in the rubber inclusion and −0.06% strain in the gelatin background). Lastly, lipid-based tissue in a 1-cm-diameter human carotid endarterectomy (CEA) sample was identified in good agreement with histology.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2017.01.015
       
  • Non-invasive Liver Ablation Using Histotripsy: Preclinical Safety Study in
           an in Vivo Porcine Model
    • Authors: Eli Vlaisavljevich; Gabe Owens; Jonathan Lundt; Dejan Teofilovic; Kimberly Ives; Alexander Duryea; Jim Bertolina; Theodore H. Welling; Zhen Xu
      Abstract: Publication date: Available online 17 March 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Eli Vlaisavljevich, Gabe Owens, Jonathan Lundt, Dejan Teofilovic, Kimberly Ives, Alexander Duryea, Jim Bertolina, Theodore H. Welling, Zhen Xu
      This study investigates the safety profile for use of histotripsy, a non-invasive ultrasonic ablation method currently being developed for the treatment of liver cancer, for liver ablation in an in vivo porcine model. Histotripsy treatments were applied to the liver and hepatic veins of 22 porcine subjects, with half of the subjects receiving systemic heparinization. Vital signs (heart rate, blood pressure, temperature, electrocardiogram and SpO2) were monitored throughout the procedure and for 1 h post-treatment. Blood was drawn at six points during the experiment to analyze blood gases, liver function and free hemoglobin levels. All treatments were guided and monitored by real-time ultrasound imaging. After treatment, the tissue was harvested for histological analysis. Results indicated that histotripsy generated well-defined lesions inside the liver and around the treated hepatic veins of all subjects in both treatment groups. Vital signs and blood analysis revealed that animals responded well to histotripsy, with all animals surviving the treatment. One animal in the non-heparinized group had a transient increase in pH and decreases in blood pressure, heart rate and PCO2 during the 15-min vessel treatment, with these changes returning to baseline levels soon after the treatment. Overall, the results indicate that histotripsy can safely be performed on the liver without the need for systemic heparinization, even in regions containing large hepatic vessels, supporting its future use for the treatment of liver cancer.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2017.01.016
       
  • Measuring Endotracheal Tube Depth by Bedside Ultrasound in Adult Patients
           in an Intensive Care Unit: A Pilot Study
    • Authors: Fenglin Dong; Canhong Zhu; Huiwen Xu; Jiajia Wang; Yehan Zhu; Qingmin Fan; Jian'an Huang; Wei Lei
      Abstract: Publication date: Available online 17 March 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Fenglin Dong, Canhong Zhu, Huiwen Xu, Jiajia Wang, Yehan Zhu, Qingmin Fan, Jian'an Huang, Wei Lei
      The aim of the study described here was to evaluate the feasibility and accuracy of measuring endotracheal tube (ETT) depth with ultrasound in adult patients in an intensive care unit (ICU). The distance between the upper margin of the cuff and the upper margin of the aortic arch (Duc-ua) of 67 ICU patients was measured by ultrasound, and the time of measurement was recorded. The level of agreement between the distance between the tip of the ETT and the carina (Dtt-c) measured by ultrasound (U-Dtt-c) and Dtt-c measured by bronchoscopy (B-Dtt-c) was assessed using linear regression and a Bland–Altman plot. There was a significant correlation between B-Dtt-c and U-Dtt-c (r = 0.844, p < 0.001). Also, the Bland–Altman plot revealed strong agreement between B-Dtt-c and U-Dtt-c. The time it took to measure ETT depth by ultrasound was 33.91 ± 5.43 s. In conclusion, bedside ultrasound provides a novel and convenient method for measuring the depth of ETT in ICU patients.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2017.01.018
       
  • Characterization of the Lung Parenchyma Using Ultrasound Multiple
           Scattering
    • Authors: Kaustav Mohanty; John Blackwell; Thomas Egan; Marie Muller
      Abstract: Publication date: Available online 16 March 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Kaustav Mohanty, John Blackwell, Thomas Egan, Marie Muller
      The purpose of the study described here was to showcase the application of ultrasound to quantitative characterization of the micro-architecture of the lung parenchyma to predict the extent of pulmonary edema. The lung parenchyma is a highly complex and diffusive medium for which ultrasound techniques have remained qualitative. The approach presented here is based on ultrasound multiple scattering and exploits the complexity of ultrasound propagation in the lung structure. The experimental setup consisted of a linear transducer array with an 8-MHz central frequency placed in contact with the lung surface. The diffusion constant D and transport mean free path L* of the lung parenchyma were estimated by separating the incoherent and coherent intensities in the near field and measuring the growth of the incoherent diffusive halo over time. Significant differences were observed between the L* values obtained in healthy and edematous rat lungs in vivo. In the control rat lung, L* was found to be 332 μm (±48.8 μm), whereas in the edematous lung, it was 1040 μm (±90 μm). The reproducibility of the measurements of L* and D was tested in vivo and in phantoms made of melamine sponge with varying air volume fractions. Two-dimensional finite difference time domain numerical simulations were carried out on rabbit lung histology images with varying degrees of lung collapse. Significant correlations were observed between air volume fraction and L* in simulation (r = −0.9542, p < 0.0117) and sponge phantom (r = −0.9932, p < 0.0068) experiments. Ex vivo measurements of a rat lung in which edema was simulated by adding phosphate-buffered saline revealed a linear relationship between the fluid volume fraction and L*. These results illustrate the potential of methods based on ultrasound multiple scattering for the quantitative characterization of the lung parenchyma.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2017.01.011
       
  • Evaluation of Post-stroke Spastic Muscle Stiffness Using Shear Wave
           Ultrasound Elastography
    • Authors: Chueh-Hung Wu; Yu-Chun Ho; Ming-Yen Hsiao; Wen-Shiang Chen; Tyng-Guey Wang
      Abstract: Publication date: Available online 9 March 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Chueh-Hung Wu, Yu-Chun Ho, Ming-Yen Hsiao, Wen-Shiang Chen, Tyng-Guey Wang
      Current clinical evaluations of post-stroke upper limb spasticity are subjective and qualitative. We proposed a quantitative measurement of post-stroke spastic muscle stiffness by using shear-wave ultrasound elastography and tested its reliability. Acoustic radiation force impulse with shear wave velocity (SWV) detection was used to evaluate stiffness of the biceps brachii muscles at 90° and 0° elbow flexion. In 21 control subjects, SWV did not significantly differ between dominant and non-dominant sides at either flexion angle (0°: p = 0.311, 90°: p = 0.436). In 31 patients who had recent stroke, SWV was significantly greater on the paretic side than on the non-paretic side at both 90° (2.23 ± 0.15 m/s vs. 1.88 ± 0.08 m/s, p = 0.036) and 0° (3.28 ± 0.11 m/s vs. 2.93 ± 0.06 m/s, p = 0.002). The physical appearance of arms and forearms of our patients and controls prevented blinding of the rater to paretic or non-paretic side. At 90°, SWV on the paretic side correlated positively with modified Ashworth scale and modified Tardieu scale (spasticity severity) and negatively with Stroke Rehabilitation Assessment of Movement score (motor function impairment). The intra-class correlation coefficients of intra-rater and inter-rater reliability for SWV measurements were classified as excellent. In conclusion, high SWV was associated with high spasticity and poor function of the post-stroke upper limb, suggesting possible use as a reliable quantitative measure for disease progression and treatment follow-up.

      PubDate: 2017-03-27T16:57:48Z
      DOI: 10.1016/j.ultrasmedbio.2016.12.008
       
  • Whole-Breast Ultrasound for Breast Screening and Archiving
    • Authors: Chiun-Sheng Huang; Ya-Wen Yang; Rong-Tai Chen; Chung-Ming Lo; Chao Lo; Ching-Fen Cheng; Chao-Shuan Lee; Ruey-Feng Chang
      Abstract: Publication date: Available online 7 March 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Chiun-Sheng Huang, Ya-Wen Yang, Rong-Tai Chen, Chung-Ming Lo, Chao Lo, Ching-Fen Cheng, Chao-Shuan Lee, Ruey-Feng Chang
      The incidence of breast cancer is increasing worldwide, reinforcing the importance of breast screening. Conventional hand-held ultrasound (HHUS) for breast screening is efficient and relatively easy to perform; however, it lacks systematic recording and localization. This study investigated an electromagnetic tracking-based whole-breast ultrasound (WBUS) system to facilitate the use of HHUS for breast screening. One-hundred nine breast masses were collected, and the detection of suspicious breast lesions was compared between the WBUS system, HHUS and a commercial automated breast ultrasound (ABUS) system. The positioning error between WBUS and ABUS (1.39 ± 0.68 cm) was significantly smaller than that between HHUS and ABUS (1.62 ± 0.91 cm, p = 0.014) and HHUS and WBUS (1.63 ± 0.9 cm, p = 0.024). WBUS is a practical clinical tool for breast screening that can be used instead of the often unavailable and costly ABUS.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2017.01.009
       
  • Pharmacokinetics of Perfluorobutane after Intra-venous Bolus Injection of
           Sonazoid in Healthy Chinese Volunteers
    • Authors: Pengfei Li; Susan Hoppmann; Ping Du; Huiling Li; Paul M. Evans; Siver A. Moestue; Weiyue Yu; Fang Dong; Hongchuan Liu; Lihong Liu
      Abstract: Publication date: Available online 7 March 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Pengfei Li, Susan Hoppmann, Ping Du, Huiling Li, Paul M. Evans, Siver A. Moestue, Weiyue Yu, Fang Dong, Hongchuan Liu, Lihong Liu
      Sonazoid is an ultrasound contrast agent based on microbubbles (MB) containing perfluorobutane (PFB) gas. Sonazoid is approved in Japan, Korea and Norway for contrast-enhanced ultrasonography of focal liver lesions and focal breast lesions (Japan only). The objective of this study was to determine the pharmacokinetics (PKs) and safety of Sonazoid in Chinese healthy volunteers (HVs) and to evaluate the potential for ethnic differences in PKs between Chinese and Caucasian HVs. Sonazoid was administered as an intra-venous bolus injection at the clinical dose of 0.12 μL or 0.60 μL MB/kg body weight to two groups of eight Chinese HVs. Expired air and blood samples were collected and analyzed using a validated gas chromatographic tandem mass spectrometry method, and the main PK parameters were calculated. The highest PFB concentrations in blood were observed shortly after intra-venous administration of Sonazoid, and elimination of PFB was rapid. In the 0.12 μL MB/kg body weight cohort, PFB concentrations above the limit of quantification were observed for only 10 to 15 min post-injection. In the 0.60 μL MB/kg body weight cohort, PFB concentrations above the limit of quantification were observed for 60 min post-injection, and the shape of the elimination curve suggested a biphasic elimination profile. The maximum observed concentration (C max) values of PFB in blood were 2.3 ± 1.1 and 19.1 ± 9.2 ng/g for the 0.12 and 0.60 μL MB/kg body weight dose groups (mean ± standard deviation). Area under the curve values were 10.1 ± 2.7 and 90.1 ± 38.3 ng × min/g for the 0.12 and 0.60 μL MB/kg body weight dose groups. C max values of PFB in exhaled air were 0.35 ± 0.2 and 2.4 ± 0.7 ng/mL for the 0.12 and 0.60 μL MB/kg body weight dose groups. Assessment of laboratory parameters, vital signs, oxygen saturation and electrocardiograms revealed no changes indicative of a concern. The PK profile and safety data generated in the Chinese HVs were comparable to previous data for Caucasian HVs.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2017.01.003
       
  • Effect of Hypoxemia on Fetal Ventricular Deformation in a Chronically
           Instrumented Sheep Model
    • Authors: Amarnath Bhide; Juha Rasanen; Heikki Huhta; Juulia Junno; Tiina Erkinaro; Pasi Ohtonen; Mervi Haapsamo; Ganesh Acharya
      Abstract: Publication date: Available online 6 March 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Amarnath Bhide, Juha Rasanen, Heikki Huhta, Juulia Junno, Tiina Erkinaro, Pasi Ohtonen, Mervi Haapsamo, Ganesh Acharya
      We hypothesized that in near-term sheep fetuses, hypoxemia changes myocardial function as reflected in altered ventricular deformation on speckle-tracking echocardiography. Fetuses in 21 pregnant sheep were instrumented. After 4 d of recovery, fetal cardiac function was assessed by echocardiography at baseline, after 30 and 120 min of induced fetal hypoxemia and after its reversal. Left (LV) and right (RV) ventricular cardiac output and myocardial strain were measured. Baseline mean (standard deviation [SD]) LV and RV global longitudinal strains were −18.7% (3.8) and −14.3% (5.3). Baseline RV global longitudinal and circumferential deformations were less compared with those of the left ventricle (p = 0.016 and p < 0.005). LV, but not RV, global longitudinal strain was decreased (p = 0.003) compared with baseline with hypoxemia. Circumferential and radial strains did not exhibit significant changes. In the near-term sheep fetus, LV global longitudinal and circumferential strains are more negative than RV strains. Acute hypoxemia leads to LV rather than RV dysfunction as reflected by decreased deformation.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2017.01.010
       
  • Assessment of Curve Flexibility on Scoliotic Surgical Candidates Using
           Ultrasound Imaging Method
    • Authors: Rui Zheng; Doug Hill; Douglas Hedden; Marc Moreau; Lawrence H. Le; Jim Raso; Edmond Lou
      Abstract: Publication date: Available online 6 March 2017
      Source:Ultrasound in Medicine & Biology
      Author(s): Rui Zheng, Doug Hill, Douglas Hedden, Marc Moreau, Lawrence H. Le, Jim Raso, Edmond Lou
      The ultrasound imaging method was implemented to assess the spinal curve flexibility of scoliotic surgical candidates, or how much correction it can achieve while patients are bending or lying down. Fifteen participants were recruited. Pre-operative radiographs and ultrasound images in both standing and bending positions were acquired. The post-operative standing radiographs were obtained 1 wk after surgery. Two raters (RZ, EL) measured the ultrasound images twice, 1 wk apart. A curve correction index (C I ) was developed to estimate the curve flexibility. The C I from the pre-operative bending radiograph, ultrasound and post-operative radiograph were 0.51 ± 0.18; R1: 0.74 ± 0.08 vs R2: 0.72 ± 0.09 and 0.60 ± 0.10, respectively. The correlation of C I between ultrasound and post-operative radiography was slightly higher than the pre-operative bending and post-operative radiography. This pilot study demonstrated the bending ultrasound method is a promising supplemental tool to assess curve flexibility before surgical intervention for scoliotic surgical candidates.

      PubDate: 2017-03-09T16:22:24Z
      DOI: 10.1016/j.ultrasmedbio.2017.01.017
       
  • Editorial Advisory Board
    • Abstract: Publication date: March 2017
      Source:Ultrasound in Medicine & Biology, Volume 43, Issue 3


      PubDate: 2017-03-09T16:22:24Z
       
 
 
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