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Samuel Beckett Today/Aujourd'hui     Full-text available via subscription   (Followers: 2)
Science and Technology of Nuclear Installations     Open Access   (Followers: 1)
Science China : Physics, Mechanics & Astronomy     Full-text available via subscription   (Followers: 1)
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Solid-State Circuits Magazine, IEEE     Hybrid Journal   (Followers: 4)
South African Journal for Research in Sport, Physical Education and Recreation     Full-text available via subscription   (Followers: 4)
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Space Weather     Full-text available via subscription   (Followers: 3)
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Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy     Hybrid Journal   (Followers: 8)
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Spectroscopy Letters: An International Journal for Rapid Communication     Hybrid Journal   (Followers: 3)
Sri Lankan Journal of Physics     Open Access  
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Women in Engineering Magazine, IEEE     Full-text available via subscription   (Followers: 8)
World Journal of Condensed Matter Physics     Open Access  
X-Acoustics: Imaging and Sensing : Photoacoustics, Thermoacoustics, Magnetoacoustics     Open Access  
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Journal Cover   Ultrasound in Medicine & Biology
  [SJR: 0.939]   [H-I: 91]   [6 followers]  Follow
    
   Full-text available via subscription Subscription journal
   ISSN (Print) 0301-5629
   Published by Elsevier Homepage  [2800 journals]
  • Masthead
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10




      PubDate: 2015-08-29T09:10:21Z
       
  • Editorial Advisory Board
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10




      PubDate: 2015-08-29T09:10:21Z
       
  • Contents
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10




      PubDate: 2015-08-29T09:10:21Z
       
  • Trauma Ultrasound
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Sirote Wongwaisayawan, Ruedeekorn Suwannanon, Thidathit Prachanukool, Pungkava Sricharoen, Nitima Saksobhavivat, Rathachai Kaewlai
      Ultrasound plays a pivotal role in the evaluation of acute trauma patients through the use of multi-site scanning encompassing abdominal, cardiothoracic, vascular and skeletal scans. In a high-speed polytrauma setting, because exsanguinations are the primary cause of trauma morbidity and mortality, ultrasound is used for quick and accurate detection of hemorrhages in the pericardial, pleural, and peritoneal cavities during the primary Advanced Trauma Life Support (ATLS) survey. Volume status can be assessed non-invasively with ultrasound of the inferior vena cava (IVC), which is a useful tool in the initial phase and follow-up evaluations. Pneumothorax can also be quickly detected with ultrasound. During the secondary survey and in patients sustaining low-speed or localized trauma, ultrasound can be used to help detect abdominal organ injuries. This is particularly helpful in patients in whom hemoperitoneum is not identified on an initial scan because findings of organ injuries will expedite the next test, often computed tomography (CT). Moreover, ultrasound can assist in detection of fractures easily obscured on radiography, such as rib and sternal fractures.


      PubDate: 2015-08-29T09:10:21Z
       
  • Acoustic Radiation Force Impulse Elastography in the Diagnosis of Thyroid
           Nodules: Useful or Not Useful'
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Yi-Feng Zhang, Hui-Xiong Xu, Jun-Mei Xu, Chang Liu, Le-Hang Guo, Lin-Na Liu, Jing Zhang, Xiao-Hong Xu, Shen Qu, Mingzhao Xing
      The goal of this study is to evaluate the diagnostic performance of acoustic radiation force impulse (ARFI) elastography for differentiating benign from malignant thyroid nodules. One hundred and seventy-four pathologically proven thyroid nodules (139 benign, 35 malignant) in 154 patients (mean age: 49.2 ± 12.1 y; range: 16–72 y) were included in this study. Conventional ultrasound (US) and ARFI elastography using virtual touch tissue imaging (VTI) and virtual touch tissue quantification (VTQ) were performed to examine the thyroid nodules. Two blinded readers with different amounts of experience independently scored the likelihood of malignancy on the basis of a five-point scale in three different image-reading sets. The diagnostic performances among different image-reading sets and between the two readers were compared. The diagnostic specificity of both readers improved significantly after reading the VTI images or both VTI and VTQ images (all p < 0.05). After review of the results of both VTI and VTQ, the numbers of correctly diagnosed nodules increased in nodules <1.0 cm for both readers and in both nodular goiter and papillary thyroid carcinoma for the junior reader (p < 0.05). The nodules with definite diagnoses (i.e., confidence levels including definite benign and definite malignant cases) increased after review of VTI and VTQ images versus conventional US for the senior reader (p < 0.05). In conclusion, adding ARFI elastography improves the specificity in diagnosing malignant thyroid nodules compared with conventional US on its own. ARFI elastography particularly facilitates the specific diagnosis for thyroid nodules smaller than 1.0 cm. ARFI elastography is also able to increase the diagnostic confidence of the readers.


      PubDate: 2015-08-29T09:10:21Z
       
  • Diagnosis of Severe Carpal Tunnel Syndrome Using Nerve Conduction Study
           and Ultrasonography
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Kazuhiro Fujimoto, Tsukasa Kanchiku, Kenji Kido, Yasuaki Imajo, Masahiro Funaba, Toshihiko Taguchi
      This study investigated the correlation between nerve conduction study and ultrasonographic findings for assessment of the usefulness of ultrasonography in determining carpal tunnel syndrome severity. Hands of adults with carpal tunnel syndrome were assessed using ultrasound and nerve conduction studies and grouped according to median nerve cross-sectional area (CSA). There were significant differences (p < 0.01) in mean median nerve CSA between controls, patients with median sensory nerve conduction velocity ≤40 m/s and patients with absent sensory nerve action potential and between controls, patients with median nerve distal motor latency ≥4.5 ms and patients with absent compound muscle action potentials of the abductor pollicis brevis. This is the first report to define median nerve CSA cutoff values (18 mm2) for determining carpal tunnel syndrome severity in patients with absent compound muscle action potentials of the abductor pollicis brevis. Median nerve CSA values below the cutoff values should prompt clinicians to consider other disorders, such as cervical compressive myelopathy.


      PubDate: 2015-08-29T09:10:21Z
       
  • Ultrasound Fetal Weight Estimation: How Accurate Are We Now Under
           Emergency Conditions'
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Kaouther Dimassi, Fatma Douik, Mariem Ajroudi, Amel Triki, Mohamed Faouzi Gara
      The primary aim of this study was to evaluate the accuracy of sonographic estimation of fetal weight when performed at due date by first-line sonographers. This was a prospective study including 500 singleton pregnancies. Ultrasound examinations were performed by residents on delivery day. Estimated fetal weights (EFWs) were calculated and compared with the corresponding birth weights. The median absolute difference between EFW and birth weight was 200 g (100–330). This difference was within ±10% in 75.2% of the cases. The median absolute percentage error was 5.53% (2.70%–10.03%). Linear regression analysis revealed a good correlation between EFW and birth weight (r = 0.79, p < 0.0001). According to Bland–Altman analysis, bias was −85.06 g (95% limits of agreement: −663.33 to 494.21). In conclusion, EFWs calculated by residents were as accurate as those calculated by experienced sonographers. Nevertheless, predictive performance remains limited, with a low sensitivity in the diagnosis of macrosomia.


      PubDate: 2015-08-29T09:10:21Z
       
  • Quantity and Quality of the Lower Extremity Muscles in Women with Knee
           Osteoarthritis
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Masashi Taniguchi, Yoshihiro Fukumoto, Masashi Kobayashi, Taku Kawasaki, Shoji Maegawa, Satoko Ibuki, Noriaki Ichihashi
      The objective of the study described here was to compare lower extremity muscle quantity and quality between individuals with and those without knee osteoarthritis (OA). Twenty-one women with knee OA (mild, n = 8; severe, n = 13) and 23 healthy patients participated. Ultrasonography was used to measure muscle thickness (MT) and echo intensity (EI) of the rectus femoris, vastus intermedius, vastus lateralis, vastus medialis, biceps femoris, gluteus maximus, gluteus medius, gastrocnemius, soleus and tibialis anterior. MTs of the vastus medialis and vastus intermedius were smaller, and EIs of the vastus medialis, vastus intermedius, gluteus medius and tibialis anterior were larger, in the severe OA group compared than in the healthy group. Compared with the healthy group, the mild OA group had decreased MT and enhanced EI. Changes in quality and quantity occurring with knee OA progression differed among muscles. In the vastus medialis, change was observed from an earlier stage.


      PubDate: 2015-08-29T09:10:21Z
       
  • Shear Wave Elastography (SWE): An Analysis of Breast Lesion
           Characterization in 83 Breast Lesions
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Alice Feldmann, Carole Langlois, Marion Dewailly, Elise Fréart Martinez, Loic Boulanger, Olivier Kerdraon, Nathalie Faye
      Qualitative and quantitative shear wave elastography (SWE) criteria were assessed to differentiate between malignant and benign breast lesions. This prospective study included 83 lesions. SWE features measured included maximal stiffness values inside the lesion (Elesion) and in the peri-lesion area (Eperilesion) and ratio values (Rlesion and Rperilesion) according to the formula Elesion or Eperilesion/Efat, with Efat corresponding to normal fatty tissue. We compared ultrasonography (B-mode), SWE and histologic sizes. With qualitative and quantitative SWE analysis, sensitivity was 94% and specificity 73%. Malignant lesions appeared more heterogeneous, with higher stiffness and ratio values than benign lesions (p < 0.001). For malignant lesions, SWE size was better correlated to histologic size than B-mode size. Using benign SWE signs to selectively downgrade category 4a and 4b lesions, the specificity improved from 13% to 51% without loss in sensitivity (100%) compared to ultrasound.


      PubDate: 2015-08-29T09:10:21Z
       
  • Sonoelastography of Plantar Fascia: Reproducibility and Pattern
           Description in Healthy Subjects and Symptomatic Subjects
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): José Ríos-Díaz, Jacinto J. Martínez-Payá, María Elena del Baño-Aledo, Ana de Groot-Ferrando, Paloma Botía-Castillo, David Fernández-Rodríguez
      The purpose of the work reported here was to describe the sonoelastographic appearance of the plantar fascia of healthy volunteers and patients with fasciitis. Twenty-three healthy subjects and 21 patients with plantar fasciitis were examined using B-mode and real-time sonoelastography (RTSR) scanning. B-Mode examination included fascia thickness and echotexture. Echogenicity and echovariation of the color histogram were analyzed. Fasciae were classified into type 1, blue (more elastic); type 2, blue/green (intermediate); or type 3, green (less elastic). RTSE revealed 72.7% of fasciae as type 2, with no significant association with fasciitis (χ2 = 3.6, df = 2, p = 0.17). Quantitative analysis of the color histogram revealed a significantly greater intensity of green (mean = 77.8, 95% confidence interval [CI] = 71.9–83.6) and blue (mean = 74.2, 95% CI = 69.7–78.8) in healthy subjects. Echovariation of the color red was 33.4% higher in the fasciitis group than in the healthy group (95% CI = 16.7–50.1). Sonoelastography with quantitative analysis of echovariation can be a useful tool for evaluation of plantar fascia pathology.


      PubDate: 2015-08-29T09:10:21Z
       
  • Use of Endoscopic Ultrasound to Evaluate Large Gastric Folds: Features
           Predictive of Malignancy
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Hyun Lim, Gin Hyug Lee, Hee Kyong Na, Ji Yong Ahn, Jeong Hoon Lee, Kwi-Sook Choi, Do Hoon Kim, Kee Don Choi, Ho June Song, Hwoon-Yong Jung, Jin-Ho Kim, Dowhan Kim, Young Soo Park
      The aim of this study was to investigate with endoscopic ultrasound (EUS) the features of the gastric wall that can be used to predict malignant disease in patients with large gastric folds. We retrospectively reviewed the EUS findings of 65 patients (26 with benign and 39 with malignant disease) with large gastric folds on endoscopy and EUS and analyzed the predictors of malignant disease (e.g., gastric wall thickness, preservation of five-layered structure, thickened layers). Gastric wall thickness (≥9.8 mm), thickened deep layer, thickened muscularis propria and non-preserved wall layer structures were significantly more prevalent in patients with malignant disease on EUS. Among them, gastric wall thickness (≥9.8 mm) (odds ratio = 6.72, 95% confidence interval = 1.23–36.73, p = 0.028) and thickened muscularis propria (odds ratio = 37.14, 95% confidence interval = 7.02–196.49, p < 0.001) were significantly associated with malignant disease. Our data indicate that EUS is a useful tool for assessing large gastric folds and that gastric wall thickness (≥9.8 mm) and thickened muscularis propria are significant features predictive of malignant disease on EUS.


      PubDate: 2015-08-29T09:10:21Z
       
  • Quantitative Contrast-Enhanced Ultrasonic Imaging Reflects
           Microvascularization in Hepatocellular Carcinoma and Prognosis after
           Resection
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Ru-Hai Zou, Qing-Guang Lin, Wei Huang, Xiao-Ling Li, Yun Cao, Jing Zhang, Jian-Hua Zhou, An-Hua Li, Laura Beretta, Chao-Nan Qian
      Our aim was to evaluate the correlation between tumor vasculature detected by pre-surgical contrast-enhanced ultrasonography and the post-surgical prognosis of patients with hepatocellular carcinoma. One hundred ninety-five patients with hepatocellular carcinoma who had undergone curative resection and pre-operative contrast-enhanced ultrasonography were enrolled. Intra-tumoral microvessels were evaluated by immunohistochemical staining for anti-CD31 and anti-CD34. On the basis of the immunohistochemical staining and morphology patterns, tumors were divided into capillary-like and sinusoid-like microvessel subtypes. The rise time of tumors was shorter in the capillary-like microvessel subtype than in the sinusoid-like microvasculature subtype (p = 0.026). Intra-tumor microvascular density (p < 0.001, hazard ratio = 0.137) and rise time (p = 0.006, hazard ratio = 2.475) were independent factors corresponding to different microvasculature types. Microvascular density, vascular invasion and wash-in perfusion index were determined to be independent factors in recurrence-free survival and overall survival. In conclusion, contrast-enhanced ultrasonography may serve as a means of non-invasive assessment of tumor angiogenesis and may be associated with the survival of patients with hepatocellular carcinoma after resection.


      PubDate: 2015-08-29T09:10:21Z
       
  • Comparison of Ultrasound Corticomedullary Strain with Doppler Parameters
           in Assessment of Renal Allograft Interstitial Fibrosis/Tubular Atrophy
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Jing Gao, Jonathan M. Rubin, William Weitzel, Jun Lee, Darshana Dadhania, Sandip Kapur, Robert Min
      To compare the capability of ultrasound strain and Doppler parameters in the assessment of renal allograft interstitial fibrosis/tubular atrophy (IF/TA), we prospectively measured ultrasound corticomedullary strain (strain) and intra-renal artery Doppler end-diastolic velocity (EDV), peak systolic velocity (PSV) and resistive index (RI) in 45 renal transplant recipients before their kidney biopsies. We used 2-D speckle tracking to estimate strain, the deformation ratio of renal cortex to medulla produced by external compression using the ultrasound transducer. We also measured Doppler EDV, PSV and RI at the renal allograft inter-lobar artery. Using the Banff scoring system for renal allograft IF/TA, 45 patients were divided into the following groups: group 1 with ≤5% (n = 12) cortical IF/TA; group 2 with 6%–25% (n = 12); group 3 with 26%–50% (n = 11); and group 4 with >50% (n = 10). We performed receiver operating characteristic curve analysis to test the accuracy of these ultrasound parameters and duration of transplantation in determining >26% cortical IF/TA. In our results, strain was statistically significant in all paired groups (all p < 0.005) and inversely correlated with the grade of cortical IF/TA (p < 0.001). However, the difference in PSV and EDV was significant only between high-grade (>26%, including 26%–50% and >50%) and low-grade (≤25%, including <5% and 6%–25%) cortical IF/TA (p < 0.001). RI did not significantly differ in any paired group (all p > 0.05). The areas under the receiver operating characteristic curve for strain, EDV, PSV, RI and duration of transplantation in determining >26% cortical IF/TA were 0.99, 0.94, 0.88, 0.52 and 0.92, respectively. Our results suggest that corticomedullary strain seems to be superior to Doppler parameters and duration of transplantation in assessment of renal allograft cortical IF/TA.


      PubDate: 2015-08-29T09:10:21Z
       
  • Ultrasonographic Features of the Major Salivary Glands
           after Radioactive Iodine Ablation in Patients with Papillary Thyroid
           Carcinoma
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Dong Wook Kim
      The aim of this study was to evaluate the ultrasonographic features of the major salivary glands (MSGs) after post-operative radioactive iodine ablation (RIA) in patients with papillary thyroid carcinoma (PTC). The study population comprised 202 consecutively registered PTC patients who had undergone total thyroidectomy, RIA and follow-up neck ultrasonography. The ultrasonographic features of the MSGs in each patient were retrospectively evaluated by a single radiologist, and the presence of post-RIA changes was determined by direct comparisons of pre- and post-RIA follow-up ultrasonographic scans. Of the 202 patients, 94 (46.5%) had post-RIA changes in the MSGs on follow-up ultrasonography. RIA dose was closely associated with the prevalence of post-RIA changes. Post-RIA changes were more common in the parotid glands (n = 93, 46.0%) than in the submandibular glands (n = 7, 3.5%). Common ultrasonographic findings representing post-RIA changes in MSGs included coarse echotexture, decreased echogenicity, lobulated margin and decreased gland size.


      PubDate: 2015-08-29T09:10:21Z
       
  • Automated Computed Tomography–Ultrasound Cross-Modality 3-D
           Contouring Algorithm for Prostate
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Denis Ermacora, Silvia Pesente, Francesco Pascoli, Sebastian Raducci, Rudy Mauro, Imad Abu Rumeileh, Frank Verhaegen, Davide Fontanarosa
      A novel fully automated algorithm is introduced for 3-D cross-modality image segmentation of the prostate, based on the simultaneous use of co-registered computed tomography (CT) and 3-D ultrasound (US) images. By use of a Gabor feature detector, the algorithm can outline in three dimensions and in cross-modality the prostate, and it can be trained and optimized on specific patient populations. We applied it to 16 prostate cancer patients and evaluated the conformity between the automatically segmented prostate contours and the contours manually outlined by an experienced physician, on the CT–US fusion, using the mean distance to conformity (MDC) index. When only the CT scans were used, the average MDC value was 4.5 ± 1.7 mm (maximum value = 9.0 mm). When the US scans also were considered, the mean ± standard deviation was reduced to 3.9 ± 0.7 mm (maximum value = 5.5 mm). The cross-modality approach acted on all the largest distance values, reducing them to acceptable discrepancies.


      PubDate: 2015-08-29T09:10:21Z
       
  • Single-Camera Closed-Form Real-Time Needle Tracking
           for Ultrasound-Guided Needle Insertion
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Mohammad Najafi, Purang Abolmaesumi, Robert Rohling
      Many common needle intervention procedures are performed with ultrasound guidance because it is a flexible, cost-effective and widely available intra-operative imaging modality. In a needle insertion procedure with ultrasound guidance, real-time calculation and visualization of the needle trajectory can help to guide the choice of puncture site and needle angle to reach the target depicted in the ultrasound image. We found that it is feasible to calculate the needle trajectory with a single camera mounted directly on the ultrasound transducer by using the needle markings. Higher accuracy is achieved compared with other similar transducer-mounted needle trackers. We used an inexpensive, real-time and easy-to-use tracking method based on an automatic feature extraction algorithm and a closed-form method for pose estimation of the needle. The overall accuracy was 0.94 ± 0.46 mm.


      PubDate: 2015-08-29T09:10:21Z
       
  • Lumbar Ultrasound Image Feature Extraction and Classification with Support
           Vector Machine
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Shuang Yu, Kok Kiong Tan, Ban Leong Sng, Shengjin Li, Alex Tiong Heng Sia
      Needle entry site localization remains a challenge for procedures that involve lumbar puncture, for example, epidural anesthesia. To solve the problem, we have developed an image classification algorithm that can automatically identify the bone/interspinous region for ultrasound images obtained from lumbar spine of pregnant patients in the transverse plane. The proposed algorithm consists of feature extraction, feature selection and machine learning procedures. A set of features, including matching values, positions and the appearance of black pixels within pre-defined windows along the midline, were extracted from the ultrasound images using template matching and midline detection methods. A support vector machine was then used to classify the bone images and interspinous images. The support vector machine model was trained with 1,040 images from 26 pregnant subjects and tested on 800 images from a separate set of 20 pregnant patients. A success rate of 95.0% on training set and 93.2% on test set was achieved with the proposed method. The trained support vector machine model was further tested on 46 off-line collected videos, and successfully identified the proper needle insertion site (interspinous region) in 45 of the cases. Therefore, the proposed method is able to process the ultrasound images of lumbar spine in an automatic manner, so as to facilitate the anesthetists' work of identifying the needle entry site.


      PubDate: 2015-08-29T09:10:21Z
       
  • A Computerized System to Assess Axillary Lymph Node Malignancy from
           Sonographic Images
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Aneta Chmielewski, Paul Dufort, Anabel M. Scaranelo
      A computational approach to classifying axillary lymph node metastasis in sonographic images is described. One hundred five ultrasound images of axillary lymph nodes from patients with breast cancer were evaluated (81 benign and 24 malignant), and each lymph node was manually segmented, delineating both the whole lymph node and internal hilum surfaces. Normalized signed distance transforms were computed from the segmented boundaries of both structures, and each pixel was then assigned coordinates in a 3-D feature space according to the pixel's intensity, its signed distance to the node boundary and its signed distance to the hilum boundary. Three-dimensional histograms over the feature space were accumulated for each node by summing over all pixels, and the bin counts served as predictor inputs to a support vector machine learning algorithm. Repeated random sampling of 80/25 train/test splits was used to estimate generalization performance and generate receiver operating characteristic curves. The optimal classifier had an area under the receiver operating characteristic curve of 0.95 and sensitivity and specificity of 0.90 and 0.90. Our results indicate the feasibility of axillary nodal staging with computerized analysis.


      PubDate: 2015-08-29T09:10:21Z
       
  • High-Frequency Acoustic Impedance Imaging of Cancer Cells
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Muhannad N. Fadhel, Elizabeth S.L. Berndl, Eric M. Strohm, Michael C. Kolios
      Variations in the acoustic impedance throughout cells and tissue can be used to gain insight into cellular microstructures and the physiologic state of the cell. Ultrasound imaging can be used to create a map of the acoustic impedance, on which fluctuations can be used to help identify the dominant ultrasound scattering source in cells, providing information for ultrasound tissue characterization. The physiologic state of a cell can be inferred from the average acoustic impedance values, as many cellular physiologic changes are linked to an alteration in their mechanical properties. A recently proposed method, acoustic impedance imaging, has been used to measure the acoustic impedance maps of biological tissues, but the method has not been used to characterize individual cells. Using this method to image cells can result in more precise acoustic impedance maps of cells than obtained previously using time-resolved acoustic microscopy. We employed an acoustic microscope using a transducer with a center frequency of 375 MHz to calculate the acoustic impedance of normal (MCF-10 A) and cancerous (MCF-7) breast cells. The generated acoustic impedance maps and simulations suggest that the position of the nucleus with respect to the polystyrene substrate may have an effect on the measured acoustic impedance value of the cell. Fluorescence microscopy and confocal microscopy were used to correlate acoustic impedance images with the position of the nucleus within the cell. The average acoustic impedance statistically differed between normal and cancerous breast cells (1.636 ± 0.010 MRayl vs. 1.612 ± 0.006 MRayl), indicating that acoustic impedance could be used to differentiate between normal and cancerous cells.


      PubDate: 2015-08-29T09:10:21Z
       
  • Signal of Interest Selection Standard for Ultrasonic Backscatter in
           Cancellous Bone Evaluation
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Chengcheng Liu, Tao Tang, Feng Xu, Dean Ta, Mami Matsukawa, Bo Hu, Weiqi Wang
      The aim of this study was to examine the effect of the backscattered signal of interest (SOI) on ultrasonic cancellous bone evaluation. In vitro backscatter measurements were performed using 16 bovine cancellous bone specimens and six different transducers with central frequencies of 0.5, 1, 2.25, 3.5, 5 and 10 MHz. The SOI for signal analysis was selected by a rectangular window. The delay (T1) and duration (T2) of the time window were varied, and the apparent integrated backscatter (AIB) and its correlation to bone volume fraction (BV/TV) were calculated. The results indicate that in addition to affecting the measured value of AIB, the SOI influences the observed correlation between AIB and BV/TV. Strong positive correlations were observed for short T1 (0.5 MHz: ≤6 μs, 1 MHz: ≤3 μs, 2.25 and 3.5 MHz: ≤2 μs, 5 and 10 MHz: ≤1 μs). However, strong negative correlations were observed when T1 was long (0.5 MHz: >9 μs, 1 MHz: >7 μs, 2.25 and 3.5 MHz: >3 μs, 5 and 10 MHz: >2 μs). The T2 value, especially low values (≤3 μs), also influenced the correlation coefficients. Positive correlations were more commonly observed at lower frequencies (i.e., 0.5–1 MHz), whereas negative correlations were more common at higher frequencies (i.e., 2.25–10 MHz). An explicit standard for in vitro SOI selection and cancellous bone assessment was proposed for a broad frequency range (0.5–10 MHz). Current conflicting findings are explained, and constructive suggestions for ultrasonic backscatter cancellous bone evaluation are provided.


      PubDate: 2015-08-29T09:10:21Z
       
  • In Vivo Measures of Shear Wave Speed as a Predictor of Tendon
           Elasticity and Strength
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Jack A. Martin, Adam H. Biedrzycki, Kenneth S. Lee, Ryan J. DeWall, Sabrina H. Brounts, William L. Murphy, Mark D. Markel, Darryl G. Thelen
      The purpose of this study was to assess the potential for ultrasound shear wave elastography (SWE) to measure tissue elasticity and ultimate stress in both intact and healing tendons. The lateral gastrocnemius (Achilles) tendons of 41 New Zealand white rabbits were surgically severed and repaired with growth factor coated sutures. SWE imaging was used to measure shear wave speed (SWS) in both the medial and lateral tendons pre-surgery, and at 2 and 4 wk post-surgery. Rabbits were euthanized at 4 wk, and both medial and lateral tendons underwent mechanical testing to failure. SWS significantly (p < 0.001) decreased an average of 17% between the intact and post-surgical state across all tendons. SWS was significantly (p < 0.001) correlated with both the tendon elastic modulus (r = 0.52) and ultimate stress (r = 0.58). Thus, ultrasound SWE is a potentially promising non-invasive technology for quantitatively assessing the mechanical integrity of pre-operative and post-operative tendons.


      PubDate: 2015-08-29T09:10:21Z
       
  • Combination of Protoporphyrin IX-mediated Sonodynamic Treatment with
           Doxorubicin Synergistically Induced Apoptotic Cell Death of a
           Multidrug-Resistant Leukemia K562/DOX Cell Line
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Xiaobing Wang, Yali Jia, Xiaomin Su, Pan Wang, Kun Zhang, Xiaolan Feng, Quanhong Liu
      The main objective of this study was to evaluate the efficacy of administration of doxorubicin (DOX) in combination with protoporphyrin IX (PpIX)-assisted low-level therapeutic ultrasound (US) in K562/DOX cells as a potential strategy in cancer therapy. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to determine the cytotoxicity of different treatments. Apoptosis was analyzed using annexin V-PE/7-amino-actinomycin D staining. Changes in DNA fragmentation, intracellular reactive oxygen species production, cellular membrane permeability, P-glycoprotein expression and DOX uptake were analyzed with flow cytometry. Under optimal conditions, PpIX-US significantly aggravated DOX-induced K562/DOX cell death, compared with either monotherapy. Synergistic potentiation of DNA damage, generation of reactive oxygen species and P-glycoprotein inhibition were observed. Plasma membrane integrity changed slightly after US exposure, and DOX uptake was notably improved after PpIX-US exposure. The results indicate that PpIX-US could increase the susceptibility of tumors to antineoplastic drugs, suggesting a clinical potential method for sonodynamic therapy-mediated tumor chemotherapy.


      PubDate: 2015-08-29T09:10:21Z
       
  • Low-Intensity Ultrasound Promotes Clathrin-Dependent Endocytosis for Drug
           Penetration into Tumor Cells
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Sophie Tardoski, Evelyne Gineyts, Jacqueline Ngo, Anthony Kocot, Philippe Clézardin, David Melodelima
      Ultrasound-mediated drug delivery is a field of research with promising results, although the exact mechanisms underlying intracellular delivery of therapeutic compounds remain to be elucidated. Many studies use drug carriers and cavitation to enhance drug uptake into tumor cells. However, cavitation could induce cell lysis and remain difficult to control and predict in vivo. In this study, low-intensity ultrasound was delivered using two transducers working at 2.9 and 1.3 MHz. The maximal peak negative pressure was 0.29 MPa to avoid cavitation. Low-intensity ultrasound induced clathrin-mediated endocytosis and forced the penetration of a bisphosphonate (zoledronic acid) into MCF-7 human breast cancer cells potentially as a result of mechanical stresses. When sonication parameters were adjusted to create mild hyperthermia in addition to the mechanical stress, further significant accumulation of ZOL was observed. These results provide better insight into the role of acoustic parameters in drug uptake.


      PubDate: 2015-08-29T09:10:21Z
       
  • Apoptosis Induced by Microbubble-Assisted Acoustic Cavitation in K562
           Cells: The Predominant Role of the Cyclosporin A-Dependent Mitochondrial
           Permeability Transition Pore
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Lu Zhao, Yi Feng, Aiwei Shi, Yujin Zong, Mingxi Wan
      Acoustic cavitation of microbubbles has been described as inducing tumor cell apoptosis that is partly associated with mitochondrial dysfunction; however, the exact mechanisms have not been fully characterized. Here, low-intensity pulsed ultrasound (1 MHz, 0.3-MPa peak negative pressure, 10% duty cycle and 1-kHz pulse repetition frequency) was applied to K562 chronic myelogenous leukemia cells for 1 min with 10% (v/v) SonoVue microbubbles. After ultrasound exposure, the apoptotic index was determined by flow cytometry with annexin V–fluorescein isothiocyanate/propidium iodide. In addition, mitochondrial membrane potential (ΔΨm) was determined with the JC-1 assay. Translocation of apoptosis-associated protein cytochrome c was evaluated by Western blotting. We found that microbubble-assisted acoustic cavitation can increase the cellular apoptotic index, mitochondrial depolarization and cytochrome c release in K562 cells, compared with ultrasound treatment alone. Furthermore, mitochondrial dysfunction and apoptosis were significantly inhibited by cyclosporin A, a classic inhibitor of the mitochondrial permeability transition pore; however, the inhibitor of Bax protein, Bax-inhibiting peptide, could not suppress these effects. Our results suggest that mitochondrial permeability transition pore opening is involved in mitochondrial dysfunction after exposure to microbubble-assisted acoustic cavitation. Moreover, the release of cytochrome c from the mitochondria is dependent on cyclosporin A–sensitive mitochondrial permeability transition pore opening, but not formation of the Bax-voltage dependent anion channel complex or Bax oligomeric pores. These data provide more insight into the mechanisms underlying mitochondrial dysfunction induced by acoustic cavitation and can be used as a basis for therapy.


      PubDate: 2015-08-29T09:10:21Z
       
  • A Lipopeptide-Based αvβ3 Integrin-Targeted Ultrasound Contrast
           Agent for Molecular Imaging of Tumor Angiogenesis
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Fei Yan, Xiuxia Xu, Yihan Chen, Zhiting Deng, Hongmei Liu, Jianrong Xu, Jie Zhou, Guanghong Tan, Junru Wu, Hairong Zheng
      The design and fabrication of targeted ultrasound contrast agents are key factors in the success of ultrasound molecular imaging applications. Here, we introduce a transformable αvβ3 integrin-targeted microbubble (MB) by incorporation of iRGD-lipopeptides into the MB membrane for non-invasive ultrasound imaging of tumor angiogenesis. First, the iRGD-lipopeptides were synthesized by conjugating iRGD peptides to distearoylphosphatidylethanolamine–polyethylene glycol 2000–maleimide. The resulting iRGD-lipopeptides were used for fabrication of the iRGD-carrying αvβ3 integrin-targeted MBs (iRGD-MBs). The binding specificity of iRGD-MBs for endothelial cells was found to be significantly stronger than that of control MBs (p < 0.01) under in vitro static and dynamic conditions. The binding of iRGD-MBs on the endothelial cells was competed off by pre-incubation with the anti-αv or anti-β3 antibody (p < 0.01). Ultrasound images taken of mice bearing 4T1 breast tumors after intravenous injections of iRGD-MBs or control MBs revealed strong contrast enhancement within the tumors from iRGD-MBs but not from the control MBs; the mean acoustic signal intensity was 10.71 ± 2.75 intensity units for iRGD-MBs versus 1.13 ± 0.18 intensity units for the control MBs (p < 0.01). The presence of αvβ3 integrin was confirmed by immunofluorescence staining. These data indicate that iRGD-MBs can be used as an ultrasound imaging probe for the non-invasive molecular imaging of tumor angiogenesis, and may have further implications for ultrasound image-guided tumor targeting drug delivery.


      PubDate: 2015-08-29T09:10:21Z
       
  • The Effect of Short Duration Ultrasound Pulses on the Interaction Between
           Individual Microbubbles and Fibrin Clots
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Christopher Acconcia, Ben Y.C. Leung, Anoop Manjunath, David E. Goertz
      In previous work, we examined microscale interactions between microbubbles and fibrin clots under exposure to 1 ms ultrasound pulses. This provided direct evidence that microbubbles were capable of deforming clot boundaries and penetrating into clots, while also affecting fluid uptake and inducing fibrin network damage. Here, we investigate the effect of short duration (15 μs) pulses on microscale bubble-clot interactions as function of bubble diameter (3–9 μm) and pressure. Individual microbubbles (n = 45) were placed at the clot boundary with optical tweezers and exposed to 1 MHz ultrasound. High-speed (10 kfps) imaging and 2-photon microscopy were performed during and after exposure, respectively. While broadly similar phenomena were observed as in the 1 ms pulse case (i.e., bubble penetration, network damage and fluid uptake), substantial quantitative differences were present. The pressure threshold for bubble penetration was increased from 0.39 MPa to 0.6 MPa, and those bubbles that did enter clots had reduced penetration depths and were associated with less fibrin network damage and nanobead uptake. This appeared to be due in large part to increased bubble shrinkage relative to the 1 ms pulse case. Stroboscopic imaging was performed on a subset of bubbles (n = 11) and indicated that complex bubble oscillations can occur during this process.


      PubDate: 2015-08-29T09:10:21Z
       
  • Microscale Acoustofluidics
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10
      Author(s): Eleanor Stride



      PubDate: 2015-08-29T09:10:21Z
       
  • “Erratum to: “Prenatal exposure to ultrasound affects learning
           and memory in young rats,” by Li Ping, Wang pei-jun, Zhang Wei.
           Ultrasound Med Biol 2015;41:644-653
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10




      PubDate: 2015-08-29T09:10:21Z
       
  • Calendar
    • Abstract: Publication date: October 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 10




      PubDate: 2015-08-29T09:10:21Z
       
  • Correlation between Quantitative Shear Wave Elastography and Pathologic
           Structures of Thyroid Lesions
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Takahiro Fukuhara, Eriko Matsuda, Yukari Endo, Masao Takenobu, Shoichiro Izawa, Kazunori Fujiwara, Hiroya Kitano
      The aim of this study was to determine the correlation between shear wave velocity (SWV) generated by acoustic radiation force impulse and the pathologic structure of thyroid lesions. A total of 599 thyroid tissue samples were divided into four groups based on pathologic structure: 254 normal thyroid tissue samples as a control, 128 with chronic autoimmune thyroiditis (CAT) that demonstrated diffuse fibrosis, 165 with benign nodules that had high cell density and 52 with papillary thyroid carcinoma (PTC) that showed high cell density and fibrosis. The mean SWVs in each group were as follows: 1.60 ± 0.18 m/s in normal thyroid, 2.55 ± 0.28 m/s in CAT, 1.72 ± 0.31 m/s in benign nodules and 2.66 ± 0.95 m/s in PTC. The SWVs of CAT and PTC were significantly higher than those of normal thyroid, (p < 0.001). SWV was significantly affected by fibrosis.


      PubDate: 2015-08-04T03:57:19Z
       
  • Three-Dimensional Transvaginal Tomographic Ultrasound Imaging for Cervical
           Cancer Staging
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Xue-Song Han, Chun-Ping Ning, Li-Tao Sun, Xiao-Ying Li, Yan-Qing Peng, Mei-Zheng Dang
      The objective of this study was to investigate the feasibility of using 3-D transvaginal tomographic ultrasound imaging (TUI) to stage patients with cervical carcinoma. Eighty women with cervical cancer who underwent transvaginal TUI examinations were enrolled. In all patients, cancer was confirmed pre-operatively by pathologic examination. Staging on the basis of clinical features, ultrasonography and magnetic resonance imaging was performed according to the International Federation of Gynecology and Obstetrics (FIGO) staging system. Clinical, TUI and magnetic resonance imaging staging was compared with that based on histology. Depth of invasion into the stroma was measured by TUI in 52 cases and compared with pathologic results. An interclass correlation coefficient was used to analyze reproducibility. In total, all 80 patients underwent surgical treatment. The accuracy of pre-operative staging, compared with histologic findings, was 92.50% for TUI, 82.50% for magnetic resonance imaging and 78.75% for clinical examination. The mean depth of lesions as measured with TUI was 12.5 ± 6.2 mm (range: 3.5–40.0 mm), and that measured on histology was 10.5 ± 8.0 mm (range: 3.0–40.0 mm). The interclass correlation coefficient of the two methods was 0.933 (95% confidence interval: 0.887–0.961). Pre-operative TUI is promising as a method for pre-operative staging of cervical carcinomas. TUI can also reliably assess lesion depth.


      PubDate: 2015-08-04T03:57:19Z
       
  • Ultrasound Imaging of Breast Tumor Perfusion
           and Neovascular Morphology
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Kenneth Hoyt, Heidi Umphrey, Mark Lockhart, Michelle Robbin, Andres Forero-Torres
      A novel image processing strategy is detailed for simultaneous measurement of tumor perfusion and neovascular morphology parameters from a sequence of dynamic contrast-enhanced ultrasound (DCE-US) images. After normalization and tumor segmentation, a global time–intensity curve describing contrast agent flow was analyzed to derive surrogate measures of tumor perfusion (i.e., peak intensity, time-to-peak intensity, area under the curve, wash-in rate, wash-out rate). A maximum intensity image was generated from these same segmented image sequences, and each vascular component was skeletonized via a thinning algorithm. This skeletonized data set and collection of vessel segments were then investigated to extract parameters related to the neovascular network and physical architecture (i.e., vessel-to-tissue ratio, number of bifurcations, vessel count, average vessel length and tortuosity). An efficient computation of local perfusion parameters was also introduced and operated by averaging time–intensity curve data over each individual neovascular segment. Each skeletonized neovascular segment was then color-coded by these local measures to produce a parametric map detailing spatial properties of tumor perfusion. Longitudinal DCE-US image data sets were collected in six patients diagnosed with invasive breast cancer using a Philips iU22 ultrasound system equipped with a L9-3 transducer and Definity contrast agent. Patients were imaged using US before and after contrast agent dosing at baseline and again at weeks 6, 12, 18 and 24 after treatment started. Preliminary clinical results suggested that breast tumor response to neoadjuvant chemotherapy may be associated with temporal and spatial changes in DCE-US-derived parametric measures of tumor perfusion. Moreover, changes in neovascular morphology parametric measures may also help identify any breast tumor response (or lack thereof) to systemic treatment. Breast cancer management from early detection to therapeutic monitoring is currently undergoing profound changes. Novel imaging techniques that are sensitive to the unique biological conditions of each individual tumor represent valuable tools in the pursuit of personalized medicine.


      PubDate: 2015-08-04T03:57:19Z
       
  • Masthead
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9




      PubDate: 2015-08-04T03:57:19Z
       
  • Reliable Protocol for Shear Wave Elastography of Lower Limb Muscles at
           Rest and During Passive Stretching
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Guillaume Dubois, Walid Kheireddine, Claudio Vergari, Dominique Bonneau, Patricia Thoreux, Philippe Rouch, Mickael Tanter, Jean-Luc Gennisson, Wafa Skalli
      Development of shear wave elastography gave access to non-invasive muscle stiffness assessment in vivo. The aim of the present study was to define a measurement protocol to be used in clinical routine for quantifying the shear modulus of lower limb muscles. Four positions were defined to evaluate shear modulus in 10 healthy subjects: parallel to the fibers, in the anterior and posterior aspects of the lower limb, at rest and during passive stretching. Reliability was first evaluated on two muscles by three operators; these measurements were repeated six times. Then, measurement reliability was compared in 11 muscles by two operators; these measurements were repeated three times. Reproducibility of shear modulus was 0.48 kPa and repeatability was 0.41 kPa, with all muscles pooled. Position did not significantly influence reliability. Shear wave elastography appeared to be an appropriate and reliable tool to evaluate the shear modulus of lower limb muscles with the proposed protocol.


      PubDate: 2015-08-04T03:57:19Z
       
  • Thyroid Nodule Parameters Influencing Performance of Ultrasound
           Elastography Using Intrinsic Compression
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Min-Hee Kim, Si Luo, Sun Hee Ko, Ja-Seong Bae, Jaechan Lim, Dong-Jun Lim, Yongmin Kim
      The influence of nodule parameters on the diagnostic accuracy of ultrasound (US) elastography in differentiating thyroid nodules was evaluated. One hundred seventy-six nodules (83 benign, 93 malignant) from 156 patients were included. Conventional B-mode and elastography examinations were performed. External compression with a transducer was not applied, as the pulsation from the carotid artery was used. Three nodule parameters (size, depth and distance to the carotid artery) were measured. The elasticity contrast index, in which increases with the stiffness of the nodules, was correlated with distance to the carotid artery (correlation coefficient = 0.283 in all nodules and 0.415 in malignant nodules, p < 0.01 in both groups). The diagnostic accuracy of elastography was significantly associated with a nodule's distance to the carotid artery (p < 0.05). No significant correlation was found between the diagnostic accuracy of elastography and the other parameters. Elastography results for nodules close to the carotid artery should be interpreted with caution.


      PubDate: 2015-08-04T03:57:19Z
       
  • Performance of 2-D Shear Wave Elastography in Liver Fibrosis Assessment
           Compared with Serologic Tests and Transient Elastography in Clinical
           Routine
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Simona Bota, Rafael Paternostro, Alexandra Etschmaier, Remy Schwarzer, Petra Salzl, Mattias Mandorfer, Christian Kienbacher, Monika Ferlitsch, Thomas Reiberger, Michael Trauner, Markus Peck-Radosavljevic, Arnulf Ferlitsch
      Liver stiffness values assessed with 2-D shear wave elastography (SWE), transient elastography (TE) and simple serologic tests were compared with respect to non-invasive assessment in a cohort of 127 consecutive patients with chronic liver diseases. The rate of reliable liver stiffness measurements was significantly higher with 2-D SWE than with TE: 99.2% versus 74.8%, p < 0.0001 (different reliability criteria used, according to current recommendations). In univariate analysis, liver stiffness measured with 2-D SWE correlated best with fibrosis stage estimated with TE (r = 0.699, p < 0.0001), followed by Forns score (r = 0.534, p < 0.0001) and King's score (r = 0.512, p < 0.0001). However, in multivariate analysis, only 2-D SWE-measured values remained correlated with fibrosis stage (p < 0.0001). The optimal 2-D SWE cutoff values for predicting significant fibrosis were 8.03 kPa for fibrosis stage ≥2 (area under the receiver operating characteristic curve = 0.832) and 13.1 kPa for fibrosis stage 4 (area under the receiver operating characteristic curve = 0.915), respectively. In conclusion, 2-D SWE can be used to obtain reliable liver stiffness measurements in almost all patients and performs very well in predicting the presence of liver cirrhosis.


      PubDate: 2015-08-04T03:57:19Z
       
  • Applicability of Shear Wave Elastography of the Major Salivary Glands:
           Values in Healthy Patients and Effects of Gender, Smoking and
           Pre-Compression
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Konstantinos Mantsopoulos, Nils Klintworth, Heinrich Iro, Alessandro Bozzato
      Our aim in this study was to determine normal shear wave elastography (SWE) values for the parenchyma of the major salivary glands and to evaluate the influences of gender, smoking, side and type of gland and varying amounts of ultrasound probe pressure on SWE values. Twenty-five consecutive healthy patients were examined with ultrasound. SWE velocities were measured with acoustic radiation force imaging in the hilum and central region of both glands with “normal” and very low pressure. Mean SWE velocities were 1.854 m/s for the parotid gland and 1.932 m/s for the submandibular gland. No statistically significant differences were detected between males and females, smokers and non-smokers, parotid and submandibular gland and left and right sides. Greater pre-compression with the ultrasound probe resulted in a statistically significant increase in the SWE values of both salivary glands (p < 0.000). The degree of pre-compression by the ultrasound transducer should be standardized, so that the reliability and reproducibility of this innovative method can be improved.


      PubDate: 2015-08-04T03:57:19Z
       
  • Use of Lung Ultrasound in Detection of Complications of Respiratory
           Distress Syndrome
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Happy K. Sawires, Eman A. Abdel Ghany, Nouran F. Hussein, Hadeel M. Seif
      Repeated chest radiography is required for the diagnosis and follow-up of neonates with respiratory distress syndrome (RDS) and carries the risk of radiation hazards. Lung ultrasound (LUS) is a non-invasive bedside diagnostic tool that has proven to be effective in the diagnosis of RDS. Our aim was to assess the role of LUS with respect to the standard chest X-ray (CXR) in the detection of complications of RDS in neonates. Ninety premature newborns of both genders with RDS (mean gestational age = 29.91 ± 1.33 wk) and 40 premature babies as a control group were involved in this study. All patients underwent initial clinical assessment as well as CXR and LUS. Those who presented with respiratory distress and/or exhibited deterioration of oxygenation parameters were followed by CXR and, within 4 h, by LUS. Alveolo-interstitial syndrome and pleural line abnormalities were detected in all cases (100%) in the initial assessment, patchy consolidation was detected in 34 cases and white lung was detected in 80 cases. Alveolo-interstitial syndrome was detected in 19 controls. In follow-up of the patients, LUS was superior to CXR in detection of consolidation and sub-pleural atelectasis, but not in detection of pneumothorax. We concluded that bedside LUS is a good non-hazardous alternative tool in the early detection and follow-up of RDS in the neonatal intensive care unit; it could be of value in reducing exposure to unnecessary radiation.


      PubDate: 2015-08-04T03:57:19Z
       
  • Editorial Advisory Board
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9




      PubDate: 2015-08-04T03:57:19Z
       
  • Contents
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9




      PubDate: 2015-08-04T03:57:19Z
       
  • Application of Ultrasonography in the Assessment of Skeletal Muscles in
           Children with and without Neuromuscular Disorders: A Systematic Review
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Nahid Rahmani, Mohammad Ali Mohseni-Bandpei, Roshanak Vameghi, Mahyar Salavati, Iraj Abdollahi
      The purpose of this study was to systematically review published studies (2000–2014) carried out on the application of ultrasonography (US) to evaluation of skeletal muscle size in children with and without neuromuscular disorders. Different databases including PubMed, Science Direct, OVID, MEDLINE, CINAHL, EMBASE, ProQuest and Google Scholar were searched. The key words used were: “children,” “ultrasound,” “skeletal muscles,” “neuromuscular disease,” “neurogenic disorders,” “spina bifida,” “myelomeningocele” and “reliability.” Eighteen articles were found to be relevant. Eight studies applied US in combination with additional methods of assessment. Four of the 18 studies did not have a control group. Ten studies applied only US in the assessment of skeletal muscles in children with and without neuromuscular diseases. In 9 studies, there were children ranging widely in age, and in 3 studies US was used to determine normal values for skeletal muscles. According to the results of these 18 reviewed articles, US is an appropriate, reliable and highly predictive method for assessment of skeletal muscles in children.


      PubDate: 2015-08-04T03:57:19Z
       
  • Intense Focused Ultrasound Stimulation of the Rotator Cuff: Evaluation of
           the Source of Pain in Rotator Cuff Tears and Tendinopathy
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Alfred C. Gellhorn, Cody Gillenwater, Pierre D. Mourad
      The objective of this preliminary study was to evaluate the ability of individual 0.1-s long pulses of intense focused ultrasound (iFU) emitted with a carrier frequency of 2 MHz to evoke diagnostic sensations when applied to patients whose shoulders have rotator cuff tears or tendinopathy. Patients were adults with painful shoulders and clinical and imaging findings consistent with rotator cuff disease. iFU stimulation of the shoulder was performed using B-mode ultrasound coupled with a focused ultrasound transducer that allowed image-guided delivery of precisely localized pulses of energy to different anatomic areas around the rotator cuff. The main outcome measure was iFU spatial average–temporal average intensity (I_SATA), and location required to elicit sensation. In control patients, iFU produced no sensation throughout the range of stimulation intensities (≤2000 W/cm2 I_SATA). In patients with rotator cuff disease, iFU was able to induce sensation in the tendons of the rotator cuff, the subacromial bursa, and the subchondral bone in patients with chronic shoulder pain and rotator cuff disease, with an average ± standard deviation intensity equaling 680 ± 281 W/cm2 I_SATA. This result suggests a primary role for these tissues in the pathogenesis of shoulder pain related to rotator cuff tendinopathy.


      PubDate: 2015-08-04T03:57:19Z
       
  • Using Passive Cavitation Images to Classify High-Intensity Focused
           Ultrasound Lesions
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Kevin J. Haworth, Vasant A. Salgaonkar, Nicholas M. Corregan, Christy K. Holland, T. Douglas Mast
      Passive cavitation imaging provides spatially resolved monitoring of cavitation emissions. However, the diffraction limit of a linear imaging array results in relatively poor range resolution. Poor range resolution has limited prior analyses of the spatial specificity and sensitivity of passive cavitation imaging in predicting thermal lesion formation. In this study, this limitation is overcome by orienting a linear array orthogonal to the high-intensity focused ultrasound propagation direction and performing passive imaging. Fourteen lesions were formed in ex vivo bovine liver samples as a result of 1.1-MHz continuous-wave ultrasound exposure. The lesions were classified as focal, “tadpole” or pre-focal based on their shape and location. Passive cavitation images were beamformed from emissions at the fundamental, harmonic, ultraharmonic and inharmonic frequencies with an established algorithm. Using the area under a receiver operating characteristic curve (AUROC), fundamental, harmonic and ultraharmonic emissions were found to be significant predictors of lesion formation for all lesion types. For both harmonic and ultraharmonic emissions, pre-focal lesions were classified most successfully (AUROC values of 0.87 and 0.88, respectively), followed by tadpole lesions (AUROC values of 0.77 and 0.64, respectively) and focal lesions (AUROC values of 0.65 and 0.60, respectively).


      PubDate: 2015-08-04T03:57:19Z
       
  • Radiofrequency Ablation for Hepatocellular Carcinoma: Utility of
           Conventional Ultrasound and Contrast-Enhanced Ultrasound in Guiding and
           Assessing Early Therapeutic Response and Short-Term Follow-Up Results
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Jing Du, Hong-Li Li, Bo Zhai, Samuel Chang, Feng-Hua Li
      The purpose of this study was to assess the efficacy of conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS) in guiding and assessing early therapeutic response to radiofrequency (RF) ablation for hepatocellular carcinomas (HCCs; up to 3 lesions, each ≤3 cm in diameter) and to report the short-term follow-up results. Between September 2011 and January 2013, 63 patients with 78 HCCs (≤3 cm) underwent conventional US- and CEUS-guided percutaneous RF ablation. CEUS was repeated after 20–30 min to assess therapeutic response, and local efficacy was further confirmed by contrast-enhanced magnetic resonance imaging (MRI) 1 mo after tumor ablation. Patients were followed periodically to look for local tumor or disease progression. Survival probability was estimated with the Kaplan–Meier method. Complete ablation was achieved for 76 (97.4%) of 78 HCCs in one (n = 73) or two (n = 3) sessions. No major complications were observed in any patient. The overall concordance in assessment of therapeutic efficacy of RF ablation between CEUS and MRI was 97.4% (76/78 tumors). The concordance test gave a value of κ = 0.74 (p < 0.001), indicating that CEUS had a high diagnostic agreement with MRI. During a mean follow-up of 20 mo, the local tumor progression rate was 5.3% (4/76 tumors). The 1-, 1.5- and 2-y cumulative survival rates were 98.4%, 96.1% and 92.6%, respectively. Although CEUS has some intrinsic limitations, the combined use of conventional US and CEUS provides a safe and efficient tool to guide RF ablation for HCCs 3 cm or smaller, with encouraging results in terms of survival rate and minimal complications. Moreover, the immediate post-procedural CEUS can be a reliable alternative to contrast-enhanced MRI for assessing the early therapeutic response to RF ablation.


      PubDate: 2015-08-04T03:57:19Z
       
  • Ultrasound-Guided Percutaneous Microwave Ablation Treatment of Initial
           Recurrent Hepatocellular Carcinoma after Hepatic Resection: Long-Term
           Outcomes
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Ting-Ting Zhang, Hong-Chang Luo, Xian Cui, Wei Zhang, Li-Ying Zhang, Xiao-Ping Chen, Kai-Yan Li
      This study aimed to evaluate the long-term outcomes after percutaneous microwave ablation (MWA) for patients with initial recurrent hepatocellular carcinoma (HCC) measuring ≤5 cm in diameter after hepatectomy. From May 2005 to December 2011, 89 patients with 116 initial recurrent HCCs after hepatectomy treated with percutaneous MWA were included in the study. One mo after MWA, the complete ablation rate was 91.0% (81/89). At 1, 3, 5 and 7 y, the respective overall and recurrence-free survival rates after percutaneous MWA were 73.3%, 53.7%, 39.6% and 17.3% and 58.5%, 26.4%, 22.0% and 11.0%. The cumulative incidence of local tumor progression (LTP) and the intra-hepatic distant recurrence (IDR)–free survival rates after MWA were 9.1%, 14.6%, 18.3% and 18.3% and 62.9%, 32.3%, 26.9% and 13.5% at 1, 3, 5 and 7 y, respectively. The multivariate analysis indicated that multiple tumors (p = 0.006), a poor Child-Pugh score (p = 0.003), serum α-fetoprotein (AFP) >100 ng/mL (p = 0.002), and MWA treatment failure (p = 0.000) were risk factors that significantly affected overall survival, and MWA treatment failure (p = 0.000) was a risk factor that significantly affected IDR-free survival. In conclusion, percutaneous MWA is an effective therapeutic technique for initial recurrent HCC measuring ≤5 cm in diameter after hepatectomy.


      PubDate: 2015-08-04T03:57:19Z
       
  • Body Positions in the Diagnosis of Right-to-Left Shunt by Contrast
           Transcranial Doppler
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Ke Han, Yingqi Xing, Yi Yang, A-Ching Chao, Wen-Yung Sheng, Han-Hwa Hu, Jiang Wu
      Contrast transcranial Doppler (c-TCD) is sensitive in detecting right-to-left shunt (RLS). However, the methodology and ideal posture are controversial. Consecutive migraine patients were prospectively examined for RLS using c-TCD. Each patient was examined while at rest and subsequently with the Valsalva maneuver (VM) in three positions: supine, left lateral decubitus and right lateral decubitus. RLS was diagnosed with at least one microbubble detected at any position. RLS was highest in the left lateral decubitus position, both during rest and with VM. The left lateral decubitus position was associated with the highest total number of microbubbles and greater shunt grades. Patients who tested positive in the other two positions had the lowest index position failure rate during rest in the left lateral decubitus position. In some patients in whom RLS is detected at rest, it may not be detected (false negative) under VM. To ensure c-TCD's the sensitivity to RLS, testing in the left lateral decubitus position at rest and under VM is suggested; testing in other positions is necessary to avoid false negatives.


      PubDate: 2015-08-04T03:57:19Z
       
  • Usefulness of Contrast Perfusion Echocardiography for Differential
           Diagnosis of Cardiac Masses
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Qiao-Ying Tang, Ling-Dan Guo, Wen-Xuan Wang, Wei Zhou, Ya-Ni Liu, Hong-Yun Liu, Li Li, You-Bin Deng
      The aim of this study was to assess the usefulness of contrast perfusion echocardiography in the differential diagnosis of different types of cardiac masses. Conventional echocardiography and contrast perfusion echocardiography were performed in 72 patients with cardiac masses. The degree of contrast enhancement of the mass and an adjacent section of myocardium after injection of contrast agent was determined by visual inspection and quantitative time–signal intensity curve analysis. The difference in maximal steady-state pixel intensity between the mass and the adjacent myocardium (ΔA mass–myocardium) was calculated. All masses had a pathologic diagnosis or resolved after anticoagulation. All 16 cardiac masses without enhancement on visual inspection were confirmed to be cardiac thrombi. Twenty-four masses with incomplete enhancement on visual inspection were recognized as benign tumors with validation methods. Of the 32 cardiac masses with complete enhancement, 30 were confirmed as malignant tumors and two as benign tumors with validation methods. The sensitivity and specificity of ΔA mass–myocardium in differentiating thrombi from tumors were 93% and 100%, respectively, and 100% and 97% in differentiating malignant tumors from benign tumors and thrombi. Both visual and quantitative assessment of degree of enhancement of cardiac masses in relation to the adjacent myocardium during contrast perfusion echocardiography had high diagnostic accuracy for differentiation of a thrombus from a tumor or a benign tumor from a malignant tumor.


      PubDate: 2015-08-04T03:57:19Z
       
  • Impact Factors and the Optimal Parameter of Acoustic Structure
           Quantification in the Assessment of Liver Fibrosis
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Yang Huang, Guang-Jian Liu, Bing Liao, Guang-Liang Huang, Jin-Yu Liang, Lu-Yao Zhou, Fen Wang, Wei Li, Xiao-Yan Xie, Wei Wang, Ming-De Lu
      The aims of the present study are to assess the impact factors on acoustic structure quantification (ASQ) ultrasound and find the optimal parameter for the assessment of liver fibrosis. Twenty healthy volunteers underwent ASQ examinations to evaluate impact factors in ASQ image acquisition and analysis. An additional 113 patients with liver diseases underwent standardized ASQ examinations, and the results were compared with histologic staging of liver fibrosis. We found that the right liver displayed lower values of ASQ parameters than the left (p = 0.000–0.021). Receive gain experienced no significant impact except gain 70 (p = 0.193–1.000). With regard to different diameter of involved vessels in regions of interest, the group ≤2.0 mm differed significantly with the group 2.1–5.0 mm (p = 0.000–0.033) and the group >5.0 mm (p = 0.000–0.062). However, the region of interest size (p = 0.438–1.000) and depth (p = 0.072–0.764) had no statistical impact. Good intra- and inter-operator reproducibilities were found in both image acquisitions and offline image analyses. In the liver fibrosis study, the focal disturbance ratio had the highest correlation with histologic fibrosis stage (r = 0.67, p < 0.001). In conclusion, the testing position, receive gain and involved vessels were the main factors in ASQ examinations and focal disturbance ratio was the optimal parameter in the assessment of liver fibrosis.


      PubDate: 2015-08-04T03:57:19Z
       
  • Clinical Evaluation of Synthetic Aperture Harmonic Imaging for Scanning
           Focal Malignant Liver Lesions
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Andreas Hjelm Brandt, Martin Christian Hemmsen, Peter Møller Hansen, Signe Sloth Madsen, Paul Suno Krohn, Theis Lange, Kristoffer Lindskov Hansen, Jørgen Arendt Jensen, Michael Bachmann Nielsen
      The purpose of the study was to perform a clinical comparison of synthetic aperture sequential beamforming tissue harmonic imaging (SASB-THI) sequences with a conventional imaging technique, dynamic receive focusing with THI (DRF-THI). Both techniques used pulse inversion and were recorded interleaved using a commercial ultrasound system (UltraView 800, BK Medical, Herlev, Denmark). Thirty-one patients with malignant focal liver lesions (confirmed by biopsy or computed tomography/magnetic resonance) were scanned. Detection of malignant focal liver lesions and preference of image quality were evaluated blinded off-line by eight radiologists. In total, 2,032 evaluations of 127 image sequences were completed. The sensitivity (77% SASB-THI, 76% DRF-THI, p = 0.54) and specificity (71% SASB-THI, 72% DRF-THI, p = 0.67) of detection of liver lesions and the evaluation of image quality (p = 0.63) did not differ between SASB-THI and DRF-THI. This study indicates the ability of SASB-THI in a true clinical setting.


      PubDate: 2015-08-04T03:57:19Z
       
  • Assessment of Liver Fibrosis with 2-D Shear Wave Elastography in
           Comparison to Transient Elastography and Acoustic Radiation Force Impulse
           Imaging in Patients with Chronic Liver Disease
    • Abstract: Publication date: September 2015
      Source:Ultrasound in Medicine & Biology, Volume 41, Issue 9
      Author(s): Ludmila Gerber, Daniela Kasper, Daniel Fitting, Viola Knop, Annika Vermehren, Kathrin Sprinzl, Martin L. Hansmann, Eva Herrmann, Joerg Bojunga, Joerg Albert, Christoph Sarrazin, Stefan Zeuzem, Mireen Friedrich-Rust
      Two-dimensional shear wave elastography (2-D SWE) is an ultrasound-based elastography method integrated into a conventional ultrasound machine. It can evaluate larger regions of interest and, therefore, might be better at determining the overall fibrosis distribution. The aim of this prospective study was to compare 2-D SWE with the two best evaluated liver elastography methods, transient elastography and acoustic radiation force impulse (point SWE using acoustic radiation force impulse) imaging, in the same population group. The study included 132 patients with chronic hepatopathies, in which liver stiffness was evaluated using transient elastography, acoustic radiation force impulse imaging and 2-D SWE. The reference methods were liver biopsy for the assessment of liver fibrosis (n = 101) and magnetic resonance imaging/computed tomography for the diagnosis of liver cirrhosis (n = 31). No significant difference in diagnostic accuracy, assessed as the area under the receiver operating characteristic curve (AUROC), was found between the three elastography methods (2-D SWE, transient elastography, acoustic radiation force impulse imaging) for the diagnosis of significant and advanced fibrosis and liver cirrhosis in the “per protocol” (AUROCs for fibrosis stages ≥2: 0.90, 0.95 and 0.91; for fibrosis stage [F] ≥3: 0.93, 0.95 and 0.94; for F = 4: 0.92, 0.96 and 0.92) and “intention to diagnose” cohort (AUROCs for F ≥2: 0.87, 0.92 and 0.91; for F ≥3: 0.91, 0.93 and 0.94; for F = 4: 0.88, 0.90 and 0.89). Therefore, 2-D SWE, ARFI imaging and transient elastography seem to be comparably good methods for non-invasive assessment of liver fibrosis.


      PubDate: 2015-08-04T03:57:19Z
       
 
 
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