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  Subjects -> PHYSICS (Total: 734 journals)
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Surface Review and Letters     Hybrid Journal   (Followers: 1)
Surface Science Reports     Full-text available via subscription   (Followers: 10)
Surface Science Spectra     Hybrid Journal  
Surface Topography : Metrology and Properties     Full-text available via subscription  
Synchrotron Radiation News     Hybrid Journal   (Followers: 1)
Synthetic Metals     Hybrid Journal   (Followers: 3)
Technical Physics     Hybrid Journal  
Technical Physics Letters     Hybrid Journal  
Tectonics     Full-text available via subscription   (Followers: 7)
The Astronomy and Astrophysics Review     Hybrid Journal   (Followers: 2)
The Chemical Physics of Solid Surfaces     Full-text available via subscription  
The European Physical Journal H     Hybrid Journal   (Followers: 1)
The European Physical Journal Plus     Open Access  
The International Journal of Multiphysics     Full-text available via subscription   (Followers: 2)
The Physics of Metals and Metallography     Hybrid Journal   (Followers: 1)
The Physics Teacher     Full-text available via subscription   (Followers: 4)
Theoretical and Computational Fluid Dynamics     Hybrid Journal   (Followers: 7)
Theoretical and Mathematical Physics     Hybrid Journal   (Followers: 4)
Transport Theory and Statistical Physics     Hybrid Journal   (Followers: 2)
Tribology International     Hybrid Journal   (Followers: 8)
Tribology Letters     Hybrid Journal   (Followers: 3)
Tribotest     Hybrid Journal   (Followers: 1)
Ultrasonics     Hybrid Journal   (Followers: 3)
Ultrasonics Sonochemistry     Hybrid Journal   (Followers: 2)
Ultrasound in Medicine & Biology     Full-text available via subscription   (Followers: 6)
Universal Journal of Physics and Application     Open Access  
Virtual Journal of Applications of Superconductivity     Hybrid Journal   (Followers: 1)
Virtual Journal of Biological Physics Research     Hybrid Journal   (Followers: 1)
Virtual Journal of Nanoscale Science & Technology     Hybrid Journal   (Followers: 1)
Virtual Journal of Quantum Information     Hybrid Journal  
Virtual Journal of Ultrafast Science     Hybrid Journal   (Followers: 7)
Western Journal of Communication     Hybrid Journal   (Followers: 4)
Women & Performance: a journal of feminist theory     Hybrid Journal   (Followers: 2)
Women in Engineering Magazine, IEEE     Full-text available via subscription   (Followers: 8)
World Journal of Condensed Matter Physics     Open Access  
Zeitschrift für angewandte Mathematik und Physik     Hybrid Journal   (Followers: 1)

  First | 1 2 3 4 5 6 | Last

Journal Cover Ultrasound in Medicine & Biology
   [8 followers]  Follow    
   Full-text available via subscription Subscription journal
     ISSN (Print) 0301-5629
     Published by Elsevier Homepage  [2563 journals]   [SJR: 0.864]   [H-I: 85]
  • Elastic Modulus of the Prostate: A New Non-invasive Feature to Diagnose
           Bladder Outlet Obstruction in Patients with Benign Prostatic Hyperplasia
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Mingbo Zhang , Shuai Fu , Yan Zhang , Jie Tang , Yun Zhou
      The purpose of our study was to develop a reliable method for the non-invasive evaluation of bladder outlet obstruction (BOO) caused by benign prostate hyperplasia (BPH). In our study, the International Prostate Symptom Score was assessed in, and trans-rectal ultrasound (TRUS) and shear wave sonoelastography (SWE) were performed on, 55 patients with BPH who had undergone urodynamic evaluation (the gold standard diagnostic procedure for BOO). The results indicated that the elastic modulus of the transitional zone was the indicator most strongly correlated with BOO stage (r = 0.666, p < 0.001), and had the largest area under the receiver operating characteristic curve, 0.826 (95% confidence interval: 0.717–0.934, p = 0.001). An elastic modulus of the transitional zone ≥32.4 kPa or a total prostate volume ≥54.4 mL was diagnostic of BOO, with a sensitivity, specificity, positive predictive value, negative predictive value and accuracy for BOO of 97.2%, 62.5%, 85.4%, 90.9% and 86.5%, respectively. The elastic modulus of the transitional zone is a promising indicator in the assessment of the severity of BOO. In addition, the combination of elastic modulus and total prostate volume was the most accurate indicator in the non-invasive diagnosis of BOO in patients with BPH.


      PubDate: 2014-06-10T15:09:35Z
       
  • Performance of Phalangeal Quantitative Ultrasound Parameters in the
           Evaluation of Reduced Bone Mineral Density Assessed By DX in Patients with
           21 Hydroxylase Deficiency
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Ezequiel M. Gonçalves , Leticia E. Sewaybricker , Fatima Baptista , Analiza M. Silva , Wellington R.G. Carvalho , Allan O. Santos , Maricilda P. de Mello , Sofia H.V. Lemos-Marini , Gil Guerra-Junior
      The purpose of this study was to verify the performance of quantitative ultrasound (QUS) parameters of proximal phalanges in the evaluation of reduced bone mineral density (BMD) in patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (21 OHD). Seventy patients with 21 OHD (41 females and 29 males), aged between 6–27 y were assessed. The QUS measurements, amplitude-dependent speed of sound (AD-SoS), bone transmission time (BTT), and ultrasound bone profile index (UBPI) were obtained using the BMD Sonic device (IGEA, Carpi, Italy) on the last four proximal phalanges in the non-dominant hand. BMD was determined by dual energy X-ray (DXA) across the total body and lumbar spine (LS). Total body and LS BMD were positively correlated to UBPI, BTT and AD-SoS (correlation coefficients ranged from 0.59–0.72, p < 0.001). In contrast, when comparing patients with normal and low (Z-score < −2) BMD, no differences were found in the QUS parameters. Furthermore, UBPI, BTT and AD-SoS measurements were not effective for diagnosing patients with reduced BMD by receiver operator characteristic curve parameters. Although the AD-SoS, BTT and UBPI showed significant correlations with the data obtained by DXA, they were not effective for diagnosing reduced bone mass in patients with 21 OHD.


      PubDate: 2014-06-10T15:09:35Z
       
  • Real-Time Elastography in the Diagnosis of Patients Suspected of Having
           Prostate Cancer: A Meta-analysis
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Binglan Zhang , Xuelei Ma , Wenli Zhan , Fuping Zhu , Minmin Li , Juan Huang , Yanyan Li , Luqi Xue , Lei Liu , Yuquan Wei
      The goal of the study described here was to assess the performance of real-time elastography (RTE) in the detection of prostate cancers using a meta-analysis. A literature search of PubMed, Medline, Embase and the Cochrane Library was conducted. Published studies that evaluated the diagnostic performance of RTE in the diagnosis of prostate cancer and using the histopathology of the radical prostatectomy specimen as a reference standard were included. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and area under the curve were calculated to examine the accuracy of RTE. A total of seven studies that included 508 patients were analyzed. The pooled sensitivity and specificity for the diagnosis of prostate cancer by RTE were 0.72 (95% confidence interval: 0.70–0.74) and 0.76 (0.74–0.78), respectively. The summary diagnostic odds ratio was 12.59 (7.26–21.84), and the area under the curve was 0.841 (Q* = 0.773). In conclusion, RTE imaging has high accuracy in the detection of prostate cancers using the histopathology of the radical prostatectomy specimen as the reference standard and may reduce the number of core biopsies in the future.


      PubDate: 2014-06-10T15:09:35Z
       
  • Contents
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8




      PubDate: 2014-06-10T15:09:35Z
       
  • Application of Ultrasound in the Assessment of Plantar Fascia in Patients
           With Plantar Fasciitis: A Systematic Review
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8
      Author(s): Mohammad Ali Mohseni-Bandpei , Masoomeh Nakhaee , Mohammad Ebrahim Mousavi , Ali Shakourirad , Mohammad Reza Safari , Reza Vahab Kashani
      Plantar fasciitis (PFS) is one of the most common causes of heel pain, estimated to affect 10% of the general population during their lifetime. Ultrasound (US) imaging technique is increasingly being used to assess plantar fascia (PF) thickness, monitor the effect of different interventions and guide therapeutic interventions in patients with PFS. The purpose of the present study was to systematically review previously published studies concerning the application of US in the assessment of PF in patients with PFS. A literature search was performed for the period 2000–2012 using the Science Direct, Scopus, PubMed, CINAHL, Medline, Embase and Springer databases. The key words used were: ultrasound, sonography, imaging techniques, ultrasonography, interventional ultrasonography, plantar fascia and plantar fasciitis. The literature search yielded 34 relevant studies. Sixteen studies evaluated the effect of different interventions on PF thickness in patients with PFS using US; 12 studies compared PF thickness between patients with and without PFS using US; 6 studies investigated the application of US as a guide for therapeutic intervention in patients with PFS. There were variations among studies in terms of methodology used. The results indicated that US can be considered a reliable imaging technique for assessing PF thickness, monitoring the effect of different interventions and guiding therapeutic interventions in patients with PFS.


      PubDate: 2014-06-10T15:09:35Z
       
  • Gray-Scale Ultrasonography Combined with Elastography Imaging for the
           Evaluation of Papillary Thyroid Microcarcinoma: As a Prognostic
           Clinicopathology Factor
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8
      Author(s): Zhan-Qiang Jin , Mei-Ying Lin , Wen-Hua Hu , Wei-Yong Li , Shao-Jun Bai
      Ultrasonography (US) is the preferred imaging modality for papillary thyroid microcarcinoma (PTMC). The aim of this study was to evaluate the importance of gray-scale ultrasound combined with elastography to predict extrathyroidal extension and cervical lymph node (LN) metastasis in patients with PTMC. We retrospectively evaluated gray-scale ultrasonic and elastographic results from 119 consecutive cases of PTMC with 138 nodules and correlated the histopathological findings. The results indicated that pathological extrathyroidal extension was significantly associated with T staging on US, extrathyroidal extension on US, bilaterality on US, boundary, strain ratio and hard malignancy as measured with the Rago score. Central LN metastasis on pathology was significantly associated with central LN metastasis on US, lateral LN metastasis on US, multifocality on US and bilaterality on US. Lateral LN metastasis on US was significantly associated with lateral LN metastasis on pathology. On multivariate analysis, T staging on US, extrathyroidal extension on US and hard malignancy as measured with the Rago score were significantly associated with pathological extrathyroidal extension. Lateral LN metastasis on US and bilaterality on US were independent factors in predicting central LN metastasis on pathology. Lateral LN metastasis on US was the predictive factor for lateral LN metastasis on pathology. US should be helpful in the diagnosis of PTMC and in the evaluation of possible PTMC recurrence on US in routine clinical practice.


      PubDate: 2014-06-10T15:09:35Z
       
  • Multimodal Evaluation of 2-D and 3-D Ultrasound, Computed Tomography and
           Magnetic Resonance Imaging in Measurements of the Thyroid Volume Using
           Universally Applicable Cross-Sectional Imaging Software: A Phantom Study
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Martin Freesmeyer , Steffen Wiegand , Jan-Henning Schierz , Thomas Winkens , Katharina Licht
      A precise estimate of thyroid volume is necessary for making adequate therapeutic decisions and planning, as well as for monitoring therapy response. The goal of this study was to compare the precision of different volumetry methods. Thyroid-shaped phantoms were subjected to volumetry via 2-D and 3-D ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI). The 3-D US scans were performed using sensor navigation and mechanical sweeping methods. Volumetry calculation ensued with the conventional ellipsoid model and the manual tracing method. The study confirmed the superiority of manual tracing with CT and MRI volumetry of the thyroid, but extended this knowledge also to the superiority of the 3-D US method, regardless of whether sensor navigation or mechanical sweeping is used. A novel aspect was successful use of the same universally applicable cross-imaging software for all modalities.


      PubDate: 2014-06-10T15:09:35Z
       
  • Percutaneous Radiofrequency Ablation of Benign Thyroid Nodules Assisted by
           a Virtual Needle Tracking System
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Giovanni Turtulici , Davide Orlandi , Angelo Corazza , Riccardo Sartoris , Lorenzo Egildo Derchi , Enzo Silvestri , Jung Hwan Baek
      Our aim was to assess the feasibility and outcome of ultrasound (US)-guided percutaneous radiofrequency (RF) ablation of benign thyroid nodules assisted by a real-time virtual needle tracking (VT) system. Forty-five patients (34 females, mean age ± standard deviation (SD): 44 ± 16 y, range: 29–68 y) with 45 benign non-functioning thyroid nodules (mean volume ± SD: 13.5 ± 6.7 mL, range: 12–22 mL) underwent VT-assisted US-guided RF ablation. Nodule volume was evaluated before treatment and during 6-mo of follow-up. Complication rates and patient satisfaction after treatment were also evaluated. By use of the VT system, the tip of the RF electrode was identified during all ablation procedures. The overall mean volume reduction and complication rate were 72.6 ± 11.3% and 2.5%, respectively. Overall satisfaction at the 6-mo follow-up was rated by patients as positive in 42 cases (93%). The VT system could be useful in thyroid nodule ablation procedures because it is able to track the RF electrode tip even when the tip is obscured by the bubbles produced by the ablative process. VT-assisted RF ablation can be a tolerable, non-surgical treatment for patients with benign non-functioning thyroid nodules.


      PubDate: 2014-06-10T15:09:35Z
       
  • Preliminary Study on the Role of Virtual Touch Tissue Quantification
           Combined with a Urinary β2-Microglobulin Test on the Early Diagnosis
           of Gouty Kidney Damage
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Fei Tian , Zheng-Bin Wang , Dong-Mei Meng , Rong-Gui Liu , Hai-Yan Zhang , Hui-Ying Li , Fei-Fei Lv
      The goal of the work described here was to evaluate the role of virtual touch tissue quantification (VTQ) combined with urinary β2-microglobulin (β2-MG) measurement in the early diagnosis of gouty kidney damage. Two hundred fifty-nine patients with gouty kidney damage and 200 healthy control subjects were tested. The shear wave velocity (SWV) of the renal parenchyma and sinus as determined with VTQ and the urinary β2-MG level of the two groups were analyzed. Although there were no significant differences in age, body mass index, creatinine level and blood urea nitrogen between the two groups (all p's > 0.05), the aforementioned parameters were higher in the group with gouty kidney damage than in the control group. Urinary β2-MG levels of the patients with kidney damage were significantly higher than those of the control subjects (t = 6.38, p < 0.01). The SWV of the renal parenchyma was higher than that of the sinus in both groups. Compared with controls, patients with kidney damage had significantly increased renal parenchyma and sinus SWVs (all p-values < 0.05). Urinary β2-MG level was positively linearly correlated with the SWV of renal parenchyma in patients with kidney damage (r = 0.442, p < 0.0001). However, there was no correlation between urinary β2-MG level and the SWV of the sinus in patients with kidney damage (r = 0). In the control group, there was no correlation between urinary β2-MG level and the SWV of the renal parenchyma or sinus. The elasticity of the kidney as determined with VTQ, combined with the urinary β2-MG level, may be helpful in the early diagnosis of gouty kidney damage.


      PubDate: 2014-06-10T15:09:35Z
       
  • Masthead
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7




      PubDate: 2014-06-10T15:09:35Z
       
  • Editorial Advisory Board
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7




      PubDate: 2014-06-10T15:09:35Z
       
  • Contents
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7




      PubDate: 2014-06-10T15:09:35Z
       
  • Quantification of Enhancement of Renal Parenchymal Masses with
           Contrast-Enhanced Ultrasound
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Yingyu Cai , Lianfang Du , Fan Li , Jiying Gu , Min Bai
      The purpose of this study was to investigate the value of quantitative assessment of enhancement in diagnosing renal cell carcinoma (RCC) with contrast-enhanced ultrasound (CEUS). A total of 73 solid renal parenchymal masses underwent both conventional ultrasound and CEUS. We compared the difference in maximum diameters on conventional ultrasound and CEUS between the benign and malignant groups. Enhancement features derived from a time-intensity curve were also analyzed. The diameters of renal cancer were found to be larger on CEUS than on conventional ultrasound (p < 0.05). When cutoff values of 4.74 s for washout time and 8.52% for enhancement intensity at 60 s for diagnosing RCCs were applied, the sensitivity, specificity and area under the receiver operating characteristic curve were 67.3%, 95.2%, 86.5% and 65.4%, 81.0%, 68.4%, respectively. The sensitivity and specificity for these two enhancement characteristics combined as a criterion for differentiating RCCs from benign lesions were 44.0% and 99.1%, respectively. Early washout in the area of maximal intensity in the interior of the lesion and prolonged washout in the whole area of the lesion are specific CEUS manifestations suggestive of RCC.


      PubDate: 2014-06-10T15:09:35Z
       
  • Re: “Acoustic Radiation Force Impulse and Supersonic Shear Imaging
           Versus Transient Elastography for Liver Fibrosis Assessment”
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8
      Author(s): Masato Yoneda , Emmanuel Thomas , Eugene R. Schiff



      PubDate: 2014-06-10T15:09:35Z
       
  • Reply to Letter to the Editor re: “Acoustic Radiation Force Impulse
           and Supersonic Shear Imaging versus Transient Elastography for Liver
           Fibrosis Assessment”
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8
      Author(s): Ioan Sporea , Roxana Şirli



      PubDate: 2014-06-10T15:09:35Z
       
  • Biomedical Signal and Imaging Processing (Second Edition) Kayvan Najarian
           and Robert Splinter. CRC Press, Boca Raton, Florida, USA, 2012, 385 pages.
           ISBN number: 9781439870334
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8
      Author(s): Robert J. Eckersley



      PubDate: 2014-06-10T15:09:35Z
       
  • Calendar
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8




      PubDate: 2014-06-10T15:09:35Z
       
  • Synergistic Ablation of Liver Tissue and Liver Cancer Cells with
           High-Intensity Focused Ultrasound and Ethanol
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8
      Author(s): Nguyen H. Hoang , Hakm Y. Murad , Sithira H. Ratnayaka , Chong Chen , Damir B. Khismatullin
      We investigated the combined effect of ethanol and high-intensity focused ultrasound (HIFU), first, on heating and cavitation bubble activity in tissue-mimicking phantoms and porcine liver tissues and, second, on the viability of HepG2 liver cancer cells. Phantoms or porcine tissues were injected with ethanol and then subjected to HIFU at acoustic power ranging from 1.2 to 20.5 W (HIFU levels 1–7). Cavitation events and the temperature around the focal zone were measured with a passive cavitation detector and embedded type K thermocouples, respectively. HepG2 cells were subjected to 4% ethanol solution in growth medium (v/v) just before the cells were exposed to HIFU at 2.7, 8.7 or 12.0 W for 30 s. Cell viability was measured 2, 24 and 72 h post-treatment. The results indicate that ethanol and HIFU have a synergistic effect on liver cancer ablation as manifested by greater temperature rise and lesion volume in liver tissues and reduced viability of liver cancer cells. This effect is likely caused by reduction of the cavitation threshold in the presence of ethanol and the increased rate of ethanol diffusion through the cell membrane caused by HIFU-induced streaming, sonoporation and heating.


      PubDate: 2014-06-10T15:09:35Z
       
  • Variations in Temperature Distribution and Tissue Lesion Formation Induced
           by Tissue Inhomogeneity for Therapeutic Ultrasound
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8
      Author(s): Zhenbo Liu , Xiasheng Guo , Juan Tu , Dong Zhang
      Tissue inhomogeneity might have an important effect on the treatment accuracy of therapeutic ultrasound. Both computer simulation and measurement were performed to study the influence of tissue inhomogeneity on the temperature distribution and tissue lesion formation induced by focused ultrasound. The inhomogeneous tissue is considered a combination of a homogeneous medium and a phase aberration screen in this article. Temperature distributions and lesion dimensions were predicted using the combination of acoustic non-linear and bio-heat transfer equations. To verify the theoretical predictions, polyethylene plates with phase distributions of different correlation lengths and standard deviations were made to mimic inhomogeneous tissues such as human abdominal tissue, and a series of experiments were performed, including acoustic and thermal measurements. The results indicate that the tissue inhomogeneity caused phase aberration of the ultrasound beam. With increasing standard deviation and correlation length of phase aberration, the scattering level of the acoustic field increased, while ultrasound-induced peak temperature and lesion size decreased. This study provides a theoretical and experimental basis for future development of accurate treatment plans for high-intensity focused ultrasound.


      PubDate: 2014-06-10T15:09:35Z
       
  • Pre-operative Detection of Thyroid Pyramidal Lobes by Ultrasound and
           Computed Tomography
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Ji Hwa Ryu , Dong Wook Kim , Taewoo Kang
      This study aimed to assess the diagnostic accuracy of pre-operative ultrasound (US) and computed tomography (CT) for detecting thyroid pyramidal lobe (TPL). A single radiologist prospectively performed thyroid US and retrospectively reviewed neck CT to detect TPLs in 135 consecutive patients scheduled for thyroid surgery. The location, size and superior extent of each TPL and its separation or continuity with the main thyroid gland were assessed by thyroid US, neck CT and surgery. The prevalence of TPLs as diagnosed by thyroid US, neck CT and surgery was 58.5% (79/135), 56.3% (76/135) and 60% (81/135), respectively. We compared US and CT detection of TPLs with surgical data to determine their sensitivity (85.2% and 91.4%), specificity (81.5% and 94.4%), positive (87.3% and 96.1%) and negative (78.6% and 87.9%) predictive values and accuracy (83.7% and 92.6%). For detecting TPLs, both neck CT and thyroid US have good diagnostic value, although neck CT is more accurate than thyroid US.


      PubDate: 2014-06-10T15:09:35Z
       
  • Severity of Spontaneous Echo Contrast in the Jugular Vein Associated with
           Ischemic Stroke
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Hung-Yi Hsu , Yu-Shan Lee , Ming-Che Ou , Chih-Ping Chung , Su-Yi Chen , Yu-Ping Ho , Han-Hwa Hu
      This study evaluated the relationship between spontaneous echo contrast (SEC) in the internal jugular vein (JV), atherosclerotic markers and ischemic stroke. One hundred twenty patients with acute ischemic stroke and 120 controls were recruited. SEC score correlated with plasma level of fibrinogen (coefficient: 0.105, p = 0.022), hemoglobin (coefficient: 0.122, p = 0.008) and presence of JV reflux (coefficient: 0.314, p < 0.001) and peak flow velocity (coefficient: −0.244, p < 0.001) in the corresponding JV, but did not correlate with carotid plaque score (coefficient: 0.042, p = 0.358) or intima-media thickness (coefficient: 0.067, p = 0.303). Multivariate regression analysis revealed that fibrinogen level, SEC score, intima-media thickness, plaque score and history of coronary artery disease were associated with acute ischemic stroke. In conclusion, the severity of SEC in the JV might represent the tendency toward thrombogenesis in diseased cerebral circulation possibly through mechanisms other than arterial atherosclerosis.


      PubDate: 2014-06-10T15:09:35Z
       
  • Four-Dimensional Echocardiography with Spatiotemporal Image Correlation
           and Inversion Mode for Detection of Congenital Heart Disease
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Yue Qin , Ying Zhang , Xiaohang Zhou , Yu Wang , Wei Sun , Lizhu Chen , Dan Zhao , Ying Zhan , Ailu Cai
      The aim of this study was to evaluate the use of 4-D echocardiography with inversion mode and spatiotemporal image correlation (IM-STIC) in the detection of normal and abnormal fetal hearts. We retrospectively studied 112 normal fetuses and 16 fetuses with a confirmed diagnosis of congenital heart disease. Two volumes were acquired from each of the fetuses using transverse and sagittal sweeps. Volumes were reconstructed with IM-STIC. In normal fetuses, IM-STIC facilitated visualization of the interior structures of the fetal heart and great vessels. The visualization rates of intended planes obtained from IM-STIC 4D data ranged from 55% to 100%. In 16 fetuses with congenital heart disease, IM-STIC was able to display the cardiac malformations using digital casting. Some of the malformations were suspected during pre-natal 2-D echocardiography, and their pre-natal IM-STIC diagnoses were confirmed by post-natal echocardiography, surgery and/or autopsy. Hence, 4-D IM-STIC allows better visualization of complex congenital heart disease and should be considered a very useful addition to 2-D echocardiography.


      PubDate: 2014-06-10T15:09:35Z
       
  • High-Resolution Ultrasonography for the Diagnosis of Brachial Plexus Root
           Lesions
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Yong-Sheng Zhu , Nan-Nan Mu , Min-Juan Zheng , Yun-Chu Zhang , Hua Feng , Rui Cong , Xiao-Dong Zhou , Ding-Zhang Chen
      The aim of this study was to investigate the feasibility of using high-resolution ultrasonography in the diagnosis of brachial plexus (BP) root lesions. A prospective study of ultrasonographic evaluation of BP nerve roots was performed in 37 patients with BP root lesions (29 with root injuries, 8 with tumors). The pre-operative ultrasonographic findings were compared with the surgical and pathohistological findings. All C5–7 roots were detected by ultrasonography in all patients, whereas 92% (68/74) of C8 and 51% (38/74) of T1 nerve roots were visualized. Among 29 patients with BP root avulsion, partial injuries or totally interrupted BP roots were detected in all patients. Cystic masses and neuromas were detected in 16 and 23 patients, respectively. In 8 patients with BP root tumors, 8 hypo-echoic masses were detected inside or partly outside of intervertebral foramina connecting to nerve roots. Surgical exploration revealed that there were 57 BP root avulsions in 29 patients. However, 2 T1 nerve root avulsions had been missed by pre-operative ultrasonography. Pathohistology revealed that all 8 BP root tumors pre-operatively diagnosed by ultrasonography were schwannomas. High-resolution ultrasonography can provide a convenient and accurate imaging modality for quick diagnosis and location of BP root lesions.


      PubDate: 2014-06-10T15:09:35Z
       
  • Masthead
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8




      PubDate: 2014-06-10T15:09:35Z
       
  • Editorial Advisory Board
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8




      PubDate: 2014-06-10T15:09:35Z
       
  • RNA Biomarker Release with Ultrasound and Phase-Change Nanodroplets
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8
      Author(s): Robert J. Paproski , Alexander Forbrich , Mary Hitt , Roger Zemp
      Microbubbles driven by ultrasound are capable of permeabilizing cell membranes and allowing biomarkers or therapeutics to exit from or enter cancer cells, respectively. Unfortunately, the relatively large size of microbubbles prevents extravasation. Lipid-based perfluorobutane microbubbles can be made seven-fold smaller by pressurization, creating 430-nm nanodroplets. The present study compares microbubbles and nanodroplets with respect to their ability to enhance miR-21 and mammaglobin mRNA release from cultured ZR-75-1 cells. Mammaglobin mRNA and miR-21 release increased with escalating concentrations of nanodroplets up to, respectively, 25- and 42-fold with 2% nanodroplets (v/v), compared with pre-ultrasound levels, whereas cell viability decreased to 62.4%. Sonication of ZR-75-1 cells incubated with microbubbles or nanodroplets caused relatively similar levels of cell death and miR-21 release, suggesting that nanodroplets are similar to microbubbles in enhancing cell permeability, but may be more advantageous because of their smaller size, which may allow extravasation through leaky tumor vasculature.


      PubDate: 2014-06-10T15:09:35Z
       
  • Quantification of Carotid Plaque Neovascularization Using
           Contrast-Enhanced Ultrasound With Histopathologic Validation
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8
      Author(s): Chaolun Li , Wanyuan He , Daqiao Guo , Lingli Chen , Xuejuan Jin , Weiping Wang , Beijian Huang , Wenping Wang
      We sought to evaluate contrast-enhanced ultrasound (CEUS) imaging for the quantification of carotid plaque neovascularization. Seventeen patients underwent carotid endarterectomy after standard ultrasound and CEUS. Semiquantitative and quantitative analyses of contrast enhancement within the plaque were performed using a visual interpretation scale and quantitative analysis software, respectively. Enhancement intensity (dB) was measured at the plaque (EIplaque). Each specimen was stained with CD34 and CD68 to assess for microvessels and macrophages, respectively. Semiquantitative CEUS analyses were correlated with neovascularization at histology (r = 0.70, p = 0.002). Quantitative analysis was also correlated with neovascularization at histology (EIplaque r = 0.81, p < 0.001). EIplaque (r = 0.64, p = 0.01) was correlated with the degree of enhancement as assessed visually. Semiquantitative and quantitative analyses were not correlated with macrophage infiltration at the plaque. Contrast enhancement in the carotid plaque was correlated with neovascularity at the histopathologic exam. Furthermore, semiquantitative and quantitative measurements were highly correlated with each other, suggesting that either can be used to detect intraplaque neovascularization.


      PubDate: 2014-06-10T15:09:35Z
       
  • Early Pregnancy Placental Bed and Fetal Vascular Volume Measurements Using
           3-D Virtual Reality
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8
      Author(s): Averil D. Reus , Josine Klop-van der Aa , Maria S. Rifouna , Anton H.J. Koning , Niek Exalto , Peter J. van der Spek , Eric A.P. Steegers
      In this study, a new 3-D Virtual Reality (3D VR) technique for examining placental and uterine vasculature was investigated. The validity of placental bed vascular volume (PBVV) and fetal vascular volume (FVV) measurements was assessed and associations of PBVV and FVV with embryonic volume, crown-rump length, fetal birth weight and maternal parity were investigated. One hundred thirty-two patients were included in this study, and measurements were performed in 100 patients. Using V-Scope software, 100 3-D Power Doppler data sets of 100 pregnancies at 12 wk of gestation were analyzed with 3D VR in the I-Space Virtual Reality system. Volume measurements were performed with semi-automatic, pre-defined parameters. The inter-observer and intra-observer agreement was excellent with all intra-class correlation coefficients >0.93. PBVVs of multiparous women were significantly larger than the PBVVs of primiparous women (p = 0.008). In this study, no other associations were found. In conclusion, V-Scope offers a reproducible method for measuring PBVV and FVV at 12 wk of gestation, although we are unsure whether the volume measured represents the true volume of the vasculature. Maternal parity influences PBVV.


      PubDate: 2014-06-10T15:09:35Z
       
  • Predominant Patterns of Median Nerve Displacement and Deformation during
           Individual Finger Motion in Early Carpal Tunnel Syndrome
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8
      Author(s): Kyrin Liong , Amitabha Lahiri , Shujin Lee , Dawn Chia , Arijit Biswas , Heow Pueh Lee
      Idiopathic carpal tunnel syndrome (CTS) is a common neuropathy, yet the pathologic changes do not explain the fleeting dynamic symptoms. Dynamic nerve-tendon interaction may be a contributing factor. Based on dynamic ultrasonographic examination of the carpal tunnel, we quantified nerve-tendon movement in thumb, index finger and middle finger flexion in normal subjects and those with mild-idiopathic CTS. Predominant motion patterns were identified. The nerve consistently moves volar-ulnarly. In thumb and index finger flexion, the associated tendons move similarly, whereas the tendon moves dorsoradially in middle finger flexion. Nerve displacement and deformation increased from thumb to index finger to middle finger flexion. Predomination motion patterns may be applied in computational simulations to prescribe specific motions to the tendons and to observe resultant nerve pressures. By identification of the greatest pressure-inducing motions, CTS treatment may be better developed. Symptomatic subjects displayed reduced nerve movement and deformation relative to controls, elucidating the physiologic changes that occur during mild CTS.


      PubDate: 2014-06-10T15:09:35Z
       
  • Comparative Study of Ultrasound and Computed Tomography for Incidentally
           Detecting Diffuse Thyroid Disease
    • Abstract: Publication date: August 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 8
      Author(s): Dong Wook Kim , Soo Jin Jung , Tae Kwun Ha , Ha Kyoung Park , Taewoo Kang
      The aim of this study was to compare the diagnostic values of thyroid ultrasound (US) and neck computed tomography (CT) in incidentally detecting diffuse thyroid disease (DTD). A single radiologist made US and CT diagnoses of incidentally detected DTD in 130 consecutive patients before thyroidectomy for various malignancies. Histopathologic examinations confirmed normal thyroid (n = 80), Hashimoto thyroiditis (n = 20), non-Hashimoto lymphocytic thyroiditis (n = 28) and diffuse hyperplasia (n = 2). Receiver operating characteristic curves revealed that the best diagnostic indices of both imaging methods were achieved on the basis of two or more abnormal imaging findings. The sensitivity, specificity and accuracy of US and CT in incidentally detecting DTD by this classification were 72% and 72%, 87.5% and 91.3% and 81.5% and 83.8%, respectively. Thyroid US and neck CT have similar diagnostic values for differentiating incidental DTD from normal thyroid.


      PubDate: 2014-06-10T15:09:35Z
       
  • Utility of Endoscopic Ultrasound (EUS)-Guided Fine-Needle Aspiration for
           Peri-arterial Soft Tissue Cuffs Without Identifiable Pancreas Mass on CT
           and EUS: A Prospective Comparative Study
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Woo Hyun Paik , Hwan Yoon , Do Hyun Park , Kyoungwon Jung , Sang Soo Lee , Dong Wan Seo , Sung Koo Lee , Myung-Hwan Kim
      Pancreatic cancer may present as a peri-arterial soft tissue cuff (PSTC) around the superior mesenteric artery or celiac axis without an identifiable pancreatic mass. We evaluated the diagnostic yield of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in patients with a PSTC without definite pancreas involvement and those with a typical pancreatic mass. The patients who underwent EUS-FNA of a PSTC without pancreatic involvement were prospectively enrolled. The patients who underwent EUS-FNA for a pancreatic mass were recruited as a control group. A total of 224 patients underwent 247 EUS-FNAs. Among the 13 patients with a PSTC, 11 were positive for malignancy as determined by EUS-FNA, with 5 diagnosed after the first session and 6 after the second session. The diagnostic yield of PSTCs by EUS-FNA was significantly lower than that for typical pancreatic masses (65% vs. 87%, p = 0.02). An on-site cytopathologist and repeated EUS-FNA are recommended to improve the diagnostic accuracy of this disease entity.


      PubDate: 2014-06-10T15:09:35Z
       
  • High-Frequency Intra-operative Ultrasound-Guided Surgery of Superficial
           Intra-cerebral Lesions via a Single-Burr-Hole Approach
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Jan-Karl Burkhardt , Carlo Serra , Marian C. Neidert , Christoph M. Woernle , Jorn Fierstra , Luca Regli , Oliver Bozinov
      The study described here examined the feasibility of using high-frequency intra-operative ultrasound (hfioUS) guidance to resect superficial intra-cerebral lesions through a single burr hole. A cohort of 23 consecutive patients with a total of 24 intra-cerebral lesions (9 intra-cerebral metastases, 8 gliomas, 4 infections, 2 lymphomas and 1 cavernoma) were studied. All lesions could be localized and successfully resected, biopsied or aspirated, and histopathological diagnoses were obtained in all cases. The mean operating time was 59.6 ± 23.9 min. The mean cross-sectional lesion size was 6.4 ± 7.6 cm2, and the mean cortex surface-to-lesion distance was 0.6 ± 0.8 cm. Our results illustrate the feasibility of identifying and resecting superficial intra-cerebral lesions under hfioUS guidance via a single-burr-hole approach. We were able to achieve short resection times with no post-operative complications in all patients, favorable conditions under which to start adjuvant therapy when indicated.


      PubDate: 2014-06-10T15:09:35Z
       
  • Comparison of the Accuracy and Reproducibility of Focused Abdominal
           Sonography for Trauma Performed by Emergency Medicine and Radiology
           Residents
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Ali Arhami Dolatabadi , Afshin Amini , Hamidreza Hatamabadi , Parisa Mohammadi , Sara Faghihi-Kashani , Hojjat Derakhshanfar , Seyed Morteza Tabatabaee , Mehrdad Moghimi , Ali Kabir
      We compared the diagnostic accuracy of emergency medicine residents (EMRs) and radiology residents (RRs) in performing focused abdominal sonography for trauma (FAST). The cohort in this prospective study comprised 200 unstable patients (163 males and 37 females; mean ± standard deviation of age, 34.3 ± 16.4 y) who presented with trauma. These patients were evaluated using FAST, first by EMRs and subsequently by RRs. Patients with positive FAST results underwent further diagnostic procedures such as computed tomography, diagnostic peritoneal lavage and laparotomy. Those with negative FAST results underwent clinical follow-up for 72 h until their condition deteriorated or they were discharged. Sensitivity, specificity, positive and negative predictive values and accuracy in evaluating free intraperitoneal fluid were 80%, 95%, 57%, 98% and 94% when FAST was performed by EMRs and 86%, 95%, 59%, 98% and 94% when FAST was performed by RRs. The level of agreement between EMRs and RRs was moderate (κ = 0.525). FAST is a useful screening tool for initial assessment of free abdominal fluid in patients with trauma. Our results indicate that EMRs can perform sonography on trauma patients as successfully as RRs.


      PubDate: 2014-06-10T15:09:35Z
       
  • False-Negative Appendicitis at Ultrasound: Nature and Association
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Patwadee Piyarom , Rathachai Kaewlai
      The objective was to describe nature and factors associated with false-negative ultrasound (US) for adult appendicitis. Patients with pathologically proven appendicitis and pre-operative US from January 2011 to May 2013 were included in this retrospective case-control study. They were divided into true-positive and false-negative groups, matched by age and gender. There were 112 patients (40 men, mean age = 40 y, 56 true positives) included. Two factors were found differ significantly: abdominal wall thickness and pain score. Greater abdominal wall thickness (18.6 mm vs. 14.9 mm, p = 0.001) and lower pain score (6.6 vs. 7.5, p = 0.018) were statistically associated with false negativity. The two groups did not differ significantly in terms of weight, height, body mass index, symptom duration, Alvarado score, US examination time, appendix position/size, perforation rate and operator. In conclusion, lower pain score and increased abdominal wall thickness are associated with false negativity in US examinations.


      PubDate: 2014-06-10T15:09:35Z
       
  • 3-D Visualization and Non-linear Tissue Classification of Breast Tumors
           Using Ultrasound Elastography In Vivo
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Ahmed Sayed , Ginger Layne , Jame Abraham , Osama M. Mukdadi
      The goal of the study described here was to introduce new methods for the classification and visualization of human breast tumors using 3-D ultrasound elastography. A tumor's type, shape and size are key features that can help the physician to decide the sort and extent of necessary treatment. In this work, tumor type, being either benign or malignant, was classified non-invasively for nine volunteer patients. The classification was based on estimating four parameters that reflect the tumor's non-linear biomechanical behavior, under multi-compression levels. Tumor prognosis using non-linear elastography was confirmed with biopsy as a gold standard. Three tissue classification parameters were found to be statistically significant with a p-value < 0.05, whereas the fourth non-linear parameter was highly significant, having a p-value < 0.001. Furthermore, each breast tumor's shape and size were estimated in vivo using 3-D elastography, and were enhanced using interactive segmentation. Segmentation with level sets was used to isolate the stiff tumor from the surrounding soft tissue. Segmentation also provided a reliable means to estimate tumors volumes. Four volumetric strains were investigated: the traditional normal axial strain, the first principal strain, von Mises strain and maximum shear strain. It was noted that these strains can provide varying degrees of boundary enhancement to the stiff tumor in the constructed elastograms. The enhanced boundary improved the performance of the segmentation process. In summary, the proposed methods can be employed as a 3-D non-invasive tool for characterization of breast tumors, and may provide early prognosis with minimal pain, as well as diminish the risk of late-stage breast cancer.


      PubDate: 2014-06-10T15:09:35Z
       
  • Acoustic Performance of Mesh Compression Paddles for a Multimodality
           Breast Imaging System
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Gerald L. LeCarpentier , Mitchell M. Goodsitt , Sacha Verweij , Jie Li , Frederic R. Padilla , Paul L. Carson
      A system incorporating automated 3-D ultrasound and digital X-ray tomosynthesis is being developed for improved breast lesion detection and characterization. The goal of this work is to develop and test candidates for a dual-modality mesh compression paddle. A Computerized Imaging Reference Systems (Norfork, VA, USA) ultrasound phantom with tilted low-contrast cylindrical objects was used. Polyester mesh fabrics (1- and 2-mm spacing), a high-density polyethylene filament grid (Dyneema, DSM Dyneema, Stanley, NC, USA) and a solid polymethylpentene (TPX; Mitsui Plastics, Inc., White Plains, NY) paddle were compared with no overlying structures using a GE Logic 9 with M12L transducer. A viscous gel provided coupling. The phantom was scanned 10 times over 9 cm for each configuration. Image volumes were analyzed for signal strength, contrast and contrast-to-noise ratio. X-ray tests confirmed X-ray transparency for all materials. By all measures, both mesh fabrics outperformed TPX and Dyneema, and there were essentially no differences between 2-mm mesh and unobstructed configurations.


      PubDate: 2014-06-10T15:09:35Z
       
  • Localization of Ultrasound-Induced In Vivo Neurostimulation in the
           Mouse Model
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Randy L. King , Julian R. Brown , Kim Butts Pauly
      Developments in the use of ultrasound to stimulate and modulate neural activity have raised the possibility of using ultrasound as a new investigative and therapeutic tool in brain research. Although the phenomenon of ultrasound-induced neurostimulation has a long history dating back many decades, until now there has been little evidence of a clearly localized effect in the brain, a necessary requirement for the technique to become genuinely useful. Here we report clearly distinguishable effects in sonicating rostral and caudal regions of the mouse motor cortex. Motor responses measured by normalized electromyography in the neck and tail regions changed significantly when sonicating the two different areas of motor cortex. Response latencies varied significantly according to sonication location, suggesting that different neural circuits are activated depending on the precise focus of the ultrasound beam. Taken together, our findings present good evidence of the ability to target selective parts of the motor cortex with ultrasound neurostimulation in the mouse, an advance that should help to set the stage for developing new applications in larger animal models, including humans.


      PubDate: 2014-06-10T15:09:35Z
       
  • Passive Cavitation Detection during Pulsed HIFU Exposures of Ex Vivo
           Tissues and In Vivo Mouse Pancreatic Tumors
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Tong Li , Hong Chen , Tatiana Khokhlova , Yak-Nam Wang , Wayne Kreider , Xuemei He , Joo Ha Hwang
      Pulsed high-intensity focused ultrasound (pHIFU) has been shown to enhance vascular permeability, disrupt tumor barriers and enhance drug penetration into tumor tissue through acoustic cavitation. Monitoring of cavitation activity during pHIFU treatments and knowing the ultrasound pressure levels sufficient to reliably induce cavitation in a given tissue are therefore very important. Here, three metrics of cavitation activity induced by pHIFU and evaluated by confocal passive cavitation detection were introduced: cavitation probability, cavitation persistence and the level of the broadband acoustic emissions. These metrics were used to characterize cavitation activity in several ex vivo tissue types (bovine tongue and liver and porcine adipose tissue and kidney) and gel phantoms (polyacrylamide and agarose) at varying peak-rare factional focal pressures (1–12 MPa) during the following pHIFU protocol: frequency 1.1 MHz, pulse duration 1 ms and pulse repetition frequency 1 Hz. To evaluate the relevance of the measurements in ex vivo tissue, cavitation metrics were also investigated and compared in the ex vivo and in vivo murine pancreatic tumors that develop spontaneously in transgenic KrasLSL.G12 D/+; p53 R172 H/+; PdxCretg/+ (KPC) mice and closely re-capitulate human disease in their morphology. The cavitation threshold, defined at 50% cavitation probability, was found to vary broadly among the investigated tissues (within 2.5–10 MPa), depending mostly on the water-lipid ratio that characterizes the tissue composition. Cavitation persistence and the intensity of broadband emissions depended both on tissue structure and lipid concentration. Both the cavitation threshold and broadband noise emission level were similar between ex vivo and in vivo pancreatic tumor tissue. The largest difference between in vivo and ex vivo settings was found in the pattern of cavitation occurrence throughout pHIFU exposure: it was sporadic in vivo, but it decreased rapidly and stopped over the first few pulses ex vivo. Cavitation activity depended on the interplay between the destruction and circulation of cavitation nuclei, which are not only used up by HIFU treatment but also replenished or carried away by circulation in vivo. These findings are important for treatment planning and optimization in pHIFU-induced drug delivery, in particular for pancreatic tumors.


      PubDate: 2014-06-10T15:09:35Z
       
  • Effect of Therapeutic Ultrasound on Folliculogenesis, Angiogenesis and
           Apoptosis After Heterotopic Mouse Ovarian Transplantation
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): N.S. Abtahi , H. Eimani , A. Vosough , Ab. Shahverdi , R. Fathi , N. Hayati , N. Nasiri
      One of the challenges in ovarian transplantation is ischemia-reperfusion damage. When transitional tissue faces an acute and critical condition in terms of blood supply (immediately after organ transplantation), treatment with low-intensity pulsed ultrasound (LIPUS) seems to be very beneficial. The aim of this study was to evaluate the effects of ultrasound therapy on heterotopic transplanted mouse ovarian tissue. Adult female Naval Medical Research Institute mice were divided into three groups. In the experimental groups, the transplanted ovary was exposed 5 min daily to ultrasound with an intensity of 0.3 W/cm2, frequency of 3 MHz and pulse mode of 1:4. The grafted ovaries were assessed with the usual histology and immunohistochemistry techniques. Results indicate that more CD31 angiogenic factor was expressed in irradiated animals than in control animals, and ultrasound therapy resulted in better follicular preservation, especially after 14 d. In conclusion, therapeutic ultrasound may accelerate and increase re-angiogenesis and can help to promote ovarian follicular growth.


      PubDate: 2014-06-10T15:09:35Z
       
  • Improved Sonothrombolysis from a Modified Diagnostic Transducer Delivering
           Impulses Containing a Longer Pulse Duration
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Juefei Wu , Feng Xie , Tanmay Kumar , Jinjin Liu , John Lof , William Shi , E. Carr Everbach , Thomas R. Porter
      Although guided high-mechanical-index (MI) impulses from a diagnostic ultrasound transducer have been used in preclinical studies to dissolve coronary arterial and microvascular thrombi in the presence of intravenously infused microbubbles, it is possible that pulse durations (PDs) longer than that used for diagnostic imaging may further improve the effectiveness of this approach. By use of an established in vitro model flow system, a total of 90 occlusive porcine arterial thrombi (thrombus age: 3–4 h) within a vascular mimicking system were randomized to 10-min treatments with two different PDs (5 and 20 μs) using a Philips S5-1 transducer (1.6-MHz center frequency) at a range of MIs (from 0.2 to 1.4). All impulses were delivered in an intermittent fashion to permit microbubble replenishment within the thrombosed vessel. Diluted lipid-encapsulated microbubbles (0.5% Definity) were infused during the entire treatment period. A tissue-mimicking phantom 5 cm thick was placed between the transducer and thrombosed vessel to mimic transthoracic attenuation. Two 20-MHz passive cavitation detection systems were placed confocal to the insonified vessel to assess for inertial cavitational activity. Percentage thrombus dissolution was calculated by weighing the thrombi before and after each treatment. Percentage thrombus dissolution was significantly higher with a 20-μs PD already at the 0.2 and 0.4 MI therapeutic impulses (54 ± 12% vs. 33 ± 17% and 54 ± 22% vs. 34 ± 17%, p < 0.05 compared with the 5-μs PD group, respectively), and where passive cavitation detection systems detected only low intensities of inertial cavitation. At higher MI settings and 20-μs PDs, percentage thrombus dissolution decreased most likely from high-intensity cavitation shielding of the thrombus. Slightly prolonging the PD on a diagnostic transducer improves the degree of sonothrombolysis that can be achieved without fibrinolytic agents at a lower mechanical index.


      PubDate: 2014-06-10T15:09:35Z
       
  • High-Intensity Focused Ultrasound-Induced, Localized Mild Hyperthermia to
           Enhance Anti-cancer Efficacy of Systemic Doxorubicin: An Experimental
           Study
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Sun Young Chae , Young-sun Kim , Min Jung Park , Jehoon Yang , Hajan Park , Mi-Sun Namgung , Hyunchul Rhim , Hyo Keun Lim
      The aim of this study was to evaluate the enhancement of the efficacy of systemic doxorubicin by pulsed high-intensity focused ultrasound (HIFU)-induced, localized mild hyperthermia. For the in vitro study, the intranuclear uptake of doxorubicin by squamous cell carcinoma (SCC)-7 cells incubated at different temperatures was compared. For the in vivo study, mice with SCC-7 tumors were assigned to either the control, conventional hyperthermia, HIFU hyperthermia, doxorubicin-alone, conventional hyperthermia + doxorubicin or HIFU hyperthermia + doxorubicin group. Conventional hyperthermia was induced by immersing the tumor in warm water (42.5°C), and HIFU hyperthermia was induced by HIFU after optimizing the parameters with direct temperature measurements (frequency = 1 MHz, pulse repetition frequency = 5 Hz, power = 12 W, duty cycle = 50%). In the in vitro study, fluorescence was more intense at 42°C than at 37°C and was time dependent. In the in vivo study, tumor growth in the HIFU hyperthermia + doxorubicin group was most prominently suppressed with the highest apoptotic index compared with all other groups (p < 0.05). Pulsed HIFU-induced localized mild hyperthermia enhanced the anti-cancer efficacy of systemic doxorubicin more than conventional mild hyperthermia.


      PubDate: 2014-06-10T15:09:35Z
       
  • Thermal Fixation of Swine Liver Tissue after Magnetic Resonance-Guided
           High-Intensity Focused Ultrasound Ablation1
    • Abstract: Publication date: July 2014
      Source:Ultrasound in Medicine & Biology, Volume 40, Issue 7
      Author(s): Frédéric Courivaud , Airazat M. Kazaryan , Alice Lund , Vivian C. Orszagh , Aud Svindland , Irina Pavlik Marangos , Per Steinar Halvorsen , Peter Jebsen , Erik Fosse , Per Kristian Hol , Bjørn Edwin
      The aim of this study was to investigate experimental conditions for efficient and controlled in vivo liver tissue ablation by magnetic resonance (MR)-guided high-intensity focused ultrasound (HIFU) in a swine model, with the ultimate goal of improving clinical treatment outcome. Histological changes were examined both acutely (four animals) and 1 wk after treatment (five animals). Effects of acoustic power and multiple sonication cycles were investigated. There was good correlation between target size and observed ablation size by thermal dose calculation, post-procedural MR imaging and histopathology, when temperature at the focal point was kept below 90°C. Structural histopathology investigations revealed tissue thermal fixation in ablated regions. In the presence of cavitation, mechanical tissue destruction occurred, resulting in an ablation larger than the target. Complete extra-corporeal MR-guided HIFU ablation in the liver is feasible using high acoustic power. Nearby large vessels were preserved, which makes MR-guided HIFU promising for the ablation of liver tumors adjacent to large veins.


      PubDate: 2014-06-10T15:09:35Z
       
  • Viscoelastic Properties of Normal and Infarcted Myocardium Measured by a
           Multifrequency Shear Wave Method: Comparison with Pressure-Segment Length
           Method
    • Abstract: Publication date: Available online 6 May 2014
      Source:Ultrasound in Medicine & Biology
      Author(s): Cristina Pislaru , Matthew W. Urban , Sorin V. Pislaru , Randall R. Kinnick , James F. Greenleaf
      Our aims were (i) to compare in vivo measurements of myocardial elasticity by shear wave dispersion ultrasound vibrometry (SDUV) with those by the conventional pressure-segment length method, and (ii) to quantify changes in myocardial viscoelasticity during systole and diastole after reperfused acute myocardial infarction. The shear elastic modulus (μ1) and viscous coefficient (μ2) of left ventricular myocardium were measured by SDUV in 10 pigs. Young's elastic modulus was independently measured by the pressure-segment length method. Measurements made with the SDUV and pressure-segment length methods were strongly correlated. At reperfusion, μ1 and μ2 in end-diastole were increased. Less consistent changes were found during systole. In all animals, μ1 increased linearly with left ventricular pressure developed during systole. Preliminary results suggest that μ1 is preload dependent. This is the first study to validate in vivo measurements of myocardial elasticity by a shear wave method. In this animal model, the alterations in myocardial viscoelasticity after a myocardial infarction were most consistently detected during diastole.


      PubDate: 2014-05-12T06:31:40Z
       
  • A Method to Validate Quantitative High-Frequency Power Doppler Ultrasound
           With Fluorescence in Vivo Video Microscopy
    • Abstract: Publication date: Available online 3 May 2014
      Source:Ultrasound in Medicine & Biology
      Author(s): Stephen Z. Pinter , Dae-Ro Kim , M. Nicole Hague , Ann F. Chambers , Ian C. MacDonald , James C. Lacefield
      Flow quantification with high-frequency (>20 MHz) power Doppler ultrasound can be performed objectively using the wall-filter selection curve (WFSC) method to select the cutoff velocity that yields a best-estimate color pixel density (CPD). An in vivo video microscopy system (IVVM) is combined with high-frequency power Doppler ultrasound to provide a method for validation of CPD measurements based on WFSCs in mouse testicular vessels. The ultrasound and IVVM systems are instrumented so that the mouse remains on the same imaging platform when switching between the two modalities. In vivo video microscopy provides gold-standard measurements of vascular diameter to validate power Doppler CPD estimates. Measurements in four image planes from three mice exhibit wide variation in the optimal cutoff velocity and indicate that a predetermined cutoff velocity setting can introduce significant errors in studies intended to quantify vascularity. Consistent with previously published flow-phantom data, in vivo WFSCs exhibited three characteristic regions and detectable plateaus. Selection of a cutoff velocity at the right end of the plateau yielded a CPD close to the gold-standard vascular volume fraction estimated using IVVM. An investigator can implement the WFSC method to help adapt cutoff velocity to current blood flow conditions and thereby improve the accuracy of power Doppler for quantitative microvascular imaging.


      PubDate: 2014-05-07T06:50:32Z
       
  • Vascular Elastography: A Validation Study
    • Abstract: Publication date: Available online 3 May 2014
      Source:Ultrasound in Medicine & Biology
      Author(s): Richard G.P. Lopata , Mathijs F.J. Peters , Jan Nijs , Cees W.J. Oomens , Marcel C.M. Rutten , Frans N. van de Vosse
      Vascular elastography techniques are promising tools for mechanical characterization of diseased arteries. These techniques are usually validated with simulations or phantoms or by comparing results with histology or other imaging modalities. In the study described here, vascular elastography was applied to porcine aortas in vitro during inflation testing (n = 10) and results were compared with those of standard bi-axial tensile testing, a technique that directly measures the force applied to the tissue. A neo-Hookean model was fit to the stress-strain data, valid for large deformations. Results indicated good correspondence between the two techniques, with GUS = 110 ± 11 kPa and G TT = 108 ± 10 kPa for ultrasound and tensile testing, respectively. Bland-Altman analysis revealed little bias (GUS−GTT = 2 ± 20 kPa). The next step will be the application of a non-linear material model that is also adaptable for in vivo measurements.


      PubDate: 2014-05-07T06:50:32Z
       
  • A Cadaveric and Preliminary Clinical Study of Ultrasonographically
           Assisted Percutaneous Carpal Tunnel Release
    • Abstract: Publication date: Available online 3 May 2014
      Source:Ultrasound in Medicine & Biology
      Author(s): Tai-Chang Chern , Kuo-Chen Wu , Lee-Wen Huang , Chung-Jung Shao , Tong-Tai Wu , Li-Chieh Kuo , I-Ming Jou
      The aim of this study was to assess the effectiveness and safety profile of a new technique for ultrasonographically assisted percutaneous carpal tunnel release. Experiments were performed on 40 hands in 20 cadavers. We first performed a detailed ultrasonographic examination and correlation study that included surgical dissection of the transverse carpal ligament, the related neurovascular structures and the bony landmarks of the radiocarpal, midcarpal and carpometacarpal joints of the right hand. We then used the measurements we made for percutaneous carpal tunnel release of the transverse carpal ligament using intra-operative ultrasonography for guidance and a hook knife on the left-hand side. The completeness of the release and the potential risks of injury to the flexor tendon and neurovascular bundles were examined. Using real-time intra-operative ultrasonographic monitoring to clearly delineate these targets, we were able to percutaneously release the transverse carpal ligament completely in 18 (90%) of the 20 hands and partially release it in 2 without injuring any neurovascular bundles. We then performed the procedure on 91 consecutive cases of carpal tunnel syndrome and found that the sensory disturbances disappeared in 100% patients 12 mo post-operatively; only 2 hands were graded as unsatisfactory. There were no intra- or post-operative complications. Based on the results from the cadaveric studies and our successful preliminary clinical outcomes, we conclude that this method is tolerable and that its clinical application can be encouraged.


      PubDate: 2014-05-07T06:50:32Z
       
  • Lipid Shedding from Single Oscillating Microbubbles
    • Abstract: Publication date: Available online 3 May 2014
      Source:Ultrasound in Medicine & Biology
      Author(s): Ying Luan , Guillaume Lajoinie , Erik Gelderblom , Ilya Skachkov , Antonius F.W. van der Steen , Hendrik J. Vos , Michel Versluis , Nico De Jong
      Lipid-coated microbubbles are used clinically as contrast agents for ultrasound imaging and are being developed for a variety of therapeutic applications. The lipid encapsulation and shedding of the lipids by acoustic driving of the microbubble has a crucial role in microbubble stability and in ultrasound-triggered drug delivery; however, little is known about the dynamics of lipid shedding under ultrasound excitation. Here we describe a study that optically characterized the lipid shedding behavior of individual microbubbles on a time scale of nanoseconds to microseconds. A single ultrasound burst of 20 to 1000 cycles, with a frequency of 1 MHz and an acoustic pressure varying from 50 to 425 kPa, was applied. In the first step, high-speed fluorescence imaging was performed at 150,000 frames per second to capture the instantaneous dynamics of lipid shedding. Lipid detachment was observed within the first few cycles of ultrasound. Subsequently, the detached lipids were transported by the surrounding flow field, either parallel to the focal plane (in-plane shedding) or in a trajectory perpendicular to the focal plane (out-of-plane shedding). In the second step, the onset of lipid shedding was studied as a function of the acoustic driving parameters, for example, pressure, number of cycles, bubble size and oscillation amplitude. The latter was recorded with an ultrafast framing camera running at 10 million frames per second. A threshold for lipid shedding under ultrasound excitation was found for a relative bubble oscillation amplitude >30%. Lipid shedding was found to be reproducible, indicating that the shedding event can be controlled.


      PubDate: 2014-05-07T06:50:32Z
       
  • Time Efficiency and Diagnostic Agreement of 2-D Versus 3-D Ultrasound
           Acquisition of the Neonatal Brain
    • Abstract: Publication date: Available online 3 May 2014
      Source:Ultrasound in Medicine & Biology
      Author(s): Javier M. Romero , Neil Madan , Ilda Betancur , Adrian Ciobanu , Erin Murphy , Danielle McCullough , P. Ellen Grant
      The purpose of this study was to compare acquisition time efficiency and diagnostic agreement of neonatal brain ultrasound (US) scans obtained with a 3-D volume US acquisition protocol and the conventional 2-D acquisition protocol. Ninety-one consecutive premature neonatal brain ultrasound scans were prospectively performed on 59 neonates with the conventional 2-D acquisition protocol. Immediately after the 2-D study, a coronal 3-D ultrasound volume was acquired and later reconstructed into axial and sagittal planes. All 59 neonates were imaged in the neonatal intensive care unit to rule out intracranial hemorrhage. Total time for 2-D and 3-D acquisition protocols was recorded, and a two-tailed t-test was used to determine if study durations differed significantly. One pediatric neuroradiologist reviewed the reformatted 3-D images, tomographic ultrasound images. Results were compared with the clinical interpretation of the 2-D conventional study. The mean scanning time for the 2-D US acquisition protocol was 10.56 min (standard deviation [SD] = 7.11), and that for the 3-D volume US acquisition protocol was 1.48 min (SD = 0.59) (p ≤ 0.001). Inter-observer agreement revealed k values of 0.84 for hydrocephalus, 0.80 for germinal matrix hemorrhage/intraventricular hemorrhage, 0.74 for periventricular leukomalacia and 0.91 for subdural collection, hence near-perfect to substantial agreement between imaging protocols. There was a significant decrease in acquisition time for the 3-D volume ultrasound acquisition protocol compared with the conventional 2-D US protocol (p = <0.001), without compromising the diagnostic quality compared with a conventional 2-D US imaging protocol.


      PubDate: 2014-05-07T06:50:32Z
       
  • Assessing the Imaging Capabilities of Radial Mechanical and Electronic
           Echo-endoscopes Using the Resolution Integral
    • Abstract: Publication date: Available online 3 May 2014
      Source:Ultrasound in Medicine & Biology
      Author(s): Scott Inglis , Anna Janeczko , William Ellis , John N. Plevris , Stephen D. Pye
      Over the past decade there have been significant advances in endoscopic ultrasound (EUS) technology. Although there is an expectation that new technology will deliver improved image quality, there are few methods or phantoms available for assessing the capabilities of mechanical and electronic EUS systems. The aim of this study was to investigate the possibility of assessing the imaging capability of available EUS technologies using measurements of the resolution integral made with an Edinburgh Pipe Phantom. Various radial EUS echo-endoscopes and probes were assessed using an Edinburgh Pipe Phantom. Measurements of the resolution integral (R), depth of field (L R) and characteristic resolution (D R) were made at all operating frequencies. The mean R value for Fuji miniprobes was 16.0. The GF-UM20 and GF-UM2000 mechanical radial scopes had mean R values of 24.0 and 28.5, respectively. The two electronic radial echo-endoscopes had similar mean R values of 34.3 and 34.6 for the Olympus GF-UE260 and Fujinon EG-530 UR scopes, respectively. Despite being older technology, the mechanical GF-UM2000 scope had superior characteristic resolution (D R ), but could not compare with the depths of field (L R ) delivered by the current generation of electronic radial scopes, especially at the standard operating frequencies of 7.5 and 12 MHz.


      PubDate: 2014-05-07T06:50:32Z
       
  • Ex Vivo and In Vivo Assessment of the Non-linearity of
           Elasticity Properties of Breast Tissues for Quantitative Strain
           Elastography
    • Abstract: Publication date: Available online 5 May 2014
      Source:Ultrasound in Medicine & Biology
      Author(s): Takeshi Umemoto , Ei Ueno , Takeshi Matsumura , Makoto Yamakawa , Hiroko Bando , Tsuyoshi Mitake , Tsuyoshi Shiina
      The aim of this study was to reveal the background to the image variations in strain elastography (strain imaging [SI]) depending on the manner of manipulation (compression magnitude) during elasticity image (EI) acquisition. Thirty patients with 33 breast lesions who had undergone surgery followed by SI assessment in vivo were analyzed. An analytical approach to tissue elasticity based on the stress-elastic modulus (Young's modulus) relationship was adopted. Young's moduli were directly measured ex vivo in surgical specimens ranging from 2.60 kPa (fat) to 16.08 kPa (invasive carcinoma) under the weak-stress condition (<0.2–0.4 kPa, which corresponds to the appropriate “light touch” technique in SI investigation. The contrast (ratio) of lesion to fat in elasticity ex vivo gradually decreased as the stress applied increased (around 1.0 kPa) on the background of significant non-linearity of the breast tissue. Our results indicate that the differences in non-linearity in elasticity between the different tissues within the breast under minimal stress conditions are closely related to the variation in EI quality. The significance of the “pre-load compression” concept in tissue elasticity evaluation is recognized. Non-linearity of elasticity is an essential attribute of living subjects and could provide useful information having a considerable impact on clinical diagnosis in quantitative ultrasound elastography.


      PubDate: 2014-05-07T06:50:32Z
       
 
 
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