for Journals by Title or ISSN
for Articles by Keywords
help
  Subjects -> PHYSICS (Total: 813 journals)
    - ELECTRICITY AND MAGNETISM (9 journals)
    - MECHANICS (21 journals)
    - NUCLEAR PHYSICS (51 journals)
    - OPTICS (90 journals)
    - PHYSICS (585 journals)
    - SOUND (25 journals)
    - THERMODYNAMICS (32 journals)

PHYSICS (585 journals)

The end of the list has been reached or no journals were found for your choice.
Journal Cover Ultrasound in Medicine & Biology
  [SJR: 0.885]   [H-I: 106]   [8 followers]  Follow
    
   Full-text available via subscription Subscription journal
   ISSN (Print) 0301-5629
   Published by Elsevier Homepage  [3175 journals]
  • Meta-Analysis: Contrast-Enhanced Ultrasound Versus Conventional Ultrasound
           for Differentiation of Benign and Malignant Breast Lesions
    • Authors: Qian Li; Min Hu; Zhikui Chen; Changtian Li; Xi Zhang; Yiqing Song; Feixiang Xiang
      Pages: 919 - 929
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Qian Li, Min Hu, Zhikui Chen, Changtian Li, Xi Zhang, Yiqing Song, Feixiang Xiang
      This meta-analysis aimed to compare the diagnostic performance of contrast-enhanced ultrasound (CEUS), conventional ultrasound (US) combined with CEUS (US + CEUS) and US for distinguishing breast lesions. From thorough literature research, studies that compared the diagnostic performance of CEUS versus US or US + CEUS versus US, using pathology results as the gold standard, were included. A total of 10 studies were included, of which 9 compared the diagnostic performance of CEUS and US, and 5 studies compared US + CEUS and US. In those comparing CEUS versus US, the pooled sensitivity was 0.93 (95% CI: 0.91–0.95) versus 0.87 (95% CI: 0.85–0.90) and pooled specificity was 0.86 (95% CI: 0.84–0.88) versus 0.72 (95% CI: 0.69–0.75). In studies comparing US + CEUS versus US, the pooled sensitivity was 0.94 (95% CI: 0.92–0.96) versus 0.87 (95% CI: 0.84–0.90) and pooled specificity was 0.86 (95% CI: 0.82–0.89) versus 0.80 (95% CI: 0.76–0.84). In terms of diagnosing breast malignancy, areas under the curve of the summary receiver operating characteristic (of both CEUS (p = 0.003) and US + CEUS (p = 0.000) were statistically higher than that of US. Both CEUS alone and US + CEUS had better diagnostic performance than US in differentiation of breast lesions, and US + CEUS also had low negative likelihood ratio.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.022
       
  • Revised Value of Contrast-Enhanced Ultrasound for Solid Hypo-Echoic
           
    • Authors: YanFang Wang; Fang Nie; Ting Liu; Dan Yang; Qi Li; Jing Li; AiLing Song
      Pages: 930 - 940
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): YanFang Wang, Fang Nie, Ting Liu, Dan Yang, Qi Li, Jing Li, AiLing Song
      The use of ultrasound in differentiation of benign and malignant solid hypo-echoic thyroid nodules is a dilemma in clinical practice. The aim of this study was to investigate the revised value of contrast-enhanced ultrasound (CEUS) for differentiating solid hypo-echoic thyroid nodules using the Thyroid Imaging Reporting and Data System (TI-RADS).The study included 135 patients with 135 nodules confirmed by fine-needle aspiration and/or surgery. Every nodule underwent both conventional US and CEUS. Binary logistic regression analysis for conventional US features revealed that irregular shape, microcalcification and height greater than width were significant malignant predictive features. Binary logistic analysis for CEUS features indicated that hetero-enhancement, slow wash-in, an ill-defined enhancement border and fast wash-out were significantly associated with malignancy. The areas under the curve of the TI-RADS, CEUS and the combination were 0.806, 0.934 and 0.950, respectively. CEUS is a potentially useful tool in the differentiation of solid hypo-echoic thyroid nodules.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2017.12.018
       
  • Prediction of Tubulointerstitial Injury in Chronic Kidney Disease Using a
           Non-Invasive Model: Combination of Renal Sonography and Laboratory
           Biomarkers
    • Authors: Wen-Qi Yang; Shan Mou; Li Xu; Feng-Hua Li; Hong-Li Li
      Pages: 941 - 948
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Wen-Qi Yang, Shan Mou, Li Xu, Feng-Hua Li, Hong-Li Li
      The goal of the study described here was to evaluate the degree of tubulointerstitial injury in patients with chronic kidney disease (CKD) using a more accurate model that combines renal sonographic parameters and laboratory biomarkers. A total of 308 patients were enrolled. The study protocol included conventional ultrasound, contrast-enhanced ultrasonography and renal biopsy. CKD patients were divided into normal and mild (≤25%), moderate (26%–50%) and severe (>50%) tubulointerstitial injury groups. We created a model comprising peak intensity, time to peak, urinary retinol-binding protein and β2-microglobulin that could discriminate severe (>50%) tubulointerstitial injury. The area under the receiver operating characteristic curve of this model was 0.832, which had better accuracy than other individual indexes, and the sensitivity and specificity were 74.2% and 82.8%, respectively. Therefore, this model may be used to evaluate the severity of tubulointerstitial injury and may have the potential to serve as an effective auxiliary method to help nephrologists evaluate patients with CKD.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.019
       
  • Full-Field-of-View Time-Harmonic Elastography of the Native Kidney
    • Authors: Stephan Rodrigo Marticorena Garcia; Markus Grossmann; Sophia Theresa Lang; Manh Nguyen Trong; Michael Schultz; Jing Guo; Bernd Hamm; Jürgen Braun; Ingolf Sack; Heiko Tzschätzsch
      Pages: 949 - 954
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Stephan Rodrigo Marticorena Garcia, Markus Grossmann, Sophia Theresa Lang, Manh Nguyen Trong, Michael Schultz, Jing Guo, Bernd Hamm, Jürgen Braun, Ingolf Sack, Heiko Tzschätzsch
      The purpose of this study was to analyze full-field-of-view maps of renal shear wave speed (SWS) measured by time-harmonic elastography (THE) in healthy volunteers in terms of reproducibility, regional variation and physiologic effects. The kidneys of 37 healthy volunteers were investigated by multifrequency THE. The complete renal parenchyma, as well as cortex and medulla, was analyzed. A subgroup was investigated to test reproducibility (n = 3). Significant differences between SWS in cortex, medulla and full parenchyma were observed (2.10 ± 0.17, 1.35 ± 0.11 and 1.71 ± 0.16 m/s, all p values < 0.001) with mean intra-volunteer standard deviations of repeated measurements of 0.04 m/s (1.6%), 0.06 m/s (4.0%) and 0.08 m/s (4.5%), respectively. No effects of kidney anatomy, age, body mass index, blood pressure and heart rate on SWS were observed. THE allows generation of full-field-of-view SWS maps of native kidneys with high reproducibility.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.007
       
  • Enlarged Size and Impaired Elastic Properties of the Ascending Aorta are
           Associated with Endothelial Dysfunction and Elevated Plasma Matrix
           Metalloproteinase-2 Level in Patients with Bicuspid Aortic Valve
    • Authors: Yi-Bin Wang; Yang Li; You-Bin Deng; Ya-Ni Liu; Jun Zhang; Jie Sun; Ying Zhu; Li Li; Qiao-Ying Tang; Wei Zhou
      Pages: 955 - 962
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Yi-Bin Wang, Yang Li, You-Bin Deng, Ya-Ni Liu, Jun Zhang, Jie Sun, Ying Zhu, Li Li, Qiao-Ying Tang, Wei Zhou
      The aim of this study was to test whether enlarged size and impaired elastic properties of the ascending aorta are associated with impaired endothelial function and increases in plasma matrix metalloproteinase (MMP)-2 concentrations in patients with bicuspid aortic valve (BAV) without significant valvular dysfunction. The size and the elasticity of the ascending aorta and the flow-mediated vasodilation (FMD) in the brachial artery in response to hyperemia were evaluated with 2-D echocardiography and high-frequency linear ultrasound in 42 patients with BAV without significant valvular dysfunction and 30 age- and sex-matched healthy controls. In the BAV group, diastolic ascending aortic diameter (AoD) (32.1 ± 8.1 mm vs. 25.3 ± 3.6 mm, p < 0.001) and aortic stiffness index (8.0 ± 5.3 vs. 4.0 ± 1.8, p < 0.001) were significantly higher, and aortic strain (7.4 ± 3.6% vs. 11.1 ± 3.0%, p < 0.001) and aortic distensibility (7.4 ± 4.1 × 10−6cm2/dyn vs. 11.1 ± 4.3 × 10−6cm2/dyn, p < 0.001) were significantly lower than those in the control group. The BAV group also had lower FMD (6.5 ± 2.2% vs. 11.9 ± 2.7%, p < 0.001) and higher plasma MMP-2 levels (226.7 ± 55.0 ng/mL vs. 177.0 ± 45.3 ng/mL, p < 0.001) compared with the control group. In the BAV group, AoD, aortic strain, aortic stiffness index and aortic distensibility significantly correlated with FMD and MMP-2 (all p < 0.05). The multivariable linear regression analysis further indicated that FMD and MMP-2 were independently associated with AoD (β = −1.1, p = 0.005, and β = 0.09, p < 0.001, respectively). These findings suggest that enlarged size and impaired elastic properties of the ascending aorta are associated with endothelial dysfunction and elevated plasma MMP-2 level in patients with BAV without significant valvular dysfunction. FMD and plasma MMP-2 level are the significant and independent predictors of dilation of the ascending aorta in patients with BAV.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.012
       
  • Shear Wave Speed Estimation Using Reverberant Shear Wave Fields:
           Implementation and Feasibility Studies
    • Authors: Juvenal Ormachea; Benjamin Castaneda; Kevin J. Parker
      Pages: 963 - 977
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Juvenal Ormachea, Benjamin Castaneda, Kevin J. Parker
      Elastography is a modality that estimates tissue stiffness and, thus, provides useful information for clinical diagnosis. Attention has focused on the measurement of shear wave propagation; however, many methods assume shear wave propagation is unidirectional and aligned with the lateral imaging direction. Any deviations from the assumed propagation result in biased estimates of shear wave speed. To address these challenges, directional filters have been applied to isolate shear waves with different propagation directions. Recently, a new method was proposed for tissue stiffness estimation involving creation of a reverberant shear wave field propagating in all directions within the medium. These reverberant conditions lead to simple solutions, facile implementation and rapid viscoelasticity estimation of local tissue. In this work, this new approach based on reverberant shear waves was evaluated and compared with another well-known elastography technique using two calibrated elastic and viscoelastic phantoms. Additionally, the clinical feasibility of this technique was analyzed by assessing shear wave speed in human liver and breast tissues, in vivo. The results indicate that it is possible to estimate the viscoelastic properties in each scanned medium. Moreover, a better approach to estimation of shear wave speed was obtained when only the phase information was taken from the reverberant waves, which is equivalent to setting all magnitudes within the bandpass equal to unity: an idealization of a perfectly isotropic reverberant shear wave field.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.011
       
  • Comparison of Two Different Ultrasound Devices Using Strain Elastography
           Technology in the Diagnosis of Breast Lesions Related to the Histologic
           Results
    • Authors: André Farrokh; Fritz Schaefer; Friedrich Degenhardt; Nicolai Maass
      Pages: 978 - 985
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): André Farrokh, Fritz Schaefer, Friedrich Degenhardt, Nicolai Maass
      This study was conducted to provide evidence that elastograms of two different devices and different manufacturers using the same technical approach provide the same diagnoses. A total of 110 breast lesions were prospectively analysed by two experts in ultrasound, using the strain elastography function from two different manufacturers (Hitachi HI-RTE, Hitachi Medical Systems, Wiesbaden, Germany; and Siemens eSie Touch, Siemens Medical Systems, Erlangen, Germany). Results were compared with the histopathologic results. Applying the Bowker test of symmetry, no statistically significant difference between the two elastography functions of these two devices was found (p = 0.120). The Cohen's kappa of k = 0.591 showed moderate strength of agreement between the two elastograms. The two examiners yielded moderate strength of agreement analysing the elastograms (Hitachi HI-RTE, k = 0.478; Siemens eSie Touch, k = 0.441). In conclusion, evidence is provided that elastograms of the same lesion generated by two different ultrasound devices equipped with a strain elastography function do not significantly differ.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.015
       
  • Orthogonal B-Mode Evaluation of Common Carotid Artery Plaques Reveals the
           Absence of Outward Remodeling
    • Authors: J. Steinbuch; F.H.B.M. Schreuder; K.D. Reesink; A.P.G. Hoeks; W.H. Mess
      Pages: 986 - 994
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): J. Steinbuch, F.H.B.M. Schreuder, K.D. Reesink, A.P.G. Hoeks, W.H. Mess
      To properly assess morphologic and dynamic parameters of arteries and plaques, we propose the concept of orthogonal distance measurements, that is, measurements made perpendicular to the local lumen axis rather than along the ultrasound beam (vertical direction for a linear array). The aim of this study was to compare orthogonal and vertical artery and lumen diameters at the site of a plaque in the common carotid artery (CCA). Moreover, we investigated the interrelationship of orthogonal diameters and plaque size and the association of artery parameters with plaque echogenicity. In 29 patients, we acquired a longitudinal B-mode ultrasound recording of plaques at the posterior CCA wall. After semi-automatic segmentation of end-diastolic frames, diameters were extracted orthogonally along the lumen axis. To establish inter-observer variability of diameters obtained at the location of maximal plaque thickness, a second observer repeated the analysis (subset N = 21). Orthogonal adventitia–adventitia and lumen diameters could be determined with good precision (coefficient of variation: 1%–5%. However, the precision of the change in lumen diameter from diastole to systole (distension) at the site of the plaque was poor (21%–50%). The orthogonal lumen diameter was significantly smaller than the vertical lumen diameter (p < 0.001). Surprisingly, the plaques did not cause outward remodeling, that is, a local increase in adventitia–adventitia distance at the site of the plaque. The intra- and inter-observer precision of diastolic–systolic plaque compression was poor and of the same order as the standard deviation of plaque compression. The orthogonal relative lumen distension was significantly lower for echogenic plaques, indicating a higher stiffness, than for echolucent plaques (p < 0.01). In conclusion, we illustrated the feasibility of extracting orthogonal CCA and plaque dimensions, albeit that the proposed approach is inadequate to quantify plaque compression.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2017.12.013
       
  • The Assessment of Diagnostic Accuracy for Basilar Artery Stenosis by
           Transcranial Color-Coded Sonography
    • Authors: Jie Yang; Yang Hua; Xiang Li; Mingjie Gao; Qiuping Li; Beibei Liu; Liqun Jiao
      Pages: 995 - 1002
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Jie Yang, Yang Hua, Xiang Li, Mingjie Gao, Qiuping Li, Beibei Liu, Liqun Jiao
      This study aimed to determine the optimal criteria for evaluating basilar artery stenosis (BAS) by transcranial color-coded sonography (TCCS). A total of 403 cases with both TCCS and digital subtraction angiography (DSA) were enrolled. Peak systolic velocity (PSV), end diastolic velocity (EDV) and mean flow velocity (MFV) of the basilar artery (BA), intracranial vertebral artery (IVA) and posterior cerebral artery (PCA) were measured. The ratios PSVBA/PSVIVA and PSVBA/PSVPCA were calculated. With DSA as the reference, the optimal criteria for grading BAS were determined by receiver operating characteristic analysis. They were as follows: PSV ≥110 cm/s, MFV ≥70 cm/s and PSVBA/PSVIVA ≥1.5 for <50% BAS; PSV ≥150 cm/s, MFV ≥90 cm/s and PSVBA/PSVIVA ≥2.0 for 50%–69% BAS; PSV ≥210 cm/s, MFV ≥120 cm/s and PSVBA/PSVIVA ≥3.0 for 70%–99% BAS. The combination of PSV, MFV and PSVBA/PSVIVA may increase the accuracy for diagnosing 70%–99% BAS.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.009
       
  • Ultrasound-Guided Percutaneous Needle Biopsy for Peripheral Pulmonary
           Lesions: Diagnostic Accuracy and Influencing Factors
    • Authors: Yu-Qing Guo; Xin-Hong Liao; Zhi-Xian Li; Yuan-Yuan Chen; Si-Da Wang; Ji-Han Wang; Xian-Shan Liao; Yuan Luo
      Pages: 1003 - 1011
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Yu-Qing Guo, Xin-Hong Liao, Zhi-Xian Li, Yuan-Yuan Chen, Si-Da Wang, Ji-Han Wang, Xian-Shan Liao, Yuan Luo
      A retrospective study was carried out to evaluate the diagnostic accuracy and the factors influencing the diagnostic accuracy of 648 procedures of ultrasound-guided percutaneous needle biopsy (PNB) for peripheral pulmonary lesions (PPLs). We reviewed the histopathology results, the clinical records and the procedure reports of these 648 biopsies and the final diagnoses of 637 PPLs to determine the diagnostic accuracy of ultrasound-guided PNB. Factors that influenced the diagnostic accuracy were assessed by analysis of the biopsy procedures, which were classified as diagnostic cases (true-positive and true-negative) and non-diagnostic cases (false-positive, false-negative and indeterminate). Statistical analyses of factors that related to patient demographic characteristics, lesion characteristics and biopsy details were performed to determine possible effects on diagnostic accuracy. Biopsies were successfully performed in all cases, and 11 patients underwent second biopsies for the same lesions. Among the 637 PPLs, there were 326 (51.2%) malignant lesions, 272 (42.7%) benign lesions and 39 (6.1%) indeterminate lesions. Of the 272 benign lesions, 114 (41.9%) were found to be tuberculous. The overall diagnostic accuracy was 81.8%, and the rates of hemoptysis, symptomatic pneumothorax and chest-tube insertion were 8.0%, 1.7% and 0.9%, respectively. Lesions sizes were divided into 3 groups according to the measurement by ultrasound. For lesions that measured ≤20 mm, 21–49 mm and ≥50 mm, the diagnostic accuracy was 72.0%, 86.8% and 79.7%, while sensitivity and specificity were 54.3%–79.2%, 88.3%–90.7% and 79.4%–89.5% and 77.3%–100%, 96.8%–100% and 58.6%–100%, respectively. Diagnostic accuracy was significantly affected by lesion size when lesion size was measured by ultrasound (p = 0.006) and computed tomography (CT) (p = 0.001). In the 3 lesion groups of ≤20 mm, 21–49 mm or ≥50 mm, diagnostic accuracy among each group was significantly different (p < 0.001). When lesion size was measured by ultrasound (p < 0.001) and CT (p < 0.001) and the 3 groups were analyzed (p < 0.001), there was a statistically significant relationship between lesion size and the presence of necrosis. The rates of the presence of necrosis in lesions that measured ≤20 mm, 21–49 mm and ≥50 mm were 3.9%, 11.7% and 28.8%, respectively. No significance was found for age (p = 0.119), gender (p = 0.25), lesion location (p = 0.55), the presence of necrosis (p = 0.226), patient position (p = 0.25), needle size (p = 0.26), puncture angle (p = 0.34) and needle passes (p = 0.21). Ultrasound-guided PNB is an effective and safe diagnostic method for PPLs; the diagnostic accuracy is significantly affected by lesion size and decreases in smaller (≤20 mm) and larger (≥50 mm) lesions.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.016
       
  • Pulmonary Capillary Hemorrhage Induced by Different Imaging Modes of
           Diagnostic Ultrasound
    • Authors: Douglas L. Miller; Zhihong Dong; Chunyan Dou; Krishnan Raghavendran
      Pages: 1012 - 1021
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Douglas L. Miller, Zhihong Dong, Chunyan Dou, Krishnan Raghavendran
      The induction of pulmonary capillary hemorrhage (PCH) is a well-established non-thermal biological effect of pulsed ultrasound in animal models. Typically, research has been done using laboratory pulsed ultrasound systems with a fixed beam and, recently, by B-mode diagnostic ultrasound. In this study, a GE Vivid 7 Dimension ultrasound machine with 10 L linear array probe was used at 6.6 MHz to explore the relative PCH efficacy of B-mode imaging, M-mode (fixed beam), color angio mode Doppler imaging and pulsed Doppler mode (fixed beam). Anesthetized rats were scanned in a warmed water bath, and thresholds were determined by scanning at different power steps, 2 dB apart, in different groups of six rats. Exposures were performed for 5 min, except for a 15-s M-mode group. Peak rarefactional pressure amplitude thresholds were 1.5 MPa for B-mode and 1.1 MPa for angio Doppler mode. For the non-scanned modes, thresholds were 1.1 MPa for M-mode and 0.6 MPa for pulsed Doppler mode with its relatively high duty cycle (7.7 × 10−3 vs. 0.27 × 10−3 for M-mode). Reducing the duration of M-mode to 15 s (from 300 s) did not significantly reduce PCH (area, volume or depth) for some power settings, but the threshold was increased to 1.4 MPa. Pulmonary sonographers should be aware of this unique adverse bio-effect of diagnostic ultrasound and should consider reduced on-screen mechanical index settings for potentially vulnerable patients.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2017.11.006
       
  • Focused Ultrasound-Induced Suppression of Auditory Evoked Potentials in
           Vivo
    • Authors: Dianne Daniels; Shirley Sharabi; David Last; David Guez; Sharona Salomon; Zion Zivli; David Castel; Alex Volovick; Javier Grinfeld; Itay Rachmilevich; Talia Amar; Sigal Liraz-Zaltsman; Narek Sargsyan; Yael Mardor; Sagi Harnof
      Pages: 1022 - 1030
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Dianne Daniels, Shirley Sharabi, David Last, David Guez, Sharona Salomon, Zion Zivli, David Castel, Alex Volovick, Javier Grinfeld, Itay Rachmilevich, Talia Amar, Sigal Liraz-Zaltsman, Narek Sargsyan, Yael Mardor, Sagi Harnof
      The goal of this study was to determine the feasibility of focused ultrasound–based neuromodulation affecting auditory evoked potentials (AEPs) in animals. Focused ultrasound–induced suppression of AEPs was performed in 22 rats and 5 pigs: Repetitive sounds were produced, and the induced AEPs were recorded before and repeatedly after FUS treatment of the auditory pathway. All treated animals exhibited a decrease in AEP amplitude post-treatment in contrast to animals undergoing the sham treatment. Suppression was weaker for rats treated at 2.3 W/cm2 (amplitudes decreased to 59.8 ± 3.3% of baseline) than rats treated at 4.6 W/cm2 (36.9 ± 7.5%, p < 0.001). Amplitudes of the treated pigs decreased to 27.7 ± 5.9% of baseline. This effect lasted between 30 min and 1 mo in most treated animals. No evidence of heating during treatment or later brain damage/edema was observed. These results demonstrate the feasibility of inducing significant neuromodulation with non-thermal, non-invasive, reversible focused ultrasound. The long recovery times may have clinical implications.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.010
       
  • Transluminal Approach with Bubble-Seeded Histotripsy for Cancer Treatment
           with Ultrasonic Mechanical Effects
    • Authors: Reiko Ashida; Ken-ichi Kawabata; Takashi Maruoka; Kazuhiro Yamanaka; Hideki Yoshikawa; Tatsuya Ioka; Kazuhiro Katayama; Sachiko Tanaka
      Pages: 1031 - 1043
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Reiko Ashida, Ken-ichi Kawabata, Takashi Maruoka, Kazuhiro Yamanaka, Hideki Yoshikawa, Tatsuya Ioka, Kazuhiro Katayama, Sachiko Tanaka
      Bubble-seeded histotripsy (BSH) is a newly developed ultrasound-based mechanical fractionation technique using locally injected phase change nanodroplets (PCNDs) as sensitizers. The PCNDs are a kind of microbubble precursor compressed into submicron-size in droplets form, which were designed for local administration and will expand into microbubbles under ultrasound exposure. Previously, we reported that a combination of PCNDs injection and pulsed high-intensity focused ultrasound (pHIFU) with an acoustic intensity as low as about 3 kW/cm2 at 1.1 MHz, which is similar to the acoustic intensity of currently available HIFU coagulation therapy, was enough to induce tissue fractionation after significant antitumor effects in an in vivo study. Toward therapeutic application of BSH to deep-seated tissues such as the pancreas, the transluminal approach, using endoscopic ultrasound was thought to be ideal. Therefore, for a preliminary examination, we developed a new transducer with a small aperture (20- × 20-mm square) and long focal length (35 mm), operating at 2.1 MHz that could be attached to an EUS-mimicking probe. With the newly developed transducer and locally injected PCNDs, predictable tissue mechanical fractionation was observed in both ex vivo and in vivo studies at acoustic intensities that were too low to induce any significant bioeffects (around 4 kW/cm2) without using PCNDs. For in situ monitoring of the treatment site during a procedure, the degree of attenuation of microbubble motions after exposing the microbubbles to pHIFU was monitored, using ultrafast echographic imaging. Microbubble movements were observed to be largest at 25–30 s after pHIFU exposure. On the contrary, after 40 s, the movement of microbubbles decreased to the same level as at the start of the procedure, suggesting that an overdose of pHIFU exposure causes coagulation attributable to the thermal effect caused by absorption of the energy. Those results were promising for expanding the application of BSH for a transluminal approach, using a small transducer under real-time monitoring.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.023
       
  • Ultrasound Irradiation Combined with Hepatocyte Growth Factor Accelerate
           the Hepatic Differentiation of Human Bone Marrow Mesenchymal Stem Cells
    • Authors: Fan Li; Yang Liu; Yingyu Cai; Xin Li; Min Bai; Ting Sun; Lianfang Du
      Pages: 1044 - 1052
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Fan Li, Yang Liu, Yingyu Cai, Xin Li, Min Bai, Ting Sun, Lianfang Du
      This study investigated the impact of ultrasound (US) irradiation on the hepatic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) induced by hepatocyte growth factor (HGF) and the possible mechanisms. We treated hBMSCs, using HGF with and without US irradiation. Cell viability and stem cell surface markers were analyzed. Hepatocyte-like cell markers and functional markers including α-fetoprotein (αFP/AFP), cytokeratin 18 (CK18), albumin (ALB) and glycogen content were analyzed at the time point of day 1, 3 and 5 after treatment. The involvement of Wnt/β-catenin signaling pathway was evaluated as well. The results showed that the US treatment at 1.0 W/cm2 or 1.5 W/cm2 for 30 s or 60 s conditions yielded favorable cell viability and engendered stem cell differentiation. At day 5, the expressions of AFP, CK18, ALB and the glycogen content were significantly elevated in the US-treated group at both messenger ribonucleic acid and protein levels (all p < 0.05), in comparison with HGF and control groups. Among all the US treated groups, the expression levels of specific hepatic markers in the (1.5 W/cm2 for 60 s) group were the highest. Furthermore, Wnt1, β-Catenin, c-Myc and Cyclin D1 were significantly increased after US irradiation (all p < 0.05), and the enhancements of c-Myc and Cyclin D1 could be obviously impaired by the inhibitor ICG-001 (p < 0.05, p < 0.05), in accordance with decreased ALB and CK18 expression and glycogen content (all p < 0.05). In conclusion, US irradiation was able to promote the hBMSCs' differentiation mediated by HGF in vitro safely, easily and controllably. The activation of Wnt/β-catenin signaling pathway was involved in this process. US irradiation could serve as a potentially beneficial tool for the research and application of stem cell differentiation.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.005
       
  • Quantitative Evaluation of Hepatic Microvascular Perfusion after
           Ischemia–Reperfusion Injury in Rabbits by Contrast-Enhanced Ultrasound
           Perfusion Imaging
    • Authors: Fang Xie; Xiang Fei; Ming-Bo Zhang; Yan Zhang; Hong-Wei Wang; Jie Tang; Wen-Bo Tang; Yu-Kun Luo
      Pages: 1053 - 1062
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Fang Xie, Xiang Fei, Ming-Bo Zhang, Yan Zhang, Hong-Wei Wang, Jie Tang, Wen-Bo Tang, Yu-Kun Luo
      The aim of this study was to evaluate microvascular perfusion after liver ischemia–reperfusion injury (IRI) in rabbits using the “flash-replenishment” method of contrast-enhanced ultrasound (CEUS) perfusion imaging. Twenty-eight rabbits underwent either 30, 60 or 90 min of ischemia and 120 min of reperfusion. CEUS perfusion imaging was performed using the “flash-replenishment” model, and hepatic microvascular perfusion parameters, including peak intensity (PI), area under the curve (AUC), and hepatic artery-to-vein transit time (HA-HVTT), were calculated. Prolonged ischemia upregulated intracellular adhesion molecule-1 (ICAM-1), alanine transaminase (ALT) and aspartate transaminase (AST) levels. Longer ischemia decreased PI and AUC, but increased HA-HVTT. The perfusion parameters were significantly correlated with Suzuki's pathology scores and ALT and AST levels. The “flash-replenishment” method of CEUS perfusion imaging is an accurate and non-invasive method for evaluating hepatic microvascular perfusion and provides a valuable experimental basis for early prediction of liver IRI damage after liver transplantation or liver resection.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.004
       
  • Simplified Preparation of αvβ3 Integrin-Targeted Microbubbles Based on a
           Clinically Available Ultrasound Contrast Agent: Validation in a
           Tumor-Bearing Mouse Model
    • Authors: Kentaro Otani; Hirohito Nishimura; Atsunori Kamiya; Mariko Harada-Shiba
      Pages: 1063 - 1073
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Kentaro Otani, Hirohito Nishimura, Atsunori Kamiya, Mariko Harada-Shiba
      The usefulness of ultrasound molecular imaging with αvβ3 integrin-targeted microbubbles for detecting tumor angiogenesis has been demonstrated. Recently, we developed αvβ3 integrin-targeted microbubbles by modifying clinically available microbubbles (Sonazoid, Daiichi-Sankyo Pharmaceuticals, Tokyo, Japan) with a secreted glycoprotein (lactadherin). The aims of our present study were to simplify the preparation of lactadherin-bearing Sonazoid and to examine the diagnostic utility of lactadherin-bearing Sonazoid for αvβ3 integrin-expressing tumor vessels by using SK-OV-3-tumor–bearing mice. By incubating 1.2 × 107 Sonazoid microbubbles with 1.0 µg lactadherin, the complicated washing and centrifugation steps during the microbubble preparation could be omitted with no significant reduction in labeling ratio of lactadherin-bearing Sonazoid. In addition, the number of Sonazoid microbubbles accumulated in the SK-OV-3 tumor was significantly increased by modifying Sonazoid with lactadherin. Our data suggest that the lactadherin-bearing Sonazoid is an easily prepared and potentially clinically translatable targeted microbubble for αvβ3 integrin-expressing vessels.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.017
       
  • Generation of Reactive Oxygen Species in Heterogeneously Sonoporated Cells
           by Microbubbles with Single-Pulse Ultrasound
    • Authors: Caixia Jia; Lin Xu; Tao Han; Ping Cai; Alfred C.H. Yu; Peng Qin
      Pages: 1074 - 1085
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Caixia Jia, Lin Xu, Tao Han, Ping Cai, Alfred C.H. Yu, Peng Qin
      To develop and realize sonoporation-based macromolecule delivery, it is important to understand the underlying cellular bioeffects involved. It is known that an appropriate level of reactive oxygen species (ROS) is necessary to maintain normal physiologic function, but excessive ROS triggers adverse downstream bioeffects. However, it is still unclear whether a relationship exists between intracellular ROS levels and sonoporation. Using a customized platform for 1.5-MHz ultrasound exposure (13.33 µs duration and 0.70 MPa peak negative pressure) and imaging the dynamics of sonoporation and intracellular ROS at the single-cell level, we quantified the exogenous molecular uptake and the concentration of intracellular ROS indicator to evaluate the extent of sonoporation and ROS change, respectively. Our results revealed that the intracellular ROS level was correlated with the degree of the sonoporation. (i) Within ~120 s of the onset of ultrasound, during which membrane perforation and complete membrane resealing occurred, intracellular ROS rapidly decreased because of extracellular diffusion of dichlorofluorescein through the perforated membrane and positively correlated with the degree of the sonoporation. (ii) In the following 270 s (120–390 s post-exposure), ROS generation in reversibly sonoporated cells gradually increased and was positively correlated with the degree of the sonoporation. (iii) The ROS level in irreversibly sonoporated cells reduced to depletion during this time interval. It is possible that ROS generation in reversibly sonoporated cells can impact their long-term fate. These results thus provide new insight into the biological response to sonoporation.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.006
       
  • Influence of Acoustic Reflection on the Inertial Cavitation Dose in a
           Franz Diffusion Cell
    • Authors: Jeremy Robertson; Sid Becker
      Pages: 1100 - 1109
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Jeremy Robertson, Sid Becker
      The exposure of the skin to low-frequency (20–100 kHz) ultrasound is a well-established method for increasing its permeability to drugs. The mechanism underlying this permeability increase has been found to be inertial cavitation within the coupling fluid. This study investigated the influence of acoustic reflections on the inertial cavitation dose during low-frequency (20 kHz) exposure in an in vitro skin sonoporation setup. This investigation was conducted using a passive cavitation detector that monitored the broadband noise emission within a modified Franz diffusion cell. Two versions of this diffusion cell were employed. One version had acoustic conditions that were similar to those of a standard Franz diffusion cell surrounded by air, whereas the second was designed to greatly reduce the acoustic reflection by submerging the diffusion cell in a water bath. The temperature of the coupling fluid in both setups was controlled using a novel thermoelectric cooling system. At an ultrasound intensity of 13.6 W/cm2, the median inertial cavitation dose when the acoustic reflections were suppressed, was found to be only about 15% lower than when reflections were not suppressed.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.021
       
  • In Vivo Imaging of Microvasculature during Anesthesia with High-Resolution
           Photoacoustic Microscopy
    • Authors: Xiang Zhang; Xiaoqin Qian; Chao Tao; Xiaojun Liu
      Pages: 1110 - 1118
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Xiang Zhang, Xiaoqin Qian, Chao Tao, Xiaojun Liu
      Anesthesia monitoring is extremely important in improving the quality of anesthesia and ensuring the safety of patients in operation. Photoacoustic microscopy (PAM) is proposed to in vivo image the skin microvasculature of 10 nude mice undergoing general anesthesia by using the isoflurane gas with a concentration of 3%. Benefiting from strong optical absorption of hemoglobin, PAM has good contrast and high resolution in mapping of microvasculature. A series of high quality images can clearly reveal the subtle changes of capillaries in morphology over time. Two indices, vessel intensity and vessel density, are extracted from these images to measure the microvasculature quantitatively. The imaging results show that the vessel intensity and density are increased over time. After 65 min, the vessel intensity increased 42.7 ± 8.6% and the density increased 28.6 ± 12.2%. These indices extracted from photoacoustic images accurately reflect the greater blood perfusion undergoing general anesthesia. Additionally, abnormal reductions of vessel intensity and density are also observed as overtime anesthesia. This preclinical study suggests that PAM holds potential to monitor anesthesia by imaging the skin microvasculature.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.018
       
  • Assessment of Systemic Adenosine Effect Using Color Doppler Ultrasound of
           the Splenic Artery—Feasibility and Potential Clinical Utility for
           Coronary Interventions
    • Authors: Oliver Klein-Wiele; Walied Sherifa; Marietta Garmer; Kaffer Kara; Dietrich Grönemeyer; Birgit Hailer
      Pages: 1119 - 1123
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Oliver Klein-Wiele, Walied Sherifa, Marietta Garmer, Kaffer Kara, Dietrich Grönemeyer, Birgit Hailer
      Adenosine induces coronary vasodilation and simultaneously reduces splanchnic perfusion. This effect can be absent in adenosine non-responders. Imaging of splanchnic arteries under adenosine assessing this effect has not been performed in humans previously. In 26 patients, splenic artery color Doppler was performed during an infusion of adenosine. Peak velocity in the splenic artery was measured before the infusion and at 2 min. Results were compared qualitatively with perfusion imaging in magnetic resonance. A total of 24 patients showed a drop of splenic artery peak velocity from 62.3 ± 18.1 to 40.4 ± 15.7 cm/s (p < 0.001), which corresponded to perfusion restriction in magnetic resonance. Two patients with constant splenic artery velocity did not show perfusion restriction. We showed feasibility of assessing changes in splenic artery velocity under adenosine for the first time in humans. Further studies are needed to investigate whether this novel application is a robust tool to rule out inadequate adenosine effect during measurement of fractional flow reserve in coronary catheterization.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.014
       
  • Local Texture Anisotropy as an Estimate of Muscle Quality in Ultrasound
           Imaging
    • Authors: Guillaume J.R. Dubois; Damien Bachasson; Lilian Lacourpaille; Olivier Benveniste; Jean-Yves Hogrel
      Pages: 1133 - 1140
      Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5
      Author(s): Guillaume J.R. Dubois, Damien Bachasson, Lilian Lacourpaille, Olivier Benveniste, Jean-Yves Hogrel
      This study introduces local pattern texture anisotropy as a novel parameter to differentiate healthy and disordered muscle and to gauge the severity of muscle impairments based on B-mode ultrasound images. Preliminary human results are also presented. A local pattern texture anisotropy index (TAI) was computed in one region of interest in the short head of the biceps brachii. The effects of gain settings and box sizes required for TAI computation were investigated. Between-day reliability was studied in patients with sporadic inclusion body myositis (n = 26). The ability of the TAI to discriminate dystrophic from healthy muscle was evaluated in patients with Duchenne muscular dystrophy and healthy controls (n = 16). TAI values were compared with a gray-scale index (GSI). TAI values were less influenced by gain settings than were GSI values. TAI had lower between-day variability (typical error = 2.3%) compared with GSI (typical error = 2.3% vs. 8.3%, respectively). Patients with Duchenne muscular dystrophy had lower TAIs than controls (0.76 ± 0.06 vs. 0.87 ± 0.03, respectively, p < 0.05). At 40% gain, TAI values correlated with percentage predicted elbow flexor strength in inclusion body myositis (R = 0.63, p < 0.001). The TAI may be a promising addition to other texture-based approaches for quantitative muscle ultrasound imaging.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2017.12.017
       
  • Microembolic Signals Predict Recurrence of Ischemic Events in Symptomatic
           Patients with Middle Cerebral Artery Stenosis
    • Authors: Xiaomin Chen; Kangding Liu; Xiujuan Wu; Sibo Wang; Ting Li; Yingqi Xing
      Pages: 747 - 755
      Abstract: Publication date: April 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 4
      Author(s): Xiaomin Chen, Kangding Liu, Xiujuan Wu, Sibo Wang, Ting Li, Yingqi Xing
      Middle cerebral artery (MCA) stenosis is a common cause of ischemic stroke in Asian populations. We sought to determine whether microembolic signals (MESs) can predict the occurrence or recurrence of ischemia in symptomatic and asymptomatic patients with MCA stenosis. The symptomatic group had a significantly higher incidence of MES (30% vs. 16.2%, p < 0.05), as well as higher incidences of cerebral infarction and transient ischemic attack (TIA) (infarction, 13.0% vs. 4.4%, OR 3.123 [95% CI, 1.049–9.294], p < 0.05; TIA, 21.0% vs. 2.9%, OR = 7.108 [95% CI, 1.808–27.949], p < 0.001) than the asymptomatic group. After a follow-up period of 0.5–4.5 y, the subgroup of MES-positive (MES+) symptomatic patients had a significantly higher incidence of TIA (36.7% vs. 14.3%, OR = 1.623 [95% CI, 1.166–2.258]; p < 0.001) than the subgroup of MES-negative (MES-) symptomatic patients. The likelihood of the early occurrence of an endpoint event was also higher in the subgroup of MES+ symptomatic patients. In the group of asymptomatic patients with MCA stenosis, no significant differences were identified between the MES+ and MES− subgroups.

      PubDate: 2018-02-26T03:18:36Z
      DOI: 10.1016/j.ultrasmedbio.2017.10.014
       
  • Microvenous Reflux in the Skin of Limbs with Superficial Venous
           Incompetence
    • Authors: Darshna Govind; Kate N. Thomas; Brigid G. Hill; Andre M. van Rij
      Pages: 756 - 761
      Abstract: Publication date: April 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 4
      Author(s): Darshna Govind, Kate N. Thomas, Brigid G. Hill, Andre M. van Rij
      This study investigated whether microvenous reflux can be detected in limbs with chronic venous disease using superb microvascular imaging (SMI) and colour Doppler imaging. Participants with venous disease (limbs, n = 26) and without venous disease (limbs, n = 10) were studied. The skin in the medial gaiter region was imaged using both SMI and colour Doppler to identify reflux in the small vessels in response to distal augmentation. The diameters and depths of responsive vessels were measured. In limbs with venous disease, reflux in response to provocation was visualised with SMI in a greater number of vessels (12/26 versus 4/26) and smaller vessels than with colour Doppler. Reflux in the superficial skin veins was demonstrated in one control participant (1/10) using SMI and in none using colour Doppler (0/10). Our study indicates that microvenous reflux is demonstrable in limbs with venous disease and that SMI is more sensitive than colour Doppler.

      PubDate: 2018-02-26T03:18:36Z
      DOI: 10.1016/j.ultrasmedbio.2017.11.014
       
  • Differentiation of Inflammatory From Fibrotic Ileal Strictures among
           Patients with Crohn's Disease Based on Visual Analysis: Feasibility Study
           Combining Conventional B-Mode Ultrasound, Contrast-Enhanced Ultrasound and
           Strain Elastography
    • Authors: Emilio Quaia; Antonio Giulio Gennari; Maria Assunta Cova; Edwin J.R. van Beek
      Pages: 762 - 770
      Abstract: Publication date: April 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 4
      Author(s): Emilio Quaia, Antonio Giulio Gennari, Maria Assunta Cova, Edwin J.R. van Beek
      The aim of this pilot study was to assess prospectively the feasibility of conventional B-mode ultrasound (US) and contrast-enhanced ultrasound (CEUS) combined with real-time strain elastography (SE) in the differentiation of inflammatory from fibrotic ileal strictures among patients with Crohn's disease (CD) based on visual analysis. Twenty non-consecutive patients (15 male and 5 female; mean age ± standard deviation, 40.2 ± 10.22 y) with CD and stricture of the terminal ileal loop were scanned by conventional B-mode US and CEUS and, subsequently, by real-time SE. Two independent readers visually classified each bowel stricture as fibrotic or inflammatory based on conventional B-mode US, CEUS, SE, individually and then for all techniques combined. All techniques combined had a higher (p < 0.05) sensitivity (reader 1, 9/20 [45%]; reader 2, 7/20 [35%]), specificity (reader 1, 5/20 [25%]; reader 2, 8/20 [40%]) and diagnostic accuracy (reader 1, 14/20 [70%]; reader 2, 15/20 [75%]) and higher (p < 0.05) area under the receiver operating characteristic curve (reader 1, 0.953; reader 2, 0.921) than individual techniques. Inter-reader agreement was fair for conventional B-mode US (k = 0.46) and CEUS (k = 0.39), moderate for SE (k = 0.6) and fair for all techniques combined (k = 0.38). Conventional B-mode US and CEUS, in combination with SE, may improve differentiation of inflammatory from fibrotic ileal strictures among patients with CD based on visual analysis.

      PubDate: 2018-02-26T03:18:36Z
      DOI: 10.1016/j.ultrasmedbio.2017.11.015
       
  • Point Shear Wave Elastography of the Spleen: Its Role in Patients with
           Portal Hypertension
    • Authors: Natalie Lucchina; Chiara Recaldini; Monica Macchi; Valeria Molinelli; Mario Montanari; Sergio Segato; Raffaele Novario; Carlo Fugazzola
      Pages: 771 - 778
      Abstract: Publication date: April 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 4
      Author(s): Natalie Lucchina, Chiara Recaldini, Monica Macchi, Valeria Molinelli, Mario Montanari, Sergio Segato, Raffaele Novario, Carlo Fugazzola
      The goals of the study described here were to evaluate the feasibility and reproducibility of measuring spleen stiffness (SS) using point shear wave elastography in a series of cirrhotic patients and to investigate whether SS, liver stiffness (LS) and other non-invasive parameters are correlated with the presence of esophagogastric varices (EVs). Fifty-four cirrhotic patients with low-grade EVs or without EVs at esophago-gastro-duodenoscopy were enrolled. They underwent abdominal ultrasound and Doppler ultrasound of hepatic vessels simultaneously with p-SWE of the liver and spleen. In 42 patients, the accuracy of LS and SS, as well as of platelet count and spleen longitudinal diameter, in predicting the presence of EVs was evaluated. The technical success was 90.74% for LS (49/54 patients) and 77.78% for SS (42/54 patients). Inter-observer agreement for SS measurement was high. Both LS and SS correlated with esophago-gastro-duodenoscopy: LS had the highest accuracy in predicting the presence of EVs (area under the receiver operating characteristic curve [AUROC] = 0.913); SS had the lowest accuracy (AUROC = 0.675); platelet count and spleen diameter had intermediate accuracy (AUROC = 0.731 and 0.729, respectively). SS did not have an advantage over LS in predicting low-grade EVs and cannot be proposed as a useful tool in the diagnostic process of cirrhotic patients who require screening esophago-gastro-duodenoscopy.

      PubDate: 2018-02-26T03:18:36Z
      DOI: 10.1016/j.ultrasmedbio.2017.11.019
       
  • Could Ultrasound Elastography Reflect Liver Function'
    • Authors: Tingting Qiu; Hong Wang; Jinzhen Song; Gang Guo; Yujun Shi; Yan Luo; Jibin Liu
      Pages: 779 - 785
      Abstract: Publication date: April 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 4
      Author(s): Tingting Qiu, Hong Wang, Jinzhen Song, Gang Guo, Yujun Shi, Yan Luo, Jibin Liu
      The purpose of this study was to investigate whether ultrasound elastography reflects liver function reserve relative to liver fibrosis histology. Sixty-five New Zealand rabbits were divided into an experimental group (n = 45) and a control group (n = 20). In the experimental group, liver fibrosis (F1–F4) was induced by subcutaneous injection of carbon tetrachloride. Point shear wave elastography and the indocyanine green (ICG) elimination test were performed for the two groups at 4-wk intervals for 56 wk. The liver stiffness value (LSV) and the ICG retention rate at 15 min (ICGR15) were obtained, and the correlation between them was investigated. The median LSVs of stages F0–F4 were 3.92 kPa (1.91–8.53 kPa), 5.02 kPa (2.39–8.91 kPa), 7.87 kPa (5.21–12.26 kPa), 12.83 kPa (5.92–16.79 kPa) and 16.64 kPa (9.76–29.50 kPa), respectively. The median ICGR15 values of stages F0–F4 were 8.7% (4.8%–15.6%), 10.8% (5.6%–20.3%), 19.2% (12.3%–26.7%), 31.0% (20.9%–41.0%) and 45.6% (22.1%–60.9%). There were significant differences in LSVs and ICGR15 values among the different stages of liver fibrosis (p < 0.01). A positive correlation was observed between LSV and ICGR15 (r = 0.7497, p < 0.0001). A strong correlation was observed between liver stiffness and liver function reserve, indicating ultrasound elastography may reflect liver function reserve in different degrees of liver fibrosis.

      PubDate: 2018-02-26T03:18:36Z
      DOI: 10.1016/j.ultrasmedbio.2017.12.015
       
  • Diaphragmatic Ultrasound Correlates with Inspiratory Muscle Strength and
           Pulmonary Function in Healthy Subjects
    • Authors: Letícia Zumpano Cardenas; Pauliane Vieira Santana; Pedro Caruso; Carlos Roberto Ribeiro de Carvalho; André Luís Pereira de Albuquerque
      Pages: 786 - 793
      Abstract: Publication date: April 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 4
      Author(s): Letícia Zumpano Cardenas, Pauliane Vieira Santana, Pedro Caruso, Carlos Roberto Ribeiro de Carvalho, André Luís Pereira de Albuquerque
      Diaphragm ultrasound (DUS) has been used to identify diaphragm dysfunction. However, its correlations with respiratory strength and lung function are unclear, even in healthy patients. A total of 64 healthy patients (30 males) had lung function and inspiratory strength (maximal inspiratory pressure and sniff nasal inspiratory pressure) measured. Gastric and oesophageal pressures were measured in a subgroup (n = 40). DUS was characterized by mobility (quiet breathing [QB] and deep breathing [DB]) and thickness (at functional residual capacity [ThFRC] and total lung capacity [ThTLC]). We calculated the thickening fraction (TF). During QB, DUS was similar between sexes. However, during DB, females had lower mobility, thickness and TF than males. Mobility at DB, ThTLC and TF significantly correlated with lung function and inspiratory strength. These correlations were affected by sex. DUS correlated with inspiratory gastric pressure. In healthy patients, DUS correlated with lung function and inspiratory strength during DB. Significant differences between genders were noticeable when DUS was performed during DB.

      PubDate: 2018-02-26T03:18:36Z
      DOI: 10.1016/j.ultrasmedbio.2017.11.020
       
  • Clinical Utility of Fetal Short-Lag Spatial Coherence Imaging
    • Authors: Will Long; Dongwoon Hyun; Kingshuk Roy Choudhury; David Bradway; Patricia McNally; Brita Boyd; Sarah Ellestad; Gregg E. Trahey
      Pages: 794 - 806
      Abstract: Publication date: April 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 4
      Author(s): Will Long, Dongwoon Hyun, Kingshuk Roy Choudhury, David Bradway, Patricia McNally, Brita Boyd, Sarah Ellestad, Gregg E. Trahey
      In this study, we evaluate the clinical utility of fetal short-lag spatial coherence (SLSC) imaging. Previous work has documented significant improvements in image quality with fetal SLSC imaging as quantified by measurements of contrast and contrast-to-noise ratio (CNR). The objective of this study was to examine whether this improved technical efficacy is indicative of the clinical utility of SLSC imaging. Eighteen healthy volunteers in their first and second trimesters of pregnancy were scanned using a modified Siemens SC2000 clinical scanner. Raw channel data were acquired for routinely examined fetal organs and used to generate fully matched raw and post-processed harmonic B-mode and SLSC image sequences, which were subsequently optimized for dynamic range and other imaging parameters by a blinded sonographer. Optimized videos were reviewed in matched B-mode and SLSC pairs by three blinded clinicians who scored each video based on overall quality, target conspicuity and border definition. SLSC imaging was highly favored over conventional imaging with SLSC scoring equal to (28.2 ± 10.5%) or higher than (63.9 ± 12.9%) B-mode for video pairs across all examined structures and processing conditions. Multivariate modeling revealed that SLSC imaging is a significant predictor of improved image quality with p ≤ 0.002. Expert-user scores for image quality support the application of SLSC in fetal ultrasound imaging.

      PubDate: 2018-02-26T03:18:36Z
      DOI: 10.1016/j.ultrasmedbio.2017.12.006
       
  • 3-D Quantitative Dynamic Contrast Ultrasound for Prostate Cancer
           Localization
    • Authors: Stefan G. Schalk; Jing Huang; Jia Li; Libertario Demi; Hessel Wijkstra; Pintong Huang; Massimo Mischi
      Pages: 807 - 814
      Abstract: Publication date: April 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 4
      Author(s): Stefan G. Schalk, Jing Huang, Jia Li, Libertario Demi, Hessel Wijkstra, Pintong Huang, Massimo Mischi
      To investigate quantitative 3-D dynamic contrast-enhanced ultrasound (DCE-US) and, in particular 3-D contrast-ultrasound dispersion imaging (CUDI), for prostate cancer detection and localization, 43 patients referred for 10–12-core systematic biopsy underwent 3-D DCE-US. For each 3-D DCE-US recording, parametric maps of CUDI-based and perfusion-based parameters were computed. The parametric maps were divided in regions, each corresponding to a biopsy core. The obtained parameters were validated per biopsy location and after combining two or more adjacent regions. For CUDI by correlation (r) and for the wash-in time (WIT), a significant difference in parameter values between benign and malignant biopsy cores was found (p < 0.001). In a per-prostate analysis, sensitivity and specificity were 94% and 50% for r, and 53% and 81% for WIT. Based on these results, it can be concluded that quantitative 3-D DCE-US could aid in localizing prostate cancer. Therefore, we recommend follow-up studies to investigate its value for targeting biopsies.

      PubDate: 2018-02-26T03:18:36Z
      DOI: 10.1016/j.ultrasmedbio.2017.12.005
       
  • Assessing Risk Category of Breast Cancer by Ultrasound Imaging
           Characteristics
    • Authors: Qiang Guo; Lei Zhang; Zhixin Di; Chunping Ning; Zhiwu Dong; Ziyao Li; Dongmo Wang; Chong Liu; Ming Zhao; Jiawei Tian
      Pages: 815 - 824
      Abstract: Publication date: April 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 4
      Author(s): Qiang Guo, Lei Zhang, Zhixin Di, Chunping Ning, Zhiwu Dong, Ziyao Li, Dongmo Wang, Chong Liu, Ming Zhao, Jiawei Tian
      The purpose of our study was to assess the potential clinical value of ultrasound imaging in predicting risk category in patients with breast cancer. Three hundred thirty-six patients were enrolled and divided into a high-risk group (99, 29.5%) and mid- to low-risk group (237, 70.5%) according to the St. Gallen risk criteria. All data were retrospectively collected to analyze correlations between ultrasound features and risk category. The results revealed that the ultrasound features of irregular shape (p = 0.002), vertical growth orientation (p = 0.002), angular contour (p = 0.022) and high color Doppler flow imaging grade (p = 0.001) tended to be present in images of the high-risk group. Therefore, tumor ultrasound features should be recognized as an ideal option for determination of risk category in patients with breast cancer.

      PubDate: 2018-02-26T03:18:36Z
      DOI: 10.1016/j.ultrasmedbio.2017.12.001
       
  • Editorial Advisory Board
    • Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5


      PubDate: 2018-04-15T17:42:25Z
       
  • Calendar
    • Abstract: Publication date: May 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 5


      PubDate: 2018-04-15T17:42:25Z
       
  • Anisotropy and Spatial Heterogeneity in Quantitative Ultrasound
           Parameters: Relevance to the Study of the Human Cervix
    • Authors: Quinton W. Guerrero; Helen Feltovich; Ivan M. Rosado-Mendez; Lindsey C. Carlson; Geng Li; Timothy J. Hall
      Abstract: Publication date: Available online 13 April 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Quinton W. Guerrero, Helen Feltovich, Ivan M. Rosado-Mendez, Lindsey C. Carlson, Geng Li, Timothy J. Hall
      Imaging biomarkers based on quantitative ultrasound can offer valuable information about properties that inform tissue function and behavior such as microstructural organization (e.g., collagen alignment) and viscoelasticity (i.e., compliance). For example, the cervix feels softer as its microstructure remodels during pregnancy, an increase in compliance that can be objectively quantified with shear wave speed and therefore shear wave speed estimation is a potential biomarker of cervical remodeling. Other proposed biomarkers include parameters derived from the backscattered echo signal, such as attenuation and backscattered power loss, because such parameters can provide insight into tissue microstructural alignment and organization. Of these, attenuation values for the pregnant cervix have been reported, but large estimate variance reduces their clinical value. That said, parameter estimates based on the backscattered echo signal may be incorrect if assumptions they rely on, such as tissue isotropy and homogeneity, are violated. For that reason, we explored backscatter and attenuation parameters as potential biomarkers of cervical remodeling via careful investigation of the assumptions of isotropy and homogeneity in cervical tissue. Specifically, we estimated the angle- and spatial-dependence of parameters of backscattered power and acoustic attenuation in the ex vivo human cervix, using the reference phantom method and electronic steering of the ultrasound beam. We found that estimates are anisotropic and spatially heterogeneous, presumably because the tissue itself is anisotropic and heterogeneous. We conclude that appropriate interpretation of imaging biomarkers of cervical remodeling must account for tissue anisotropy and heterogeneity.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.02.008
       
  • Quantitative Measurement of Erythrocyte Aggregation as a Systemic
           Inflammatory Marker by Ultrasound Imaging: A Systematic Review
    • Authors: Prajwal Gyawali; Daniela Ziegler; Jean-François Cailhier; André Denault; Guy Cloutier
      Abstract: Publication date: Available online 13 April 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Prajwal Gyawali, Daniela Ziegler, Jean-François Cailhier, André Denault, Guy Cloutier
      This systematic review is aimed at answering two questions: (i) Is erythrocyte aggregation a useful biomarker in assessing systemic inflammation' (ii) Does quantitative ultrasound imaging provide the non-invasive option to measure erythrocyte aggregation in real time' The search was executed through bibliographic electronic databases CINAHL, EMB Review, EMBASE, MEDLINE, PubMed and the grey literature. The majority of studies correlated elevated erythrocyte aggregation with inflammatory blood markers for several pathologic states. Some studies used “erythrocyte aggregation” as an established marker of systemic inflammation. There were limited but promising articles regarding the use of quantitative ultrasound spectroscopy to monitor erythrocyte aggregation. Similarly, there were limited studies that used other ultrasound techniques to measure systemic inflammation. The quantitative measurement of erythrocyte aggregation has the potential to be a routine clinical marker of inflammation as it can reflect the cumulative inflammatory dynamics in vivo, is relatively simple to measure, is cost-effective and has a rapid turnaround time. Technologies like quantitative ultrasound spectroscopy that can measure erythrocyte aggregation non-invasively and in real time may offer the advantage of continuous monitoring of the inflammation state and, thus, may help in rapid decision making in a critical care setup.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.02.020
       
  • Can Biannual Ultrasound Surveillance Detect Smaller Second Cancers or
           Detect Cancers Earlier in Patients with Breast Cancer History'
    • Authors: Jai Kyung You; Mi Kyung Song; Min Jung Kim; Eun-Kyung Kim; Hee Jung Moon; Ji Hyun Youk; Jung Hyun Yoon; Vivian Youngjean Park; Seho Park; Seung Il Kim; Byeong-Woo Park
      Abstract: Publication date: Available online 10 April 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Jai Kyung You, Mi Kyung Song, Min Jung Kim, Eun-Kyung Kim, Hee Jung Moon, Ji Hyun Youk, Jung Hyun Yoon, Vivian Youngjean Park, Seho Park, Seung Il Kim, Byeong-Woo Park
      The aim of the work described here was to evaluate whether surveillance with biannual ultrasound (US) plus annual mammography (biannual group) for women with a history of breast cancer surgery results in earlier detection or in the detection of smaller second cancers than annual US plus mammography (annual group). Additionally, we compared the prevalence of distant metastases or palpable second cancers between the biannual and annual groups. The institutional review board of our institution approved this retrospective study, and patient consent was waived. Between January 2011 and December 2012, we retrospectively reviewed the clinical and imaging follow-up of 3023 patients with mammographic and US surveillance after breast cancer surgery to assess second cancers detected by local surveillance (locoregional recurrence, contralateral breast cancer or distant metastasis). The biannual and annual groups were divided with respect to the mean surveillance interval and compared with respect to clinicopathologic findings. Multivariable logistic regression with propensity score methods was used to examine the effect of the type of surveillance on outcomes. As for the size of the second cancer, no difference was seen between the biannual and annual groups (12.8 ± 6.6 mm vs. 14.1 ± 7.1 mm, p = 0.461); neither was there a significant difference between the groups in the presence of symptoms at the time of diagnosis of the second cancer (17.0% [8/47] vs. 10% [2/20], p = 0.711). Regardless of detection by local surveillance, the prevalence of distant metastases did not differ between the two groups (1.1% [27/2370] vs. 1.0% [7/653], p = 0.88) on univariate or multivariate analysis. The results of our retrospective study indicate that second cancers detected by biannual US surveillance in patients with a history of breast cancer surgery are not smaller and do not occur earlier than those detected by annual US surveillance. However, a randomized controlled study is required to verify these results before they can be generalized to clinical practice.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.02.019
       
  • Virtual Touch Tissue Quantification for Assessing Renal Pathology in
           Idiopathic Nephrotic Syndrome
    • Authors: Xue Yang; Ning Yu; Jing Yu; Hongqiao Wang; Xiumei Li
      Abstract: Publication date: Available online 9 April 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Xue Yang, Ning Yu, Jing Yu, Hongqiao Wang, Xiumei Li
      The aim of this study was to evaluate Virtual Touch tissue quantification in assessing renal interstitial fibrosis in patients with idiopathic nephrotic syndrome. Ninety patients with idiopathic nephrotic syndrome were assigned to mild, moderate and severe groups depending on the degree of renal interstitial fibrosis on histopathologic examination of renal biopsy specimens. Thirty healthy patients were also selected as the control group. Virtual Touch tissue quantification was performed to measure the shear wave velocity of the renal parenchyma. There was no statistically significant difference in shear wave velocity between the mild and control groups (p > 0.05); however, the moderate and severe groups did significantly differ compared with the control (p < 0.001). The area under the receiver operating characteristic curve value for the shear wave velocity of renal interstitial fibrosis in the moderate group versus the control and mild groups together was 0.869 (95% confidence interval: 0.791–0.947) and that in the severe group versus the control, mild and moderate groups together was 0.954 (95% confidence interval: 0.917–0.998). The corresponding best cutoff points were 2.41 and 2.77 m/s, with sensitivities of 91.7% and 86.8%, specificities of 78.0% and 92.0%, negative predictive values 0.907 and 0.907, positive predictive values 0.800 and 0.971 and Youden index values of 0.697 and 0.788, respectively. Virtual Touch tissue quantification may non-invasively and quantitatively estimate the degree of renal interstitial fibrosis in patients with idiopathic nephrotic syndrome as a baseline for monitoring progression and treatment response.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.02.012
       
  • Contrast-Enhanced Ultrasound-Guided Fine-Needle Aspiration for Sentinel
           Lymph Node Biopsy in Early-Stage Breast Cancer
    • Authors: Jieyu Zhong; De-sheng Sun; Wei Wei; Xiaoling Liu; Jun Liu; Xiaoqin Wu; Yusen Zhang; Haiyu Luo; Yongbin Li
      Abstract: Publication date: Available online 6 April 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Jieyu Zhong, De-sheng Sun, Wei Wei, Xiaoling Liu, Jun Liu, Xiaoqin Wu, Yusen Zhang, Haiyu Luo, Yongbin Li
      The purpose of this study was to assess whether translymphatic contrast-enhanced ultrasound (CEUS) combined with fine-needle aspiration (FNA) can be used pre-operatively to assess the status of axillary lymph nodes in early-stage breast cancer patients. Furthermore, we wanted to determine whether this less invasive method could potentially be a pre-operative surgical strategy. One hundred sixty-four sentinel lymph nodes (SLNs) were detected by CEUS after intradermal injection of microbubbles in 126 cases. One hundred twenty of 126 cases (95.24%) were accurately diagnosed with the SLN-FNA method. All 6 false-negative cases were due to micrometastasis or macrometastasis. There were no false-positive results after CEUS-guided FNA biopsy based on post-operative histopathological results. In conclusion, translymphatic CEUS combined with SLN-FNA is a less traumatic approach that has high accuracy in the pre-operative evaluation of axillary lymph node status. It might have the potential to be as reliable an indicator for axillary lymph node dissection as SLN biopsy.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.03.005
       
  • High-Dynamic-Range Ultrasound: Application for Imaging Tendon Pathology
    • Authors: Yiming Xiao; Mathieu Boily; Hoda Sadat Hashemi; Hassan Rivaz
      Abstract: Publication date: Available online 5 April 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Yiming Xiao, Mathieu Boily, Hoda Sadat Hashemi, Hassan Rivaz
      Raw ultrasound (US) signal has a very high dynamic range (HDR) and, as such, is compressed in B-mode US using a logarithmic function to fit within the dynamic range of digital displays. However, in some cases, hyper-echogenic tissue can be overexposed at high gain levels with the loss of hypo-echogenic detail at low gain levels. This can cause the loss of anatomic detail and tissue texture and frequent and inconvenient gain adjustments, potentially affecting the diagnosis. To mitigate these drawbacks, we employed tone mapping operators (TMOs) in HDR photography to create HDR US. We compared HDR US produced from three different popular TMOs (Reinhard, Drago and Durand) against conventional US using a simulated US phantom and in vivo images of patellar tendon pathologies. Based on visual inspection and assessments of structural fidelity, image entropy and contrast-to-noise ratio metrics, Reinhard and Drago TMOs substantially improved image detail and texture.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.03.004
       
  • One-Lung Flooding Enables Ultrasound-Guided Transthoracic Needle Biopsy of
           Pulmonary Nodules with High Sensitivity
    • Authors: Thomas Günter Lesser; Iver Petersen; Frank Pölzing; Frank Wolfram
      Abstract: Publication date: Available online 4 April 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Thomas Günter Lesser, Iver Petersen, Frank Pölzing, Frank Wolfram
      Ultrasound-guided transthoracic needle biopsy (USgTTNB) can only be used for peripheral tumours that contact the pleura. Sonographic accessibility of the entire lung can be achieved using one-lung flooding. In this study, feasibility, sensitivity and complication rate of USgTTNB of lung nodules after one-lung flooding in an ex vivo and in vivo lung tumour model were assessed. USgTTNB was performed ex vivo after one-lung flooding in 10 resected human lung lobes containing carcinoma or metastasis. USgTTNB after one-lung flooding and simulation of a lung nodule was conducted in vivo in 5 animals. Transthoracic sonography and chest X-ray were obtained 30 min after reventilation. The lungs were examined macroscopically and histopathologically. The pathologic diagnosis was confirmed in 85.7% and 100% of tumours after first and second puncture attempts, respectively. The successful puncture rate in vivo was 90%. Neither pneumothorax nor bleeding was observed. One-lung flooding enables USgTTNB of lung nodules with a high sensitivity and minimal risk of complications in a pre-clinical model.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.03.003
       
  • High-Frequency Quantitative Ultrasound for Imaging Prostate Cancer Using a
           Novel Micro-Ultrasound Scanner
    • Authors: Daniel Rohrbach; Brian Wodlinger; Jerrold Wen; Jonathan Mamou; Ernest Feleppa
      Abstract: Publication date: Available online 4 April 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Daniel Rohrbach, Brian Wodlinger, Jerrold Wen, Jonathan Mamou, Ernest Feleppa
      Currently, biopsies guided by transrectal ultrasound (TRUS) are the only method for definitive diagnosis of prostate cancer. Studies by our group suggest that quantitative ultrasound (QUS) could provide a more sensitive means of targeting biopsies and directing focal treatments to cancer-suspicious regions in the prostate. Previous studies have utilized ultrasound signals at typical clinical frequencies, i.e., in the 6-MHz range. In the present study, a 29-MHz, TRUS, micro-ultrasound system and transducer (ExactVu micro-ultrasound, Exact Imaging, Markham, Canada) was used to acquire radio frequency data from 163 patients immediately before 12-core biopsy procedures, comprising 1956 cores. These retrospective data are a subset of data acquired in an ongoing, multisite, 2000-patient, randomized, clinical trial (clinicaltrials.gov NCT02079025). Spectrum-based QUS estimates of effective scatter diameter (ESD), effective acoustic concentration (EAC), midband (M), intercept (I) and slope (S) as well as envelope statistics employing a Nakagami distribution were used to train linear discriminant classifiers (LDCs) and support vector machines (SVMs). Classifier performance was assessed using area-under-the-curve (AUC) values obtained from receiver operating characteristic (ROC) analyses with 10-fold cross validation. A combination of ESD and EAC parameters resulted in an AUC value of 0.77 using a LDC. When Nakagami-µ or prostate-specific antigen (PSA) values were added as features, the AUC value increased to 0.79. SVM produced an AUC value of 0.77, using a combination of envelope and spectral QUS estimates. The best classification produced an AUC value of 0.81 using an LDC when combining envelope statistics, PSA, ESD and EAC. In a previous study, B-mode-based scoring and evaluation using the PRI-MUS protocol produced a maximal AUC value of 0.74 for higher Gleason-score values (GS >7) when read by an expert. Our initial results with AUC values of 0.81 are very encouraging for developing a new, predominantly user-independent, prostate-cancer, risk-assessing tool.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.02.014
       
  • Hepatic Steatosis Assessment with Ultrasound Small-Window Entropy Imaging
    • Authors: Zhuhuang Zhou; Dar-In Tai; Yung-Liang Wan; Jeng-Hwei Tseng; Yi-Ru Lin; Shuicai Wu; Kuen-Cheh Yang; Yin-Yin Liao; Chih-Kuang Yeh; Po-Hsiang Tsui
      Abstract: Publication date: Available online 2 April 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Zhuhuang Zhou, Dar-In Tai, Yung-Liang Wan, Jeng-Hwei Tseng, Yi-Ru Lin, Shuicai Wu, Kuen-Cheh Yang, Yin-Yin Liao, Chih-Kuang Yeh, Po-Hsiang Tsui
      Nonalcoholic fatty liver disease is a type of hepatic steatosis that is not only associated with critical metabolic risk factors but can also result in advanced liver diseases. Ultrasound parametric imaging, which is based on statistical models, assesses fatty liver changes, using quantitative visualization of hepatic-steatosis–caused variations in the statistical properties of backscattered signals. One constraint with using statistical models in ultrasound imaging is that ultrasound data must conform to the distribution employed. Small-window entropy imaging was recently proposed as a non–model-based parametric imaging technique with physical meanings of backscattered statistics. In this study, we explored the feasibility of using small-window entropy imaging in the assessment of fatty liver disease and evaluated its performance through comparisons with parametric imaging based on the Nakagami distribution model (currently the most frequently used statistical model). Liver donors (n = 53) and patients (n = 142) were recruited to evaluate hepatic fat fractions (HFFs), using magnetic resonance spectroscopy and to evaluate the stages of fatty liver disease (normal, mild, moderate and severe), using liver biopsy with histopathology. Livers were scanned using a 3-MHz ultrasound to construct B-mode, small-window entropy and Nakagami images to correlate with HFF analyses and fatty liver stages. The diagnostic values of the imaging methods were evaluated using receiver operating characteristic curves. The results demonstrated that the entropy value obtained using small-window entropy imaging correlated well with log10(HFF), with a correlation coefficient r = 0.74, which was higher than those obtained for the B-scan and Nakagami images. Moreover, small-window entropy imaging also resulted in the highest area under the receiver operating characteristic curve (0.80 for stages equal to or more severe than mild; 0.90 for equal to or more severe than moderate; 0.89 for severe), which indicated that non–model-based entropy imaging—using the small-window technique—performs more favorably than other techniques in fatty liver assessment.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.03.002
       
  • Max dD/Dt: A Novel Parameter to Assess Fetal Cardiac Contractility and a
           Substitute for Max dP/Dt
    • Authors: Yasuyuki Fujita; Ryo Kiyokoba; Yasuo Yumoto; Kiyoko Kato
      Abstract: Publication date: Available online 2 April 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Yasuyuki Fujita, Ryo Kiyokoba, Yasuo Yumoto, Kiyoko Kato
      Aortic pulse waveforms are composed of a forward wave from the heart and a reflection wave from the periphery. We focused on this forward wave and suggested a new parameter, the maximum slope of aortic pulse waveforms (max dD/dt), for fetal cardiac contractility. Max dD/dt was calculated from fetal aortic pulse waveforms recorded with an echo-tracking system. A normal range of max dD/dt was constructed in 105 healthy fetuses using linear regression analysis. Twenty-two fetuses with suspected fetal cardiac dysfunction were divided into normal and decreased max dD/dt groups, and their clinical parameters were compared. Max dD/dt of aortic pulse waveforms increased linearly with advancing gestational age (r = 0.93). The decreased max dD/dt was associated with abnormal cardiotocography findings and short- and long-term prognosis. In conclusion, max dD/dt calculated from the aortic pulse waveforms in fetuses can substitute for max dP/dt, an index of cardiac contractility in adults.

      PubDate: 2018-04-15T17:42:25Z
      DOI: 10.1016/j.ultrasmedbio.2018.02.001
       
  • Editorial Advisory Board
    • Abstract: Publication date: April 2018
      Source:Ultrasound in Medicine & Biology, Volume 44, Issue 4


      PubDate: 2018-02-26T03:18:36Z
       
  • Clinicopathological and Ultrasonic Features of Triple-Negative Breast
           Cancers: A Comparison with Hormone Receptor-Positive/Human Epidermal
           Growth Factor Receptor-2-Negative Breast Cancers
    • Authors: Dongmo Wang; Kai Zhu; Jiawei Tian; Ziyao Li; Guoqing Du; Qiang Guo; Tong Wu; Juan Li
      Abstract: Publication date: Available online 23 February 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): Dongmo Wang, Kai Zhu, Jiawei Tian, Ziyao Li, Guoqing Du, Qiang Guo, Tong Wu, Juan Li
      The purpose of this study was to analyze the clinicopathological and ultrasound characteristics of triple-negative breast cancers (TNBCs) and compare these findings with those for hormone receptor-positive (HR-positive)/human epidermal growth factor receptor-2-negative (HER-2-negative) tumors. Seventy-five TNBCs and 135 HR-positive/HER-2-negative breast cancers were reviewed. Data from conventional ultrasound, Doppler vascularity and elastography were included in the analysis. TNBCs had a higher histologic grade and Ki-67 level. On ultrasound, TNBCs often appeared as microlobulated, markedly hypo-echoic masses with an abrupt interface boundary, posterior acoustic enhancement, absence of calcifications and more characteristics of surrounding tissue. Results from multivariate regression analysis revealed that margin, posterior acoustic features and surrounding tissue features of tumors were independent predictive factors in differentiating TNBCs from HR-positive/HER-2-negative tumors. Our results suggest that a thorough evaluation of sonographic findings might be useful in discriminating between TNBCs and HR-positive/HER-2-negative tumors, which may provide accurate evidence for clinical early diagnosis.

      PubDate: 2018-02-26T03:18:36Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.013
       
  • Measuring the Absolute Concentration of Microparticles in Suspension Using
           High-Frequency B-Mode Ultrasound Imaging
    • Authors: John H. Lee; Duane S. Boning; Brian W. Anthony
      Abstract: Publication date: Available online 23 February 2018
      Source:Ultrasound in Medicine & Biology
      Author(s): John H. Lee, Duane S. Boning, Brian W. Anthony
      Concentration measurement of particles in suspension is an important procedure performed in biological and clinical laboratories. Existing methods based on instruments such as hemocytometers, Coulter counters and flow cytometers are often laborious, destructive and incapable of in vivo measurements. On the other hand, an ultrasound-based method can be non-destructive and non-invasive and have the potential for in vivo measurement. In this work, a method is presented that estimates absolute particle concentration from high-frequency B-mode ultrasound images of a sample. The method is based on the detection and characterization of the echoes from individual particles to estimate the effective slice thickness of the image. Calibration using a reference sample is not required because the estimation is entirely image based. The particle type differential is also performed by using the backscatter coefficient of each detected echoes. The method is demonstrated by measuring microsphere suspensions as well as human T-cell suspensions. The proposed method has a wide range of potential clinical applications including non-invasive measurement of cell concentration in biological fluids such as cerebrospinal fluid.

      PubDate: 2018-02-26T03:18:36Z
      DOI: 10.1016/j.ultrasmedbio.2018.01.008
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs
Your IP address: 54.144.14.134
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-