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  1. Liu KF, Chai HK, Mehrabi N, Yoshikazu K, Shiotani T
    ScientificWorldJournal, 2014;2014:194295.
    PMID: 24737961 DOI: 10.1155/2014/194295
    Imaging techniques are high in demand for modern nondestructive evaluation of large-scale concrete structures. The travel-time tomography (TTT) technique, which is based on the principle of mapping the change of propagation velocity of transient elastic waves in a measured object, has found increasing application for assessing in situ concrete structures. The primary aim of this technique is to detect defects that exist in a structure. The TTT technique can offer an effective means for assessing tendon duct filling of prestressed concrete (PC) elements. This study is aimed at clarifying some of the issues pertaining to the reliability of the technique for this purpose, such as sensor arrangement, model, meshing, type of tendon sheath, thickness of sheath, and material type as well as the scale of inhomogeneity. The work involved 2D simulations of wave motions, signal processing to extract travel time of waves, and tomography reconstruction computation for velocity mapping of defect in tendon duct.
    Matched MeSH terms: Elasticity Imaging Techniques/methods*
  2. Ng YZ, Lai LL, Wong SW, Mohamad SY, Chuah KH, Chan WK
    PLoS One, 2021;16(5):e0250300.
    PMID: 33939744 DOI: 10.1371/journal.pone.0250300
    BACKGROUND & AIM: We studied FibroTouch (FT) and Fibroscan (FS) examination results and their repeatability when performed by healthcare personnel of different background.

    METHODS: FT and FS examinations were performed on patients with chronic liver disease by two operators, a doctor and a nurse, twice on each patient, at two different time points, independent of each other.

    RESULTS: The data for 163 patients with 1304 examinations was analyzed. There was strong correlation between FT and FS for attenuation parameter (Spearman's rho 0.76, p<0.001) and liver stiffness measurement (LSM) (Spearman's rho 0.70, p<0.001). However, FT produced higher value at lower attenuation parameter and LSM, and lower value at higher attenuation parameter and LSM. There was substantial agreement when using 15kPa LSM cut-off, but only moderate agreement when using 10kPa and 20kPa LSM cut-offs and 248dB/m, 268dB/m and 280dB/m attenuation parameter cut-offs. The IQR for attenuation parameter and IQR/median for LSM were significantly lower for FT compared with FS (4dB/m vs 27dB/m, p<0.001, and 10 vs 12, p<0.001, respectively). The intra- and inter-observer reliability of attenuation parameter and LSM using FT and FS were good to excellent with intraclass correlation coefficients 0.89-0.99. FT had shorter examination time (33s vs 47s, p<0.001) and less invalid measurements (0 vs 2, p<0.001).

    CONCLUSION: Measurements obtained with FT and FS strongly correlated, but significant differences in their absolute values, consistency, examination time and number of invalid measurements were observed. Either device can be used by healthcare personnel of different backgrounds when sufficiently trained.

    Matched MeSH terms: Elasticity Imaging Techniques/methods
  3. Acharya UR, Ng WL, Rahmat K, Sudarshan VK, Koh JEW, Tan JH, et al.
    Comput Biol Med, 2017 12 01;91:13-20.
    PMID: 29031099 DOI: 10.1016/j.compbiomed.2017.10.001
    Shear wave elastography (SWE) examination using ultrasound elastography (USE) is a popular imaging procedure for obtaining elasticity information of breast lesions. Elasticity parameters obtained through SWE can be used as biomarkers that can distinguish malignant breast lesions from benign ones. Furthermore, the elasticity parameters extracted from SWE can speed up the diagnosis and possibly reduce human errors. In this paper, Shearlet transform and local binary pattern histograms (LBPH) are proposed as an original algorithm to differentiate malignant and benign breast lesions. First, Shearlet transform is applied on the SWE images to acquire low frequency, horizontal and vertical cone coefficients. Next, LBPH features are extracted from the Shearlet transform coefficients and subjected to dimensionality reduction using locality sensitivity discriminating analysis (LSDA). The reduced LSDA components are ranked and then fed to several classifiers for the automated classification of breast lesions. A probabilistic neural network classifier trained only with seven top ranked features performed best, and achieved 98.08% accuracy, 98.63% sensitivity, and 97.59% specificity in distinguishing malignant from benign breast lesions. The high sensitivity and specificity of our system indicates that it can be employed as a primary screening tool for faster diagnosis of breast malignancies, thereby possibly reducing the mortality rate due to breast cancer.
    Matched MeSH terms: Elasticity Imaging Techniques/methods*
  4. Petroff D, Blank V, Newsome PN, Shalimar, Voican CS, Thiele M, et al.
    Lancet Gastroenterol Hepatol, 2021 03;6(3):185-198.
    PMID: 33460567 DOI: 10.1016/S2468-1253(20)30357-5
    BACKGROUND: Diagnostic tools for liver disease can now include estimation of the grade of hepatic steatosis (S0 to S3). Controlled attenuation parameter (CAP) is a non-invasive method for assessing hepatic steatosis that has become available for patients who are obese (FibroScan XL probe), but a consensus has not yet been reached regarding cutoffs and its diagnostic performance. We aimed to assess diagnostic properties and identify relevant covariates with use of an individual patient data meta-analysis.

    METHODS: We did an individual patient data meta-analysis, in which we searched PubMed and Web of Science for studies published from database inception until April 30, 2019. Studies reporting original biopsy-controlled data of CAP for non-invasive grading of steatosis were eligible. Probe recommendation was based on automated selection, manual assessment of skin-to-liver-capsule distance, and a body-mass index (BMI) criterion. Receiver operating characteristic methods and mixed models were used to assess diagnostic properties and covariates. Patients with non-alcoholic fatty liver disease (NAFLD) were analysed separately because they are the predominant patient group when using the XL probe. This study is registered with PROSPERO, CRD42018099284.

    FINDINGS: 16 studies reported histology-controlled CAP including the XL probe, and individual data from 13 papers and 2346 patients were included. Patients with a mean age of 46·5 years (SD 14·5) were recruited from 20 centres in nine countries. 2283 patients had data for BMI; 673 (29%) were normal weight (BMI <25 kg/m2), 530 (23%) were overweight (BMI ≥25 to <30 kg/m2), and 1080 (47%) were obese (BMI ≥30 kg/m2). 1277 (54%) patients had NAFLD, 474 (20%) had viral hepatitis, 285 (12%) had alcohol-associated liver disease, and 310 (13%) had other liver disease aetiologies. The XL probe was recommended in 1050 patients, 930 (89%) of whom had NAFLD; among the patients with NAFLD, the areas under the curve were 0·819 (95% CI 0·769-0·869) for S0 versus S1 to S3 and 0·754 (0·720-0·787) for S0 to S1 versus S2 to S3. CAP values were independently affected by aetiology, diabetes, BMI, aspartate aminotransferase, and sex. Optimal cutoffs differed substantially across aetiologies. Risk of bias according to QUADAS-2 was low.

    INTERPRETATION: CAP cutoffs varied according to cause, and can effectively recognise significant steatosis in patients with viral hepatitis. CAP cannot grade steatosis in patients with NAFLD adequately, but its value in a NAFLD screening setting needs to be studied, ideally with methods beyond the traditional histological reference standard.

    FUNDING: The German Federal Ministry of Education and Research and Echosens.

    Matched MeSH terms: Elasticity Imaging Techniques/methods*
  5. Leong SS, Wong JHD, Md Shah MN, Vijayananthan A, Jalalonmuhali M, Chow TK, et al.
    Nephrology (Carlton), 2021 Jan;26(1):38-45.
    PMID: 33058334 DOI: 10.1111/nep.13805
    AIM: Renal biopsy is the gold standard for the histological characterization of chronic kidney disease (CKD), of which renal fibrosis is a dominant component, affecting its stiffness. The aim of this study was to investigate the correlation between kidney stiffness obtained by shear wave elastography (SWE) and renal histological fibrosis.

    METHODS: Shear wave elastography assessments were performed in 75 CKD patients who underwent renal biopsy. The SWE-derived estimates of the tissue Young's modulus (YM), given as kilopascals (kPa), were measured. YM was correlated to patients' renal histological scores, broadly categorized into glomerular, tubulointerstitial and vascular scores.

    RESULTS: Young's modulus correlates significantly with tubulointerstitial score (ρ = 0.442, P 

    Matched MeSH terms: Elasticity Imaging Techniques/methods*
  6. Leong SS, Wong JHD, Md Shah MN, Vijayananthan A, Jalalonmuhali M, Ng KH
    Br J Radiol, 2018 Sep;91(1089):20180235.
    PMID: 29869920 DOI: 10.1259/bjr.20180235
    OBJECTIVE: To investigate the use of shear wave elastography (SWE)-derived estimates of Young's modulus (YM) as an indicator to detect abnormal renal tissue diagnosed by estimated glomerular filtration rate (eGFR).

    METHODS: The study comprised 106 chronic kidney disease (CKD) patients and 203 control subjects. Conventional ultrasound was performed to measure the kidney length and cortical thickness. SWE imaging was performed to measure renal parenchymal stiffness. Diagnostic performance of SWE and conventional ultrasound were correlated with serum creatinine, urea levels and eGFR.

    RESULTS: Pearson's correlation coefficient revealed a negative correlation between YM measurements and eGFR (r = -0.576, p < 0.0001). Positive correlations between YM measurements and age (r = 0.321, p < 0.05), serum creatinine (r = 0.375, p < 0.0001) and urea (r = 0.287, p < 0.0001) were also observed. The area under the receiver operating characteristic curve for SWE (0.87) was superior to conventional ultrasound alone (0.35-0.37). The cut-off value of less or equal to 4.31 kPa suggested a non-diseased kidney (80.3% sensitivity, 79.5% specificity).

    CONCLUSION: SWE was superior to renal length and cortical thickness in detecting CKD. A value of 4.31 kPa or less showed good accuracy in determining whether a kidney was diseased or not. Advances in knowledge: On SWE, CKD patients show greater renal parenchymal stiffness than non-CKD patients. Determining a cut-off value between normal and diseased renal parenchyma may help in early non-invasive detection and management of CKD.

    Matched MeSH terms: Elasticity Imaging Techniques/methods*
  7. Chan WK, Nik Mustapha NR, Mahadeva S, Wong VW, Cheng JY, Wong GL
    J Gastroenterol Hepatol, 2018 Oct;33(10):1787-1794.
    PMID: 29603365 DOI: 10.1111/jgh.14150
    BACKGROUND AND AIM: There are limited studies on controlled attenuation parameter (CAP) using Fibroscan XL probe for the diagnosis of hepatic steatosis grade. The aim of this study was to determine whether previously defined optimal cut-offs for CAP using the M probe could be applied for the XL probe.

    METHODS: Adult patients with chronic liver disease who had a liver biopsy and examination with both the M and XL probes were included. Previously defined optimal cut-offs for CAP using the M probe were used for the diagnosis of steatosis grades ≥S1, ≥S2, and S3 (248, 268, and 280 dB/m, respectively).

    RESULTS: Data for 180 patients were analyzed (mean age 53.7 ± 10.8 years; central obesity 84.5%; non-alcoholic fatty liver disease 86.7%). The distribution of steatosis grades was S0, 9.4%; S1, 28.3%; S2, 43.9%, and S3, 18.3%. The sensitivity, specificity, positive predictive value, and negative predictive value of CAP using the M/XL probe for the diagnosis of steatosis grade ≥S1 was 93.9%/93.3%, 58.8%/58.8%, 95.6%/95.6%, and 50.0%/47.6%, respectively. These values were 94.6%/94.6%, 41.2%/44.1%, 72.6%/73.6%, and 82.4%/83.3%, respectively, for ≥S2, and 87.9%/87.9%, 27.2%/27.9%, 21.3%/21.5%, and 90.9%/91.1%, respectively, for S3.

    CONCLUSION: The same cut-off values for CAP may be used for the M and XL probes for the diagnosis of hepatic steatosis grade.

    Matched MeSH terms: Elasticity Imaging Techniques/methods*
  8. Chan WK, Petta S, Noureddin M, Goh GBB, Wong VW
    Aliment Pharmacol Ther, 2024 Jun;59 Suppl 1:S23-S40.
    PMID: 38813831 DOI: 10.1111/apt.17866
    BACKGROUND: Metabolic dysfunction-associated steatotic liver disease (MASLD) is currently the most common chronic liver disease and an important cause of cirrhosis and hepatocellular carcinoma. It is strongly associated with type 2 diabetes and obesity. Because of the huge number of patients at risk of MASLD, it is imperative to use non-invasive tests appropriately.

    AIMS: To provide a narrative review on the performance and limitations of non-invasive tests, with a special emphasis on the impact of diabetes and obesity.

    METHODS: We searched PubMed and Cochrane databases for articles published from 1990 to August 2023.

    RESULTS: Abdominal ultrasonography remains the primary method to diagnose hepatic steatosis, while magnetic resonance imaging proton density fat fraction is currently the gold standard to quantify steatosis. Simple fibrosis scores such as the Fibrosis-4 index are well suited as initial assessment in primary care and non-hepatology settings to rule out advanced fibrosis and future risk of liver-related complications. However, because of its low positive predictive value, an abnormal test should be followed by specific blood (e.g. Enhanced Liver Fibrosis score) or imaging biomarkers (e.g. vibration-controlled transient elastography and magnetic resonance elastography) of fibrosis. Some non-invasive tests of fibrosis appear to be less accurate in patients with diabetes. Obesity also affects the performance of abdominal ultrasonography and transient elastography, whereas magnetic resonance imaging may not be feasible in some patients with severe obesity.

    CONCLUSIONS: This article highlights issues surrounding the clinical application of non-invasive tests for MASLD in patients with type 2 diabetes and obesity.

    Matched MeSH terms: Elasticity Imaging Techniques/methods
  9. Zakaria NM, Yusoff NI, Hardwiyono S, Nayan KA, El-Shafie A
    ScientificWorldJournal, 2014;2014:594797.
    PMID: 25276854 DOI: 10.1155/2014/594797
    Enhanced resonance search (ERS) is a nondestructive testing method that has been created to evaluate the quality of a pavement by means of a special instrument called the pavement integrity scanner (PiScanner). This technique can be used to assess the thickness of the road pavement structure and the profile of shear wave velocity by using the principle of surface wave and body wave propagation. In this study, the ERS technique was used to determine the actual thickness of the asphaltic pavement surface layer, while the shear wave velocities obtained were used to determine its dynamic elastic modulus. A total of fifteen locations were identified and the results were then compared with the specifications of the Malaysian PWD, MDD UKM, and IKRAM. It was found that the value of the elastic modulus of materials is between 3929 MPa and 17726 MPa. A comparison of the average thickness of the samples with the design thickness of MDD UKM showed a difference of 20 to 60%. Thickness of the asphalt surface layer followed the specifications of Malaysian PWD and MDD UKM, while some of the values of stiffness obtained are higher than the standard.
    Matched MeSH terms: Elasticity Imaging Techniques/methods*
  10. Chan WK, Nik Mustapha NR, Mahadeva S
    J Gastroenterol Hepatol, 2014;29(7):1470-6.
    PMID: 24548002 DOI: 10.1111/jgh.12557
    Controlled attenuation parameter (CAP) has been suggested as a noninvasive method for detection and quantification of hepatic steatosis. We aim to study the diagnostic performance of CAP in nonalcoholic fatty liver disease (NAFLD) patients.
    Matched MeSH terms: Elasticity Imaging Techniques/methods*
  11. Leong SS, Wong JHD, Md Shah MN, Vijayananthan A, Jalalonmuhali M, Ng KH
    Ultrasound Med Biol, 2019 06;45(6):1417-1426.
    PMID: 30962016 DOI: 10.1016/j.ultrasmedbio.2019.01.024
    The purpose of this study was to assess the potential of shear wave elastography (SWE) as an indicator of abnormal kidney function defined by radiolabeled glomerular filtration rate (GFR). Fifty-seven patients referred for 51Cr-ethylenediaminetetraacetic acid GFR and 99mTc-dimercaptosuccinic acid renal scintigraphy were included. Young's modulus (YM) measured with SWE and kidney length, volume, cortical thickness and parenchymal echogenicity measured with conventional ultrasound were correlated with patients' GFR and renal scintigraphy results. Spearman correlation coefficients between SWE and GFR were negative for the right (r = -0.635, p < 0.0001) and left (r = -0.817, p < 0.0001) kidneys. Positive correlations between left renal cortical thickness (r = 0.381, p = 0.04) and left kidney volume (r = 0.356, p = 0.019) with GFR were reported. SWE correctly predicted the dominant functioning kidney in 94.7% of cases. The area under the receiver operating characteristic curve for SWE (0.800) was superior to that for conventional ultrasound (0.252-0.415). The cutoff value of ≥5.52 kPa suggested a kidney function ≤60 mL/min/1.73 m2 (82.4% sensitivity and 76.2% specificity). SWE has advantages over conventional ultrasound in assessing kidney function and distinguishing the dominant functioning kidney.
    Matched MeSH terms: Elasticity Imaging Techniques/methods
  12. Chuah KH, Lai LL, Vethakkan SR, Nik Mustapha NR, Mahadeva S, Chan WK
    J Gastroenterol Hepatol, 2020 Aug;35(8):1404-1411.
    PMID: 31907981 DOI: 10.1111/jgh.14978
    BACKGROUND AND AIM: Repeating liver stiffness measurement (LSM) was recently reported to improve accuracy to diagnose fibrosis stage in patients with non-alcoholic fatty liver disease (NAFLD). There are to date no other studies confirming this finding. This aims to evaluate the accuracy of repeating LSM for the diagnosis of fibrosis stage in NAFLD patients.

    METHODS: Retrospective analysis of prospectively collected data on adult NAFLD patients who had two FibroScan examination within 6 months prior to liver biopsy. F3-F4 fibrosis was excluded using LSM cut-off of 7.9 kPa.

    RESULTS: A total of 136 patients were recruited. Eighty-five percent (115/136) of patients had high baseline LSM (≥ 7.9 kPa). Among them, 25% (29/115) had low repeat LSM (

    Matched MeSH terms: Elasticity Imaging Techniques/methods*
  13. Mahadeva S, Mahfudz AS, Vijayanathan A, Goh KL, Kulenthran A, Cheah PL
    J Dig Dis, 2013 Nov;14(11):604-10.
    PMID: 23859493 DOI: 10.1111/1751-2980.12088
    To determine the accuracy of transient elastography (TE) and factors associated with discordance between TE and liver histology in patients with non-alcoholic fatty liver disease (NAFLD).
    Matched MeSH terms: Elasticity Imaging Techniques/methods*
  14. Alhabshi SM, Rahmat K, Abdul Halim N, Aziz S, Radhika S, Gan GC, et al.
    Ultrasound Med Biol, 2013 Apr;39(4):568-78.
    PMID: 23384468 DOI: 10.1016/j.ultrasmedbio.2012.10.016
    The purpose of this study was to evaluate the diagnostic value of qualitative and semi-quantitative assessment of ultrasound elastography in differentiating between benign and malignant breast lesions. This prospective study was conducted in two tertiary medical centers. Consecutive B-mode ultrasound and real-time elastographic images were obtained for 67 malignant and 101 benign breast lesions in 168 women. Four experienced radiologists analyzed B-mode ultrasound alone and B-mode ultrasound combined with elastography independently. Conventional ultrasound findings were classified according to the American College of Radiology Breast Imaging Reporting and Data System classification. The elastographic assessment was based on qualitative and semi-quantitative parameters (i.e., strain pattern, width ratio, strain ratio). The sensitivity and specificity of combined elastography and conventional ultrasound were significantly higher than that of conventional ultrasound alone. The sensitivity, specificity, positive predictive value and negative predictive value was 97%, 61.4%, 62.5% and 96.8%, respectively, for conventional ultrasound and 100%, 93%, 99% and 90%, respectively, for combined technique. The semi-quantitative assessment with strain ratio and width ratio in elastography were the most useful parameters in differentiating between benign and malignant breast lesions. Cut-off point values for width ratio of more than 1.1 and strain ratio of more than 5.6 showed a high predictive value of malignancy with specificities of 84% and 76%, respectively (p 
    Matched MeSH terms: Elasticity Imaging Techniques/methods*
  15. Newsome PN, Sasso M, Deeks JJ, Paredes A, Boursier J, Chan WK, et al.
    Lancet Gastroenterol Hepatol, 2020 04;5(4):362-373.
    PMID: 32027858 DOI: 10.1016/S2468-1253(19)30383-8
    BACKGROUND: The burden of non-alcoholic fatty liver disease (NAFLD) is increasing globally, and a major priority is to identify patients with non-alcoholic steatohepatitis (NASH) who are at greater risk of progression to cirrhosis, and who will be candidates for clinical trials and emerging new pharmacotherapies. We aimed to develop a score to identify patients with NASH, elevated NAFLD activity score (NAS≥4), and advanced fibrosis (stage 2 or higher [F≥2]).

    METHODS: This prospective study included a derivation cohort before validation in multiple international cohorts. The derivation cohort was a cross-sectional, multicentre study of patients aged 18 years or older, scheduled to have a liver biopsy for suspicion of NAFLD at seven tertiary care liver centres in England. This was a prespecified secondary outcome of a study for which the primary endpoints have already been reported. Liver stiffness measurement (LSM) by vibration-controlled transient elastography and controlled attenuation parameter (CAP) measured by FibroScan device were combined with aspartate aminotransferase (AST), alanine aminotransferase (ALT), or AST:ALT ratio. To identify those patients with NASH, an elevated NAS, and significant fibrosis, the best fitting multivariable logistic regression model was identified and internally validated using boot-strapping. Score calibration and discrimination performance were determined in both the derivation dataset in England, and seven independent international (France, USA, China, Malaysia, Turkey) histologically confirmed cohorts of patients with NAFLD (external validation cohorts). This study is registered with ClinicalTrials.gov, number NCT01985009.

    FINDINGS: Between March 20, 2014, and Jan 17, 2017, 350 patients with suspected NAFLD attending liver clinics in England were prospectively enrolled in the derivation cohort. The most predictive model combined LSM, CAP, and AST, and was designated FAST (FibroScan-AST). Performance was satisfactory in the derivation dataset (C-statistic 0·80, 95% CI 0·76-0·85) and was well calibrated. In external validation cohorts, calibration of the score was satisfactory and discrimination was good across the full range of validation cohorts (C-statistic range 0·74-0·95, 0·85; 95% CI 0·83-0·87 in the pooled external validation patients' cohort; n=1026). Cutoff was 0·35 for sensitivity of 0·90 or greater and 0·67 for specificity of 0·90 or greater in the derivation cohort, leading to a positive predictive value (PPV) of 0·83 (84/101) and a negative predictive value (NPV) of 0·85 (93/110). In the external validation cohorts, PPV ranged from 0·33 to 0·81 and NPV from 0·73 to 1·0.

    INTERPRETATION: The FAST score provides an efficient way to non-invasively identify patients at risk of progressive NASH for clinical trials or treatments when they become available, and thereby reduce unnecessary liver biopsy in patients unlikely to have significant disease.

    FUNDING: Echosens and UK National Institute for Health Research.

    Matched MeSH terms: Elasticity Imaging Techniques/methods*
  16. Vairavan R, Abdullah O, Retnasamy PB, Sauli Z, Shahimin MM, Retnasamy V
    Curr Med Imaging Rev, 2019;15(2):85-121.
    PMID: 31975658 DOI: 10.2174/1573405613666170912115617
    BACKGROUND: Breast carcinoma is a life threatening disease that accounts for 25.1% of all carcinoma among women worldwide. Early detection of the disease enhances the chance for survival.

    DISCUSSION: This paper presents comprehensive report on breast carcinoma disease and its modalities available for detection and diagnosis, as it delves into the screening and detection modalities with special focus placed on the non-invasive techniques and its recent advancement work done, as well as a proposal on a novel method for the application of early breast carcinoma detection.

    CONCLUSION: This paper aims to serve as a foundation guidance for the reader to attain bird's eye understanding on breast carcinoma disease and its current non-invasive modalities.

    Matched MeSH terms: Elasticity Imaging Techniques/methods
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