Evaluation of Inter-System Variability in Liver Stiffness Measurements

Abstract Aim The primary aim of this study was to determine the inter-system variability of liver stiffness measurements (LSMs) in patients with varying degrees of liver stiffness. The secondary aim was to determine the inter-observer variability of measurements. Materials and Methods 21 individuals affected by chronic hepatitis C and 5 healthy individuals were prospectively enrolled. The assessment of LSMs was performed using six ultrasound (US) systems, four of which with point shear wave elastography (p-SWE) and two with 2 D shear wave elastography (2D-SWE) systems. The Fibroscan (Echosens, France) was used as the reference standard. Four observers performed the measurements in pairs (A-B, C-D). The agreement between different observers or methods was calculated using Lin’s concordance correlation coefficient. The Bland-Altman limits of agreement (LOA) were calculated as well. Results There was agreement above 0.80 for all pairs of systems. The mean difference between the values of the systems with 2D-SWE technique was 1.54 kPa, whereas the maximum mean difference between the values of three out of four systems with the pSWE technique was 0.79 kPa. The intra-patient concordance for all systems was 0.89 (95 % CI: 0.83 – 0.94). Inter-observer agreement was 0.96 (95 % CI: 0.94 – 0.98) for the pair of observers A-B and 0.93 (95 % CI: 0.89 – 0.96) for the pair of observers C-D. Conclusion The results of this study show that the agreement between LSMs performed with different US systems is good to excellent and the overall inter-observer agreement in “ideal conditions” is above 0.90 in expert hands.

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2D-shear wave elastography: number of acquisitions can be reduced according to clinical setting

Insights into Imaging ◽

10.1186/s13244-021-01090-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Marco Dioguardi Burgio ◽

Jules Grégory ◽

Maxime Ronot ◽

Riccardo Sartoris ◽

Gilles Chatellier ◽

...

Keyword(s):

Shear Wave ◽

Liver Stiffness ◽

Shear Wave Elastography ◽

Mean Value ◽

Factors Affecting ◽

Absolute Value ◽

Factors Associated ◽

Supersonic Shear Imaging ◽

The Mean ◽

The Difference

Abstract Background The factors affecting intra-operator variability of two-dimensional shear wave elastography (2D-SWE) have not been clearly established. We evaluated 2D-SWE variability according to the number of measurements, clinical and laboratory features, and liver stiffness measurements (LSM). Methods At least three LSM were performed in 452 patients who underwent LSM by 2D-SWE (supersonic shear imaging) out of an initial database of 1650 patients. The mean value of the three LSM was our best measurement method. Bland–Altman plots were used to evaluate intra-operator variability when considering only one, or the first two measurements. Variability was assessed by taking the absolute value of the difference between the first LSM and the mean of the three LSM. Logistic regression was used to assess the factors associated with the highest tertile of variability. Results The limit of agreement was narrower with the mean of the first and second measurements than with each measurement taken separately (− 2.83 to 2.99 kPa vs. − 5.86 to 6.21 kPa and − 5.77 to 5.73 kPa for the first and second measurement, respectively). A BMI ≥ 25 kg/m2 and a first LSM by 2D-SWE ≥ 7.1 kPa increased the odds of higher variability by 3.4 and 3.9, respectively. Adding a second LSM didn’t change the variability in patients with BMI < 25 and a first LSM by 2D-SWE < 7.1 kPa. Conclusions Intra-operator variability of LSM by 2D-SWE increases with both a high BMI and high LSM value. In patients with BMI < 25 kg/m2 and a first LSM < 7.1 kPa we recommend performing only one LSM.

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Comparison of zero heat flux and double sensor thermometers during spinal anaesthesia: a prospective observational study

Journal of Clinical Monitoring and Computing ◽

10.1007/s10877-021-00799-6 ◽

2022 ◽

Author(s):

Sirkka-Liisa Lauronen ◽

Maija-Liisa Kalliomäki ◽

Jarkko Kalliovalkama ◽

Antti Aho ◽

Heini Huhtala ◽

...

Keyword(s):

Heat Flux ◽

Core Temperature ◽

Spinal Anaesthesia ◽

Prospective Observational Study ◽

Repeated Measurements ◽

Mean Difference ◽

Concordance Correlation ◽

Limits Of Agreement ◽

Non Invasive ◽

The Mean

AbstractBecause of the difficulties involved in the invasive monitoring of conscious patients, core temperature monitoring is frequently neglected during neuraxial anaesthesia. Zero heat flux (ZHF) and double sensor (DS) are non-invasive methods that measure core temperature from the forehead skin. Here, we compare these methods in patients under spinal anaesthesia. Sixty patients scheduled for elective unilateral knee arthroplasty were recruited and divided into two groups. Of these, thirty patients were fitted with bilateral ZHF sensors (ZHF group), and thirty patients were fitted with both a ZHF sensor and a DS sensor (DS group). Temperatures were saved at 5-min intervals from the beginning of prewarming up to one hour postoperatively. Bland–Altman analysis for repeated measurements was performed and a proportion of differences within 0.5 °C was calculated as well as Lin`s concordance correlation coefficient (LCCC). A total of 1261 and 1129 measurement pairs were obtained. The mean difference between ZHF sensors was 0.05 °C with 95% limits of agreement − 0.36 to 0.47 °C, 99% of the readings were within 0.5 °C and LCCC was 0.88. The mean difference between ZHF and DS sensors was 0.33 °C with 95% limits of agreement − 0.55 to 1.21 °C, 66% of readings were within 0.5 °C and LCCC was 0.59. Bilaterally measured ZHF temperatures were almost identical. DS temperatures were mostly lower than ZHF temperatures. The mean difference between ZHF and DS temperatures increased when the core temperature decreased.Trial registration: The study was registered in ClinicalTrials.gov on 13th May 2019, Code NCT03408197.

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How many measurements are needed for liver stiffness assessment by 2D-Shear Wave Elastography (2D-SWE) and which value should be used: the mean or median?

Medical Ultrasonography ◽

10.11152/mu.2013.2066.154.isp2 ◽

2013 ◽

Vol 15 (4) ◽

pp. 268-272 ◽

Cited By ~ 44

Author(s):

Ioan Sporea

Keyword(s):

Shear Wave ◽

Liver Stiffness ◽

Shear Wave Elastography ◽

The Mean

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Liver Elastography in Healthy Children Using Three Different Systems – How Many Measurements Are Necessary?

Ultraschall in der Medizin - European Journal of Ultrasound ◽

10.1055/a-1283-5906 ◽

2020 ◽

Author(s):

Anders Batman Mjelle ◽

Anesa Mulabecirovic ◽

Roald Flesland Havre ◽

Edda Jonina Olafsdottir ◽

Odd Helge Gilja ◽

...

Keyword(s):

Shear Wave ◽

Transient Elastography ◽

Intraclass Correlation ◽

Age Groups ◽

Liver Stiffness ◽

Shear Wave Elastography ◽

Healthy Children ◽

Significant Difference ◽

Pediatric Liver Disease ◽

Liver Elastography

Abstract Purpose Liver elastography is increasingly being applied in screening for and follow-up of pediatric liver disease, and has been shown to correlate well with fibrosis staging through liver biopsy. Because time is of the essence when examining children, we wanted to evaluate if a reliable result can be achieved with fewer acquisitions. Materials and Methods 243 healthy children aged 4–17 years were examined after three hours of fasting. Participants were divided into four age groups: 4–7 years; 8–11 years; 12–14 years and 15–17 years. Both two-dimensional shear wave elastography (2D-SWE; GE Logiq E9) and point shear wave elastography (pSWE; Samsung RS80A with Prestige) were performed in all participants, while transient elastography (TE, Fibroscan) was performed in a subset of 87 children aged 8–17 years. Median liver stiffness measurement (LSM) values of 3, 4, 5, 6, 7, and 8 acquisitions were compared with the median value of 10 acquisitions (reference standard). Comparison was performed for all participants together as well as within every specific age group. We investigated both the intraclass correlation coefficient (ICC) with absolute agreement and all outliers more than 10 %, 20 % or ≥ 0.5 or 1.0 kPa from the median of 10 acquisitions. Results For all three systems there was no significant difference between three and ten acquisitions, with ICCs ≥ 0.97. All systems needed 4 acquisitions to achieve no LSM deviating ≥ 1.0 kPa of a median of ten. To achieve no LSM deviating ≥ 20 % of a median of ten acquisitions, pSWE and TE needed 4 acquisitions, while 2D-SWE required 6 acquisitions. Conclusion Our results contradict recommendations of 10 acquisitions for pSWE and TE and only 3 for 2D-SWE.

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Noninvasive Assessment of Liver Diseases using 2D Shear Wave Elastography

Journal of Gastrointestinal and Liver Diseases ◽

10.15403/jgld.2014.1121.254.lup ◽

2016 ◽

Vol 25 (4) ◽

pp. 525-532 ◽

Cited By ~ 8

Author(s):

Monica Lupșor-Platon ◽

Radu Badea ◽

Mirela Gersak ◽

Anca Maniu ◽

Ioana Rusu ◽

...

Keyword(s):

Shear Wave ◽

Predictive Value ◽

Liver Diseases ◽

Venous Pressure ◽

Liver Stiffness ◽

Shear Wave Elastography ◽

Acoustic Radiation Force Impulse ◽

Two Dimensional ◽

Non Invasive ◽

Examination Technique

There has been great interest in the development of non-invasive techniques for the diagnosis of liver fibrosis in chronic liver diseases, including ultrasound elastographic methods. Some of these methods have already been adequately studied for the non-invasive assessment of diffuse liver diseases. Others, however, such as two-dimensional Shear Wave Elastography (SWE), of more recent appearance, have yet to be validated and some aspects are for the moment incompletely elucidated. This review discusses some of the aspects related to two-dimensional SWE: the examination technique, the examination performance indicators, intra and interobserver agreement and clinical applications. Recommendations for a high-quality examination technique are formulated. Key words: – – – Two-dimensional Shear Wave Elastography. Abbreviations: 2D- SWE: Two-dimensional Shear Wave Elastography; 3D- SWE: Three-dimensional Shear Wave Elastography; AUROC: area under the receiver operating characteristic curves; ARFI Acoustic Radiation Force Impulse Elastography; EFSUMB: European Federation of Societies for Ultrasound in Medicine and Biology; HVPG: hepatic venous pressure gradient; LS: liver stiffness; LR: likelihood ratio; NPV: negative predictive value; PPV: positive predictive value; ROI: region of interest; RT-E: Real Time-Elastography; Se: sensitivity; Sp: specificity; TE: Transient Elastography; US: ultrasound; VM: valid measurement; E: Young’s modulus

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