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Normative values of thymus in healthy children; stiffness by shear wave elastography.

ABSTRACT: PURPOSE:Thymus grows after birth, reaches maximal size after the first few years and involutes by puberty. Because of the postnatal developmental and involutional duration, we aimed toinvestigate normal stiffness values of mediastinal thymus by shear wave elastography (SWE) in different age groups of children and discuss imaging findings of thymus. METHODS:We prospectively examined 146 children (90 girls, 56 boys) who underwent a thyroid or neck ultrasound examination. All subjects underwent ultrasound and SWE evaluation of mediastinal thymus by parasternal and suprasternal approach. We subdivided the subjects based on the ages as 0 to 2 months (group 1), >2 to 6 months (group 2); >6 months to 2 years (group 3), >2 to 5 years (group 4), >5 to 8 years (group 5), and greater than 8 years old (group 6).We investigated differences of mean shear wave elasticity (kPa) and shear wave velocity (m/sec) values among age groups and the association of SWE values with age, body mass index (BMI), height, and weight of the patients. RESULTS:Medians and ranges of age, height, weight, and BMI were 24 (2-84) months, 85 (55-120) cm, 12(4.55-22) kg, 15.37 (13.92-17.51) kg/m2, 11 (2.64-23.15) cc, respectively. Mean shear wave elasticity of thymus when all participants were included was 6.76±1.04 kPa. Differences of mean elasticity values among age groups and also gender groups were not statistically significant. There were highly significant negative correlations among age (r:0.3), height (r:0.26), weight (r:0.3) with elasticity and also velocity values (p<0.001). The thymus elasticity is negatively correlated with age. CONCLUSION:Quantitative evaluation of the thymus by SWE provides normative stiffness values based on age and gender groups. The thymus elasticity decreases with increased age, height and weight.

SUBMITTER: Bayramoglu Z

PROVIDER: S-EPMC7051269 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature

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Normative values of thymus in healthy children; stiffness by shear wave elastography.

Bayramoğlu Zuhal Z Öztürk Mehmet M Çalışkan Emine E Ayyıldız Hakan H Adaletli İbrahim İ

Diagnostic and interventional radiology (Ankara, Turkey) 20200301 2

<h4>Purpose</h4>Thymus grows after birth, reaches maximal size after the first few years and involutes by puberty. Because of the postnatal developmental and involutional duration, we aimed toinvestigate normal stiffness values of mediastinal thymus by shear wave elastography (SWE) in different age groups of children and discuss imaging findings of thymus.<h4>Methods</h4>We prospectively examined 146 children (90 girls, 56 boys) who underwent a thyroid or neck ultrasound examination. All subject ...[more]

PMID: 32116221

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Project description:BackgroundPediatric patients with liver disease require noninvasive monitoring to evaluate the risk of fibrosis progression. This study aimed to identify the significant factors affecting liver stiffness values using two-dimensional shear-wave elastography (2D-SWE), and determine whether liver stiffness can predict the fibrosis stage of various childhood liver diseases.MethodsThis study included 30 children (22 boys and 8 girls; mean age, 5.1 ± 6.1 years; range, 7 days-17.9 years) who had undergone biochemical evaluation, 2D-SWE examination, histopathologic analysis of fibrosis grade (F0 to F3), assessment of necroinflammatory activity, and steatosis grading between August 2016 and March 2020. The liver stiffness from 2D-SWE was compared between fibrosis stages using Kruskal-Wallis analysis. Factors that significantly affected liver stiffness were evaluated using univariate and multivariate linear regression analyses. The diagnostic performance was determined from the area under the receiver operating curve (AUC) values of 2D-SWE liver stiffness.ResultsLiver stiffness at the F0-1, F2, and F3 stages were 7.9, 13.2, and 21.7 kPa, respectively (P < 0.001). Both fibrosis stage and necroinflammatory grade were significantly associated with liver stiffness (P < 0.001 and P = 0.021, respectively). However, in patients with alanine aminotransferase (ALT) levels below 200 IU/L, the only factor affecting liver stiffness was fibrosis stage (P = 0.030). The liver stiffness value could distinguish significant fibrosis (≥ F2) with an AUC of 0.950 (cutoff value, 11.3 kPa) and severe fibrosis (F3 stage) with an AUC of 0.924 (cutoff value, 18.1 kPa). The 2D-SWE values for differentiating significant fibrosis were 10.5 kPa (≥ F2) and 18.1 kPa (F3) in patients with ALT levels below 200 IU/L.ConclusionThe liver stiffness values on 2D-SWE can be affected by both fibrosis and necroinflammatory grade and can provide excellent diagnostic performance in evaluating the fibrosis stage in various pediatric liver diseases. However, clinicians should be mindful of potential confounders, such as necroinflammatory activity or transaminase level, when performing 2D-SWE measurements for liver fibrosis staging.

Project description:Objectives:The aim of the study was to compare elastographic means in parathyroid adenomas, using shear wave elastography and strain elastography. Methods:This prospective study examined 20 consecutive patients diagnosed with primary hyperparathyroidism and parathyroid adenoma, confirmed by biochemical assay, technetium-99 sestamibi scintigraphy, and pathology report, after parathyroid surgery. All patients were examined on conventional 2B ultrasound, 2D shear wave elastography, and strain elastography. We determined using 2D shear wave elastography (SWE) the elasticity index (EI) in parathyroid adenoma, thyroid parenchyma, and surrounding muscle and examined using strain elastography the parathyroid adenoma, and determined the strain ratio with the thyroid tissue and muscle tissue. Results:All patients had positive sestamibi scintigraphy and underwent surgery, with confirmation of parathyroid adenoma in all cases. The mean parathormone (PTH) value before surgery was 153.29?pg/ml (36.5, 464.8) and serum calcium concentration was 10.5?mg/dl (9, 11.5). We compared using 2D-SWE and strain elastography parathyroid adenoma with thyroid tissue and with surrounding muscle. The mean EI measured by SWE in parathyroid adenoma was 4.74?±?2.74?kPa and in thyroid parenchyma was 11.718?±?4.206?kPa (mean difference?=?6.978?kPa, p < 0.001), and the mean EI value in muscle tissue was 16.362?±?3.829?kPa (mean difference?=?11.622, p < 0.001). Using ROC analysis, we found that an EI below 7?kPa correctly identifies parathyroid tissue. We evaluated parathyroid adenomas using strain elastography by color mapping and strain ratio as a semiquantitative measurement; however, we could not find any statistical correlation comparing the strain ratio obtained from the parathyroid adenoma with the thyroid tissue (p=0.485). Conclusion:Ultrasound elastography is a helpful tool in identifying parathyroid adenomas. A cutoff value below 7?kPa can be used in 2D-SWE. Color maps in strain elastography without adding strain ratio can be used, parathyroid adenoma being identified as score 1 in the Rago criteria.

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Normative values of thymus in healthy children; stiffness by shear wave elastography.

Publications

Normative values of thymus in healthy children; stiffness by shear wave elastography.

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