Ultrasound measures of tendon thickness: Intra-rater, Inter-rater and Inter-machine reliability.

BACKGROUND: Ultrasound imaging is often used by physiotherapists and other healthcare professionals but the reliability of image acquisition with different ultrasound machines is unknown. The objective was to compare the intra-rater, inter-rater and intermachine reliability of thickness measurements of the plantar fascia (PF), Achilles tendon (AT), patellar tendon (PT) and elbow common extensor tendon (ECET) with musculoskeletal ultrasound imaging (MSUS). METHODS: Tendon thickness was measured in four anatomical structures (14 participants, 28 images per tendon) by two sonographers and with two different ultrasound machines. Intraclass Correlation Coefficients (ICCs) and Bland-Altman plots were calculated. The standard error of measurement (SEM) and minimum detectable difference (MDD) were calculated. RESULTS: Inter-rater reliability was excellent for AT (ICC=0.98; 95% CI= 0.96-0.99) and very good for PT (ICC=0.85; 95% CI = 0.67-0.93) and ECET (ICC=0.81; 95% CI= 0.72-0.94). Reliability for PF was moderate, with an ICC of 0.63 (CI 95%= 0.20-0.83). Bland-Altman plot for inter-machine reliability showed a mean difference of 1 m for PF measurements and a mean difference of 4 m and 20 m for AT and PT. The relative SEMs were below 7% and the MDCs were below 0.7 mm. CONCLUSION: The MSUS reliability in measuring thickness of the four tendons is confirmed by the homogeneous readings intra sonographers, between operators and between different machines. Level of evidence: Tendon thickness can be measured reliably on different ultrasound devices, which is an important step forward in the use of this technique in daily clinical practice and research. LEVEL OF EVIDENCE: III.

Sonoelastography of Plantar Fascia: Reproducibility and Pattern Description in Healthy Subjects and Symptomatic Subjects.

The purpose of the work reported here was to describe the sonoelastographic appearance of the plantar fascia of healthy volunteers and patients with fasciitis. Twenty-three healthy subjects and 21 patients with plantar fasciitis were examined using B-mode and real-time sonoelastography (RTSR) scanning. B-Mode examination included fascia thickness and echotexture. Echogenicity and echovariation of the color histogram were analyzed. Fasciae were classified into type 1, blue (more elastic); type 2, blue/green (intermediate); or type 3, green (less elastic). RTSE revealed 72.7% of fasciae as type 2, with no significant association with fasciitis (χ(2) = 3.6, df = 2, p = 0.17). Quantitative analysis of the color histogram revealed a significantly greater intensity of green (mean = 77.8, 95% confidence interval [CI] = 71.9-83.6) and blue (mean = 74.2, 95% CI = 69.7-78.8) in healthy subjects. Echovariation of the color red was 33.4% higher in the fasciitis group than in the healthy group (95% CI = 16.7-50.1). Sonoelastography with quantitative analysis of echovariation can be a useful tool for evaluation of plantar fascia pathology.

Biomechanics of the Median Nerve During Stretching as Assessed by Ultrasonography.

The objective of this observational cross-sectional study was to investigate the normal motion of the median nerve when stretched during a neurodynamic exercise. In recent years, ultrasonography has been increasingly accepted as an imaging technique for examining peripheral nerves in vivo, offering a reliable and noninvasive method for a precise evaluation of nerve movement. Transverse motion of the median nerve in the arm during a neurodynamic test was measured. A volunteer sample of 22 healthy subjects (11 women) participated in the study. Nerve displacement and deformation were assessed by dynamic ultrasonography. Excellent interobserver agreement was obtained, with kappa coefficient of .7-.8. Ultrasonography showed no lateral motion during wrist extension in 68% of nerves, while 73% moved dorsally, with statistically significant differences between sexes (ORlat = 6.3; 95% CI = 1.4-27.7 and ORdor = 8.3; 95% CI = 1.6-44.6). The cross-sectional area was significantly greater in men (3.6 mm2). Quantitative analysis revealed no other statistically significant differences. Our results provide evidence of substantial individual differences in median nerve transverse displacement in response to a neurodynamic exercise.

[Reliability and reproducibility of a morpho-textural image analysis method over a patellar ligament ultrasonography]. / Fiabilidad y reproducibilidad de un nuevo método de análisis morfotextural de imágenes ecográficas del tendón rotuliano.

OBJECTIVE: Image analysis techniques over ultrasonograms may be useful to extract quantitative information. Because ecography and the selection of the area of interest are technician-dependent, the objective of this work was to calculate the reliability and the reproducibility of the analysis method. MATERIAL AND METHODS: Test-retest reliability study on 60 cross-sectional patellar ligament ultrasonograms on 1cm of patella were carried out. Sonosite Titan L-38 (5-10 MHz) and the Image analysis software J v1.40 were used. Morphometric variables were: perimeter, area, width, thickness, and mean echogenity; textural variables were: uniformity, homogeneity and entropy. The intraclass correlation coefficient (ICC) was calculated with a confidence interval of 95%. RESULTS: Intraclass correlation coefficients over 0.70 were found, with an agreement ranging from good to very good in all of the variables both for the intra ecography and inter ecography studies. CONCLUSION: Very good levels of reliability and internal consistency were seen, demonstrating that from the statistical point of view, the variability introduced by the technician is not significant. This method can be taken as a reference to analyze the reliability between several ultrasonographers.