Is the location of the signal intensity weighted centroid a reliable measurement of fluid displacement within the disc?

2018 ◽  
Vol 63 (4) ◽  
pp. 453-460 ◽  
Author(s):  
Vahid Abdollah ◽  
Eric C. Parent ◽  
Michele C. Battié
Keyword(s):  
Signal Intensity ◽  
Water Distribution ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Region Of Interest ◽  
Rater Reliability ◽  
Fluid Displacement ◽  
Intraclass Correlation Coefficients ◽  
The Mean ◽  
Standard Error Of Measurement

Abstract Degenerated discs have shorter T2-relaxation time and lower MR signal. The location of the signal-intensity-weighted-centroid reflects the water distribution within a region-of-interest (ROI). This study compared the reliability of the location of the signal-intensity-weighted-centroid to mean signal intensity and area measurements. L4-L5 and L5-S1 discs were measured on 43 mid-sagittal T2-weighted 3T MRI images in adults with back pain. One rater analysed images twice and another once, blinded to measurements. Discs were semi-automatically segmented into a whole disc, nucleus, anterior and posterior annulus. The coordinates of the signal-intensity-weighted-centroid for all regions demonstrated excellent intraclass-correlation-coefficients for intra- (0.99–1.00) and inter-rater reliability (0.97–1.00). The standard error of measurement for the Y-coordinates of the signal-intensity-weighted-centroid for all ROIs were 0 at both levels and 0 to 2.7 mm for X-coordinates. The mean signal intensity and area for the whole disc and nucleus presented excellent intra-rater reliability with intraclass-correlation-coefficients from 0.93 to 1.00, and 0.92 to 1.00 for inter-rater reliability. The mean signal intensity and area had lower reliability for annulus ROIs, with intra-rater intraclass-correlation-coefficient from 0.5 to 0.76 and inter-rater from 0.33 to 0.58. The location of the signal-intensity-weighted-centroid is a reliable biomarker for investigating the effects of disc interventions.

scholarly journals Acceleration of 2D-MR fingerprinting by reducing the number of echoes with increased in-plane resolution: a volunteer study

2020 ◽  
Vol 33 (6) ◽  
pp. 783-791
Author(s):  
Yusuke Yokota ◽  
Tomohisa Okada ◽  
Yasutaka Fushimi ◽  
Akira Yamamoto ◽  
Satoshi Nakajima ◽  
...  
Keyword(s):  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Region Of Interest ◽  
Intraclass Correlation Coefficients ◽  
Coefficients Of Variation ◽  
Volunteer Study ◽  
The Mean ◽  
T1 And T2 ◽  
High Repeatability ◽  
Measurement Repeatability

Abstract Objective To compare the absolute values and repeatability of magnetic resonance fingerprinting (MRF) with 3000 and 1500 echoes/slice acquired in 41 s and 20 s (MRF3k and MRF1.5k, respectively). Materials and methods MRF3k and MRF1.5k scans based on fast imaging with steady precession (FISP) were conducted using a 3 T scanner. Inter-scan agreement and intra-scan repeatability were investigated in 41 and 28 subjects, respectively. Region-of-interest (ROI) analysis was conducted on T1 values of MRF3k by two raters, and their agreement was evaluated using intraclass correlation coefficients (ICCs). Between MRF3k and MRF1.5k, differences in T1 and T2 values and inter-measurement correlation coefficients (CCs) were investigated. Intra-measurement repeatability was evaluated using coefficients of variation (CVs). A p value < 0.05 was considered statistically significant. Results The ICCs of ROI measurements were 0.77–0.96. Differences were observed between the two MRF scans, but the CCs of the overall ROIs were 0.99 and 0.97 for the T1 and T2 values, respectively. The mean and median CVs of repeatability were equal to or less than 1.58% and 3.13% in each of the ROIs for T1 and T2, respectively; there were some significant differences between MRF3k and MRF1.5k, but they were small, measuring less than 1%. Discussion Both MRF3k and MRF1.5k had high repeatability, and a strong to very strong correlation was observed, with a trend toward slightly higher values in MRF1.5k.

scholarly journals An Electromyographic Analysis of the Deep Cervical Flexor Muscles in Performance of Craniocervical Flexion

2003 ◽  
Vol 83 (10) ◽  
pp. 899-906 ◽  
Author(s):  
Deborah Falla ◽  
Gwendolen Jull ◽  
Paul Dall'Alba ◽  
Alberto Rainoldi ◽  
Roberto Merletti
Keyword(s):  
Muscle Activity ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Bipolar Electrodes ◽  
Intraclass Correlation Coefficients ◽  
Reliability Estimates ◽  
Flexor Muscles ◽  
The Mean ◽  
Electromyographic Analysis ◽  
Electromyographic Signals

Abstract Background and Purpose. This study evaluated an electromyographic technique for the measurement of muscle activity of the deep cervical flexor (DCF) muscles. Electromyographic signals were detected from the DCF, sternocleidomastoid (SCM), and anterior scalene (AS) muscles during performance of the craniocervical flexion (CCF) test, which involves performing 5 stages of increasing craniocervical flexion range of motion—the anatomical action of the DCF muscles. Subjects. Ten volunteers without known pathology or impairment participated in this study. Methods. Root-mean-square (RMS) values were calculated for the DCF, SCM, and AS muscles during performance of the CCF test. Myoelectric signals were recorded from the DCF muscles using bipolar electrodes placed over the posterior oropharyngeal wall. Reliability estimates of normalized RMS values were obtained by evaluating intraclass correlation coefficients and the normalized standard error of the mean (SEM). Results. A linear relationship was evident between the amplitude of DCF muscle activity and the incremental stages of the CCF test (F=239.04, df=36, P&lt;.0001). Normalized SEMs in the range 6.7% to 10.3% were obtained for the normalized RMS values for the DCF muscles, providing evidence of reliability for these variables. Discussion and Conclusion. This approach for obtaining a direct measure of the DCF muscles, which differs from those previously used, may be useful for the examination of these muscles in future electromyographic applications.

scholarly journals A Quantitative Comparison of Multispectral Refraction Topography and Autorefractometer in Young Adults

2021 ◽  
Vol 8 ◽  
Author(s):  
Yunru Liao ◽  
Zhenlan Yang ◽  
Zijing Li ◽  
Rui Zeng ◽  
Jing Wang ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Pearson Correlation ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
High Agreement ◽  
Intraclass Correlation Coefficients ◽  
Repeatability And Reproducibility ◽  
The Mean

Purpose: Purpose of this study is to evaluate the measuring consistency of central refraction between multispectral refraction topography (MRT) and autorefractometry.Methods: This was a descriptive cross-sectional study including subjects in Sun Yat-sen Memorial Hospital from September 1, 2020, to December 31, 2020, ages 20 to 35 years with a best corrected visual acuity of 20/20 or better. All patients underwent cycloplegia, and the refractive status was estimated with autorefractometer, experienced optometrist and MRT. We analyzed the central refraction of the autorefractometer and MRT. The repeatability and reproducibility of values measured using both devices were evaluated using intraclass correlation coefficients (ICCs).Results: A total of 145 subjects ages 20 to 35 (290 eyes) were enrolled. The mean central refraction of the autorefractometer was −4.69 ± 2.64 diopters (D) (range −9.50 to +4.75 D), while the mean central refraction of MRT was −4.49 ± 2.61 diopters (D) (range −8.79 to +5.02 D). Pearson correlation analysis revealed a high correlation between the two devices. The intraclass correlation coefficient (ICC) also showed high agreement. The intrarater and interrater ICC values of central refraction were more than 0.90 in both devices and conditions. At the same time, the mean central refraction of experienced optometrist was −4.74 ± 2.66 diopters (D) (range −9.50 to +4.75D). The intra-class correlation coefficient of central refraction measured by MRT and subjective refraction was 0.939.Conclusions: Results revealed that autorefractometry, experienced optometrist and MRT show high agreement in measuring central refraction. MRT could provide a potential objective method to assess peripheral refraction.

scholarly journals Agreement between the Open Barbell and Tendo Linear Position Transducers for Monitoring Barbell Velocity during Resistance Exercise

Sports ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 125
Author(s):  
Adam M. Gonzalez ◽  
Gerald T. Mangine ◽  
Robert W. Spitz ◽  
Jamie J. Ghigiarelli ◽  
Katie M. Sell
Keyword(s):  
Repeated Measures ◽  
Peak Velocity ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Moderate Intensity ◽  
Mean Velocity ◽  
Intraclass Correlation Coefficients ◽  
Coefficients Of Variation ◽  
Repeated Measures Analysis ◽  
Standard Error Of Measurement

To determine the agreement between the Open Barbell (OB) and Tendo weightlifting analyzer (TWA) for measuring barbell velocity, eleven men (19.4 ± 1.0 y) performed one set of 2–3 repetitions at four sub-maximal percentage loads, [i.e., 30, 50, 70, and 90% one-repetition maximum (1RM)] in the back (BS) and front squat (FS) exercises. During each repetition, peak and mean barbell velocity were recorded by OB and TWA devices, and the average of the 2–3 repetitions was used for analyses. Although the repeated measures analysis of variance revealed significantly (p ≤ 0.005) greater peak and mean velocity scores from OB across all intensities, high intraclass correlation coefficients (ICC2,K = 0.790–0.998), low standard error of measurement (SEM2,K = 0.040–0.119 m·s−1), and coefficients of variation (CV = 2–4%) suggested consistency between devices. Positive (r = 0.491–0.949) Pearson correlations between averages and differences (between devices) in peak velocity, as well as associated Bland-Altman plots, showed greater differences occurred as the velocity increased, particularly at low-moderate intensity loads. OB consistently provides greater barbell velocity scores compared to TWA, and the differences between devices were more apparent as the peak velocity increased with low-to-moderate loads. Strength coaches and athletes may find better agreement between devices if the mean velocity scores are only considered.

Reliability and validity of the iSense optical scanner for measuring volume of transtibial residual limb models

2018 ◽  
Vol 43 (2) ◽  
pp. 213-220 ◽  
Author(s):  
Lucy Armitage ◽  
Li Khim Kwah ◽  
Lauren Kark
Keyword(s):  
Intraclass Correlation ◽  
Reliability And Validity ◽  
Correlation Coefficients ◽  
Criterion Validity ◽  
Residual Limb ◽  
Limb Volume ◽  
Rater Reliability ◽  
Measuring Volume ◽  
Intraclass Correlation Coefficients ◽  
Optical Scanner

Background: Residual limb volume is often measured as part of routine care for people with amputations. These measurements assist in the timing of prosthetic fitting or replacement. In order to make well informed decisions, clinicians need access to measurement tools that are valid and reliable. Objectives: To assess the reliability and criterion validity of the iSense optical scanner in measuring volume of transtibial residual limb models. Study Design: Three assessors performed two measurements each on 13 residual limb models with an iSense optical scanner (3D systems, USA). Intra-rater and inter-rater reliability were calculated using intraclass correlation coefficients. Bland Altman plots were inspected for agreement. Criterion validity was assessed using a steel rod of known dimensions. Ten repeated measurements were performed by one assessor. A t-test was used to determine differences between measured and true rod volume. Results: Intra-rater reliability was excellent (range of intraclass correlation coefficients: 0.991–0.997, all with narrow 95% confidence intervals). While the intraclass correlation coefficients suggest excellent inter-rater reliability between all three assessors (range of intraclass correlation coefficients: 0.952–0.986), the 95% confidence intervals were wide between assessor 3 and the other two assessors. Poor agreement with assessor 3 was also seen in the Bland-Altman plots. Criterion validity was very poor with a significant difference between the mean iSense measurement and the true rod volume (difference: 221.18 mL; p < 0.001). Conclusions: Although intra-rater reliability was excellent for the iSense scanner, we did not find similar results for inter-rater reliability and validity. These results suggest that further testing of the iSense scanner is required prior to use in clinical practice. Clinical relevance The iSense offers a low cost scanning option for residual limb volume measurement. Intra-rater reliability was excellent, but inter-rater reliability and validity were such that clinical adoption is not indicated at present.

The choice of chromogen and reliability of contact rhinoscopy in the irradiated nasopharynx

2007 ◽  
Vol 122 (2) ◽  
pp. 177-180 ◽  
Author(s):  
Martin W Pak ◽  
Samuel Chow ◽  
C A van Hasselt
Keyword(s):  
Methylene Blue ◽  
Squamous Metaplasia ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Cross Sectional ◽  
Vital Stain ◽  
Intraclass Correlation Coefficients ◽  
Observer Reliability ◽  
Blue Stain ◽  
The Mean

AbstractA cross-sectional randomised single blind study was conducted to assess how concentrations of chromogen (vital stain) and the characteristics of the assessors affect the assessment of contact rhinoscopy. Twenty-eight patients who had undergone external radiotherapy for nasopharyngeal carcinoma were assessed by contact rhinoscopy using 0.5 per cent and 1 per cent methylene blue stain on opposite sides of the nasopharynx. Three independent observers assessed the visual clarity of the 45 contact endoscopic images showing squamous metaplasia according to a visual analogue scale. The intraclass correlation coefficients were 0.916 to 0.957 and 0.839 to 0.964 for intra-observer reliability of assessors in the groups of 0.5 per cent and 1 per cent stains, respectively. The intraclass correlation coefficients for inter-observer reliability of assessors were 0.884 and 0.885 in the groups of 0.5 per cent and 1 per cent stains, respectively. The mean scores of clarity of the cellular details were statistically higher in the group of 1 per cent stain among all assessors. These results showed that the assessment of squamous metaplasia by contact endoscopy is highly reliable irrespective of the clinical experience and knowledge of histopathology of the assessors. One per cent methylene blue should be the vital stain of choice in contact endoscopy.

Reliability of Autism-Tics, AD/HD, and other Comorbidities (A–TAC) Inventory in a Test-Retest Design

2014 ◽  
Vol 114 (1) ◽  
pp. 93-103 ◽  
Author(s):  
Tomas Larson ◽  
Eva Norén Selinus ◽  
Clara Hellner Gumpert ◽  
Thomas Nilsson ◽  
Nóra Kerekes ◽  
...  
Keyword(s):  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Population Based ◽  
Autism Spectrum ◽  
Good Test ◽  
Rater Reliability ◽  
Retest Reliability ◽  
Intraclass Correlation Coefficients ◽  
Intraclass Correlations ◽  
Test Retest Reliability

The Autism-Tics, AD/HD, and other Comorbidities (A–TAC) inventory is used in epidemiological research to assess neurodevelopmental problems and coexisting conditions. Although the A–TAC has been applied in various populations, data on retest reliability are limited. The objective of the present study was to present additional reliability data. The A–TAC was administered by lay assessors and was completed on two occasions by parents of 400 individual twins, with an average interval of 70 days between test sessions. Intra- and inter-rater reliability were analysed with intraclass correlations and Cohen's κ. A–TAC showed excellent test-retest intraclass correlations for both autism spectrum disorder and attention deficit hyperactivity disorder (each at .84). Most modules in the A–TAC had intra- and inter-rater reliability intraclass correlation coefficients of ≥ .60. Cohen's κ indicated acceptable reliability. The current study provides statistical evidence that the A–TAC yields good test-retest reliability in a population-based cohort of children.

Reliability of assessment of medical students’ non-technical skills using a behavioural marker system: does clinical experience matter?

2020 ◽  
pp. bmjstel-2020-000705
Author(s):  
Benjamin Clarke ◽  
Samantha E Smith ◽  
Emma Claire Phillips ◽  
Ailsa Hamilton ◽  
Joanne Kerins ◽  
...  
Keyword(s):  
Medical Students ◽  
Clinical Experience ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Technical Skills ◽  
Rater Reliability ◽  
Single Measure ◽  
Marker System ◽  
Intraclass Correlation Coefficients ◽  
Reliability Coefficients

IntroductionNon-technical skills are recognised to play an integral part in safe and effective patient care. Medi-StuNTS (Medical Students’ Non-Technical Skills) is a behavioural marker system developed to enable assessment of medical students’ non-technical skills. This study aimed to assess whether newly trained raters with high levels of clinical experience could achieve reliability coefficients of >0.7 and to compare differences in inter-rater reliability of raters with varying clinical experience.MethodsForty-four raters attended a workshop on Medi-StuNTS before independently rating three videos of medical students participating in immersive simulation scenarios. Data were grouped by raters’ levels of clinical experience. Inter-rater reliability was assessed by calculating intraclass correlation coefficients (ICC).ResultsEleven raters with more than 10 years of clinical experience achieved single-measure ICC of 0.37 and average-measures ICC of 0.87. Fourteen raters with more than or equal to 5 years and less than 10 years of clinical experience achieved single-measure ICC of 0.09 and average-measures ICC of 0.59. Nineteen raters with less than 5 years of clinical experience achieved single-measure ICC of 0.09 and average-measures ICC 0.65.ConclusionsUsing 11 newly trained raters with high levels of clinical experience produced highly reliable ratings that surpassed the prespecified inter-rater reliability standard; however, a single rater from this group would not achieve sufficiently reliable ratings. This is consistent with previous studies using other medical behavioural marker systems. This study demonstrated a decrease in inter-rater reliability of raters with lower levels of clinical experience, suggesting caution when using this population as raters for assessment of non-technical skills.

WITHIN-DAY AND BETWEEN-DAY RELIABILITY OF A FBG-BASED SMART SOCK SYSTEM FOR MEASURING ACTIVE TOE FLEXION DISPLACEMENT OF THE HALLUX

2021 ◽  
pp. 2150057
Author(s):  
PUI WAH KONG ◽  
JING WEN PAN ◽  
DANIEL T. P. FONG ◽  
YIXUAN LEOW ◽  
YIMIN LIU ◽  
...  
Keyword(s):  
Wearable Sensors ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Repeated Measurements ◽  
Intraclass Correlation Coefficients ◽  
Paired Samples ◽  
Test Retest Reliability ◽  
And Control ◽  
Standard Error Of Measurement ◽  
Prototype Design

This study examined the test-retest reliability of hallux flexion displacement measured using a smart sock system with embedded fiber Bragg grating (FBG) sensors. Thirty female participants consisting of 15 hallux valgus (HV) patients and 15 control participants were recruited. Maximum active hallux flexion displacement was measured twice on each participant in the first visit; the same procedures were repeated 7 days later. Intraclass correlation coefficients (ICC2,1) and standard error of measurement (SEM) were applied to test within-day and between-day reliability. Paired-samples T-test was performed to compare the displacements between trials. Results showed almost perfect within-day reliability for both HV and control groups ([Formula: see text] and 0.977, respectively) with small SEM (both 0.5[Formula: see text]cm). However, fair to moderate between-day reliability was found (0.323 and 0.438, respectively). Significant differences were found between repeated measurements taken on the same day (mean [Formula: see text][Formula: see text]cm, [Formula: see text]) and on different days (mean [Formula: see text][Formula: see text]cm, [Formula: see text]), though the effect size was small. The poorer between-day reliability is likely due to the inconsistency in fitting the sock onto the foot. Future optimization of the prototype design is called for to improve the fitting consistency of wearable sensors onto patients.

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