The effect of scan parameters on cone beam CT trabecular bone microstructural measurements of the human mandible
34
Citation
39
Reference
10
Related Paper
Citation Trend
Abstract:
The objective of this study was to investigate the effect of different cone beam CT scan parameters on trabecular bone microstructure measurements. A human mandibular cadaver was scanned using a cone beam CT (3D Accuitomo 170; J.Morita, Kyota, Japan). 20 cone beam CT images were obtained using 5 different fields of view (4×4 cm, 6×6 cm, 8×8 cm, 10×10 cm and 10×5 cm), 2 types of rotation steps (180° and 360°) and 2 scanning resolutions (standard and high). Image analysis software was used to assess the trabecular bone microstructural parameters (number, thickness and spacing). All parameters were measured twice by one trained observer. Intraclass correlation coefficients showed high intraobserver repeatability (intraclass correlation coefficient, 0.95-0.97) in all parameters across all tested scan parameters. Trabecular bone microstructural measurements varied significantly, especially in smaller fields of view (p = 0.001). There was no significant difference in the trabecular parameters when using different resolutions (number, p = 0.988; thickness, p = 0.960; spacing, p = 0.831) and rotation steps (number, p = 1.000; thickness, p = 0.954; spacing, p = 0.759). The scan field of view significantly influences the trabecular bone microstructure measurements. Rotation steps (180° or 360°) and resolution (standard or high) selections are not relevant.Keywords:
Repeatability
Abstract Criteria are given for the choice of scale prior to estimation of repeatability. Recommendations of Bland and Altman should then be used for expressing repeatability and agreement of methods of measurement on the same scale. Repeatability of measurements on different scales should be compared using the appropriate ratio of variances, or intraclass correlation coefficient. A reference range for diagnosis requires a high ratio of between‐subject variation to total variation. The index of separation between diseased and healthy subjects should be used whenever possible. Changes within patients should be compared with reference change ranges, and not against the diagnostic range.
Repeatability
Coefficient of variation
Cite
Citations (157)
The accuracy, reliability and reproducibility of electric pulp tests (EPT) have been investigated but there is conflicting information about their repeatability. The aim of this study was to investigate whether EPT are repeatable over time. EPT results from 180 healthy teeth in 39 patients with 2-10 readings per tooth (total 692 readings) were analysed. Single measures intraclass correlation coefficients (ICC) ranged from 0.776 to 0.845 in teeth with 2-7 repeated measures (P < 0.001), indicating good repeatability. With eight or more measures per tooth, the ICC was low, indicating poor repeatability over longer follow-up times, but only seven teeth in two subjects were included in this analysis. The Pearson correlation showed no statistically significant correlation for 2-7 readings but when all readings were included, there was a statistically significant negative correlation. Hence, EPT has good repeatability.
Repeatability
Cite
Citations (4)
To determine repeatability and reproducibility of A-scan biometry quantitative findings in order to uniformly evaluate lenticular cataract changes.Seventeen eyes from seventeen cataract patients were examined by three (trainee ophthalmologists). Results (ratio of mean internal lens spikes height/lens anterior surface spike height) were compared using coefficient of variation (CV), repeatability coefficient (CR), and intraclass correlation coefficients (ICC).Intra-observer consistency was CV = 0.36, CR = 0.49, and ICC = 0.778 for the first operator; CV = 0.33, CR = 0.52, and ICC = 0.642 for the second operator; and CV = 0.32, CR = 0.53, and ICC = 0.567 for the third operator. Concerning inter-observer agreement: CV (in 6 of 7 eyes) was > 8%, CR was > 0.21, and intraclass correlation coefficient for all eyes was < 0.81.Regarding repeatability and reproducibility, although there is a tendency for statistical significance, variability of the results does not allow the use of the method as a complementary clinical tool for comparing results. Standardization of this procedure, in order to achieve higher test reliability, might be the aim of relevant future studies, although there are a number of points that have to be addressed.
Repeatability
Coefficient of variation
Cite
Citations (3)
<b><i>Purpose:</i></b> The aim of this study was to evaluate the repeatability and reproducibility of foveal avascular zone (FAZ) area measurements using AngioPlex spectral domain optical coherence tomography (OCT) angiography in normal subjects. <b><i>Methods:</i></b> Twenty-two healthy subjects (25 eyes) underwent FAZ area measurements with AngioPlex OCT. Each volunteer was separately examined 3 consecutive times by the 2 experienced observers. The FAZ area was measured using ImageJ software. Intraobserver repeatability was evaluated by calculating the coefficient of variation (CoV) and intraclass correlation coefficient (ICC). Interobserver reproducibility was also assessed using the Bland-Altman test and concordance correlation coefficient (CCC). <b><i>Results:</i></b> The FAZ areas were measured as 0.373 ± 0.109 and 0.377 ± 0.112 mm<sup>2</sup> by observers 1 and 2, respectively. The repeatability assessment of the FAZ area measurements yielded CoV values of 0.029 and 0.034 and ICC values of 0.997 and 0.996 by observers 1 and 2, respectively. The mean difference between the 2 observers was 0.004. CCC values ranged from 0.9705 to 0.9844. <b><i>Conclusions:</i></b> The FAZ area measurements obtained using AngioPlex OCT showed a good repeatability and reproducibility in healthy subjects. Excellent reliability makes AngioPlex OCT a valid device for measuring the FAZ area.
Repeatability
Foveal avascular zone
Coefficient of variation
Concordance correlation coefficient
Cite
Citations (51)
Apps for smartphones that can measure the breathing rate easily can be downloaded.The aim of this study was to demonstrate agreement in measuring breath rates between the stethoscope and Breath Counter health app.We performed a repeatability study with 56 healthy volunteers. The patient's demographic data and breathing rates per minute were collected. Breathing rates were measured via two methods: (1) using a stethoscope placed in the upper area of the right lung and (2) a Breath Counter app developed by Vadion on a Samsung Fold smartphone.This study demonstrated high repeatability and validity with respect to the breathing rate parameter of healthy adults using the aforementioned 2 systems. Intrasession repeatability measure using the intraclass correlation coefficient was >0.962, indicating excellent repeatability. Moreover, the intraclass correlation coefficient between methods was 0.793, indicating good repeatability, and coefficients of variation of method errors values were 1.83% with very low values in terms of other repeatability parameters. We found significant correlation coefficients and no systematic differences between the app and stethoscope methods.The app method may be attractive to individuals who require repeatability in a recreational setting.
Repeatability
Stethoscope
Coefficient of variation
Cite
Citations (0)
Repeatability
Cite
Citations (32)
Abstract Objective To assess the intra‐ and interobserver reproducibility of songographic measurement of fetal femur length between 10 and 16 weeks of gestation. Methods Femur length was measured three times by the same trained observer in each fetus of 136 pregnant women. A second trained observer then repeated the measurements. The coefficient of variation, intraclass correlation coefficient and repeatability coefficient with 95% CIs were calculated for each observer and between the two observers. Results The inter‐ and intraobserver repeatabilities of femur length were good. For interobserver correlation, the coefficient of variation was 4.6% (95% CI, 3.0–6.2), the intraclass correlation coefficient was 0.82 (95% CI, 0.69–0.95) and the repeatability coefficient was 2.1 (95% CI, 1.8–2.7). For intraobserver correlation, the coefficient of variation was 4.2% (95% CI, 3.2–5.6), the intraclass correlation coefficient was 0.91 (95% CI, 0.75–0.97) and the repeatability coefficient was 3.23 (95% CI, 2.33–3.86) for Observer 2. Similar results were obtained for the other observer. Conclusion Transvaginal femur length measurement is technically feasible and easy to perform between 10 and 16 weeks of gestation. The high degree of intra‐ and interobserver repeatability indicates it to be a reproducible method. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Repeatability
Cite
Citations (11)
Few studies assess repeatability and reproducibility in registers of resonance frequency analysis (a value of dental implant stability).Few studies assess repeatability and reproducibility in resonance frequency analyses (implant stability evaluation). This study is aimed at assessing reliability (repeatabilty and reproducibility) in the Osstell Mentor® system using the intraclass correlation coefficient (ICC) as the statistical method.ISQ measurements of RFA were carried out by means of the Osstell Mentor® instrument in 58 implants in 19 patients. Six measurements were performed on each implant by means of two different Smart-Pegs (I and II). Three consecutive measurements were registered with each transducer.Average ISQ varied from 72.43 to 72.60 and 73.26 in the first, second and third measurements, respectively with the SamrtPeg I and from 72.98 to 73.26 and 73.74 in the first, second and third measurements, respectively with the SamrtPeg II . Exactly equal values were observed in 10.43 and 12.1% of the cases with Smart-Pegs I and II, respectively. The intraclass correlation coefficient was 0.96 and 0.96 for Smart Pegs I and II, respectively. Repeatability and reproducibility was 0.97 for both Smart-Pegs I and II.The RFA system contributed by Osstell Mentor® renders almost perfect reproducibility and repeatability, as proven by statistical analysis carried out by means of ICC with 95% confidence level. This instrument contributes highly reliable RFA measurements in dental implants.
Repeatability
Resonance frequency analysis
Cite
Citations (44)
Repeatability
Cite
Citations (24)
Abstract To identify robust and reproducible methods of cerebellar morphometry that can be used in future large-scale structural MRI studies, we investigated the replicability, repeatability, and longterm reproducibility of three fully-automated software tools: FreeSurfer, CERES, and ACAPULCO. Replicability was defined as computational replicability, determined by comparing two analyses of the same high-resolution MRI data set performed with identical analysis software and computer hardware. Repeatability was determined by comparing the analyses of two MRI scans of the same participant taken during two independent MRI sessions on the same day for the Kirby-21 study. Long-term reproducibility was assessed by analyzing two MRI scans of the same participant in the longitudinal OASIS-2 study. We determined percent difference, the image intraclass correlation coefficient, the coefficient of variation, and the intraclass correlation coefficient between two analyses. Our results show that CERES and ACAPULCO use stochastic algorithms that result in surprisingly high differences between identical analyses for ACAPULCO and small differences for CERES. Changes between two consecutive scans from the Kirby-21 study were less than ±5% in most cases for FreeSurfer and CERES (i.e., demonstrating high repeatability). As expected, long-term reproducibility was lower than repeatability for all software tools. In summary, CERES is an accurate, as demonstrated before, and reproducible tool for fully-automated segmentation and parcellation of the cerebellum. We conclude with recommendations for the assessment of replicability, repeatability, and longterm reproducibility in future studies on cerebellar structure.
Repeatability
Coefficient of variation
Cite
Citations (2)