scholarly journals Intra- and inter-rater reliability of compressed breast thickness, applied force, and pressure distribution in screening mammography

2021 ◽  
Vol 10 (12) ◽  
pp. 205846012110620
Author(s):  
Martina Voigt ◽  
Anetta Bolejko ◽  
Magnus Dustler
Keyword(s):  
Pressure Distribution ◽  
Contact Area ◽  
Center Of Mass ◽  
Intraclass Correlation ◽  
Screening Mammography ◽  
Applied Force ◽  
Rater Reliability ◽  
Time Points ◽  
Breast Compression ◽  
Breast Thickness

Background Ensuring equivalent and reproducible breast compression between mammographic screening rounds is important for the diagnostic performance of mammography, yet the extent to which screening mammography positioning and compression is reproducible for the individual woman is unknown. Purpose To investigate the intra- and inter-rater reliability of breast compression in screening mammography. Materials and Methods Eleven breast-healthy women participated in the study. Two experienced radiographers independently positioned and compressed the breasts of each participant in two projections—right craniocaudal and left mediolateral oblique—and at two time points. The spatial pressure distribution on the compressed breast was measured using a pressure sensor matrix. Applied force, compressed breast thickness, force in field of view, contact area, mean pressure, and center of mass (anterio-posterior and mediolateral axes) were measured. The reliabilities of the measures between the time points for each radiographer (intra-rater reliability) and between the radiographers (inter-rater reliability) were analyzed using the intraclass correlation coefficient (ICC). Results Intra- and inter-rater reliabilities from both projections demonstrated good to excellent ICCs (≥0.82) for compressed breast thickness, contact area, and anterio-posterior center of mass. The other measures produced ICCs that varied from poor (≤0.42) to excellent (≥0.93) between time points and between radiographers. Conclusion Intra- and inter-rater reliability of breast compression was consistently high for compressed breast thickness, contact area, and anterio-posterior center of mass but low for mediolateral center of mass and applied force. Further research is needed to establish objective and clinically useful parameters for the standardization of breast compression.

Distribution of pressure on the breast in mammography using flexible and rigid compression plates: implications on patient handling

2020 ◽  
pp. 028418512097692
Author(s):  
Magnus Dustler ◽  
Daniel Förnvik ◽  
Pontus Timberg ◽  
Sophia Zackrisson ◽  
Serge Muller
Keyword(s):  
Mammography Screening ◽  
Pressure Sensors ◽  
Applied Force ◽  
Flexible Plate ◽  
Thoracic Region ◽  
Patient Handling ◽  
Breast Compression ◽  
Compression Plate ◽  
Perceived Pain ◽  
Breast Thickness

Background Breast compression in mammography is important but is a source of discomfort and has been linked to screening non-attendance. Reducing compression has little effect on breast thickness, and likely little effect on image quality, due to force being absorbed in the stiff juxta thoracic area instead of in the central breast. Purpose To investigate whether a flexible compression plate can redistribute force to the central breast and whether this affects perceived pain. Material and Methods Twenty-eight women recalled from mammography screening were compressed with flexible and rigid plates while retaining force and positioning, 15 in the craniocaudal (CC) view and 13 in the mediolateral oblique (MLO) view. Pressure distribution was continuously measured using pressure sensors. Results The flexible plate showed greater mean breast pressure in both views: 2.8 versus 2.3 kPa for CC (confidence interval [CI] = 0.2–0.8) and 1.0 versus 0.5 kPa for MLO (CI = 0.2–0.6). The percentage of applied force distributed to the breast was significantly higher with the flexible plate, both on CC (36% vs. 22%, CI = 1–11) and MLO (30% vs. 14%, CI = 4–13). Conclusion The flexible plate redistributes pressure to the central breast, achieving a better compression, particularly in the MLO view, though much applied force is still applied to the juxta thoracic region.

Measurement and Visualization of the Contact Pressure Distribution of Rubber Disks and Tires

1995 ◽  
Vol 23 (4) ◽  
pp. 238-255 ◽  
Author(s):  
E. H. Sakai
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Contact Area ◽  
Light Absorption ◽  
Lateral Force ◽  
Contact Pressure Distribution ◽  
High Definition ◽  
The Road ◽  
Close Relationship ◽  
Processing Techniques

Abstract The contact conditions of a tire with the road surface have a close relationship to various properties of the tire and are among the most important characteristics in evaluating the performance of the tire. In this research, a new measurement device was developed that allows the contact stress distribution to be quantified and visualized. The measuring principle of this device is that the light absorption at the interface between an optical prism and an evenly ground or worn rubber surface is a function of contact pressure. The light absorption can be measured at a number of points on the surface to obtain the pressure distribution. Using this device, the contact pressure distribution of a rubber disk loaded against a plate was measured. It was found that the pressure distribution was not flat but varied greatly depending upon the height and diameter of the rubber disk. The variation can be explained by a “spring” effect, a “liquid” effect, and an “edge” effect of the rubber disk. Next, the measurement and image processing techniques were applied to a loaded tire. A very high definition image was obtained that displayed the true contact area, the shape of the area, and the pressure distribution from which irregular wear was easily detected. Finally, the deformation of the contact area and changes in the pressure distribution in the tread rubber block were measured when a lateral force was applied to the loaded tire.

scholarly journals Ultrasound Imaging Evaluation of Textural Features in Athletes with Soleus Pathology—A Novel Case-Control Study

2021 ◽  
Vol 18 (4) ◽  
pp. 1983 ◽  
Author(s):  
Blanca De-la-Cruz-Torres ◽  
Emmanuel Navarro-Flores ◽  
Daniel López-López ◽  
Carlos Romero-Morales
Keyword(s):  
Ultrasound Imaging ◽  
Soleus Muscle ◽  
Muscle Injury ◽  
Intraclass Correlation ◽  
Muscle Thickness ◽  
Tendon Injury ◽  
Muscle Injuries ◽  
Imaging Evaluation ◽  
Rater Reliability ◽  
Group A

Background: the aim of this study was to compare the echotexture of patients with soleus muscle injury and age matched controls. Methods: a sample of 62 athletes was recruited at the private clinic and was divided in two group: a healthy group (n = 31) and a soleus pathology group whose athletes had soleus muscle injury, located in the central tendon (n = 31). The muscle thickness (MTh), echointensity (EI) and echovariation (EV) were analyzed. An intra-rater reliability test (Intraclass Correlation Coefficient-ICC) was performed in order to analyze the reliability of the values of the measurements. Results: Sociodemographic variables did not show statistically significant differences (p > 0.05). Ultrasound imaging measurements who reported statistically significant differences were EI (p = 0.001) and standard deviation (SD) (p = 0.001). MTh and EV variables did not show statistically significant differences (p = 0.381 and p = 0.364, respectively). Moreover, reliability values for the MTh (ICC = 0.911), EI (ICC = 0.982), SD (ICC = 0.955) and EV (ICC = 0.963). Based on these results the intra-rater reliability was considered excellent. Conclusion: Athletes with a central tendon injury of soleus muscle showed a lower EI when they were compared to healthy athletes. The echogenicity showed by the quantitative ultrasound imaging measurement may be a more objective parameter for the diagnosis and follow-up the soleus muscle injuries.

The motion of rotating cylinders sliding on pebbled ice

2000 ◽  
Vol 77 (11) ◽  
pp. 847-862 ◽  
Author(s):  
MRA Shegelski ◽  
M Reid ◽  
R Niebergall
Keyword(s):  
Thin Film ◽  
Liquid Film ◽  
Contact Area ◽  
Relative Velocity ◽  
Thin Liquid Film ◽  
Center Of Mass ◽  
Translational Motion ◽  
Rotating Cylinder ◽  
Outer Edge ◽  
Slow Rotation

We consider the motion of a cylinder with the same mass and sizeas a curling rock, but with a very different contact geometry.Whereas the contact area of a curling rock is a thin annulus havinga radius of 6.25 cm and width of about 4 mm, the contact area of the cylinderinvestigated takes the form of several linear segments regularly spacedaround the outer edge of the cylinder, directed radially outward from the center,with length 2 cm and width 4 mm. We consider the motion of this cylinderas it rotates and slides over ice having the nature of the ice surfaceused in the sport of curling. We have previously presented a physicalmodel that accounts for the motion of curling rocks; we extend this modelto explain the motion of the cylinder under investigation. In particular,we focus on slow rotation, i.e., the rotational speed of the contact areasof the cylinder about the center of mass is small compared to thetranslational speed of the center of mass.The principal features of the model are (i) that the kineticfriction induces melting of the ice, with the consequence that thereexists a thin film of liquid water lying between the contact areasof the cylinder and the ice; (ii) that the radial segmentsdrag some of the thin liquid film around the cylinder as it rotates,with the consequence that the relative velocity between the cylinderand the thin liquid film is significantly different than the relativevelocity between the cylinder and the underlying solid ice surface.Since it is the former relative velocity that dictates the nature of themotion of the cylinder, our model predicts, and observations confirm, thatsuch a slowly rotating cylinder stops rotating well before translationalmotion ceases. This is in sharp contrast to the usual case of most slowlyrotating cylinders, where both rotational and translational motion ceaseat the same instant. We have verified this prediction of our model bycareful comparison to the actual motion of a cylinder having a contactarea as described.PACS Nos.: 46.00, 01.80+b

scholarly journals Intra-Rater (Live vs. Video Assessment) and Inter-Rater (Expert vs. Novice) Reliability of the Test of Gross Motor Development—Third Edition

2021 ◽  
Vol 18 (4) ◽  
pp. 1652
Author(s):  
Aida Carballo-Fazanes ◽  
Ezequiel Rey ◽  
Nadia C. Valentini ◽  
José E. Rodríguez-Fernández ◽  
Cristina Varela-Casal ◽  
...  
Keyword(s):  
Physical Education ◽  
Motor Development ◽  
Intraclass Correlation ◽  
Slow Motion ◽  
Healthy Children ◽  
Gross Motor ◽  
Rater Reliability ◽  
Video Assessment ◽  
Gross Motor Development ◽  
Ball Skills

The Test of Gross Motor Development (TGMD) is one of the most common tools for assessing the fundamental movement skills (FMS) in children between 3 and 10 years. This study aimed to examine the intra-rater and inter-rater reliability of the TGMD—3rd Edition (TGMD-3) between expert and novice raters using live and video assessment. Five raters [2 experts and 3 novices (one of them BSc in Physical Education and Sport Science)] assessed and scored the performance of the TGMD-3 of 25 healthy children [Female: 60%; mean (standard deviation) age 9.16 (1.31)]. Schoolchildren were attending at one public elementary school during the academic year 2019–2020 from Santiago de Compostela (Spain). Raters scored each children performance through two viewing moods (live and slow-motion). The ICC (Intraclass Correlation Coefficient) was used to determine the agreement between raters. Our results showed moderate-to-excellent intra-rater reliability for overall score and locomotor and ball skills subscales; moderate-to-good inter-rater reliability for overall and ball skills; and poor-to-good for locomotor subscale. Higher intra-rater reliability was achieved by the expert raters and novice rater with physical education background compared to novice raters. However, the inter-rater reliability was more variable in all the raters regardless of their experience or background. No significant differences in reliability were found when comparing live and video assessments. For clinical practice, it would be recommended that raters reach an agreement before the assessment to avoid subjective interpretations that might distort the results.

A method for tire wet grip performance evaluation based on grounding characteristics

2021 ◽  
pp. 095440702110158
Author(s):  
Chen Liang ◽  
Maoqing Shan ◽  
Guolin Wang ◽  
Daqian Zhu ◽  
Xingpeng Chen
Keyword(s):  
Pressure Distribution ◽  
Contact Area ◽  
Central Area ◽  
Principal Component ◽  
Area Ratio ◽  
Width Ratio ◽  
Characteristic Parameters ◽  
Radial Tire ◽  
Optical Test ◽  
Wet Grip

The wet grip performance of tire is one of the important performances affecting vehicle safety. The steering, acceleration, and braking of the vehicle are directly affected by the grounding characteristics between the radial tire and the ground. In order to study the influence of grounding characteristics of the tire on wet grip performance, ten 205/55R16 tires produced by different manufacturers were selected and tested. The grounding characteristics of the tires were tested using an optical test rig for tire grounding pressure distribution, considering inflation pressure distribution, load and wheel alignment. The tire-road contact area was subdivided into five parts, and 69 parameters were used to describe the grounding characteristics. A software was proposed to process the test results automatically, and 69 grounding characteristic parameters of each tire were obtained. Correlation analysis on tire wet grip performance and grounding characteristics was used for selecting the principal parameters. Finally, eight grounding characteristic parameters related to tire wet grip performance was obtained. Among them are five grounding characteristic parameters (central area rectangle ratio, central area width, internal shoulder length-to-width ratio, external and internal shoulder contact area ratio, external and internal shoulder impression area ratio) which have high correlation to tire wet grip performance, and three grounding characteristic parameters (external shoulder width, external shoulder length-to-width ratio, external and internal shoulder width ratio) which have low correlation to the wet grip performance of the tire. The principal component analysis method was used to analyze the highly correlated grounding characteristic parameters, and the regression equation for evaluating tire wet grip performance was fitted. The comparison of experimental and fitted values show that the errors are within 4%. The result demonstrates that, the method for evaluating wet grip performance of the radial tire through tire-road grounding characteristics was achieved.

Validity and reliability of a wearable-controlled serious game and goniometer for telemonitoring of wrist fracture rehabilitation

2021 ◽  
Author(s):  
Henriëtte A. W. Meijer ◽  
Maurits Graafland ◽  
Miryam C. Obdeijn ◽  
Marlies P. Schijven ◽  
J. Carel Goslings
Keyword(s):  
Range Of Motion ◽  
Intraclass Correlation ◽  
Internal Validity ◽  
Wrist Fracture ◽  
Serious Game ◽  
Reference Standard ◽  
Validity And Reliability ◽  
Good Reliability ◽  
Rater Reliability ◽  
Flexion Extension

Abstract Purpose To determine the validity of wrist range of motion (ROM) measurements by the wearable-controlled ReValidate! wrist-rehabilitation game, which simultaneously acts as a digital goniometer. Furthermore, to establish the reliability of the game by contrasting ROM measurements to those found by medical experts using a universal goniometer. Methods As the universal goniometer is considered the reference standard, inter-rater reliability between surgeons was first determined. Internal validity of the game ROM measurements was determined in a test–retest setting with healthy volunteers. The reliability of the game was tested in 34 patients with a restricted range of motion, in whom the ROM was measured by experts as well as digitally. Intraclass-correlation coefficients (ICCs) were determined and outcomes were analyzed using Bland–Altman plots. Results Inter-rater reliability between experts using a universal goniometer was poor, with ICCs of 0.002, 0.160 and 0.520. Internal validity testing of the game found ICCs of − 0.693, 0.376 and 0.863, thus ranging from poor to good. Reliability testing of the game compared to medical expert measurements, found that mean differences were small for the flexion–extension arc and the radial deviation-ulnar deviation arc. Conclusion The ReValidate! game is a reliable home-monitoring device digitally measuring ROM in the wrist. Interestingly, the test–retest reliability of the serious game was found to be considerably higher than the inter-rater reliability of the reference standard, being healthcare professionals using a universal goniometer. Trial registration number (internal hospital registration only) MEC-AMC W17_003 #17.015.

scholarly journals In Vitro and In Vivo Assessment of a New Workflow for the Acquisition of Mandibular Kinematics Based on Portable Tracking System with Passive Optical Reflective Markers

2021 ◽  
Vol 11 (9) ◽  
pp. 3947
Author(s):  
Marco Farronato ◽  
Gianluca M. Tartaglia ◽  
Cinzia Maspero ◽  
Luigi M. Gallo ◽  
Vera Colombo
Keyword(s):  
Measurement Error ◽  
Tracking System ◽  
Intraclass Correlation ◽  
Optical Tracking ◽  
Optical Tracking System ◽  
Rater Reliability ◽  
Tracking Device ◽  
Mandibular Kinematics

Clinical use of portable optical tracking system in dentistry could improve the analysis of mandibular movements for diagnostic and therapeutic purposes. A new workflow for the acquisition of mandibular kinematics was developed. Reproducibility of measurements was tested in vitro and intra- and inter-rater repeatability were assessed in vivo in healthy volunteers. Prescribed repeated movements (n = 10) in three perpendicular directions of the tracking-device coordinate system were performed. Measurement error and coefficient of variation (CV) among repetitions were determined. Mandibular kinematics of maximum opening, left and right laterality, protrusion and retrusion of five healthy subjects were recorded in separate sessions by three different operators. Obtained records were blindly examined by three observers. Intraclass correlation coefficient (ICC) was calculated to estimate inter-rater and intra-rater reliability. Maximum in vitro measurement error was 0.54 mm and CV = 0.02. Overall, excellent intra-rater reliability (ICC > 0.90) for each variable, general excellent intra-rater reliability (ICC = 1.00) for all variables, and good reliability (ICC > 0.75) for inter-rater tests were obtained. A lower score was obtained for retrusion with “moderate reliability” (ICC = 0.557) in the inter-rater tests. Excellent repeatability and reliability in optical tracking of primary movements were observed using the tested portable tracking device and the developed workflow.

Comparing Reliability Between 3D Imaging And 2D Photography For External Nasal Anthropometry

2021 ◽  
Author(s):  
Yoon-Soo Seo ◽  
Ki-Hun Jo ◽  
Jun-Sang CHA ◽  
Joo-Yeon Kim ◽  
Jae-Hwan Kwon
Keyword(s):  
3D Imaging ◽  
Intraclass Correlation ◽  
Digital Camera ◽  
Angular Parameter ◽  
Good Reliability ◽  
Rater Reliability ◽  
3D Images ◽  
Imaging Result ◽  
External Nose ◽  
2D And 3D

Abstract Background: This study investigates and compare the reliability and reproducibility of two facial anthropometric methods about external nasal angles, 3D imaging and conventional 2D photography. Methods: 2D photograph images and 3D images about external nose of 30 volunteers were taken using digital camera and Morpheus 3D scanner. To evaluate intra-rater reliability, each images were taken over two different days for each subject by the same researcher. To evaluate inter-rater reliability, another researcher took each images for each subject on the first day. The reliability of each method for measuring 4 external nasal angle is obtained using intraclass correlation coefficient (ICC) and compared.Results: Inter-rater and intra-rater reliability of both 3D imaging and 2D photography had excellent agreement in all 4 nasal angles. In the nasofacial angular parameter, Inter-rater ICC, 2D photography was significantly higher than 3D imaging. Result of intra-rater ICC also showed both 3D imaging and 2D photography had good reliability in all 4 nasal angles. Similar to those of inter-rater ICC, nasofacial angular parameter showed statistically significant differences between 3D imaging and 2D photography.Conclusion: In terms of reliability, both 2D and 3D showed appropriate anthropometric results and considering its own advantage, each methods can be used complementarily.

Variation in Cervical Length over Time during a Single Transvaginal Ultrasound Examination

2018 ◽  
Vol 36 (08) ◽  
pp. 781-784
Author(s):  
Katherine A. Connolly ◽  
Luciana Vieira ◽  
Elizabeth M. Yoselevsky ◽  
Stephanie Pan ◽  
Joanne L. Stone
Keyword(s):  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Ultrasound Examination ◽  
Transvaginal Ultrasound ◽  
Intraclass Correlation ◽  
Cervical Length ◽  
Linear Mixed Effect Model ◽  
Mixed Effect ◽  
Time Points ◽  
Significant Difference

Objective To quantify the degree of change in cervical length (CL) over a 3-minute transvaginal ultrasound. Study Design We conducted a prospective observational study of nulliparous patients who underwent routine transvaginal CL screening at the time of their second-trimester ultrasound. We recorded CL at four time points (0, 1, 2, 3 minutes) and compared these values to determine the minute-to-minute change within a single patient. Results A total of 771 patients were included. The mean gestational age was 20.8 weeks (±0.84). We used a linear mixed effect model to assess if each minute during the ultrasound is associated with a change in CL. The intraclass correlation coefficient between minute 0 to minute 3 was 0.82 (95% confidence interval: 0.80, 0.84). This indicates that there is a relatively high within-patient correlation in CL during their ultrasound. Additionally, we stratified patients based on their starting CL; the intraclass correlation coefficient remained high for all groups. We additionally compared CL at each minute. Although there is a statistically significant difference between several time points, the actual difference is small and not clinically meaningful. Conclusion The variation in CL over a 3-minute transvaginal ultrasound examination is not clinically significant. It may be reasonable to conduct this examination over a shorter period.

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