Development of a new 360-degree surface topography application

BackgroundSurface-topography has been used for almost two decades in the radiation-free clinical evaluation of spinal posture. So far, it was limited to the analysis of back surface and spine. In order to better understand, diagnose and treat complex spinal pathologies, it is important to measure the whole torso.Research questionPurpose of this study was to introduce and test an application that allows 360° reconstruction and analysis of the patient’s torso.MethodsThe application uses the information gathered from eight distinct scans and angles. For validation we used an Alderson phantom as an anthropomorphic body. Defined areas and volumes were measured by CT and surface-topography. Inter- and intra-rater reliability was tested in 35 healthy subjects by two observers.ResultsThe results revealed good correspondence between systems in the imaging and evaluation of the Alderson model (5.3–0.5%). Inter- (0.9–0.98) and intra-rater reliability (0.8–0.95) testing revealed good and excellent results in the detection of almost all body surface structures and measurement of areas and volumes. Only area and volume measurements using jugular notch as a reference showed partly moderate results in reliability (0.62–0.93) testing.SignificanceWe were able to introduce a novel 360° torso scan application using surface topography to reconstruct torso measurements. The results of our study showed its high validity and reliability. In the future, this application needs to be tested in patients with spinal pathologies. In summary, this new application may help to better understand, diagnose and treat patients with pathologies of torso and spine.     

The TiltMeter app is a novel and accurate measurement tool for the weight bearing lunge test

ObjectivesThe weight bearing lunge test is increasing being used by health care clinicians who treat lower limb and foot pathology. This measure is commonly established accurately and reliably with the use of expensive equipment. This study aims to compare the digital inclinometer with a free app, TiltMeter on an Apple iPhone.DesignThis was an intra-rater and inter-rater reliability study. Two raters (novice and experienced) conducted the measurements in both a bent knee and straight leg position to determine the intra-rater and inter-rater reliability. Concurrent validity was also established.MethodsAllied health practitioners were recruited as participants from the workplace. A preconditioning stretch was conducted and the ankle range of motion was established with the weight bearing lunge test position with firstly the leg straight and secondly with the knee bent. The measurement device and each participant were randomised during measurement.ResultsThe intra-rater reliability and inter-rater reliability for the devices and in both positions were all over ICC 0.8 except for one intra-rater measure (Digital inclinometer, novice, ICC 0.65). The inter-rater reliability between the digital inclinometer and the tilmeter was near perfect, ICC 0.96 (CI: 0.898–0.983); Concurrent validity ICC between the two devices was 0.83 (CI: ?0.740 to 0.445).ConclusionsThe use of the Tiltmeter app on the iPhone is a reliable and inexpensive tool to measure the available ankle range of motion. Health practitioners should use caution in applying these findings to other smart phone equipment if surface areas are not comparable.     

Extraction of gait parameters from marker-free video recordings of Timed Up-and-Go tests: Validity,inter- and intra-rater reliability

BackgroundWe study dual-task performance with marker-free video recordings of Timed Up-and-Go tests (TUG) and TUG combined with a cognitive/verbal task (TUG dual-task, TUGdt).Research questionCan gait parameters be accurately estimated from video-recorded TUG tests by a new semi-automatic method aided by a technique for human 2D pose estimation based on deep learning?MethodsThirty persons aged 60−85 years participated in the study, conducted in a laboratory environment. Data were collected by two synchronous video-cameras and a marker-based optoelectronic motion capture system as gold standard, to evaluate the gait parameters step length (SL), step width (SW), step duration (SD), single-stance duration (SSD) and double-stance duration (DSD). For reliability evaluations, data processing aided by a deep neural network model, involved three raters who conducted three repetitions of identifying anatomical keypoints in recordings of one randomly selected step from each of the participants. Validity was analysed using 95 % confidence intervals (CI) and p-values for method differences and Bland-Altman plots with limits of agreement. Inter- and intra-rater reliability were calculated as intraclass correlation coefficients (ICC) and standard errors of measurement. Smallest detectable change was calculated for inter-rater reliability.ResultsMean ddifferences between video and the motion capture system data for SW, DSD, and SSD were significant (p < 0.001). However, mean differences for all parameters were small (-6.4%–13.0% of motion capture system) indicating good validity. Concerning reliability, almost all 95 % CI of the ICC estimates exceeded 0.90, indicating excellent reliability. Only inter-rater reliability for SW (95 % CI = 0.892;0.973) and one rater’s intra-rater reliability for SSD (95 % CI = 0.793;0.951) were lower, but still showed good to excellent reliability.SignificanceThe presented method for extraction of gait parameters from video appears suitable for valid and reliable quantification of gait. This opens up for analyses that may contribute to the knowledge of cognitive-motor interference in dual-task testing.     

Characterization of normative angular joint kinematics during two functional upper limb tasks

BackgroundOptical motion capture is a powerful tool for assessing upper body kinematics, including compensatory movements, in different populations. However, the lack of a standardized protocol with clear functional relevance hinders its clinical acceptance.Research questionThe objective of this study was to use motion capture to: (1) characterize angular joint kinematics in a normative population performing two complex, yet standardized upper limb tasks with clear functional relevance; and (2) assess the protocol’s intra-rater reliability.MethodsTwenty non-disabled adults performed the previously developed Pasta Box Task and Cup Transfer Task. The kinematics of the upper body were captured using an optoelectronic motion capture system and rigid plates with reflective markers. Angular joint trajectories, peak angle, range of motion (RoM), and peak angular velocity were extracted for the trunk, shoulder, elbow, forearm, and wrist. Intra-class correlation was used to assess the intra-rater reliability of the kinematic measures.ResultsBoth tasks required minimal trunk motion. Cross-body movements required greater RoM at the trunk, shoulder, and elbow joints compared to movements in front of the body. Reaches to objects further away from the body required greater trunk and elbow joint RoM compared to reaches to objects closer to the body. Transporting the box of pasta required the wrist to maintain an extended position. The two different grasp patterns in the Cup Transfer Task forced the wrist into a flexed and ulnar-deviated position for the near cup, and an extended and radial-deviated position for the far cup. For both tasks, the majority of measures displayed intra-class correlation values above 0.75, indicating good reliability.SignificanceOur protocol and functional tasks elicit a degree of movement sensitivity that is not available in current clinical assessments. Our study also provides a comprehensive dataset that can serve as a normative benchmark for quantifying movement compensations following impairment.     

Radiography and photogrammetry-based methods of assessing cervical spine posture in the sagittal plane: A systematic review with meta-analysis

BackgroundThere are numerous radiography and photogrammetry-based methods of assessing the cervical spine posture in the sagittal plane. The choice of instrument should be based on scientific parameters such as validity and reliability, thus avoiding restrictions to the applicability of the instrument.Research questionWhat radiography and photogrammetry-based methods used to assess the cervical spine posture in the sagittal plane are valid and/or reliable?MethodsSystematic searches were conducted following Meta-analysis of Observational Studies in Epidemiology guidelines. Methodological quality was assessed according to the Brink & Louw appraisal tool.ResultsTwenty-one studies were included in the qualitative analysis. Twenty different methods of calculating cervical spine posture in the sagittal plane were found. Two studies included validation measures, 16 studies assessed inter-rater reliability, and 17 studies assessed intra-rater reliability. Fourteen studies were included for the quantitative analysis. The meta-analysis shows that the cervical arrow and cervical lordosis photogrammetry-based methods present very high intra-rater reliability. In radiography, the meta-analysis also showed that the Cobb method (inferior C2 - inferior C7), Cobb method (middle C1 - inferior C7), absolute rotation angle, and Gore angle (C2-C7) present very high inter-rater reliability, and the Cobb method (inferior C2 - inferior C7) and absolute rotation angle present very high intra-rater reliability.SignificanceThis systematic review presents an overview of the methods used to assess cervical spine posture and the respective information on validity and reliability. This panorama facilitates the choice of method when conducting radiography or photogrammetry-based assessment of the cervical spine in the sagittal plane. In addition, it shows the need for new studies that investigate the accuracy and precision of these methods for their possible use in larger studies.     

Validity and reliability of an iPad with a three-dimensional camera for posture imaging

BackgroundIt is important to quantify a static posture to evaluate the need for and effectiveness of interventions such as physical management, physiotherapy, spinal orthosis or surgical treatment on the alignment of body segments. Motion analysis systems can be used for this purpose, but they are expensive, require a high degree of technical experience and are not easily accessible. A simpler method is needed to quantify static posture. Research objective: Assess validity and inter and intra rater reliability using an iPad with a 3-D camera to evaluate posture and postural deformity.MethodA 3-D model of a lying posture, created using an iPad with a 3-D camera, was compared to a Qualisys motion analysis system of the same lying posture, the latter used as the gold standard. Markers on the trunk and the leg were captured by both systems, and results from distance and angle measurements were compared.ResultsAll intra-class correlation coefficient values were above 0.98, the highest systematic error was 4.3 mm for length measurements and 0.2° for angle measurements. Significance: A 3-D model of a person, with markers on anatomical landmarks, created with an iPad with a 3-D camera, is a valid and reliable method of quantifying static posture.ConclusionAn iPad with a 3-D camera is a relatively inexpensive, valid and reliable method to quantify static posture in a clinical environment.     

Verification of reliability and validity of motion analysis systems during bilateral squat using human pose tracking algorithm

BackgroundThe human tracking algorithm called OpenPose can detect joint points and calculate joint angles. However, the reliability and validity of OpenPose have not been clarified yet.Research question: Are there the enough reliability and validity of OpenPose based motion analysis?Methods20 healthy young subjects participated in this study. The motion task was a bilateral squat. The joint angles of the trunk, hip, knee, and ankle were calculated using OpenPose and VICON. Kinematic measurements by three-dimensional motion analysis devices were recorded using VICON. Simultaneously, the images were taken with a digital camera from the right side. After the images were processed with OpenPose, joint angles were calculated from estimated joint points. To confirm the test-retest reliability within device, intraclass correlation coefficients [ICC (1, 3)] were calculated. To confirm the validity, linear regression analysis and ICC (2, 1) between the data obtained by OpenPose and VICON were calculated. Furthermore, the agreement between the data obtained by OpenPose and VICON was assessed by Bland-Altman analysis.ResultsICCs (1, 3) of the data obtained by OpenPose and VICON were almost perfect. There were significant associations between the data obtained by OpenPose and VICON. ICCs (2, 1) between the data obtained by OpenPose and VICON were almost perfect or substantial for trunk, knee and ankle joints, and fair on the hip joint. There were fixed biases on knee and ankle joints, and proportional biases on trunk and hip joint.SignificanceOpenPose based motion analysis is reliable and has the advantage of being low cost and easier to operate than conventional methods. In future, to consider the clinical utility of OpenPose, it is necessary to identify the error between the true values indicating actual joint movement and data obtained by OpenPose with its correction for fixed and proportional biases.(295 words)     

Intra-rater and inter-rater reliability,minimal detectable change,and construct validity of the Edinburgh Visual Gait Score in children with cerebral palsy

BackgroundThe Edinburgh Visual Gait Score (EVGS) has been used for observational gait assessment in children with cerebral palsy (CP). However, the measurement error of the EVGS and its detailed relationship with gross motor function remain unclear.Research questionsThis study aimed to confirm the intra-rater and inter-rater reliability as well as the minimal detectable change (MDC) values for the EVGS with the use of the video analysis software and examine the relationship between the EVGS and the Gross Motor Function Measure 66 (GMFM-66) with regard to construct validity.MethodsThis cross-sectional study was conducted for 62 children (mean age 11.3 ± 3.9 years) with spastic CP at Gross Motor Function Classification System (GMFCS) level I (32 children), II (25 children) or III (5 children). Three raters independently scored the EVGS using Kinovea video analysis software. The intra-rater and inter-rater reliability were calculated using intra-class correlation coefficients (ICC_2,1), and the MDC₉₀ was calculated using standard error of measurement. The construct validity was examined by correlating the EVGS with the GMFM-66.ResultsThe EVGS showed good or excellent reliability within each rater (ICC_2,1 = 0.90–0.97) and between raters (ICC_2,1 = 0.91). The MDC₉₀ of the EVGS ranged from 3.6 to 6.0. There was a significant correlation between the EVGS and the GMFM-66 (r = − 0.69 to − 0.73, p < 0.001).SignificanceThe intra-rater and inter-rater reliability of the EVGS is sufficient for observational gait assessment. The high correlation between the EVGS and the GMFM-66 supports its construct validity. The authors propose an MDC of 6.0 for the EVGS. These results can help in the application of EVGS to children with CP at GMFCS level I-II with mild to moderate gait pathology, as there were few children with CP at GMFCS level III.     

Is it safe for extended-role radiographers to measure migration percentage in children with cerebral palsy?

IntroductionIn the surveillance of children with cerebral palsy, the measurement of migration percentage is used to identify children at risk of hip dislocation. Early identification of children at risk facilitates early intervention with less invasive surgical procedures to prevent further deterioration.The aim of this study is to evaluate the safety of the measurements of migration percentage for surveillance in cerebral palsy by extended-role radiographers by evaluating the reliability and validity of measurements performed by these professionals.MethodsA sample of thirty pelvic x-rays were selected from the local cerebral palsy database. A range of hip displacement was selected including some challenging borderline x-rays. All ten extended-role radiographers completed measurements using TraumaCAD which were repeated at a minimum of 4 weeks.Inter-rater and intra-rater reliability was calculated using intraclass correlation coefficients. The accuracy and safety of the system was evaluated by converting measurements into referral categories (red, amber or green) and cohen's kappa was calculated when categories were compared to measurements to orthopaedic surgeonResultsThe inter-rater reliability between radiographers was 0.938 (95% CI 0.914–0.991). The intra-rater reliability was 0.941 (95% CI 0.931–0.949).The percentage agreement was 94.8% for green, 93.8% for amber and 98.2% for red hips. The weighted kappa value was 0.923 (95% CI 0.889–0.957).ConclusionThe reliability and accuracy of radiographer measurement of migration percentage is excellent. It is safe for radiographers to calculate the migration percentage using semi-automated software for the surveillance of children with cerebral palsy.Implications for practiceWe recommend the measurement of migration percentage may be performed by extended-role radiographers to deliver accurate and reliable measurements for use in cerebral palsy surveillance.     

Functional movement screen test: A reliable screening test for young elite ice hockey players

ObjectivesTo determine inter-rater and intra-rater reliability of the Functional Movement Screen (FMS) test among young elite hockey players.DesignReliability study.SettingInter-rater reliability was evaluated by two raters in the field. All performances were videotaped. Two other raters evaluated the videos once and then again 6 weeks later to determine intra-rater reliability. A weighted kappa statistic was used to analyze intra-rater and inter-rater reliability of each FMS sub-test, while an intra-class correlation coefficient (ICC) was calculated for the total score.ParticipantsTwenty-eight male hockey players aged 13–16.Main OutcomeFMS total and sub-tests scores.ResultsThe video raters demonstrated excellent intra-rater reliability for the total score, with an ICC of 0.96 (95% CI; 0.92–0.98) and 0.96 (95% CI; 0.91–0.98). The field raters achieved excellent inter-rater reliability for the total score, with an ICC of 0.96 (95% CI; 0.92–0.98). Sub-test analysis showed good agreement among all four raters for five of the seven main sub-tests.ConclusionFMS is a reliable test for young elite hockey players. Further research should be done to assess the predictive validity of the FMS test within this population so that physiotherapists may eventually use it as an injury prevention tool.     

Intra-rater reliability,inter-rater reliability and minimal detectable change of the posterior shoulder endurance test in elite athletes

ObjectiveInvestigate intra-rater and inter-rater reliability of the posterior shoulder endurance test (PSET) and calculate minimal detectable change (MDC) to establish measurement properties and inform use of the PSET in practice.Study designTest-retest reliability. Setting: British Canoe Slalom National Training Centre.ParticipantsTwelve participants (7 male, 5 female; 22.5 ± 4.48 years; 73.4 ± 6.36 kg) were investigated by two physiotherapists with >10 years’ experience.Main outcome measureIntraclass correlation coefficients (ICC) were calculated for intra-rater reliability (ICC 3,1) and inter-rater reliability (ICC 2,1) and used to calculate MDC.ResultsIntra-rater reliability scores were 0.84 and 0.85 for rater A and B, respectively, with 95% confidence interval (CI) crossing moderate to excellent reliability for both raters (0.5–0.75 and > 0.9). Inter-rater reliability scores were 0.74 and 0.63 at baseline and follow-up, respectively, with 95% CI crossing poor to good reliability in both time points (<0.5 and >0.75). MDC95% for intra-rater scores was 6 repetitions, MDC95% for inter-rater scores was 8 repetitions at baseline and 9 repetitions at follow-up.ConclusionThe PSET has acceptable intra-rater reliability but further work is needed to narrow the CI to an appropriate level for inter-rater reliability. The MDC calculated helps clinicians interpret changes in tests scores.     

Excellent reliability of toe strength measurements in children aged ten to twelve years achieved with a novel fixed dynamometer

BackgroundStronger toe flexor muscles improve performance outcomes in children, including balance, sprinting, jumping and side stepping. Toe flexor strength (TFS) is recommended as part of the clinical assessment of foot function in children. Fixed dynamometry, rather than handheld, is the gold standard of measurement; however, it can be prohibitively costly. No fixed dynamometer reliability studies on toe flexion have been conducted in children to date.Research questionsDoes the novel fixed hand-held dynamometer (HHD) protocol provide reliable intra-rater and test-retest measurements of toe flexor strength in children aged 10 to 12?MethodsTwo trials were recorded from 14 healthy children (10–12 years), 7–14 days apart by the same rater. A Lafayette HHD (model 01163) measured peak force. The HHD was secured in a mobile custom mould below a step with a strap, which secured the foot of the participant. The receptor pads of the HHD were level with the upper surface of the step, maintaining neutral toe joints at rest. The participant was seated on an adjustable stool to ensure the hip, knee and ankle were each at 90° flexion, with the testing foot flat on the upper surface of the step. The averages of three maximal five second efforts were used for data analysis using a two-way mixed effects model with repeated measures ANOVA (intraclass correlation coefficient ICC 3,3). Standard error of measurement (SEM) was calculated to determine the absolute between trial variability.ResultsThe novel fixed HHD protocol provided excellent test-retest reliability with small measurement error for hallux (ICC 3,3 = 0.93, 95 % CI 0.78−0.98, SEM = 4.31 N) and lesser toe flexor strength testing (ICC 3,3 = 0.96, 95 % CI 0.87−0.99, SEM = 1.86 N).SignificanceThe fixed HHD protocol described in this study has excellent reliability for the test-retest evaluation of children’s toe flexor strength.     

Is markerless,smart phone recorded two-dimensional video a clinically useful measure of relevant lower limb kinematics in runners with patellofemoral pain? A validity and reliability study

ObjectivesInvestigate the validity and reliability of markerless, smart phone collected, two-dimensional (2D) video, analysed using the ‘Hudl technique’ application, compared to three-dimensional (3D) kinematics during running, in participants with patellofemoral pain (PFP).DesignValidity/reliability study.SettingBiomechanics laboratory.ParticipantsMales/females with PFP (n = 21, 10 males, 11 females, age 32.1 months [±12.9]).Main outcome measuresManually synchronised 2D and 3D measurement of peak hip adduction (HADD) and peak knee flexion (KFLEX) during running.Results2D and 3D measures of peak KFLEX (p = 0.02, d = 1.13), but not peak HADD (p = 0.25, d = −0.27), differed significantly. Poor validity was identified for 2D measurement of peak HADD (ICC 0.06, 95% CI -0.35, 0.47) and peak KFLEX ICC 0.42, 95% CI (−0.10, 0.75). Moderate intra-rater reliability was identified for both variables (ICC 0.61–65), alongside moderate inter-rater reliability for peak KFLEX (ICC 0.71) and poor inter-rater reliability for peak HADD (ICC 0.31).ConclusionsMeasurement of peak HADD and KFLEX in runners with PFP using markerless, smart phone collected 2D video, analysed using the Hudl technique Application is invalid, with poor to moderate reliability. Investigation of alternate 2D video approaches to increase precision is warranted. At present, 2D video analysis of running using Hudl Technique cannot be advocated.     

Reliability and validity of a return to sports testing battery for the shoulder

ObjectiveTo determine the validity, intra- and inter-rater, and absolute reliability of a return to sport testing battery for the shoulder in a healthy cohort.DesignCross-sectional design. All participants completed a battery of strength (isokinetic, isometric, and repetition to failure) and functional assessments on two occasions. Concurrent validity to isokinetic testing was assessed, and intra-rater, inter-rater, and absolute reliability were established for all assessments.SettingControlled clinical environment.ParticipantsThirty healthy adults active in recreational sports participated, mean age 24.0 ± 1.6 years;Main outcome measuresCorrelations (Pearson’s r), reliability (Intraclass Correlation Coefficient), Standard error of the measurement, Minimal detectable change.ResultsCorrelations to isokinetic assessments at 60° & 180°/second were moderate to strong for isometric (r: 0.68–0.80) and functional testing (r: 0.55–0.83) and weak for repetition to failure testing (r: 0.37–0.74). All isokinetic (ICC: 0.88–0.94), isometric (ICC: 0.83–0.94), and functional assessments (ICC: 0.80–0.92) had good to excellent intra-rater reliability, while repetition to failure testing had poor to moderate reliability (ICC: 0.48–0.57). The inter-rater reliability of the isometric assessments was moderate to excellent (ICC: 0.71–0.92) across movements. Expressed as a percentage of the mean, the standard error of the measurement ranged from 7% to 25% and the minimal detectable change ranged from 20% to 69% across all assessment methods.ConclusionThe isokinetic, isometric, and functional assessments used in this return to sports testing battery demonstrates acceptable validity and reliability. Further refinement to the methods used to assess muscular endurance is needed to improve reliability. This study offers clinicians information that can be utilized in clinical decision-making as it relates the testing battery’s psychometric properties.     

Intra- and interrater reliability of the ‘lumbar-locked thoracic rotation test’ in competitive swimmers ages 10 through 18 years

ObjectivesMeasuring thoracic spine mobility can be of interest to competitive swimmers as it has been associated with shoulder girdle function and scapular position in subjects with and without shoulder pain. At present, no reliability data of thoracic spine mobility measurements are available in the swimming population. This study aims to evaluate the within-session intra- and interrater reliability of the “lumbar-locked rotation test” for thoracic spine rotation in competitive swimmers aged 10 to 18 years. This reliability study is part of a larger prospective cohort study investigating potential risk factors for the development of shoulder pain in competitive swimmers.DesignWithin-session, intra- and inter-rater reliability.SettingCompetitive swimming clubs in Belgium.Participants21 competitive swimmers.Main outcome measuresIntra- and inter-rater reliability of the lumbar-locked thoracic rotation test.ResultsIntraclass correlation coefficients (ICCs) ranged from 0.91 (95% CI 0.78 to 0.96) to 0.96 (0.89–0.98) for intra-rater reliability. Results for inter-rater reliability ranged from 0.89 (0.72–0.95) to 0.86 (0.65–0.94) respectively for right and left thoracic rotation.ConclusionResults suggest good to excellent reliability of the lumbar-locked thoracic rotation test, indicating this test can be used reliably in clinical practice.     

Relationship between foot posture index and weight bearing computed tomography 3D biometrics to define foot alignment

BackgroundThe Foot Posture Index (FPI) was originally validated only against two dimensional radiographic imaging at the time of its inception since weight bearing three dimensional (3D) imaging did not exist. This technology is now widely available but it is not known if the FPI will continue to correlate well against it.Research question: How does the clinical assessment tool of FPI correlate against 3D biometrics of foot alignment assessed on weight bearing computerised tomography (WBCT)?MethodsThe FPI and 3D biometrics of 66 feet in 33 patients presenting to a single foot and ankle unit were assessed by two observers independently. All measurements were assessed for intra-rater and inter-rater reliability, and the association between the clinically assessed FPI and radiologically assessed 3D biometrics was identified.ResultsThe FPI demonstrated excellent intra-rater and good inter-rater reliability. All 3D biometric measures demonstrated excellent intra-rater and inter-rater reliability. A strong and significant correlation was identified between the FPI and 3D biometrics overall although subgroup analysis revealed the strength of association dropped when the hindfoot had a valgus alignment.SignificanceThis study confirmed that the FPI is a valid tool for assessing foot position. However, correlation between the FPI and 3D biometrics fell in the valgus aligned hindfoot so caution must be used when the FPI is used for assessment in this population.     

The evaluation of an inexpensive, 2D,video based gait assessment system for clinical use

The purpose of this study was to investigate the clinical potential of an augmented-video-based-portable-system (AVPS). The AVPS included a walkway grid mat made of vinyl flooring, flat paper bull's eye markers, four photoswitches mounted on tripods, a light-indicator, a video camera, and a computer with ProTrainer System software. The AVPS output was compared to a “gold standard” 3D Vicon Motion Analysis System both statically and dynamically over a fixed range (?90° to +90°) using a two-segment-goniometric-rig marked with both bull's eye and retroreflective markers. At each segment angle position, three trials of data were captured. The reliability of the AVPS was also tested using three raters. Further twelve, young, healthy subjects participated in a concurrent validity study in which they performed six gait trials which were simultaneously recorded by both systems. Both motion analysis systems showed low levels of intra subject variability in all kinematic variables indicated by the size of the standard deviations across the six trials. There were no significant differences between the motion systems with respect to the kinematic variables (P > 0.05). The results showed a high intra- and inter-rater reliability for both the kinematic and temporo-spatial parameters. With respect to gait events the lowest ICC value for the intra-rater reliability test was 0.993 for the kinematic variables, and ranged from 0.941 to 0.956 for the temporo-spatial variables and 0.731 to 0.954 for the tibia inclination angles. The validation data suggest the AVPS is capable of generating highly reliable and repeatable data when applied to normal subjects and could be used within the clinical setting.     

Image quality of bedside chest radiographs in intensive care beds with integrated detector tray: A phantom study

IntroductionVendors offer intensive care beds with integrated detector trays for bedside radiography, promoting better ergonomics and patient comfort. However, no documentation of the effects on diagnostic image quality has been located. This study examines measured and subjective image quality of supine bedside chest radiographs with and without use of such a detector tray.MethodsA contrast-detail phantom (CDRAD 2.0) was exposed using standard supine chest exposure parameters. Plexiglass plates of 16 and 21 cm were placed in front to simulate patient attenuation for standard and adipose patients. Exposures were repeated with the detector placed in tray and directly in bed. Images were analysed using dedicated software giving a figure-of-merit IQFinv. Results were compared using ANOVA. Then an anthropomorphic chest phantom (Lungman) was exposed using the same parameters, and the same placements of the detector. Exposures were done with and without extra conformal tissue to simulate varying patient sizes, and with and without added typical intensive care equipment. Images were analysed by two radiologists using a three-point scale, on five image quality criteria. Radiologist also stated whether the images were sufficient for diagnosis. Results were compared using Visual Grading Characteristics, using dedicated software, resulting in Areas Under the Curve (AUC-VGC) for each combination and criteria. Inter- and intra-rater reliability were assessed with kappa statistics. Composite Visual Grading Analysis (VGAS) scores were calculated for each image. Both IQFinv and were normalized and compared.ResultsFor all criteria both IQFinv and AUC-VGC was significantly better when exposing the detector directly in bed, than with the detector placed in the tray across all exposures. When stratified into thin and adipose patients, IQFinv decreased significantly for thin patients, while VGAS-scores did not. For adipose patients, both figures were significantly lower with the detector in the tray.ConclusionUse of detector tray for bedside chest imaging decreases image quality.Implications for practiceRadiographers should critically evaluate image quality and experimentally determine optimal exposure factors, when taking equipment with integrated trays into use.     

单纯CT伪影对放疗剂量计算的影响

目的 通过人为制造CT伪影,来研究实际临床操作中单纯伪影对放疗剂量计算的影响。方法 对替换钛合金组件前后的模体进行CT扫描,统计替换前后不同位置的CT值;将钛合金区域的CT值修正为水模体的CT值,并采用Varian的各向异性分析算法（AAA）、Acuros XB （AXB）算法和Pinnacle系统的筒串卷积算法（CCC）3种算法,对替换钛合金组件前后的模体进行剂量计算,统计替换前后不同位置的绝对剂量值,并进行分析。结果 Varian和Pinnacle系统对评价CT值大小比较一致。对于均匀模体,CT值偏差30 HU以下时,3种不同的算法在距离体表0.5 cm时,剂量偏差最大达到12.0%,最小为6.0%;1.5 cm以上偏差的绝对值均<1.0%。对于肺部模体来说,Varian的AAA算法和AXB算法在CT值相差15 HU的情况下,剂量值相差在1.0%左右;但Pinnacle系统的CCC算法在同样情况下剂量值相差较大,相差5.0%左右。结论 CT伪影对放疗剂量计算存在明显影响,导致组织剂量分布发生变化,可能造成浅部肿瘤照射剂量不足,深部肿瘤过量照射。     

Sensitivity and reproducibility of a new fast 3D segmentation technique for clinical MR-based brain volumetry in multiple sclerosis

Fast, reliable and easy-to-use methods to quantify brain atrophy are of increasing importance in clinical studies on neuro-degenerative diseases. Here, ILAB 4, a new volumetry software that uses a fast semi-automated 3D segmentation of thin-slice T1-weighted 3D MR images based on a modified watershed transform and an automatic histogram analysis was evaluated. It provides the cerebral volumes: whole brain, white matter, gray matter and intracranial cavity. Inter- and intra-rater reliability and scan-rescan reproducibility were excellent in measuring whole brain volumes (coefficients of variation below 0.5%) of volunteers and patients. However, gray and white matter volumes were more susceptible to image quality. High accuracy of the absolute volume results (+/-5 ml) were shown by phantom and preparation measurements. Analysis times were 6 min for processing of 128 slices. The proposed technique is reliable and highly suitable for quantitative studies of brain atrophy, e.g., in multiple sclerosis.