3-dimensional Measurement Research Articles

The Impact of Multimorbidity Burden, Frailty Risk Scoring, and 3-Directional Morphological Indices vs. Testing for CSF Responsiveness in Normal Pressure Hydrocephalus.

Objective: Multimorbidity burden across disease cohorts and variations in clinico-radiographic presentations within normal pressure hydrocephalus (NPH) confound its diagnosis, and the assessment of its amenability to interventions. We hypothesized that novel imaging techniques such as 3-directional linear morphological indices could help in distinguishing between hydrocephalus vs. non-hydrocephalus and correlate with responsiveness to external lumbar drainage (CSF responsiveness) within NPH subtypes.Methodology: Twenty-one participants with NPH were recruited and age-matched to 21 patients with Alzheimer’s Disease (AD) and 21 healthy controls (HC) selected from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database. Patients with NPH underwent testing via the NPH programme with external lumbar drainage (ELD); pre- and post-ELD MRI scans were obtained. The modified Frailty Index (mFI-11) was used to stratify the NPH cohort, including Classic and Complex subtypes, by their comorbidity and frailty risks. The quantitative imaging network tool 3D Slicer was used to derive traditional 2-dimensional (2d) linear measures; Evans Index (EI), Bicaudate Index (BCI) and Callosal Angle (CA), along with novel 3-directional (3d) linear measures; z-Evans Index and Brain per Ventricle Ratio (BVR). 3-Dimensional (3D) ventricular volumetry was performed as an independent correlate of ventriculomegaly to CSF responsiveness.Results: Mean age for study participants was 71.14 ± 6.3 years (18, 85.7% males). The majority (15/21, 71.4%) of participants with NPH comprised the Complex subtype (overlay from vascular risk burden and AD); 12/21 (57.1%) were Non-Responders to ELD. Frailty alone was insufficient in distinguishing between NPH subtypes. By contrast, 3d linear measures distinguished NPH from both AD and HC cohorts, but also correlated to CSF responsiveness. The z-Evans Index was the most sensitive volumetric measure of CSF responsiveness (p = 0.012). Changes in 3d morphological indices across timepoints distinguished between Responders vs. Non-Responders to lumbar testing. There was a significant reduction of indices, only in Non-Responders and across multiple measures (z-Evans Index; p = 0.001, BVR at PC; p = 0.024). This was due to a significant decrease in ventricular measurement (p = 0.005) that correlated to independent 3D volumetry (p = 0.008).Conclusion. In the context of multimorbidity burden, frailty risks and overlay from neurodegenerative disease, 3d morphological indices demonstrated utility in distinguishing hydrocephalus vs. non-hydrocephalus and degree of CSF responsiveness. Further work may support the characterization of patients with Complex NPH who would best benefit from the risks of interventions.

Abstract 14452: Echocardiographic Evaluation of Donor Cardiac Structure and Function Following Reanimation Using Normothermic Regional Perfusion in Donation After Circulatory Death

Introduction: As heart transplantation from donation after circulatory death (DCD) continues to increase, preliminary results suggest outcomes comparable to donation after brain death. It is unknown if the obligatory period of warm ischemia experienced during DCD withdrawal process causes immediate changes in cardiac allograft function. Methods: We retrospectively reviewed and compared pre-donation with post reanimation echocardiographic findings in all DCD donors at our institution from Jan to March 2021. All DCD donor organs were reanimated with in-situ thoracoabdominal normothermic regional perfusion (NRP) after circulatory death. Echocardiographic assessment included: a) 2-dimensional and speckle-tracking measures of chamber size and function; b) ejection fraction (EF); c) fractional area change (FAC); and d) global longitudinal strain (GLS). Results: Altogether 3 DCD heart donations were performed during the study period. Basic demographics and withdrawal ischemic time periods are depicted in Table 1. There were no changes in LV EF and RV FAC when comparing the pre-donation and the post-reanimation echocardiogram. There was a minimal decrease in LV GLS and RV free-wall systolic strain in 2 of the 3 donors following reanimation (Table 2). Conclusions: DCD cardiac allografts reanimated with NRP demonstrated no change in echocardiographic parameters used for a standard donor heart evaluation and were successfully transplanted. Findings suggest donor cardiac function is not clinically different from the pre-donation in DCD hearts reanimated after a relatively short functional ischemic time and without need for inotropic support.

Non-Persistence with Medication as a Mediator for the Social Inequality in Risk of Major Adverse Cardiovascular Events in Patients with Incident Acute Coronary Syndrome: A Nationwide Cohort Study.

AimLow socioeconomic status is associated with higher risk of major adverse cardiovascular events (MACE) among patients with incident acute coronary syndrome (ACS). We examined whether non-persistence with antiplatelet and statin therapy mediated the income- and educational-related inequality in risk of MACE.MethodsUsing national registers, all Danish patients diagnosed with incident ACS from 2010 to 2017 were identified. The primary outcome (MACE) comprised all-cause death, cardiac death and cardiac readmission. Risk of MACE was handled by discrete time analyses using inverse probability of treatment weights. The mediator variable comprised non-persistence to a combined 2-dimensional measure of statin and antiplatelet treatment. The mediation analysis was evaluated by population average effects.ResultsThe study population was 45,874 patients, of whom 16,958 (37.0%) were non-persistent with medication and 16,365 (35.7%) suffered MACE during the median follow-up of 3.5 years. Compared to patients with low income, the adjusted hazard ratio of MACE was lowered by 33% (HR: 0.67, 95% CI: 0.61–0.72) in men and by 34% (HR: 0.66, 95% CI: 0.61–0.72) in women with high income, respectively. Similar results were observed according to level of education. A socioeconomic difference in risk of non-persistence was found in men but not women and only in relation to income. The lower risk of non-persistence observed in high-income men mediated the lower risk of MACE by 12.6% (95% CI: 11.1–14.1%) compared with low-income men.ConclusionNon-persistence with medication mediated some of the income-related inequality in risk of MACE in men, but not women, with incident ACS.

High Tibial Osteotomy With Miniaci Planning Using Manual and Semiautomated Digital Measures

Background:Inadequate deformity analysis and planning before high tibial osteotomy (HTO) may result in correction errors with unsatisfactory clinical results.Indications:The purpose of this article is to describe the deformity analysis and preoperative planning before HTO. This surgery is effective for young patients with compartmental mild knee osteoarthritis. A partial deformity analysis without considering the femoral or intra-articular deformity may lead to overcorrection or excessive joint line obliquity. Preoperative planning using the Miniaci method with manual or semiautomated digital measures may help to prevent these types of errors.Technique Description:Landmarks are used at the proximal femoral side, distal condyles, proximal tibial plateau, and talus borders to define angles automatically on PeekMed software. Fujisawa point is determined to be 50% of the length of the proximal tibia, and Miniaci method is performed after defining the weightbearing line. The method can be performed manually or semiautomatically with the software. In this last case, the optimal procedure to be done to correct the malalignment is proposed by the software which automatically does the opening of the osteotomy to match the desired weightbearing axis and displays the size of the wedge in millimeters.Results:The intraobserver and interobserver reproducibility were performed by 2 different analyses and 2 different observers. The precision of the measures was confirmed based on computed tomographic (CT) scan 3-dimensional measures defined as the gold standard. All the intraobserver and interobserver reproducibility correlation coefficients and precision were satisfactory compared with the gold standard. Hip-knee-ankle angle may vary because of weightbearing situations between CT and long-axis x-rays.Discussion/Conclusion:The interest of semiautomated software for angular value measurements is now well recognized, and the inclusion of anatomical landmarks allows accurate and reproducible angular value measurements. Automatic knee osteotomy planning analyzes the metaphyseal deformity of both the tibia and the femur, and the software suggests the optimal procedure with the degree of openness to obtain the desired mechanical axis without creating excessive joint line obliquity

294 Evaluation of radiographic response in the intact renal mass (intact-Rmass) to immune checkpoint inhibitor (ICI) combination regimens in patients with metastatic renal cell carcinoma (mRCC)

BackgroundAs most of the patients previously enrolled in trials had nephrectomy before starting systemic treatment (syst-Rx), the response of the intact-Rmass to novel ICI and tyrosine kinase inhibitor (TKI) combination regimens is not well described.MethodsA retrospective review of 227 patients with mRCC who were treated with ICI (single agent or combinations) in the 1st- or 2nd-line was conducted. Following the appropriate regulatory process, collaborators from 6 US sites collected clinical, pathological, and outcome data via chart review. Overall response was investigator-assessed for all patients with at least one post-treatment scan or evidence of clinical progression after treatment initiation. Overall radiographic response (ORR) represents any radiographic response in the metastatic disease per investigator’s assessment. To accurately assess response in intact-Rmass, 3-dimensional measurement of the intact-Rmass was performed and Rmass volume was calculated at baseline and at the time of best overall response for 1st- and 2nd-line therapy. Radiographic response in intact-Rmass is defined as >30% decrease in the Rmass volume.ResultsMedian age at diagnosis was 62 years, 69% were male, 82% had clear cell histology. 15% and 12% had sarcomatoid and rhabdoid features, respectively. Overall, 82 patients (36%) had a measurable intact-Rmass while receiving syst-Rx. 63 (28%) patients never had a nephrectomy, and 10 (4%) patients had delayed nephrectomy after a good overall response to syst-Rx. 108 (48%) received ICI in 1st-line (88/108 received ipilimumab/nivolumab combination). 91 (40%), and 18 (8%) patients received TKI, or ICI+TKI in 1st-line. 161 (71%) and 86 (38%) of the patients received 2nd-line and 3rd-line therapy, respectively. 104 (46%) received ICI in 2nd-line (75/104 treated with single-agent ICI). 48 (21%), and 4 (2%) patients received TKI, or ICI+TKI in 2nd-line. Radiographic response in intact-Rmass for evaluable patients is summarized in table 1. The highest response rates in intact-Rmass were seen with ICI+TKI combinations. Higher rates of radiographic response in intact-Rmass were seen in patients treated with ICI in 1st-line compared to 2nd-line, possibly related to higher usage of ICI combinations (ipilimumab/nivolumab) in 1st-line. Overall metastatic disease response to different regimens in the 1st-line or 2nd-line was not different based on the history of nephrectomy prior to syst-Rx (table 2).Abstract 294 Table 1Radiographic response (≥30% decrease in volume) in the intact renal massAbstract 294 Table 2Overall radiographic response (ORR) per investigator assessmentConclusionsHigher radiographic response rates in the intact-Rmass were seen in patients treated with ICI+TKI and ICI in the 1st-line. There was no significant difference in overall metastatic disease response to 1st- or 2nd-line treatment based on the history of nephrectomy prior to syst-Rx.Ethics ApprovalEach of the 6 participating centers had their IRB approved protocol for retrospective study and data collection. Data Use Agreements were obtained for each center to share limited data set data with University of Wisconsin - Madison (IRB protocol UW17148 # 2018–0213). Final analysis was performed at University of Wisconsin.Consent not applicable to retrospective studies.

Nomograms of fetal cardiothoracic ratio from 17 to 37weeks' gestation as assessed by three different measurement techniques and their correlation with gestational age.

To create nomograms for fetal cardiothoracic (CT) ratio as assessed by three different 2-dimensional sonographic measurements, including CT diameter, circumference, and area ratios, in Thai fetuses with a gestational age (GA) of 17-37weeks, and to evaluate both their correlation with GA or biparietal diameter (BPD) and variability among the three measurement methods. Two-dimensional sonographic measurements of fetal CT ratio in 4-chamber view were assessed by three different measurement techniques. The 95% reference intervals and Z-scores of all measurement methods based on GA or BPD were constructed. Intraclass correlation coefficients (ICC) for the reproducibility of each technique were compared. A total of 511 uncomplicated singleton pregnancies were included. The fetal CT ratio values by all measurement techniques gradually and smoothly increased with increasing GA and BPD. The fetal CT circumference ratio showed the least correlation with both GA and BPD. The intraobserver and interobserver reliability coefficients of all techniques demonstrated almost excellent agreement (all ICCs at least 0.87). Reference intervals and Z-score reference ranges were developed using three different techniques for fetal CT ratio with a GA of 17-37weeks. These nomograms are a simple and reliable screening tool for identifying abnormal fetal heart size.

Three-dimensional comparison of mandibular morphology in young people with Treacher Collins syndrome and Pierre Robin sequence

Treacher Collins syndrome (TCS) and nonsyndromic Pierre Robin sequence (PRS) share mandibular deficiency as a similar clinical finding. This study aimed to compare the mandibular size and morphology of subjects with TCS and PRS. Group TCS was composed of 17 subjects (7 male, 10 female) with a mean age of 11.5years (standard deviation, 4.4) from a single center. Group PRS was composed of 17 subjects paired by age and sex with group TCS. Preorthodontic cone-beam computed tomography examinations of all patients were evaluated using Mimics Innovation Suite 17.0 (Materialise, Leuven, Belgium). Nine 3-dimensional measurements were performed in segmented 3D images of the mandible. Intragroup comparisons were performed using paired t tests. Intergroup comparisons were performed using analysis of variance and Tukey tests. The significance level considered was 5%. TCS showed a significant dimensional difference between less and more affected sides for ramus, condyles, and mandibular body. The mandibular dimensions in PRS were more symmetrical. Group TCS presented a smaller mandibular effective length and mandibular body length compared with PRS. The condyle width and height and the ramus width were also decreased in TCS. The gonial angle was greater in TCS compared with the PRS group. Young subjects with TCS presented a smaller, more vertical, and more asymmetrical mandible compared with nonsyndromic PRS.

Assessment of Progressive Collapsing Foot Deformity Using Semiautomated 3D Measurements Derived From Weightbearing CT Scans

In progressive collapsing foot deformity (PCFD), hind- and midfoot deformities can be hard to characterize based on weightbearing plain radiography. Semiautomated 3-dimensional (3D) measurements derived from weightbearing computed tomography (WBCT) scans may provide a more accurate deformity assessment. In the present study, automated 3D measurements based on WBCT were used to compare hindfoot alignment of healthy individuals to patients with PCFD. The WBCT scans of 20 patients treated at our institution with either a flexible (N = 10) or rigid (N = 10) PCFD were compared with the WBCT scans of a control group of 30 healthy individuals. Using semiautomated image analysis software, from each set of 3D voxel images, we measured the talar tilt (TT), hindfoot moment arm (HMA), talocalcaneal angle (TCA; axial/lateral), talonavicular coverage (TNC), and talocalcaneal overlap (TCO). The presence of medial facet subluxation as well as sinus tarsi/subfibular impingement was additionally assessed. With the exception of the TCA (axial/lateral), the analyzed measurements differed between healthy individuals and patients with PCFD. The TCA axial correlated with the TNC in patients with PCFD. An increased TCO combined with sinus tarsi impingement raised the probability of predicting a deformity as rigid. Using 3D measurements, in this relatively small cohort of patients, we identified relevant variables associated with a clinical presentation of flexible or rigid PCFD. An increased TCO combined with sinus tarsi impingement raised the probability of predicting a deformity as rigid. Such WBCT-based markers possibly can help the surgeon in decision-making regarding the appropriate surgical strategy (eg, osteotomies vs realignment arthrodesis). However, prospective studies are necessary to confirm the utility of the proposed parameters in the treatment of PCFD. Level III, case-control study.

Prognostic performance in lung cancer according to tumor size: Comparison of axial, multiplanar, and 3-dimensional CT measurement to pathological size

PurposeThis study aimed to compare the prognostic performance of clinical T staging based on axial, multiplanar, and 3-dimensional measurement on CT with that of pathological T staging in patients with non-small cell lung cancer. MethodPatients with surgically resected lung cancer without pathological node metastasis between June 2010 and December 2017 were retrospectively included. Clinical T stages were determined based on the maximal tumor size on axial, multiplanar (axial, coronal, and sagittal) images and 3-dimensional tumor mask. The prognostic performances of clinical and pathological T staging for disease-free survival (DFS) were compared using the concordance indices (C-indices). ResultsA total of 544 patients (64.7 ± 9.7 years, 352 men) were included; 160 patients (29.4%) experienced events including 29 (5.3%) who expired. The median DFS was 44.1 months. The mean tumor size on axial, multiplanar images, 3-dimensional tumor mask, and pathology was 30.8 ± 17.3, 33.9 ± 19.4, 39.2 ± 21.4, and 33.4 ± 18.0 mm, respectively. Clinical staging based on multiplanar measurement showed a higher agreement (67.5% [367/544]) with pathological staging than axial (60.5% [329/544]) and 3-dimensional measurement (50.9% [277/544]) based staging did (p = .0005 and <.0001, respectively). The adjusted C-indices of axial, multiplanar, 3-dimensional, and pathological tumor stages were 0.66 (95% confidence interval [CI]: 0.66–0.67), 0.66 (95% CI: 0.66–0.66), 0.67 (95% CI: 0.67–0.67), and 0.67 (95% CI: 0.66–0.67), respectively (p > .05). ConclusionsThe prognostic performances of tumor staging according to size measurement methods were not significantly different. Multiplanar measurement may be preferable for clinical staging considering its highest agreement with pathological staging.

Construct validity and reliability of tests for sacroiliac dysfunction: standing flexion test (STFT) and sitting flexion test (SIFT).

Sacroiliac dysfunction is characterized by a hypomobility of the range of motion of the joint, followed by a positional change regarding the relationship between the sacrum and the iliac. In general, the clinical tests that evaluate the sacroiliac joint (SIJ) and its dysfunctions lack validity and reliability values. This article aims to evaluate the construct validity and intra- and inter-rater reliability of the standing flexion test (STFT) and sitting flexion test (SIFT). In this prospective study, the sample consisted of 30 individuals of both sexes, and the evaluation team was composed of five researchers. The evaluations took place on two different days: first day, inter-rater reliability and construct validity; and second day, intra-rater reliability. The reference standard for the construct validity was 3-dimensional measurements obtained utilizing the BTS SMART-DX system. For statistical analysis, the percentage (%) agreement and the kappa statistic (K) were utilized. The construct validity was determined for STFT (70% agreement; K=0.49; p<0.01) and SIFT (56.7% agreement; K=0.29; p<0.05). The intra-rater reliability was determined for STFT (66.3% agreement; K=0.43; p<0.01) and SIFT (56.7% agreement; K=0.38; p<0.01). The inter-rater reliability was determined for STFT (10% agreement; K=-0.02; p=0.825) and SIFT (13.3% agreement; K=0.01; p=0.836). The STFT confirmed the construct validity and was reliable when applied by the same rater to healthy people, even if the rater had no experience. It was not possible to achieve minimum scores using the SIFT either for construct validity or reliability. We suggest that further studies be conducted to investigate the measurement properties of palpatory clinical tests for SIJ mobility, especially in symptomatic patients.

Development and assessment of 3-dimensional computed tomography measures of proximal humeral bone density: a comparison to established 2-dimensional measures and intraoperative findings in patients undergoing shoulder arthroplasty.

BackgroundThe purpose of this study was to develop novel three-dimensional (3D) measures of bone density from computed tomography (CT) scans and to compare them with validated two-dimensional (2D) radiographic assessments of bone density. Patient demographic data were also analyzed to see if there were any predictors of bone density (age, sex, etiology).MethodsThe study group consisted of 290 consecutive patients undergoing primary shoulder arthroplasty surgery (total anatomic, reverse, and hemiarthroplasty). All underwent preoperative CT imaging. Three 3D CT measurements (metaphysis cancellous, metaphysis cortical, and proximal diaphysis) were developed and automated into software. The developed 3D measurements were compared with validated 2D measures (Tingart and Gianotti Index). Patient demographic data were correlated with these measurements. The difference between the size of the final sounder and of the final stem was calculated as Delta.ResultsThere was moderately strong correlation between Tingart and Gianotti measures (0.674, P < .001), as well as between 3D metaphysis cancellous measurements and Tingart (0.645, P < .001). Decreased bone density was highly correlated with female sex. Tingart (area under the curve [AUC]: 0.87, 95% confidence interval [CI]: 0.82-0.91) and 3D metaphysis cancellous (AUC: 0.78, 95% CI: 0.72-0.84) had the highest correlation. These were significantly more than other measures of bone density (P < .01). Decreased bone density measured with Tingart also had moderate correlation with advanced age (AUC: 0.67, 95% CI: 0.6-0.73), but less so for etiology (AUC: 0.62, 95% CI: 0.55-0.69). The 3D metaphysis cancellous measure had lower correlation with age (AUC: 0.59, 95% CI: 0.52-0.66) and etiology (AUC: 0.59, 95% CI: 0.52-0.65). The highest correlation with Delta (the difference between the final sounder and the stem size) was with the 3D metaphysis cancellous measure (AUC: 0.67, 95% CI: 0.59-0.73), followed by Tingart (AUC: 0.647, 95% CI: 0.57-0.671). A multiple regression model to predict Delta demonstrated the stronger prediction using 3D metaphysis cancellous (analysis of variance F-ratio of 42.6, P < .001) than Tingart (35.9, P < .001).ConclusionThis study demonstrates that automated measures of bone density can be obtained from 3D CT scans. Of the three novel 3D measurements of bone density, the humeral metaphysis cancellous measurement was most correlated to the known 2D measures and most correlated to the intraoperative assessment of bone density (delta).

Accuracy and Reliability of Single-Camera Measurements of Ankle Clonus and Quadriceps Hyperreflexia

ObjectiveTo evaluate the accuracy and reliability of a simple, single-camera smartphone-based method, named the Reflex Tracker (RT) system, for measuring reflex threshold angles related to ankle clonus and quadriceps hyperreflexia. DesignA prospective comparison study using a high-fidelity reference standard was constructed employing a 2 × 2 × 2 factorial design, with factors of rater (tester) type (student and experienced physical therapist), joint (ankle and knee), and repetition (2 per condition). SettingThis multicenter study was conducted at 4 outpatient rehabilitation clinics. ParticipantsA convenience sample of 14 individuals with a neurologic condition presented with 20 lower limbs that exhibited ankle clonus and/or quadriceps hyperreflexia and were included in the study. Also participating in the study were 8 student and 8 experienced physical therapist raters (testers) (N=16). InterventionsNot applicable. Main Outcome MeasuresThe plantar flexor reflex threshold angle (PFRTA) related to ankle clonus and the quadriceps reflex threshold angle (QRTA) related to quadriceps hyperreflexia were quantified. ResultsPFRTA and QRTA results were compared between the smartphone RT method and synchronous 3-dimensional inertial measurement unit (IMU) sensor motion capture. Mean difference (bias) was minimal between RT and IMU measurements for PFRTA (bias≤0.2°) and QRTA (bias≤1.2°). Intrarater reliability for PFRTA ranged from 0.85-0.90 using RT and from 0.85-0.87 using IMU; QRTA ranged from 0.97-0.98 using RT and from 0.96-0.99 using IMU. Intersensor reliability for PFRTA and QRTA was 0.97 and 0.99, respectively. Minimum detectable change for PFRTA ranged from 7.1°- 8.7° and for QRTA ranged from 6.1°-8.3°. ConclusionsRT performed comparable to IMU for accurate and reliable measurement of PFRTA and QRTA to quantify ankle clonus and quadriceps hyperreflexia in clinical settings.

High Reliability for Semiautomated 3D Measurements Based on Weightbearing CT Scans.

A reliable assessment of the ankle using weightbearing radiography remains challenging. Semiautomated 3-dimensional (3D) measurements derived from weightbearing computed tomography (WBCT) scans may provide a more reliable approach. Thirty healthy individuals without any foot and ankle disorder were analyzed. We assessed 6 widely used ankle parameters (4 angles and 2 distances) using either semiautomated 3D (based on WBCT scans) or traditional 2-dimensional (2D; based on conventional radiographs) measurements. The reliability and discrepancy between both techniques were compared using intraclass correlation coefficients and the Bland-Altman method. Five of 6 variables showed a lower reliability when derived from 2D measurements. The mean of 3 variables differed between the techniques: the 3D technique assessed that the talonavicular coverage angle was 18.9 degrees higher, the axial talocalcaneal angle was 5.5 degrees higher, and the talocalcaneal overlap was 3.7 mm lower when compared with 2D measurements. Semiautomated 3D measurements derived from WBCT scans provide more reliable information on ankle alignment compared with 2D measurements based on weightbearing radiographs. Future studies may show to what extent these parameters could contribute to current diagnostic algorithms and treatment concepts. Not applicable.

Remote Instruction Using Dvd For Mechanical Stress Free Walking (msfw) Promotion Program In Older Adults

PURPOSE: Under the COVID-19 pandemic crisis, it is important to develop physical activity promotion program with online, remote instruction. Based on our previous research findings and experiences, we have developed the mechanical stress free walking (MFSW) program using DVD for adults, particularly with advanced joint degeneration. The purpose of this study was to examine the effectiveness of the MFSW program using DVD in older adults during the COVID-19 pandemic. METHODS: Men (n = 16) and women (n = 53) who were healthy and able to walk on their own at average walking speed about 5 km/h participated in this study. The participants (average age 75.1 ± 4.86 years old) received the MSFW DVD instruction program included an educational component stressing 4 walking tips: 1) walking with the upper body upright, 2) catching the ground softly, 3) taking the width of the left and right feet, and 4) not twisting the knee joints. Before starting and after completing the DVD instruction program, each participant completed 3-dimensional walking acceleration measurement (Safety Walk Navi: Descente Ltd, Tokyo, Japan). RESULTS: The downward and lateral acceleration were significantly decreased, from 1.654 ± 0.150 g to 1.604 ± 0.151 g** and from 0.855 ± 0.291 g to 0.804 ± 0.250 g*, respectively (** P < 0.01 *P < 0.05). There were no significant decreases in forward and upward acceleration, from 0.692 ± 0.209 g to 0.665 ± 0.208 g, and from 0.443 ± 0.125 g to 0.428 ± 0.119 g, respectively. CONCLUSIONS: Our results demonstrate that DVD remote instruction program leads to improvements in older adults’ MSFW. Our next goal is to develop the MSFW remote program for health professionals, thus they can deliver DVD remote instruction program to older adults who practice social distancing and engage in MSFW at home settings.

Examining the Effects of Fluid Velocity Gradients on 4D Digital Holographic PIV/PTV Measurements

4D digital holographic PIV/PTV (4D-DHPIV/PTV) methods have demonstrated theoretical viability due to their relative ease of setup and high spatial resolution (Soria (2018)). This study investigates how velocity gradients related to different flow regimes and their magnitudes affect 3-component–3-dimensional (3C-3D) digital holographic PIV measurement uncertainty. The error introduced by velocity gradients within the interrogation volume is studied by simulating particles in a velocity field, with a given constant velocity gradient superimposed on a uniform flow from which a time-series of hologram pairs are generated and the 3C-3D velocity fields and their errors are determined using 4D-DHPIV/PTV Sun et al. (2020). Hologram pairs are simulated by modelling the propagation and particlediffraction of coherent laser light using the angular spectrum method (Goodman (1996)). The hologram reconstruction then involves direct reconstruction, followed by deconvolution, a particle position refinement and a hologram subtraction step (Sun et al. (2020)). The particle positions obtained from 4D-DHPIV/PTV are then used to resolve particle displacement measurements using 3D cross-correlation digital analysis with a 3D Gaussian fit to sub-pixel resolution (Soria (2006)). The effects of velocity gradients on the displacement uncertainty and bias error have been investigated by undertaking Monte Carlo simulations under a range of velocity gradient environments. Specifically, 5 common velocity gradients have been studied, which included pure strain, pure vorticity and x, y and z-directional shear. The results indicate that the novel 4D-DHPIV/PTV has poorer accuracy and precision in the z-propagation axis, resulting in larger minimum uncertainties and bias errors. The errors in the z axis are also significantly less affected by velocity gradients in the z direction when compared to the effects of x and y directional velocity gradients on x and y errors respectively. Furthermore, the rate of cross-correlation maximum and SNR decrease are approximately 1.36 times slower due to velocity gradients in the z axis than other axes.

Using differential phase for 3D localization of tracer particles in digital inline holographic microscopy PIV/PTV (DIHM-PIV/PTV)

Digital inline holographic microscopy PIV/PTV (DIHM-PIV/PTV) has the ability to provide 4-dimensional (4D), i.e. time-resolved, 3-component 3-dimensional (3C-3D) flow measurement with high spatial and temporal resolution, compact optical setup and minimal calibration Sun et al. (2020) compared to most other volumetric techniques such as tomo-PIV, defocusing PIV, etc. Despite all these advantages DIHMPIV/PTV has not yet developed into a standard laboratory tool due to some major limitations such as the extended depth-of-focus (DOF) problem and the virtual image effect which cause artefacts in the standard reconstruction volume limiting the seeding concentration and thus the achievable velocity spatial resolution. In order to mitigate the above-mentioned limitations we present a novel particle localization and extraction methodology which allows the minimization of these artefacts from the standard reconstruction and perform PIV/PTV analysis on the particle volume fields only. The proposed algorithm is based on the differential phase, which is the axial phase shift of the object wave compared to the reference plane wave propagation.

Prediction of quadriceps tendon-patellar bone autograft diameter in adolescents with 2-dimensional magnetic resonance imaging and anthropometric measures.

This study evaluates the correlation between the bone end and soft tissue end of the quadriceps tendon-patellar bone autograft (QPA) size and pre-operative MRI measurements of the quadriceps tendon along sections to be included in the graft harvest in adolescents. We also assessed association between graft diameter and anthropometric measures (height, weight, and BMI), age, and sex. Patients (10-18years) who underwent QPA ACL reconstruction and had a pre-operative MRI were considered for inclusion. Age, height, and weight, tibial and femoral side graft diameter, and patellar bone block dimensions were collected. Using a pre-operative 2D sagittal plane MRI, we measured the quadriceps at 10-mm increments above the patella, up to 40mm. We assessed correlation between the bone-end graft diameter and the AP measure at 10mm above the patella, and correlation between the soft-tissue end graft diameter and the most proximal AP measure. A total of 103 patients were included. A significant correlation between the soft-tissue side graft diameter and most proximal AP measurement was observed (rs = 0.51; p < 0.001). However, measurements significantly underestimated the soft-tissue end graft diameter (9.6 ± 0.8 vs. 7.4 ± 1.1; p < 0.001). There was no correlation between the bone-end graft diameter and AP measurement 10mm above the patella. Anthropometric measures were not associated with graft size. Skeletal maturity was associated with smaller graft size (p = 0.08). Soft-tissue end graft diameter is associated with the AP measure of the quadriceps at 20-40mm above the superior pole of the patella.

Visceral Adipose Tissue Volumetrics Inform Odds of Treatment Response and Risk of Subsequent Surgery in IBD Patients Starting Antitumor Necrosis Factor Therapy.

Data describing the effect of obesity on antitumor necrosis factor (anti-TNF) treatment response are inconsistent. Visceral adipose tissue (VAT) is a superior marker of adiposity to body mass index. However, its effect on treatment response is unclear. We aimed to evaluate the effect of VAT on anti-TNF treatment response. Inflammatory bowel disease (IBD) patients starting anti-TNF agents between January 1, 2009, and July 31, 2019, were included. 3-dimensional measurements of VAT volume and visceral fat index (visceral:subcutaneous adipose tissue ratio; VFI) were obtained from computed tomography (CT) scans. Subjects were categorized by predefined volume cutoffs (<1500cm3, 1500-2999cm3, ≥3000cm3) and VFI (<0.33, 0.33-0.66, ≥0.67). Primary outcomes included a composite treatment response end point at 6 and 12 months. Secondary outcomes were surgery at 6 and 12 months. Multivariable logistic regression was used to calculate adjusted odds ratio (aOR) and 95% confidence interval (CI). The final cohort included 176 patients. No significant differences in treatment response at 6 months was observed. At 12 months, compared with volume <1500cm3, patients with volume 1500-2999cm3 had higher odds of response (aOR, 3.52; 95% CI, 1.16-10.71; P = .023), whereas volume ≥3000cm3 did not. Compared with VFI<0.33, VFI ≥0.67 had higher odds of surgery at 6 (aOR, 48.22; 95% CI, 4.73-491.57; P = .023) and 12 months (aOR, 20.94; 95% CI, 3.14-139.67; P = .004). Post hoc analysis suggested VAT may affect drug pharmacokinetics. We found VAT volume is associated with anti-TNF treatment response in a nondose dependent manner, and VFI may inform risk of surgery after anti-TNF initiation. If confirmed by prospective studies, VAT volumetrics are potentially useful biomarkers to inform IBD treatment decisions.

Quantitative characterisation of ballistic cartridge cases from micro-CT

Evaluation of cartridge cases is essential within forensic ballistic analysis and is used in an attempt to establish a connection to the weapon used to fire it. This study consists of two experiments. The aims of Experiment 1 were to establish whether micro-CT is appropriate and repeatable for ballistic cartridge case analysis and if measurements can be extracted repeatably and reliably. Experiment 2 aimed to compare cartridge cases from two weapons to establish the magnitude of variation within and between weapons. A total of 48 cartridge cases fired by two distinct weapons were collected and micro-CT scanned to a high resolution. One randomly selected cartridge was scanned ten times under the same conditions to ensure repeatability of the scanning conditions in Experiment 1. Three novel measurements to quantitatively assess the firing pin impressions were proposed in Experiment 1 and comparatively analysed from two weapons in Experiment 2. Experiment 1 showed that micro-CT is an effective and highly repeatable and reliable method for 3-dimensional imaging and measurement of ballistic cartridge cases. Furthermore, high agreement for inter-rater reliability was found between five raters. Quantitative micro-CT analysis of the firing pin impression measurements in Experiment 2 showed a significant difference between the two studied weapons using Welch’s t-test (p < 0.01). This study shows the advantage and reliability of utilising micro-CT for firing pin impression analysis. Quantitation of the firing pin impression allows distinction between the weapons studied. With expansion to further weapons, application of this methodology could complement current analysis techniques through classification models.

A FLEXIBLE AND ROBUST 3D COORDINATE MEASUREMENT SYSTEM BASED ON WHITE LIGHT INTERFEROMETRY FOR DEVIATION MEASUREMENTS ON SWISS-TYPE TURNING MACHINES

The calibration of machine tools or industrial robots needs high precision 3-dimensional coordinate measurements. Common available systems still have the need of ambitious and time extensive processes to fulfill the requested requirements. Therefore there is a strong request for fully automated systems that allow an autonomous and easy to handle procedure for 3D volumetric deviation measurements. This exactly is the intension of the here presented 3D Coordinate Measurement System. The so called µ-GPS System is based on reliable white light interferometer and robust technology. The 3D coordinates are determined via trilateration from three measured distances like it is known from the global GPS. Mainly two parts, the sensor unit (transceiver unit) including the emitter and the reference base (three cat’s-eyes) which includes the three reflectors are mounted in the workspace of the machine. A model to evaluate the signals was developed which allows in combination with a 3-dimensional failure correction a 3D accuracy of more than 5 microns. This application will be the base for an exemplary and fully automated calibration process of Swiss-type turning machines. As these machines are used in high volume manufacturing for precision parts, they need to be assembled and calibrated very accurately. For the long term stability the µ-GPS System can be easily assembled in the Swiss-type turning machine so that thermal deviations and abrasion can be measured and compensated in the control. The robust and easy handling of the µ-GPS System later allows an expansion of the showcase to robots and other machine tools.