The impact of an active and passive industrial back exoskeleton on functional performance.

Due to differences in actuation and design, active and passive industrial back exoskeletons could influence functional performance, i.e., work performance, perceived task difficulty, and discomfort, differently. Therefore, this study investigated and compared the impact of the active CrayX (7 kg) and passive Paexo Back (4.5 kg) on functional performance. Eighteen participants performed twelve work-related tasks with both types of exoskeletons and without (NoExo). The CrayX hindered work performance up to 22% in multiple tasks, compared to the Paexo Back and NoExo, while work performance between NoExo and the Paexo Back condition was more comparable, except for stair climbing (13% hindrance). Perceived task difficulty and discomfort seldomly varied between both exoskeletons. Although the CrayX shows promise to benefit workers, limitations in hindrance and comfort should first be addressed. The Paexo Back has demonstrated an advantage in certain static tasks. However, increasing its potential across a broader range of tasks seems warranted.Practitioner Summary: Differences between industrial back exoskeletons with regard to functional performance, i.e. work performance, discomfort and perceived task difficulty, were investigated by evaluating the active CrayX and passive Paexo Back back exoskeletons. The CrayX significantly hindered functional performance, while the Paexo Back seldomly affected functional performance.Abbreviations: WMSD: Work-related musculoskeletal disorder; NoExo: No Exoskeleton; GD: General discomfort; PTD: Perceived task difficulty; BMI: Body Mass Index.

Physical activity increases synovial fluid in ankle tendon sheaths: an adjustment of MR Criteria is needed.

OBJECTIVES: To compare the amount of fluid in synovial sheaths of the ankle before and after running. Our hypothesis was that this amount would increase and that the threshold for what is normally acceptable should be adjusted after physical activity. METHODS: Twenty-one healthy volunteers (n = 42 ankles) ran for 40 min on a treadmill. They underwent 3 T MRI before and immediately after running using a dedicated ankle coil. The images were stored and subsequently measured in a standardized way and independently read by two readers for fluid in the tendon sheaths in the retro and inframalleolar area. Statistics were performed for each tendon (Wilcoxon signed rank test), and also for the pooled data. Intraclass correlation coefficients were calculated. RESULTS: For reader 1, for all tendons the values after running increased without reaching statistical significance. For reader 2 this was not the case for all tendons but for most. When all the data were pooled (n = 800 measurements), the statistical difference before and after running was significant (p < 0.001). CONCLUSION: Data pre and post-running show a trend of increasing synovial fluid, however, not significant for each individual tendon. The pooled data for all tendons, (n = 800) show a statistically significant increase after running (p < 0.001). The clinical implication is that the threshold for normally acceptable fluid should be adjusted if the patient undergoes an MR study after recent physical activity.

Influence of medial and lateral imaging plane inclination on assessment of trochlear depth, sulcus angle, and facet asymmetry in the setting of trochlear anatomy: a cadaveric study.

PURPOSE: (1) to assess the influence of medial or lateral imaging plane inclination on the measurement of sulcus angle, trochlear depth, and facet asymmetry on transverse cross-sectional images. (2) to assess the effect of measurement level (height) on these respective parameters. MATERIALS AND METHODS: Twenty dry femurs (9 left, 11 right) were imaged with CT. A 3D dataset was obtained from which axial images were reconstructed in the ideal plane without inclination as well as with 8° of medial and lateral inclination. Sulcus angle, trochlear depth, and facet asymmetry were measured on the 3 image sets. In addition, the measurements were performed at 5 mm and 10 mm from the superior margin of the medial trochlear facet. Statistical analysis consisted of the Wilcoxon test and calculation of measurement variation. RESULTS: There were no statistically significant differences between the indicated measurements on the reference set compared to medial or lateral inclination. All measurements were significantly different depending on measurement height. CONCLUSION: Medial or lateral inclination in the transverse imaging plane of 8° does not influence the values of typical parameters used for the assessment of trochlear dysplasia. The measurement height has a significant influence, and a consensus should be found as to which is the optimal measurement height.

Pseudo-tear appearance of the Achilles tendon on MR imaging in normal volunteers.

PURPOSE: The aim of this study was to confirm our clinical observation that a pseudo-tear appearance of the Achilles tendon is commonly seen on MRI and is of no clinical relevance. MATERIALS AND METHODS: Forty-one ankles were imaged on a 3 T MR system, and PD weighted images with fat saturation were obtained in three orthogonal planes (TR, 2969 ms; TE, 30 ms; NA, 2; slice thickness, 2.5 mm). Volunteer exclusion criteria were symptoms of Achilles tendon pathology (such as acute or chronic posterior heel pain), history of trauma or surgery of the Achilles tendon. Internal signal of the Achilles tendon on axial and sagittal images was assessed independently by two observers. Internal signal of the Achilles tendon was classified from homogenously dark to different degree of hyperintense signal, where 0 means no internal hyperintensity, 1-minimal hyperintensity, 2-moderate and 3-marked. Descriptive statistics were calculated. Correlation between the two readers was also assessed. Two fresh cadavers were used in this study, one specimen being sliced in the sagittal plane and one specimen being dissected by an experienced anatomist. RESULTS: Twenty one volunteers (8 men, 13 women), mean age of 24.7 years (19-43 years) were included in the study. On sagittal images both raters appreciated any degree of hyperintense signal in 59% of tendons. On axial images any degree of hyperintensity was seen in almost half of the cases (46 vs. 49%). Minimal hyperintensities were seen most commonly. Cohen's kappa coefficient for sagittal images was 0.964 (almost perfect agreement); for axial images 0.764 (substantial agreement). The anatomical studies demonstrated that the Achilles tendon is made up of different components that are partially separated and twist around each other explaining the pseudo-tear appearance. CONCLUSION: The Achilles tendon is frequently not homogenously dark in normal volunteers as would be expected. Hyperintense signal is common in the long and short axis and related to the underlying anatomical features.

Fluid distribution in ankle tendon sheaths in healthy volunteers: MRI findings.

PURPOSE: To assess normal distribution of fluid in the tendon sheaths of the ankle. METHODS: 21 healthy volunteers were evaluated. Bilateral ankle MRI was performed on a 3T unit with PD-weighted images with fat saturation. The images were interpreted by two radiologists separately, and the short-axis dimension of fluid amount was measured. Bland-Altman plots and correlation plots were used to assess consistency between readers. RESULTS: There were 13 men and 8 women. The mean age was 24.7 years. Fluid in the retromalleolar part of the peroneus longus was seen in three ankles of three volunteers and in the inframalleolar part in three ankles of three volunteers. Fluid in the retromalleolar part of the peroneus brevis was seen in four ankles of three volunteers and in the inframalleolar part in three ankles of two volunteers. Fluid in the retromalleolar part of the tibialis posterior was seen in 37 ankles of 20 volunteers and in the inframalleolar part in 38 ankles of 21 volunteers Fluid in the retromalleolar part of the flexor digitorum was seen in 14 ankles of eight volunteers and in the inframalleolar part in 11 ankles of eight volunteers Fluid in the retromalleolar part of the flexor hallucis longus was seen in 23 ankles of 16 volunteers and in the inframalleolar part in 17 ankles of 11 volunteers. CONCLUSION: Fluid is common in the retro- and inframalleolar parts of the medial tendons. Fluid is virtually absent in the peroneal tendons and anterior tendon sheaths in normal volunteers.

Pseudo-tear appearance of the posterior tibiotalar ligament on fluid-sensitive sequences.

PURPOSE: This study aimed at studying the MR imaging appearance of the tibiotalar ligament in asymptomatic volunteers. MATERIALS AND METHODS: Fourty-two ankles were imaged on a 3T MR system using proton density weighted images with fat saturation (TR, 2969 ms; TE 30 ms; NA, 2; slice thickness, 2.5 mm). Subjects with acute ankle conditions or history of previous trauma were not included in the study group. Images were obtained in the three orthogonal planes. The posterior tibiotalar ligament was assessed on coronal imaging, by consensus of two radiologists. The signal intensity was recorded as isointense, hypointense, or hyperintense relative to muscle. The morphology of the ligament was classified as homogenous or striated. Descriptive statistics were obtained. RESULTS: There were 8 men and 14 women with a mean age of 24.7 years (range 19-43 years). The ligaments were classified as hyperintense in 30/42 (70%) of ankles and isointense in 9/42 (21%) of ankles. A striated appearance was seen in 34/42 (80%) of ankles. CONCLUSION: The posterior deep deltoid ligament is commonly hyperintense. It is usually striated although it can be homogeneously hyperintense. This appearance simulates a tear.

Forefoot Pain in the Lesser Toes: Anatomical Considerations and Magnetic Resonance Imaging Findings.

Various conditions may result in forefoot pain. Magnetic resonance (MR) imaging allows accurate assessment of many of these conditions. We provide an overview of forefoot disorders divided into bones, capsule and plantar plate, musculotendinous structures, neurovascular structures, and subcutaneous tissue. We review normal anatomical features as well as MR imaging findings of common disorders.

Self-perceived fatigue in adolescents in relation to body composition and physical outcomes.

BackgroundIncreased self-perceived fatigue (SpF) has already been identified in chronic conditions such as obesity, but it is also a growing problem in school-attending adolescents (±25%). This study tried to link body composition to SpF and physical activity/performance. Additionally, indicators for fatigue were determined.MethodsA total of 452 adolescents were recruited. Body composition was measured and physical activity, physical performance, and SpF were assessed. Based on the total SpF (Multidimensional Fatigue Inventory) outcomes, three groups were created: low fatigue (LF) medium fatigue (MF) and high fatigue (HF).ResultsFat was significantly lower in the LF group compared with MF (P<0,05) and HF (P<0.01). Grip endurance was increased in LF (P<0.05) and MF (P<0.01) compared with HF; similar results were found with the Cooper test. Sport Index was increased in LF compared with MF and HF (P<0.01). Fat and physical activity were related to fatigue (P<0.01). Decreased fatigue resistance, Sport Index and higher fat percentage increased the chance of being extremely fatigued.ConclusionThis study emphasizes the importance of using fat mass and fat percentage instead of body mass index when screening adolescents. To prevent increased SpF, it is necessary to stimulate youngsters to be physically active and to promote healthy behaviors.

Improved cognitive functioning in obese adolescents after a 30-week inpatient weight loss program.

INTRODUCTION: Studies linked obesity with a large number of medical conditions including decreased cognitive functioning. The relation between BMI and cognition was proven in adults, but in adolescents the results are conflicting. Further, limited data are available on the impact of weight loss on cognition. This study analyzed the impact of a 30-week lasting weight loss program on cognition and determined the impact of changes in body composition and self-perceived fatigue on changes in cognition. METHODS: Sixty-two obese adolescents were evaluated at baseline and after 30 weeks. Stroop test (ST; selective attention), Continuous Performance Test (CPT; sustained attention) and Ray Auditory verbal learning test (RAVLT; short-term memory) were assessed. Additionally, body composition parameters and fatigue (MFI-20) were evaluated. RESULTS: Improved reaction times were found for ST and CPT after the intervention, but were independent for reductions in BMI, fat mass, fat%, and fatigue. Short memory also improved with decreased fatigue as an influencing parameter. Accuracy of ST and CPT showed no significant changes. CONCLUSION: A 30-week lasting inpatient weight loss program improved selective attention, sustained attention, and short-term memory. Changes in body composition did not explain the improvements in cognitive functioning. Decreased fatigue resulted in improved aspects of cognition.

Ultrasound of the Distal Insertions of the Ankle and Foot Tendons With Anatomical Correlation: A Review.

The distal insertions of the tendons crossing the ankle as well as the tendons originating in the foot are less well known by radiologists. We review the anatomy and ultrasound appearance of these insertions using our own cadaveric sectioning and dissection. The ultrasound images were correlated with anatomical slices. Occasionally magnetic resonance images were also used for better understanding. Understanding the normal appearance of these tendon insertions is important for diagnosing pathology in this region.

Reproducibility of the kinematics in rotational high-velocity, low-amplitude thrust of the upper cervical spine: a cadaveric study.

OBJECTIVE: This study aimed to investigate the reproducibility of the kinematics in rotational high-velocity, low-amplitude (HVLA) thrust of the upper cervical spine. METHODS: Twenty fresh human cervical specimens were studied in a test-retest situation with 2 manual therapists. Kinematics of C1-C2 and C0-C1 were examined during segmental rotational HVLA manipulation through an ultrasound-based tracking system. The thrust moment was analyzed by 3-dimensional aspects: the range of motion of axial rotation, flexion-extension, lateral banding, and the cross-correlation between the axial rotation and the coupled lateral banding components. RESULTS: During rotational HVLA thrust on C1-C2, the main axial rotation demonstrates an intraexaminer relationship varying from almost perfect to fair (intraclass correlation coefficient =0.71; intraclass correlation coefficient = 0.35) and a substantial interexaminer correlation of 0.73. CONCLUSIONS: This study showed substantial levels of reliability for the main axial rotation component of segmental manual rotational HVLA thrust on C1-C2. Intra- and interrater reliability for flexion-extension, lateral bending, and cross-correlation was low.

Accuracy and concordance of anthropometry for measuring regional fat distribution in adults aged 20-55 years.

OBJECTIVES: This study aimed to assess the accuracy and concordance of anthropometrically derived prediction equations for the estimation of regional fat mass (FM) distribution. METHODS: Sixty-two white males and 50 females with a large range of age (20-55 years) and BMI (16.6-33.4 kg/m(2)) were included. Whole body dual energy X-ray absorptiometry (DXA) scans were acquired and anthropometric prediction equations for regional FM were developed and cross-validated. On the basis of the total sample two anthropometrically derived indices of FM distribution [Formula: see text] ratio and [Formula: see text] ratio were compared with their DXA analogues. RESULTS: In both sexes multiple linear regression models predicted the regional DXA fat masses with good accuracy (P < 0.001). In men mean bias (limits of agreement) were: -6.8 g (-535,364) for FM(arms), 65 g (-1921,2052) for FM(trunk), -21 g (-1374,1332) for FM(legs), -0.2% (-5.0,4.7) for %FM(trunk) and -0.5% (-6.8,5.8) for %FM(legs). In women mean difference (limits of agreement) were: -86 g (-463,450) for FM(arms), 30 g (-1784,1844) for FM(trunk), -278 g (-1782,1227) for FM(legs), 0.4% (-5.5,6.3) for %FM(trunk), and 0.3% (-8.3,8.9) for %FM(legs). No systematic (constant and proportional) differences between methods for the determination of FM distribution ratios were found, suggesting method interchangeability. The concordance for subject classification based on t-scores according to the National Health and Nutrition Examination Survey (NHANES) was significant (P < 0.001), with substantial agreement for [Formula: see text] ratio (κ(w) = 0.80) and [Formula: see text] ratio (κ(w) = 0.75). CONCLUSION: Anthropometric variables offer promise to the development of simple, noninvasive, and inexpensive screening to identify individuals with abnormal FM distribution. The anthropometrically derived indices of FM distribution demonstrate sufficient accuracy for clinical use. Am. J. Hum. Biol., 2013. © 2012 Wiley Periodicals, Inc.

Lymphoscintigraphy as a Therapeutic Guidance Tool Can Improve Manual Lymphatic Drainage for the Physical Treatment of Patients with Upper Limb Lymphedema: Randomized Clinical Trial.

Background: The purpose of this study was to measure the effects of lymphoscintigraphically guided manual lymphatic drainage (LG-MLD) and to compare it with standardized manual lymphatic drainage (St-MLD). Materials and Methods: Fifty-two patients with lymphedema of the upper limb who underwent lymphoscintigraphy were randomly allocated into two groups. Following the phase of physical activity, the control group underwent two phases of St-MLD as the experimental group underwent a first phase of St-MLD followed by a second phase of LG-MLD. Areas of interest were then selected [in particular, dermal backflow (DBF) and axillary lymph nodes (LN)], radioactive activities were quantified for each of these areas. Results: If a first phase of St-MLD increased the LN activity by 28% on average, the findings indicated that for the second phase of DLM, LG-MLD was 19% more efficient than St-MLD in increasing LN activity. If a period of rest does not influence the lymph charge of DBF areas, physical activity leads to an average activity increase of 17%, whereas LG-MLD and St-MLD lead to an activity decrease of 11%. Conclusions: For patients with lymphedema, the findings indicate that MLD can increase the lymphatic flow toward the lymphatic nodes by 28% on average and can decrease the charge in the areas of DBF by 11% on average. Moreover, lymphoscintigraphy can be an important therapeutic tool because LG-MLD significantly increases lymphatic flow by 19% more than St-MLD. Concerning the areas of DBF, the LG-MLD and St-MLD decrease the charge in these areas with the same intensity.

Stent appearance in a novel silicon-based photon-counting CT prototype: ex vivo phantom study in head-to-head comparison with conventional energy-integrating CT.

BACKGROUND: In this study, stent appearance in a novel silicon-based photon-counting computed tomography (Si-PCCT) prototype was compared with a conventional energy-integrating detector CT (EIDCT) system. METHODS: An ex vivo phantom was created, consisting of a 2% agar-water mixture, in which human-resected and stented arteries were individually embedded. Using similar technique parameters, helical scan data was acquired using a novel prototype Si-PCCT and a conventional EIDCT system at a volumetric CT dose index (CTDIvol) of 9 mGy. Reconstructions were made at 502 and 1502 mm2 field-of-views (FOVs) using a bone kernel and adaptive statistical iterative reconstruction with 0% blending. Using a 5-point Likert scale, reader evaluations were performed on stent appearance, blooming and inter-stent visibility. Quantitative image analysis was performed on stent diameter accuracy, blooming and inter-stent distinction. Qualitative and quantitative differences between Si-PCCT and EIDCT systems were tested with a Wilcoxon signed-rank test and a paired samples t-test, respectively. Inter- and intra-reader agreement was assessed using the intraclass correlation coefficient (ICC). RESULTS: Qualitatively, Si-PCCT images were rated higher than EIDCT images at 150-mm FOV, based on stent appearance (p = 0.026) and blooming (p = 0.015), with a moderate inter- (ICC = 0.50) and intra-reader (ICC = 0.60) agreement. Quantitatively, Si-PCCT yielded more accurate diameter measurements (p = 0.001), reduced blooming (p < 0.001) and improved inter-stent distinction (p < 0.001). Similar trends were observed for the images reconstructed at 50-mm FOV. CONCLUSIONS: When compared to EIDCT, the improved spatial resolution of Si-PCCT yields enhanced stent appearance, more accurate diameter measurements, reduced blooming and improved inter-stent distinction. KEY POINTS: • This study evaluated stent appearance in a novel silicon-based photon-counting computed tomography (Si-PCCT) prototype. • Compared to standard CT, Si-PCCT resulted in more accurate stent diameter measurements. • Si-PCCT also reduced blooming artefacts and improved inter-stent visibility.

A cross-sectional case-control study on the structural connectome in recovered hospitalized COVID-19 patients.

COVID-19 can induce neurological sequelae, negatively affecting the quality of life. Unravelling this illness's impact on structural brain connectivity, white-matter microstructure (WMM), and cognitive performance may help elucidate its implications. This cross-sectional study aimed to investigate differences in these factors between former hospitalised COVID-19 patients (COV) and healthy controls. Group differences in structural brain connectivity were explored using Welch-two sample t-tests and two-sample Mann-Whitney U tests. Multivariate linear models were constructed (one per region) to examine fixel-based group differences. Differences in cognitive performance between groups were investigated using Wilcoxon Rank Sum tests. Possible effects of bundle-specific FD measures on cognitive performance were explored using a two-group path model. No differences in whole-brain structural organisation were found. Bundle-specific metrics showed reduced fiber density (p = 0.012, Hedges' g = 0.884) and fiber density cross-section (p = 0.007, Hedges' g = 0.945) in the motor segment of the corpus callosum in COV compared to healthy controls. Cognitive performance on the motor praxis and digit symbol substitution tests was worse in COV than healthy controls (p < 0.001, r = 0.688; p = 0.013, r = 422, respectively). Associations between the cognitive performance and bundle-specific FD measures differed significantly between groups. WMM and cognitive performance differences were observed between COV and healthy controls.

The innervation of the axillary arch determined by surface stimulodetection electromyography.

The axillary arch (AA) is a muscular anatomical variation in the fossa axillaris that has been extensively studied in cadaveric specimens. Within these dissections, different innervations of the AA have been proposed, but this has never been explored in vivo. Knowledge of the innervation of the AA is required in order to better understand its function (e.g. predisposition for certain sports and/or activities, understanding shoulder injuries in overhead sports). Here, we report on the use of surface stimulodetection electromyography (SSEMG) to resolve the innervation of the AA in 20 subjects (12 women, eight men - mean age of 21.3 ± 2.7 years) with a uni- or bilateral AA. SSEMG of each muscle [M. latissimus dorsi (MLD) and M. pectoralis major] was performed with a four-channel electrostimulation measuring system in order to determine the innervation of the AA. The results showed co-contraction of the MLD in 85% of the subjects after AA stimulation. In the remaining subjects, no specific localized response was observed due to non-specific nerve stimulation, inherent to the proximity of the brachial plexus in these individuals. Our findings demonstrate that SSEMG exploration offers a practical and reliable tool for investigating anatomical aspects of muscle innervation in vivo. Using this approach, we conclude that the AA receives the same innervation as the MLD (the N. thoracodorsalis), and may be considered a muscular extension of the latter.

Prediction of segmental lean mass using anthropometric variables in young adults.

The aim of the present study was to develop and cross-validate anthropometrical prediction equations for segmental lean tissue mass (SLM). One hundred and seventeen young healthy Caucasians (67 men and 50 women; mean age: 31.9 ± 10.0 years; Body Mass Index: 24.3 ± 3.2 kg · m(-2)) were included. Body mass (BM), stretch stature (SS), 14 circumferences (CC), 13 skinfolds (SF) and 4 bone breadths (BB) were used as anthropometric measurements. Segmental lean mass of both arms, trunk and both legs were measured by dual energy X-ray absorptiometry as the criterion method. Three prediction equations for SLM were developed as follows: arms = 40.394(BM) + 169.836(CCarm-tensed) + 399.162(CCwrist) - 85.414(SFtriceps) - 39.790(SFbiceps) - 7289.190, where Adj.R (2) = 0.97, P < 0.001, and standard error of estimate (SEE) = 355 g;trunk = 181.530(BM) + 155.037(SS) + 534.818(CCneck) + 175.638(CCchest) - 88.359(SFchest) - 147.232(SFsupraspinale) - 46522.165, where Adj.R(2) = 0.97, P < 0.001, and SEE = 1077g; and legs = 55.838(BM) + 88.356(SS) + 235.579(CCmid-thigh) + 278.595(CCcalf) + 288.984(CCankle) - 84.954(SFfront-thigh) - 53.009(SFmedial calf) - 28522.241, where Adj.R (2) = 0.96, P < 0.001, and SEE = 724 g. Cross-validation statistics showed no significant differences (P < 0.05) between observed and predicted SLM. Root mean squared errors were smallest for arms (362 g), followed by legs (820 g) and trunk (1477 g). These new prediction equations allow an accurate estimation of segmental lean mass in groups of young adults, but estimation errors of 8 to 14% can occur in certain individuals.

Minimally Invasive Pronator Quadratus Sparing Approach versus Extended Flexor Carpi Radialis Approach with Pronator Quadratus Repair for Volar Plating in Distal Radial Fractures.

Background Several volar plating techniques exist to treat distal radial fractures. Question We investigated minimally invasive plate osteosynthesis (MIPO) with pronator quadratus (PQ) sparing versus conventional flexor carpi radialis approach for volar plating with PQ repair after distal radial fractures during the first postoperative year. Patients and Methods Prospective data of two consecutive cohorts were compared: 62 patients in MIPO group with an average age of 61.2 years and 66 patients in PQ repair group with an average age of 61.4 years completed the entire follow-up period. Results Range of motion was not significantly different, except flexion-extension that was significantly higher in the MIPO group. Quick Disabilities of the Arm, Shoulder and Hand was significantly lower in the MIPO group. Pain visual analogue scale was only significantly lower at 6 weeks. Grip strength measurements and patient satisfaction were not significantly different. Conclusions MIPO volar plating with PQ sparing is a surgical technique that can be chosen according to surgeon's preference and expertise, resulting in a better flexion-extension mobility and function score according to our study. Level of evidence This is a Level 3 study.

T2-weighted turbo spin-echo magnetic resonance imaging of canine brain anatomy at 1.5T, 3T, and 7T field strengths.

Post-mortem T2 weighted images of canine heads were acquired at 1.5T, 3T, and 7T. This study aimed to (1) identify anatomical structures of the canine brain using an ultra-high-field magnetic resonance imaging (MRI) (7T) to help to facilitate their localization on high field MRI images (3T and 1.5T), where these structures may appear less well defined and delineated and (2) evaluate the visibility of canine brain anatomical structures on 1.5T, 3T, and 7T MRI images for optimizing clinical utility. Our hypothesis was that the provided subjective image quality comparison at different field strengths may offer a general baseline for canine brain anatomy and may help clinicians evaluate MRI options better. Six canine heads were examined with 1.5T, 3T, and 7T MRI scanners. T2-weighted images were acquired in three orthogonal planes at each field strength using a turbo spin-echo sequence. Fifty neuroanatomic structures were identified and evaluated on the 7T MR images; subsequently, those were found on the 3T and 45 out of the 50 structures were detected on the 1.5T imaging. The structures that were not able to be identified on the 1.5T imaging included the septum pellucidum, oculomotor nucleus, substantia nigra, claustrum, and thalamic nucleus griseus. Images acquired at 7T were subjective of higher spatial and contrast resolution. However, the ultra-high-field images were prone to artifacts at the interface between tissues of different magnetic properties. In conclusion, 3T MR imaging appears to be the best comprise for evaluating canine brain anatomy on MRI with fewer imaging artifacts.

Feasibility and Tolerance of Fingertip Peripheral Arterial Tonometry Measurements in School-Aged Children.

Background: Assessment of the endothelial function of the microvasculature by peripheral arterial tonometry (PAT) has gained increasing popularity in pediatrics. Discomfort or experienced pain during fingertip PAT has only been studied in adolescents and adults. Methods: In 142 children (aged 4-11 years old), a fingertip PAT with a commercial device (EndoPAT 2000®) as well as a caliper and ultrasound examination of peripheral skinfolds were performed as part of a cross-sectional cohort study. In 110 children, Faces Pain Scale (FPS-R) data were collected after PAT and skinfold measurements by caliper and ultrasound. Results: In 111 out of the 142 PAT measurements (78.2%), a reactive hyperemia index (RHI) could be obtained. The most frequent error messages by the software was a "too noisy" and/or a "poor quality" signal. The success rate was higher in children aged older than 6 years (83.1 vs. 44.4%; p < 0.001). Median (range) FPS-R after PAT was 0 (range 0-6) but was significantly higher than the median pain experienced after caliper measurements of peripheral skinfolds (p < 0.001). No pain was experienced by 59 of the 110 children (54.1%). Conclusion: PAT testing is feasible in the great majority of school-aged children, and the procedure is well-tolerated.