Quantitative maps of rotating frame relaxation (RFR) time constants are sensitive and useful magnetic resonance imaging tools with which to evaluate tissue integrity in vivo. However, to date, only moderate image resolutions of 1.6 x 1.6 x 3.6 mm3 have been used for whole-brain coverage RFR mapping in humans at 3 T. For more precise morphometrical examinations, higher spatial resolutions are desirable. Towards achieving the long-term goal of increasing the spatial resolution of RFR mapping without increasing scan times, we explore the use of the recently introduced Transform domain NOise Reduction with DIstribution Corrected principal component analysis (T-NORDIC) algorithm for thermal noise reduction. RFR acquisitions at 3 T were obtained from eight healthy participants (seven males and one female) aged 52 ± 20 years, including adiabatic T1ρ, T2ρ, and nonadiabatic Relaxation Along a Fictitious Field (RAFF) in the rotating frame of rank n = 4 (RAFF4) with both 1.6 x 1.6 x 3.6 mm3 and 1.25 x 1.25 x 2 mm3 image resolutions. We compared RFR values and their confidence intervals (CIs) obtained from fitting the denoised versus nondenoised images, at both voxel and regional levels separately for each resolution and RFR metric. The comparison of metrics obtained from denoised versus nondenoised images was performed with a two-sample paired t-test and statistical significance was set at p less than 0.05 after Bonferroni correction for multiple comparisons. The use of T-NORDIC on the RFR images prior to the fitting procedure decreases the uncertainty of parameter estimation (lower CIs) at both spatial resolutions. The effect was particularly prominent at high-spatial resolution for RAFF4. Moreover, T-NORDIC did not degrade map quality, and it had minimal impact on the RFR values. Denoising RFR images with T-NORDIC improves parameter estimation while preserving the image quality and accuracy of all RFR maps, ultimately enabling high-resolution RFR mapping in scan times that are suitable for clinical settings.
- MeSH
- algoritmy MeSH
- analýza hlavních komponent MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie * metody MeSH
- mapování mozku MeSH
- mozek * diagnostické zobrazování MeSH
- poměr signál - šum * MeSH
- rotace MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Úvod: Dystonie je syndrom charakterizovaný trvalou svalovou kontrakcí, která má za následek rotační a opakované pohyby částí těla nebo abnormální postoje. Přesná patofyziologie idiopatické dystonie je stále nejasná. Systematický výzkum mimovolných pohybů charakterizovaných stálou lateralitou postojů nebo pohybů nebyl proveden. Cílem naší studie bylo určit symetrii denzity dopaminových D2 receptorů pomocí 123I-IBZM SPECT ve vztahu k rotaci hlavy u pacientů s jednostrannou nebo lateralizovanou dystonií. Metody: Vyšetřili jsme 17 pacientů s klinickou diagnózou cervikální dystonie. Jednalo se o 11 mužů a 6 žen průměrného věku 48 let (25–64). Strukturální poruchy mozku byly vyloučeny pomocí CT a MRI. K hodnocení dopaminových receptorů jsme použili 123I-IBZM, pro zobrazení jsme použili dvoudetektorovou SPECT gama kameru. Hodnotili jsme velikost a intenzitu akumulace radiofarmaka včetně její symetrie ve striatu pomocí pěti různých metod. Rovněž jsme hodnotili spolehlivost metod pomocí inter- a intraobserver variability a metodologické variability. Výsledky: Všechny testované metody, které jsme použili pro hodnocení symetrie akumulace 123I-IBZM ve striatu, jsou stejně spolehlivé včetně nejjednoduššího vizuálního hodnocení. Korelace s klinickým nálezem byla lepší u kvantitativního hodnocení. U 13 ze 17 pacientů s rotační cervikální dystonií byla denzita dopaminových D2 receptorů ve striatu vyšší ispilaterálně vůči směru rotace hlavy. Závěr: Asymetrická hustota dopaminových receptorů, která koresponduje se stranou motorické a posturální asymetrie, podporuje představu, že směr rotačního chování zvířat a směr cervikální dystonie u lidí může být predisponován.
Introduction: Dystonia is a syndrome characterized by sustained muscle contractions frequently causing twisting and repetitive movements of the relative part of the body or abnormal postures. The precise pathophysiology of idiopathic dystonia is still unclear. Systematic investigation of involuntary movements characterized by constant laterality of posture and motion has not yet been done. The aim of our study was to determine the symmetry of the density of dopamine D2 receptors with 123I-IBZM SPECT in relation to the head rotation in patients suffering from unilateral or lateralized dystonia. Methods: Seventeen patients with a clinical diagnosis of cervical dystonia participated in our study. There were 11 men and 6 women. The mean age was 48 years (25 to 64). Structural lesions of the brain were excluded by CT or MRI. The dopamine D2 receptor ligand used was 123I-IBZM. Imaging was performed with a dual-head SPECT gamma camera. We quantified the area as well as radioactivity accumulation within the striatum and its symmetry using five different methods. We assessed reliability by intraobserver and interobserver (2 readers) variability as well as methodological variability. Results: From all the tested methods used for symmetry/asymmetry of 123I-IBZM uptake evaluation in striatum no one is more reproducible than the others including the most simple visual assessment. The correspondence with clinical findings was better for quantitative methods. In our study in 13 of 17 patients with (rotational) cervical dystonia the dopamine D2 receptors density predominated in the striatum ipsilateral to the rotation of the head. Conclusions: The asymmetric accumulation of dopamine D2 receptors corresponding to the side of motor and postural asymmetry supports the view that the direction of circling behavior in animals and the direction of cervical dystonia in human beings might be predisposed.
- MeSH
- corpus striatum diagnostické zobrazování patologie MeSH
- dospělí MeSH
- dystonie diagnostické zobrazování patofyziologie MeSH
- hlava - pohyby MeSH
- jednofotonová emisní výpočetní tomografie * metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- radiofarmaka analýza terapeutické užití MeSH
- receptory dopaminu D2 * fyziologie MeSH
- rotace MeSH
- statistika jako téma MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- klinická studie MeSH
BACKGROUND CONTEXT: Physiological ranges and dynamic changes of atlantoaxial rotation (ROTC1/2), total cervical spine rotation (ROTCs) and the percentage of ROTC1/2 from ROTCs (ROTCperc) for different age groups have not yet been investigated in a sufficiently sized cohort. Furthermore, it is not clear whether demographic variables such a sex, smoking status or diabetes affect ROTC1/2, ROTCs and ROTCperc. PURPOSE: Obtain physiological ranges of ROTC1/2, ROTCs and ROTCperc for different age groups and determine their age-based dynamics. Investigate whether ROTC1/2, ROTCs and ROTCperc are affected by sex, smoking status or diabetes. DESIGN: Observational cross-sectional study. PATIENT SAMPLE: Patients undergoing elective CT examinations of the head and neck region between August 2020 and January 2022. OUTCOME MEASURES: Ranges of motion of ROTC1/2, ROTCs and ROTCperc in degrees. METHODS: A total of 308 subjects underwent dynamic rotational CT examinations of the upper cervical spine. Patients were divided into three age categories A1 (27-49 years), A2 (50-69 years) and A3 (≥70 years). Category A3 was further divided into B1 (70-79 years) and B2 (≥80 years). Values of ROTC1/2, ROTCs and ROTCperc were compared between all age groups, males and females, smokers and nonsmokers, diabetics a nondiabetics. Dynamics of ROTC1/2, ROTCs related to age and sex were visualized using scatterplot and trendline models. RESULTS: ROTC1/2 significantly decreased from group A1 (64.4°) to B2 (46.7°) as did ROTCs from A1 (131.2°) to B2 (97.6°). No significant differences of ROTperc were found between groups A1-B2 with values oscillating between 49% and 51%. Smoking and diabetes did not significantly affect ROTC1/2, ROTCs and ROTCperc, females had significantly higher ROTCs than males. Males and females demonstrated a different dynamic of ROTC1/2 and ROTCs demonstrated by out scatterplot and trendline models. CONCLUSIONS: Both ROTC1/2 and ROTCs significantly decrease with age, whereas ROTCperc remains stable. Females demonstrated higher ROTCs and their decrease of ROTC1/2 and ROTCs occurred in higher age groups compared to males. The functional repercussions atlantoaxial fusion are variable based on patient age and sex and should be taken into account prior to surgery.
- MeSH
- atlantoaxiální kloub * diagnostické zobrazování MeSH
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- krční obratle * chirurgie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- předškolní dítě MeSH
- průřezové studie MeSH
- rotace MeSH
- rozsah kloubních pohybů fyziologie MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- pozorovací studie MeSH
- práce podpořená grantem MeSH
Random Forest is an ensemble of decision trees based on the bagging and random subspace concepts. As suggested by Breiman, the strength of unstable learners and the diversity among them are the ensemble models' core strength. In this paper, we propose two approaches known as oblique and rotation double random forests. In the first approach, we propose rotation based double random forest. In rotation based double random forests, transformation or rotation of the feature space is generated at each node. At each node different random feature subspace is chosen for evaluation, hence the transformation at each node is different. Different transformations result in better diversity among the base learners and hence, better generalization performance. With the double random forest as base learner, the data at each node is transformed via two different transformations namely, principal component analysis and linear discriminant analysis. In the second approach, we propose oblique double random forest. Decision trees in random forest and double random forest are univariate, and this results in the generation of axis parallel split which fails to capture the geometric structure of the data. Also, the standard random forest may not grow sufficiently large decision trees resulting in suboptimal performance. To capture the geometric properties and to grow the decision trees of sufficient depth, we propose oblique double random forest. The oblique double random forest models are multivariate decision trees. At each non-leaf node, multisurface proximal support vector machine generates the optimal plane for better generalization performance. Also, different regularization techniques (Tikhonov regularization, axis-parallel split regularization, Null space regularization) are employed for tackling the small sample size problems in the decision trees of oblique double random forest. The proposed ensembles of decision trees produce trees with bigger size compared to the standard ensembles of decision trees as bagging is used at each non-leaf node which results in improved performance. The evaluation of the baseline models and the proposed oblique and rotation double random forest models is performed on benchmark 121 UCI datasets and real-world fisheries datasets. Both statistical analysis and the experimental results demonstrate the efficacy of the proposed oblique and rotation double random forest models compared to the baseline models on the benchmark datasets.
- MeSH
- algoritmy * MeSH
- analýza hlavních komponent MeSH
- rotace MeSH
- support vector machine * MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Ankle Kinesio-taping (KT) is being globally used an intervention to provide the ankle joint complex with sufficient support against sudden excessive mechanical stress during various activities. However, its effects on proximal joints are unclear. This study investigated the impact of ankle KT on ankle-knee joint coupling in sagittal, frontal and transverse planes. METHODS: Adopting a pretest post-test study design, 30 collegiate athletes with chronic ankle instability performed 3 single-leg drop landings in each non-taped and Kinesio-taped conditions and their movement kinematics were recorded using 6 optoelectronic cameras. RESULTS: The ankle angular velocities in sagittal (P=0.038, d=0.64) and transverse planes (P=0.001, d=0.95) decreased after KT application, while the knee internal rotation velocities increased (P=0.020, d=0.51). The coupling angles revealed that the ankle movement ratios significantly decreased in 3 planes in comparison with knee movement ratios. CONCLUSIONS: Outcomes of this study illustrated that application of ankle KT leaves the individuals with a stiffer ankle joint, which increases the mechanical stresses to this joint and decreases its stiffness in absorbing the applied shocks. Further, ankle KT application resulted in more knee internal rotation moments and may increase the risk of knee injuries during landing after a long-term usage in patients with instability ankle sprain.
- MeSH
- biomechanika MeSH
- dospělí MeSH
- hlezenní kloub fyziologie MeSH
- kolenní kloub fyziologie MeSH
- lidé MeSH
- nestabilita kloubu prevence a kontrola MeSH
- poranění kolena etiologie MeSH
- poranění kotníku prevence a kontrola MeSH
- rotace škodlivé účinky MeSH
- tejpovací páska škodlivé účinky MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Cervikokraniální syndrom zahrnuje bolest hlavy způsobenou poruchou v oblasti krční páteře. Terapie cervikokraniálního syndromu vyžaduje komplexní multioborový přístup s využitím farmakologické léčby i nefarmakologických postupů vč. rehabilitační a myoskeletální medicíny. Mobilizace a manipulace byly vyhodnoceny jako postupy přínosné při léčbě poruch krční páteře. Cílem práce bylo zhodnotit účinky manipulace krční páteře podle principů myoskeletální medicíny. Do studie bylo zařazeno 103 probandů s diagnostikovaným cervikokraniálním syndromem, kteří byli náhodně rozděleni do kontrolní a experimentální skupiny. V kontrolní skupině probandi absolvovali standardní rehabilitační myoskeletální léčbu. V experimentální skupině byla ke standardní myoskeletální rehabilitační léčbě přidána vstupně jednorázová nárazová manipulace krční páteře. Naše studie prokázala, že manipulace krční páteře vede bezprostředně po zákroku k signifikantnímu zlepšení hybnosti. Po 6týdenní komplexní terapii pozorujeme zlepšení hybnosti a zmírnění bolesti krční páteře v obou sledovaných skupinách. Lepší efekty pozorujeme v experimentální skupině, avšak tyto rozdíly jsou u našeho souboru pacientů nesignifikantní.
The symptoms of cervicocranial syndrome include headache caused by cervical spine disorder. The treatment of cervicocranial syndrome requires a comprehensive multidisciplinary approach using pharmacological treatment and non-drug procedures, including physiotherapy and myoskeletal therapy. There is a consensus that the physiotherapy procedures of mobilization and manipulation are beneficial in the treatment of cervical spine disorders. The aim of the study was to evaluate the effects of manipulation therapy of the cervical spine according to the principles of myoskeletal medicine. The study included 103 patients with cervicocranial syndrome, who were randomly divided into a control and an experimental group. The control group underwent standard physiotherapy myoskeletal treatment. In addition to the standard physiotherapy myoskeletal treatment, the experimental group received one initial thrust manipulation of the cervical spine at the very beginning of the treatment. The results of our study showed that the manipulation of the cervical spine led to a significant increase in immediate mobility after the therapy. An improvement of cervical spine mobility and pain reduction were observed in both groups after six weeks of comprehensive physiotherapy myoskeletal treatment. The differences between the experimental group and controls were shown to be non-significant.
- Klíčová slova
- cervikokraniální syndrom, manipulace páteře,
- MeSH
- bolesti hlavy * rehabilitace MeSH
- klinická studie jako téma MeSH
- krční obratle patologie MeSH
- lidé MeSH
- management bolesti metody MeSH
- muskuloskeletální manipulace * metody MeSH
- plexus cervicalis patologie MeSH
- rotace MeSH
- techniky fyzikální terapie MeSH
- Check Tag
- lidé MeSH
PURPOSE OF THE STUDY The purpose of the study was to evaluate tibio-femoral rotation during a simulated squat and to investigate the relationship between the rotational position of the femur in full extension and the amount of external rotation of the femur on the tibia during flexion. MATERIAL AND METHODS Part 1: MRIs of volunteers Data on healthy knees of 10 volunteers were obtained using 2D MRI measurements. The foot and the ankle were fixed to prevent rotation and adduction/abduction movements. Sagittal MRIs of the knees have been performed in 4 positions of flexion. The amount of longitudinal rotation in each position of flexion was calculated. Part 2: Mathematical model experiment a) The model of the femur has been positioned in the 3D coordinate system in full extension and at 12.8° of internal rotation and then flexed to 90° without longitudinal rotation. The distance between the centre of the femoral head and the sagittal plane passing through the centre of the knee was then measured. b) Subsequently, the femur was flexed and rotation allowed to retain femoral head within the sagittal plane. The amount of femoral rotation was then calculated. RESULTS Part 1: In full extension the femur was on average in 12.8° of IR relative to the tibia. By 90° flexion femur rotated on average 12.2° externally. Part 2: a)From full extension to 90° flexion the femoral head moved 93.1 mm laterally from the sagittal plane. b)Between full extension and 90° flexion the femur rotated 12.8° externally, a degree which corresponds to the amount of initial internal rotation of the femur in full extension. DISCUSSION The most important finding of the presented in vivo study lies in the fact that in normal knees with tibia rotationally fixed flexion is always coupled with femoral external rotation in order to keep the femoral head in the acetabulum. This rotation is obligatory. CONCLUSIONS We have demonstrated that if the tibia is rotationally fixed, the knee flexion is possible only when accompanied by femoral external rotation to keep the femoral head in the acetabulum. A mathematical description of the experiment has been proposed, the results of which confirm the stated premise. This finding can be explained by initial internal rotation of the femur in full extension of the knee and is allowed by the shape of articulating bones and tension of soft tissues Key words: knee, terminal extension, knee rotation, knee movement, MRI, hip joint.
- MeSH
- biologické modely MeSH
- biomechanika MeSH
- femur diagnostické zobrazování fyziologie MeSH
- kolenní kloub diagnostické zobrazování fyziologie MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- rotace MeSH
- rozsah kloubních pohybů MeSH
- tibie diagnostické zobrazování fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Given by χ torsional angles, rotamers describe the side-chain conformations of amino acid residues in a protein based on the rotational isomers (hence the word rotamer). Constructed rotamer libraries, based on either protein crystal structures or dynamics studies, are the tools for classifying rotamers (torsional angles) in a way that reflect their frequency in nature. Rotamer libraries are routinely used in structure modeling and evaluation. In this perspective article, we would like to encourage researchers to apply rotamer analyses beyond their traditional use. Molecular dynamics (MD) of proteins highlight the in silico behavior of molecules in solution and thus can identify favorable side-chain conformations. In this article, we used simple computational tools to study rotamer dynamics (RD) in MD simulations. First, we isolated each frame in the MD trajectories in separate Protein Data Bank files via the cpptraj module in AMBER. Then, we extracted torsional angles via the Bio3D module in R language. The classification of torsional angles was also done in R according to the penultimate rotamer library. RD analysis is useful for various applications such as protein folding, study of rotamer-rotamer relationship in protein-protein interaction, real-time correlation between secondary structures and rotamers, study of flexibility of side chains in binding site for molecular docking preparations, use of RD as guide in functional analysis and study of structural changes caused by mutations, providing parameters for improving coarse-grained MD accuracy and speed, and many others. Major challenges facing RD to emerge as a new scientific field involve the validation of results via easy, inexpensive wet-lab methods. This realm is yet to be explored.
We present the ROCA (ROad Curvature Analyst) software, in the form of an ESRI ArcGIS Toolbox, intended for vector line data processing. The software segments road network data into tangents and horizontal curves. Horizontal curve radii and azimuth of tangents are then automatically computed. Simultaneously, additional frequently used road section characteristics are calculated, such as the sinuosity of a road section (detour ratio), the number of turns along an individual road section and the average cumulative angle for a road section. The identification of curves is based on the naïve Bayes classifier and users are allowed to prepare their own training data files. We applied ROCA software to secondary roads within the Czech road network (9,980 km). The data processing took less than ten minutes. Approximately 43% of the road network in question consists of 42,752 horizontal curves. The ROCA software outperforms other existing automatic methods by 26% with respect to the percentage of correctly identified curves. The segmented secondary roads within the Czech road network can be viewed on the roca.cdvgis.cz/czechia web-map application. We combined data on road geometry with road crashes database to develop the crash modification factors for horizontal curves with various radii. We determined that horizontal curves with radii of 50 m are approximately 3.7 times more hazardous than horizontal curves with radii accounting for 1000 m. ROCA software can be freely downloaded for noncommercial use from https://roca.cdvinfo.cz/ website.
- MeSH
- automobily normy MeSH
- bezpečnost MeSH
- dopravní nehody prevence a kontrola MeSH
- geografické informační systémy MeSH
- lidé MeSH
- pomůcky pro sebeobsluhu * MeSH
- řízení motorových vozidel * normy MeSH
- rotace * MeSH
- rozpoznávání automatizované metody MeSH
- software * normy MeSH
- životní prostředí - projekt MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
PURPOSE: The objective of this study was to evaluate knee rotational stability at least 2 years after anatomic single-bundle anterior cruciate ligament (ACL) reconstruction (SB) and double-bundle ACL reconstruction (DB) in comparison with the contralateral healthy knee joint. The Cincinnati, Lysholm and IKDC scores were analysed too. METHODS: There were 40 patients in both groups, the mean follow-up was 27 months. For all measurements, the navigation system OrthoPilot was used. Measurement started with the patient in the standing position in neutral rotation. Then, the patient achieved in 30° knee flexion under weight-bearing maximal external trunk rotation and returned to the neutral position. The same measurement was done for the internal trunk rotation. For the anterior-posterior stability, KT-1000 arthrometer was used. All measurements were repeated three times for each knee joint. RESULTS: After the DB reconstruction, the mean external rotation of the tibia (ER) was 8.2° and the internal rotation (IR) was 10.2°. In the contralateral healthy knee joint, ER was 8.5° (p = 0.597) and IR was 12.1° (p = 0.064). After the SB reconstruction, ER was 9.4° and IR was 13.1°. In the contralateral healthy knee joint, ER was 7.7° (p = 0.066) and IR was 9.8° (p = 0.005). Anterior-posterior translation was to the same extent for both groups. CONCLUSIONS: The DB reconstruction of the ACL restores the rotational stability of the knee joint without any significant difference in comparison to the contralateral healthy knee (p > 0.05). The main finding of this study is that the internal rotational stability of the knee joint after the anatomic SB technique is not sufficient.
- MeSH
- biomechanika MeSH
- dospělí MeSH
- kolenní kloub patofyziologie chirurgie MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- následné studie MeSH
- nestabilita kloubu patofyziologie chirurgie MeSH
- poranění předního zkříženého vazu patofyziologie chirurgie MeSH
- rekonstrukce předního zkříženého vazu * MeSH
- rotace MeSH
- rozsah kloubních pohybů fyziologie MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
