Automatic extraction of the mid-sagittal plane using an ICP variant

NASA Astrophysics Data System (ADS)

Fieten, Lorenz; Eschweiler, Jörg; de la Fuente, Matías; Gravius, Sascha; Radermacher, Klaus

2008-03-01

Precise knowledge of the mid-sagittal plane is important for the assessment and correction of several deformities. Furthermore, the mid-sagittal plane can be used for the definition of standardized coordinate systems such as pelvis or skull coordinate systems. A popular approach for mid-sagittal plane computation is based on the selection of anatomical landmarks located either directly on the plane or symmetrically to it. However, the manual selection of landmarks is a tedious, time-consuming and error-prone task, which requires great care. In order to overcome this drawback, previously it was suggested to use the iterative closest point (ICP) algorithm: After an initial mirroring of the data points on a default mirror plane, the mirrored data points should be registered iteratively to the model points using rigid transforms. Finally, a reflection transform approximating the cumulative transform could be extracted. In this work, we present an ICP variant for the iterative optimization of the reflection parameters. It is based on a closed-form solution to the least-squares problem of matching data points to model points using a reflection. In experiments on CT pelvis and skull datasets our method showed a better ability to match homologous areas.

Measurement of lumbar spine intervertebral motion in the sagittal plane using videofluoroscopy.

PubMed

Harvey, Steven; Hukins, David; Smith, Francis; Wardlaw, Douglas; Kader, Deiary

2016-08-10

Static radiographic techniques are unable to capture the wealth of kinematic information available from lumbar spine sagittal plane motion. Demonstration of a viable non-invasive technique for acquiring and quantifying intervertebral motion of the lumbar spine in the sagittal plane. Videofluoroscopic footage of sagittal plane lumbar spine flexion-extension in seven symptomatic volunteers (mean age = 48 yrs) and one asymptomatic volunteer (age = 54 yrs) was recorded. Vertebral bodies were digitised using customised software employing a novel vertebral digitisation scheme that was minimally affected by out-of-plane motion. Measurement errors in intervertebral rotation (± 1°) and intervertebral displacement (± 0.5 mm) compare favourably with the work of others. Some subjects presenting with an identical condition (disc prolapse) exhibited a similar column vertebral flexion-extension relative to S1 (L3: max. 5.9°, min. 5.6°), while in others (degenerative disc disease) there was paradoxically a significant variation in this measurement (L3: max. 28.1°, min. 0.7°). By means of a novel vertebral digitisation scheme and customised digitisation/analysis software, sagittal plane intervertebral motion data of the lumbar spine data has been successfully extracted from videofluoroscopic image sequences. Whilst the intervertebral motion signatures of subjects in this study differed significantly, the available sample size precluded the inference of any clinical trends.

Gender difference of ankle stability in the sagittal and frontal planes.

PubMed

Hanzlick, Harrison; Hyunglae Lee

2017-07-01

This paper offers quantification of ankle stability in relation to simulated haptic environments of varying stiffness. This study analyzes the stability trends of male and female subjects independently over a wide range of simulated environments after subjects were exposed to vigorous position perturbation. Ankle stability was quantified for both degrees-of-freedom of the ankle in the sagittal and frontal planes. Subjects' stability consistently decreased when exposed to environments of negative simulated stiffness. In the frontal plane, male and female subjects exhibited nearly identical stability levels. In the sagittal plane, however, male subjects demonstrated marginally more stability than female subjects in environments with negative stiffness. Results of this study are beneficial to understanding situations in which the ankle is likely to lose stability, potentially resulting in injury.

Reliability and reproducibility analysis of the Cobb angle and assessing sagittal plane by computer-assisted and manual measurement tools.

PubMed

Wu, Weifei; Liang, Jie; Du, Yuanli; Tan, Xiaoyi; Xiang, Xuanping; Wang, Wanhong; Ru, Neng; Le, Jinbo

2014-02-06

Although many studies on reliability and reproducibility of measurement have been performed on coronal Cobb angle, few results about reliability and reproducibility are reported on sagittal alignment measurement including the pelvis. We usually use SurgimapSpine software to measure the Cobb angle in our studies; however, there are no reports till date on its reliability and reproducible measurements. Sixty-eight standard standing posteroanterior whole-spine radiographs were reviewed. Three examiners carried out the measurements independently under the settings of manual measurement on X-ray radiographies and SurgimapSpine software on the computer. Parameters measured included pelvic incidence, sacral slope, pelvic tilt, Lumbar lordosis (LL), thoracic kyphosis, and coronal Cobb angle. SPSS 16.0 software was used for statistical analyses. The means, standard deviations, intraclass and interclass correlation coefficient (ICC), and 95% confidence intervals (CI) were calculated. There was no notable difference between the two tools (P = 0.21) for the coronal Cobb angle. In the sagittal plane parameters, the ICC of intraobserver reliability for the manual measures varied from 0.65 (T2-T5 angle) to 0.95 (LL angle). Further, for SurgimapSpine tool, the ICC ranged from 0.75 to 0.98. No significant difference in intraobserver reliability was found between the two measurements (P > 0.05). As for the interobserver reliability, measurements with SurgimapSpine tool had better ICC (0.71 to 0.98 vs 0.59 to 0.96) and Pearson's coefficient (0.76 to 0.99 vs 0.60 to 0.97). The reliability of SurgimapSpine measures was significantly higher in all parameters except for the coronal Cobb angle where the difference was not significant (P > 0.05). Although the differences between the two methods are very small, the results of this study indicate that the SurgimapSpine measurement is an equivalent measuring tool to the traditional manual in coronal Cobb angle, but is advantageous in spino

Reliability and reproducibility analysis of the Cobb angle and assessing sagittal plane by computer-assisted and manual measurement tools

PubMed Central

2014-01-01

Background Although many studies on reliability and reproducibility of measurement have been performed on coronal Cobb angle, few results about reliability and reproducibility are reported on sagittal alignment measurement including the pelvis. We usually use SurgimapSpine software to measure the Cobb angle in our studies; however, there are no reports till date on its reliability and reproducible measurements. Methods Sixty-eight standard standing posteroanterior whole-spine radiographs were reviewed. Three examiners carried out the measurements independently under the settings of manual measurement on X-ray radiographies and SurgimapSpine software on the computer. Parameters measured included pelvic incidence, sacral slope, pelvic tilt, Lumbar lordosis (LL), thoracic kyphosis, and coronal Cobb angle. SPSS 16.0 software was used for statistical analyses. The means, standard deviations, intraclass and interclass correlation coefficient (ICC), and 95% confidence intervals (CI) were calculated. Results There was no notable difference between the two tools (P = 0.21) for the coronal Cobb angle. In the sagittal plane parameters, the ICC of intraobserver reliability for the manual measures varied from 0.65 (T2–T5 angle) to 0.95 (LL angle). Further, for SurgimapSpine tool, the ICC ranged from 0.75 to 0.98. No significant difference in intraobserver reliability was found between the two measurements (P > 0.05). As for the interobserver reliability, measurements with SurgimapSpine tool had better ICC (0.71 to 0.98 vs 0.59 to 0.96) and Pearson’s coefficient (0.76 to 0.99 vs 0.60 to 0.97). The reliability of SurgimapSpine measures was significantly higher in all parameters except for the coronal Cobb angle where the difference was not significant (P > 0.05). Conclusion Although the differences between the two methods are very small, the results of this study indicate that the SurgimapSpine measurement is an equivalent measuring tool to the traditional manual

Lower extremity energy absorption and biomechanics during landing, part I: sagittal-plane energy absorption analyses.

PubMed

Norcross, Marc F; Lewek, Michael D; Padua, Darin A; Shultz, Sandra J; Weinhold, Paul S; Blackburn, J Troy

2013-01-01

Eccentric muscle actions of the lower extremity absorb kinetic energy during landing. Greater total sagittal-plane energy absorption (EA) during the initial impact phase (INI) of landing has been associated with landing biomechanics considered high risk for anterior cruciate ligament (ACL) injury. We do not know whether groups with different INI EA magnitudes exhibit meaningful differences in ACL-related landing biomechanics and whether INI EA might be useful to identify ACL injury-risk potential. To compare biomechanical factors associated with noncontact ACL injury among sagittal-plane INI EA groups and to determine whether an association exists between sex and sagittal-plane INI EA group assignment to evaluate the face validity of using sagittal-plane INI EA to identify ACL injury risk. Descriptive laboratory study. Research laboratory. A total of 82 (41 men, 41 women; age = 21.0 ± 2.4 years, height = 1.74 ± 0.10 m, mass = 70.3 ± 16.1 kg) healthy, physically active individuals volunteered. We assessed landing biomechanics using an electromagnetic motion-capture system and force plate during a double-legged jump-landing task. Total INI EA was used to group participants into high, moderate, and low tertiles. Sagittal- and frontal-plane knee kinematics; peak vertical and posterior ground reaction forces (GRFs); anterior tibial shear force; and internal hip extension, knee extension, and knee varus moments were identified and compared across groups using 1-way analyses of variance. We used a χ (2) analysis to compare male and female representation in the high and low groups. The high group exhibited greater knee-extension moment and posterior GRFs than both the moderate (P < .05) and low (P < .05) groups and greater anterior tibial shear force than the low group (P < .05). No other group differences were noted. Women were not represented more than men in the high group (χ(2) = 1.20, P = .27). Greater sagittal-plane INI EA likely indicates greater ACL loading

Does Shoe Collar Height Influence Ankle Joint Kinematics and Kinetics in Sagittal Plane Maneuvers?

PubMed Central

Yang, Yang; Fang, Ying; Zhang, Xini; He, Junliang; Fu, Weijie

2017-01-01

The Objective of the study is to investigate the effects of basketball shoes with different collar heights on ankle kinematics and kinetics and athletic performance in different sagittal plane maneuvers. Twelve participants who wore high-top and low-top basketball shoes (hereafter, HS and LS, respectively) performed a weight-bearing dorsiflexion (WB-DF) maneuver, drop jumps (DJs), and lay-up jumps (LJs). Their sagittal plane kinematics and ground reaction forces were recorded using the Vicon motion capture system and Kistler force plates simultaneously. Moreover, ankle dorsiflexion and plantarflexion angles, moment, power, stiffness, and jump height were calculated. In the WB-DF test, the peak ankle dorsiflexion angle (p = 0.041) was significantly smaller in HS than in LS. Additionally, the peak ankle plantarflexion moment (p = 0.028) and power (p = 0.022) were significantly lower in HS than in LS during LJs but not during DJs. In both jumping maneuvers, no significant differences were found in the jump height or ankle kinematics between the two shoe types. According to the WB-DF test, increasing shoe collar height can effectively reduce the ankle range of motion in the sagittal plane. Although the HS did not restrict the flexion–extension performance of the ankle joint during two jumping maneuvers, an increased shoe collar height can reduce peak ankle plantarflexion moment and peak power during the push-off phase in LJs. Therefore, a higher shoe collar height should be used to circumvent effects on the partial kinetics of the ankle joint in the sagittal plane. Key points An increased shoe collar height effectively reduced ankle joint ROM in the sagittal plane in weight-bearing dorsiflexion maneuver. Shoe collar height did not affect sagittal plane ankle kinematics and had no effect on performance during realistic jumping. Shoe collar height can affect the ankle plantarflexion torque and peak power during the push-off phase in lay-up jump. PMID:29238255

A systematic review of the angular values obtained by computerized photogrammetry in sagittal plane: a proposal for reference values.

PubMed

Krawczky, Bruna; Pacheco, Antonio G; Mainenti, Míriam R M

2014-05-01

Reference values for postural alignment in the coronal plane, as measured by computerized photogrammetry, have been established but not for the sagittal plane. The objective of this study is to propose reference values for angular measurements used for postural analysis in the sagittal plane for healthy adults. Electronic databases (PubMed, BVS, Cochrane, Scielo, and Science Direct) were searched using the following key words: evaluation, posture, photogrammetry, and software. Articles published between 2006 and 2012 that used the PAS/SAPO (postural assessment software) were selected. Another inclusion criterion was the presentation of, at least, one of the following measurements: head horizontal alignment, pelvic horizontal alignment, hip angle, vertical alignment of the body, thoracic kyphosis, and lumbar lordosis. Angle samples of the selected articles were grouped 2 by 2 in relation to an overall average, which made possible total average, variance, and SD calculations. Six articles were included, and the following average angular values were found: 51.42° ± 4.87° (head horizontal alignment), -12.26° ± 5.81° (pelvic horizontal alignment), -6.40° ± 3.86° (hip angle), and 1.73° ± 0.94° (vertical alignment of the body). None of the articles contained the measurements for thoracic kyphosis and lumbar lordosis. The reference values can be adopted as reference for postural assessment in future researches if the same anatomical points are considered. Copyright © 2014 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

Lower Extremity Energy Absorption and Biomechanics During Landing, Part I: Sagittal-Plane Energy Absorption Analyses

PubMed Central

Norcross, Marc F.; Lewek, Michael D.; Padua, Darin A.; Shultz, Sandra J.; Weinhold, Paul S.; Blackburn, J. Troy

2013-01-01

Context: Eccentric muscle actions of the lower extremity absorb kinetic energy during landing. Greater total sagittal-plane energy absorption (EA) during the initial impact phase (INI) of landing has been associated with landing biomechanics considered high risk for anterior cruciate ligament (ACL) injury. We do not know whether groups with different INI EA magnitudes exhibit meaningful differences in ACL-related landing biomechanics and whether INI EA might be useful to identify ACL injury-risk potential. Objective: To compare biomechanical factors associated with noncontact ACL injury among sagittal-plane INI EA groups and to determine whether an association exists between sex and sagittal-plane INI EA group assignment to evaluate the face validity of using sagittal-plane INI EA to identify ACL injury risk. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: A total of 82 (41 men, 41 women; age = 21.0 ± 2.4 years, height = 1.74 ± 0.10 m, mass = 70.3 ± 16.1 kg) healthy, physically active individuals volunteered. Intervention(s): We assessed landing biomechanics using an electromagnetic motion-capture system and force plate during a double-legged jump-landing task. Main Outcome Measure(s): Total INI EA was used to group participants into high, moderate, and low tertiles. Sagittal- and frontal-plane knee kinematics; peak vertical and posterior ground reaction forces (GRFs); anterior tibial shear force; and internal hip extension, knee extension, and knee varus moments were identified and compared across groups using 1-way analyses of variance. We used a χ2 analysis to compare male and female representation in the high and low groups. Results: The high group exhibited greater knee-extension moment and posterior GRFs than both the moderate (P < .05) and low (P < .05) groups and greater anterior tibial shear force than the low group (P < .05). No other group differences were noted. Women were not represented more than

Alteration of the end-plane angle in press-fit cylindrical stem radial head prosthesis: an in vitro study.

PubMed

Luenam, Suriya; Chalongviriyalert, Piti; Kosiyatrakul, Arkaphat; Thanawattano, Chusak

2012-01-01

Many studies comparing the morphology of native radial head with the prosthesis have been published. However, there is limited information regarding the postoperative alignment of the articular surface following the radial head replacement. The purpose of this study is to evaluate the alteration of the end-plane angle in the modular radial head prosthesis with a press-fit cementless cylindrical stem. The study used 36 cadaveric radii. The press-fit size prosthesis with cylindrical stem was inserted into each specimen. The end-plane angles of the radial head before and after prosthetic replacement, were measured in coronal and sagittal planes with a digital inclinometer. The data were analyzed by paired t-test. From paired t-test, there were statistically symmetrical end-plane angles before and after radial head replacement in both coronal and sagittal planes (p-value < 0.01). The mean of radial head end-plane angle alteration in the coronal plane was 3.62° (SD, 2.76°) (range, 0.3°-8.9°). In the sagittal plane, the mean of alteration was 5.85° (SD, 3.56°) degrees (range, 0.3° - 14.2°). The modular radial head prosthesis with cylindrical stem is in vitro able to restore the native end-plane angles of radial heads statistically when used in a press-fit fashion.

Clinical validation of coronal and sagittal spinal curve measurements based on three-dimensional vertebra vector parameters.

PubMed

Somoskeöy, Szabolcs; Tunyogi-Csapó, Miklós; Bogyó, Csaba; Illés, Tamás

2012-10-01

� (Group 4; n=49), and above 75° (Group 5; n=22). All study subjects were examined by EOS 2D imaging, resulting in anteroposterior (AP) and lateral (LAT) full spine, orthogonal digital X-ray images, in standing position. Conventional coronal and sagittal curvature measurements including sagittal L5 vertebra wedges were determined by 3 experienced examiners, using traditional Cobb methods on EOS 2D AP and LAT images. Vertebra vector-based measurements were performed as published earlier, based on computer-assisted calculations of corresponding spinal curvature. Vertebra vectors were generated by dedicated software from sterEOS 3D spine models reconstructed from EOS 2D images by the same three examiners. Manual measurements were performed by each examiner, thrice for sterEOS 3D reconstructions and twice for vertebra vector-based measurements. Means comparison t test, Pearson bivariate correlation analysis, reliability analysis by intraclass correlation coefficients for intraobserver reproducibility and interrater reliability were performed using SPSS v16.0 software. In comparison with manual 2D methods, only small and nonsignificant differences were detectable in vertebra vector-based curvature data for coronal curves and thoracic kyphosis, whereas the found difference in L1-L5 lordosis values was shown to be strongly related to the magnitude of corresponding L5 wedge. Intraobserver reliability was excellent for both methods, and interrater reproducibility was consistently higher for vertebra vector-based methods that was also found to be unaffected by the magnitude of coronal curves or sagittal plane deviations. Vertebra vector-based angulation measurements could fully substitute conventional manual 2D measurements, with similar accuracy and higher intraobserver reliability and interrater reproducibility. Vertebra vectors represent a truly 3D solution for clear and comprehensible 3D visualization of spinal deformities while preserving crucial parametric information for

Video raster stereography back shape reconstruction: a reliability study for sagittal, frontal, and transversal plane parameters.

PubMed

Schroeder, J; Reer, R; Braumann, K M

2015-02-01

As reliability of raster stereography was proved only for sagittal plane parameters with repeated measures on the same day, the present study was aiming at investigating variability and reliability of back shape reconstruction for all dimensions (sagittal, frontal, transversal) and for different intervals. For a sample of 20 healthy volunteers, intra-individual variability (SEM and CV%) and reliability (ICC ± 95% CI) were proved for sagittal (thoracic kyphosis, lumbar lordosis, pelvis tilt angle, and trunk inclination), frontal (pelvis torsion, pelvis and trunk imbalance, vertebral side deviation, and scoliosis angle), transversal (vertebral rotation), and functional (hyperextension) spine shape reconstruction parameters for different test-retest intervals (on the same day, between-day, between-week) by means of video raster stereography. Reliability was high for the sagittal plane (pelvis tilt, kyphosis and lordosis angle, and trunk inclination: ICC > 0.90), and good to high for lumbar mobility (0.86 < ICC < 0.97). Apart from sagittal plane spinal alignment, there was a lack of certainty for a high reproducibility indicated by wider ICC confidence intervals. So, reliability was fair to high for vertebral side deviation and the scoliosis angle (0.71 < ICC < 0.95), and poor to good for vertebral rotation values as well as for frontal plane upper body and pelvis position parameters (0.65 < ICC < 0.92). Coefficients for the between-day and between-week interval were a little lower than for repeated measures on the same day. Variability (SEM) was less than 1.5° or 1.5 mm, except for trunk inclination. Relative variability (CV) was greater in global trunk position and pelvis parameters (35-98%) than in scoliosis (14-20%) or sagittal sway parameters (4-8 %). Although we found a lower reproducibility for the frontal plane, raster stereography is considered to be a reliable method for the non-invasive, three-dimensional assessment of spinal alignment in normal non

Comparison of the Multidetector-row Computed Tomographic Angiography Axial and Coronal Planes' Usefulness for Detecting Thoracodorsal Artery Perforators

PubMed Central

Kim, Jong Gyu

2012-01-01

Background During the planning of a thoracodorsal artery perforator (TDAP) free flap, preoperative multidetector-row computed tomographic (MDCT) angiography is valuable for predicting the locations of perforators. However, CT-based perforator mapping of the thoracodorsal artery is not easy because of its small diameter. Thus, we evaluated 1-mm-thick MDCT images in multiple planes to search for reliable perforators accurately. Methods Between July 2010 and October 2011, 19 consecutive patients (13 males, 6 females) who underwent MDCT prior to TDAP free flap operations were enrolled in this study. Patients ranged in age from 10 to 75 years (mean, 39.3 years). MDCT images were acquired at a thickness of 1 mm in the axial, coronal, and sagittal planes. Results The thoracodorsal artery perforators were detected in all 19 cases. The reliable perforators originating from the descending branch were found in 14 cases, of which 6 had transverse branches. The former were well identified in the coronal view, and the latter in the axial view. The location of the most reliable perforators on MDCT images corresponded well with the surgical findings. Conclusions Though MDCT has been widely used in performing the abdominal perforator free flap for detecting reliable perforating vessels, it is not popular in the TDAP free flap. The results of this study suggest that multiple planes of MDCT may increase the probability of detecting the most reliable perforators, along with decreasing the probability of missing available vessels. PMID:22872839

Sagittal plane analysis of the spine and pelvis in degenerative lumbar scoliosis.

PubMed

Han, Fei; Weishi, Li; Zhuoran, Sun; Qingwei, Ma; Zhongqiang, Chen

2017-01-01

Previous studies have reported the normative values of pelvic sagittal parameters, but no study has analyzed the sagittal spino-pelvic alignment in degenerative lumbar scoliosis (DLS) and its role in the pathogenesis. Retrospective analysis was applied to 104 patients with DLS, together with 100 cases of asymptomatic young adults as a control group and another control group consisting of 145 cases with cervical spondylosis. The coronal and sagittal parameters were measured on the anteroposterior and lateral radiograph of the whole spine in the DLS group as well as in the two control groups. Statistical analysis showed that the DLS group had a higher pelvic incidence (PI) value (50.5° ± 10.2°), than the normal control group (with PI 47.2° ± 8.8°) and the cervical spondylosis group (46.9° ± 9.1°). In DLS group, there were 38 cases (36.5%) complicated with degenerative lumbar spondylolisthesis, who had higher PI values than patients without it. Besides, the lumbar lordosis (LL) and sacral slope (SS) of DLS group were lower; the scoliosis Cobb's angle was correlated with pelvic tilt (PT); thoracic kyphosis was correlated with LL, SS, and PT; and LL was correlated with other sagittal parameters. Patients with DLS may have a higher PI, which may impact the pathogenesis of DLS. A high PI value is probably associated with the high prevalence of degenerative lumbar spondylolisthesis among DLS patients. In DLS patients, the lumbar spine maintains the ability of regulating the sagittal balance, and the regulation depends more on thoracic curve.

Metacarpal geometry changes during Thoroughbred race training are compatible with sagittal-plane cantilever bending.

PubMed

Merritt, J S; Davies, H M S

2010-11-01

Bending of the equine metacarpal bones during locomotion is poorly understood. Cantilever bending, in particular, may influence the loading of the metacarpal bones and surrounding structures in unique ways. We hypothesised that increased amounts of sagittal-plane cantilever bending may govern changes to the shape of the metacarpal bones of Thoroughbred racehorses during training. We hypothesised that this type of bending would require a linear change to occur in the combined second moment of area of the bones for sagittal-plane bending (I) during race training. Six Thoroughbred racehorses were used, who had all completed at least 4 years of race training at a commercial stable. The approximate change in I that had occurred during race training was computed from radiographic measurements at the start and end of training using a simple model of bone shape. A significant (P < 0.001), approximately linear pattern of change in I was observed in each horse, with the maximum change occurring proximally and the minimum change occurring distally. The pattern of change in I was compatible with the hypothesis that sagittal-plane cantilever bending governed changes to the shape of the metacarpal bones during race training. © 2010 EVJ Ltd.

A comparison of economy and sagittal plane trunk movements among back-, back/front- and head-loading.

PubMed

Hudson, Sean; Cooke, Carlton; Davies, Simeon; West, Sacha; Gamieldien, Raeeq; Low, Chris; Lloyd, Ray

2018-05-14

It has been suggested that freedom of movement in the trunk could influence load carriage economy. This study aimed to compare the economy and sagittal plane trunk movements associated with three load carriage methods that constrain posture differently. Eighteen females walked at 3 km.h -1 with loads of 0, 3, 6, 9, 12, 15 and 20 kg carried on the back, back/front and head. Load carriage economy was assessed using the Extra Load Index (ELI). Change in sagittal plane trunk forward lean and trunk angle excursion from unloaded to loaded walking were assessed. Results show no difference in economy between methods (p = 0.483), despite differences in the change in trunk forward lean (p = 0.001) and trunk angle excursion (p = 0.021) from unloaded to loaded walking. We conclude that economy is not different among the three methods of load carriage, despite significant differences in sagittal plane trunk movements.

Ipsilateral wrist-ankle movements in the sagittal plane encoded in extrinsic reference frame.

PubMed

Muraoka, Tetsuro; Ishida, Yuki; Obu, Takashi; Crawshaw, Larry; Kanosue, Kazuyuki

2013-04-01

When performing oscillatory movements of two joints in the sagittal plane, there is a directional constraint for performing such movements. Previous studies could not distinguish whether the directional constraint reflected movement direction encoded in the extrinsic (outside the body) reference frame or in the intrinsic (the participants' torso/head) reference frame since participants performed coordinated movements in a sitting position where the torso/head was stationary relative to the external world. In order to discern the reference frame in the present study, participants performed paced oscillatory movements of the ipsilateral wrist and ankle in the sagittal plane in a standing position so that the torso/head moved relative to the external world. The coordinated movements were performed in one of two modes of coordination, moving the hand upward concomitant with either ankle plantarflexion or ankle dorsiflexion. The same directional mode relative to extrinsic space was more stable and accurate as compared with the opposite directional mode. When forearm position was changed from the pronated position to the supinated position, similar results were obtained, indicating that the results were independent of a particular coupling of muscles. These findings suggest that the directional constraint on ipsilateral joints movements in the sagittal plane reflects movement direction encoded in the extrinsic reference frame. Copyright © 2013 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Sagittal plane tilting deformity of the patellofemoral joint: a new concept in patients with chondromalacia patella.

PubMed

Aksahin, Ertugrul; Aktekin, Cem Nuri; Kocadal, Onur; Duran, Semra; Gunay, Cüneyd; Kaya, Defne; Hapa, Onur; Pepe, Murad

2017-10-01

The aims of this study were to evaluate sagittal plane alignment in patients with chondromalacia patella via magnetic resonance imaging (MRI), analyse the relationships between the location of the patellar cartilaginous lesions and sagittal alignment and finally investigate the relationships between the sagittal plane malalignment and patellofemoral loadings using by finite element analysis. Fifty-one patients who were diagnosed with isolated modified Outerbridge grade 3-4 patellar chondromalacia based on MRI evaluation and 51 control subjects were evaluated. Chondromalacia patella patients were divided into three subgroups according to the chondral lesion location as superior, middle and inferior. The patella-patellar tendon angle (P-PT) was used for evaluation of sagittal alignment of patellofemoral joint. Each subgroup was compared with control group by using P-PT angle. To investigate the biomechanical effects of sagittal plane malpositioning on patellofemoral joint, bone models were created at 30°, 60° and 90° knee flexion by using mean P-PT angles, which obtained from patients with chondromalacia patellae and control subjects. The total loading and contact area values of the patellofemoral joints were investigated by finite element analysis. The mean age of all participants was 52.9 ± 8.2 years. The mean P-PT angle was significantly lower in chondromalacia group (142.1° ± 3.6°) compared to control group (144.5° ± 5.3°) (p = 0.008). Chondral lesions were located in superior, middle and inferior zones in 16, 20 and 15 patients, respectively. The mean P-PT angles in patients with superior (141.8 ± 2.7) and inferior subgroups (139.2 ± 2.3) were significantly lower than the values in the control group (p < 0.05). The contact area values were detected higher in models with chondromalacia than in the control models at the same flexion degrees. There were increased loadings at 30° and 90° flexions in the sagittal patellar tilt models

MRI to delineate the gross tumor volume of nasopharyngeal cancers: which sequences and planes should be used?

PubMed

Popovtzer, Aron; Ibrahim, Mohannad; Tatro, Daniel; Feng, Felix Y; Ten Haken, Randall K; Eisbruch, Avraham

2014-09-01

Magnetic resonance imaging (MRI) has been found to be better than computed tomography for defining the extent of primary gross tumor volume (GTV) in advanced nasopharyngeal cancer. It is routinely applied for target delineation in planning radiotherapy. However, the specific MRI sequences/planes that should be used are unknown. Twelve patients with nasopharyngeal cancer underwent primary GTV evaluation with gadolinium-enhanced axial T1 weighted image (T1) and T2 weighted image (T2), coronal T1, and sagittal T1 sequences. Each sequence was registered with the planning computed tomography scans. Planning target volumes (PTVs) were derived by uniform expansions of the GTVs. The volumes encompassed by the various sequences/planes, and the volumes common to all sequences/planes, were compared quantitatively and anatomically to the volume delineated by the commonly used axial T1-based dataset. Addition of the axial T2 sequence increased the axial T1-based GTV by 12% on average (p = 0.004), and composite evaluations that included the coronal T1 and sagittal T1 planes increased the axial T1-based GTVs by 30% on average (p = 0.003). The axial T1-based PTVs were increased by 20% by the additional sequences (p = 0.04). Each sequence/plane added unique volume extensions. The GTVs common to all the T1 planes accounted for 38% of the total volumes of all the T1 planes. Anatomically, addition of the coronal and sagittal-based GTVs extended the axial T1-based GTV caudally and cranially, notably to the base of the skull. Adding MRI planes and sequences to the traditional axial T1 sequence yields significant quantitative and anatomically important extensions of the GTVs and PTVs. For accurate target delineation in nasopharyngeal cancer, we recommend that GTVs be outlined in all MRI sequences/planes and registered with the planning computed tomography scans.

Impact of sagittal spinopelvic alignment on clinical outcomes after decompression surgery for lumbar spinal canal stenosis without coronal imbalance.

PubMed

Hikata, Tomohiro; Watanabe, Kota; Fujita, Nobuyuki; Iwanami, Akio; Hosogane, Naobumi; Ishii, Ken; Nakamura, Masaya; Toyama, Yoshiaki; Matsumoto, Morio

2015-10-01

The object of this study was to investigate correlations between sagittal spinopelvic alignment and improvements in clinical and quality-of-life (QOL) outcomes after lumbar decompression surgery for lumbar spinal canal stenosis (LCS) without coronal imbalance. The authors retrospectively reviewed data from consecutive patients treated for LCS with decompression surgery in the period from 2009 through 2011. They examined correlations between preoperative or postoperative sagittal vertical axis (SVA) and radiological parameters, clinical outcomes, and health-related (HR)QOL scores in patients divided according to SVA. Clinical outcomes were assessed according to Japanese Orthopaedic Association (JOA) and visual analog scale (VAS) scores. Health-related QOL was evaluated using the Roland-Morris Disability Questionnaire (RMDQ) and the JOA Back Pain Evaluation Questionnaire (JOABPEQ). One hundred nine patients were eligible for inclusion in the study. Compared to patients with normal sagittal alignment prior to surgery (Group A: SVA < 50 mm), those with preoperative sagittal imbalance (Group B: SVA ≥ 50 mm) had significantly smaller lumbar lordosis and thoracic kyphosis angles and larger pelvic tilt. In Group B, there was a significant decrease in postoperative SVA compared with the preoperative SVA (76.3 ± 29.7 mm vs. 54.3 ± 39.8 mm, p = 0.004). The patients in Group B with severe preoperative sagittal imbalance (SVA > 80 mm) had residual sagittal imbalance after surgery (82.8 ± 41.6 mm). There were no significant differences in clinical and HRQOL outcomes between Groups A and B. Compared to patients with normal postoperative SVA (Group C: SVA < 50 mm), patients with a postoperative SVA ≥ 50 mm (Group D) had significantly lower JOABPEQ scores, both preoperative and postoperative, for walking ability (preop: 36.6 ± 26.3 vs. 22.7 ± 26.0, p = 0.038, respectively; postop: 71.1 ± 30.4 vs. 42.5 ± 29.6, p < 0.001) and social functioning (preop: 38.7 ± 18.5 vs. 30

Three-dimensional shear wave elastography for differentiation of breast lesions: An initial study with quantitative analysis using three orthogonal planes.

PubMed

Wang, Qiao

2018-05-25

To prospectively evaluate the diagnostic performance of three-dimensional (3D) shear wave elastography (SWE) for breast lesions with quantitative stiffness information from transverse, sagittal and coronal planes. Conventional ultrasound (US), two-dimensional (2D)-SWE and 3D-SWE were performed for 122 consecutive patients with 122 breast lesions before biopsy or surgical excision. Maximum elasticity values of Young's modulus (Emax) were recorded on 2D-SWE and three planes of 3D-SWE. Area under the receiver operating characteristic curve (AUC), sensitivity and specificity of US, 2D-SWE and 3D-SWE were evaluated. Two combined sets (i.e., BI-RADS and 2D-SWE; BI-RADS and 3D-SWE) were compared in AUC. Observer consistency was also evaluated. On 3D-SWE, the AUC and sensitivity of sagittal plane were significantly higher than those of transverse and coronal planes (both P < 0.05). Compared with BI-RADS alone, both combined sets had significantly (P < 0.05) higher AUCs and specificities, whereas, the two combined sets showed no significant difference in AUC (P > 0.05). However, the combined set of BI-RADS and sagittal plane of 3D-SWE had significantly higher sensitivity than the combined set of BI-RADS and 2D-SWE. The sagittal plane shows the best diagnostic performance among 3D-SWE. The combination of BI-RADS and 3D-SWE is a useful tool for predicting breast malignant lesions in comparison with BI-RADS alone.

Radiographic diagnosis of sagittal plane rotational displacement in pelvic fractures: a cadaveric model and clinical case study.

PubMed

Shui, Xiaolong; Ying, Xiaozhou; Kong, Jianzhong; Feng, Yongzeng; Hu, Wei; Guo, Xiaoshan; Wang, Gang

2015-08-01

Our objective was to measure the sagittal plane rotational (flexion and extension) displacement of hemipelvis radiologically and analyze the ratio of flexion and extension displacement of unstable pelvic fractures. We used 8 cadaveric models to study the radiographic evidence of pelvic fractures in the sagittal plane. We performed pelvic osteotomy on 8 cadavers to simulate anterior and posterior pelvic ring injury. Radiological data were measured in the flexion and extension group under different angles (5°, 10°, 15°, 20°, and 25°). We retrospectively reviewed 164 patients who were diagnosed with a unilateral fracture of the pelvis. Pelvic ring displacement was identified and recorded radiographically in cadaveric models. The flexion and extension displacement of pelvic fractures was measured in terms of the vertical distance of fracture from the top of iliac crest to the pubic tubercle (CD) or from the top of iliac crest to the lowest point of ischial tuberosity (AB). Fifty-seven pelves showed flexion displacement and 15 showed extension displacement. Closed reduction including internal fixation and external fixation was successfully used in 141 cases (86.0 %). The success rates of closed reduction in flexion and extension displacement groups were 77 and 73 %, respectively, which were lower than in unstable pelvic ring fractures. The sagittal plane rotation (flexion and extension) displacement of pelvic fractures could be measured by special points and lines on the radiographs. Minimally invasive reduction should be based on clearly identified differences between the sagittal plane rotation and the vertical displacement of pelvic fractures.

The Effect of Sagittal Plane Deformities after Tibial Plateau Fractures to Functions and Instability of Knee Joint.

PubMed

Erdil, M; Yildiz, F; Kuyucu, E; Sayar, Ş; Polat, G; Ceylan, H H; Koçyiğit, F

2016-01-01

The objective of this study is to evaluate the effect of posterior tibial slope after fracture healing on antero-posterior knee laxity, functional outcome and patient satisfaction. 126 patients who were treated for tibial plateau fractures between 2008-2013 in the orthopedics and traumatology department of our institution were evaluated for the study. Patients were treated with open reduction and internal fixation, arthroscopy assisted minimally invasive osteosynthesis or conservative treatment. Mean posterior tibial slope after the treatment was 6.91 ± 5.11 and there was no significant difference when compared to the uninvolved side 6.42 ± 4,21 (p = 0.794). Knee laxity in anterior-posterior plane was 6.14 ± 2.11 and 5.95 ± 2.25 respectively on healthy and injured side. The difference of mean laxity in anterior-posterior plane between two sides was statistically significant. In this study we found no difference in laxity between the injured and healthy knees. However Tegner score decreased significantly in patients who had greater laxity difference between the knees. We did not find significant difference between fracture type and laxity, IKDC functional scores independent of the ligamentous injury. In conclusion despite coronal alignment is taken into consideration in treatment of tibial plateau fractures, sagittal alignment is reasonably important for stability and should not be ignored.

[Tibiotalocalcaneal arthrodesis using a retrograde nail locked in the sagittal plane].

PubMed

Veselý, R; Procházka, V; Visna, P; Valentová, J; Savolt, J

2008-04-01

To evaluate our experience with the use of a retrograde nail locked in the sagittal plane for tibiotalocalcaneal arthrodesis indicated in severe post-traumatic arthritis of the ankle. Twenty patients, 16 men and four women at an average age of 58.7 years (range, 23 to 72) were evaluated. All patients had severe post-traumatic changes in the talocrural and talocalcaneal joints. Five patients also had an equinus deformity. In two patients arthrodesis followed the treatment of purulent arthritis of the talocrural joint. A local fasciocutaneous flap was used for soft tissue reconstruction in three patients. All patients were operated on using the standard surgical technique. METHODS With the patient in a supine position, reamed by hand with the use of a driving rod, a straight retrograde AAN Orthofix nail was inserted through the heel bone and talus into the distal tibia and locked in these bones in the sagittal plane. No complications such as injury to the neurovascular plexus or pseudoarthrosis were recorded. Four patients showed a reaction to the proximal locking screw on the proximal tibial surface, which was treated by earlier screw removal under topical anaesthesia. Due to infectious complications, the nail had to be removed prematurely in one patient. The average Foot Function Index was 12 points (range, 10 to 15) and the average ankle-hindfoot score was 67.6 points (range, 59 to 84). Thirteen patients (65 %) were not limited in their daily activities or recreational sports, six (30 %) experienced pain in sports but not daily activities and one patient (5 %) reported pain even when walking. All fusions healed in the correct position within 18 weeks. Tibiotalocalcaneal arthrodesis is not a frequent surgical procedure in either trauma surgery or orthopaedics. For this complicated procedure, rather than intramedullary nails, internal fixation with screws or plates or external fixation are preferred. The high rate of bony healing can be explained by maintenance of

Does correction of preoperative coronal imbalance make a difference in outcomes of adult patients with deformity?

PubMed

Daubs, Michael D; Lenke, Lawrence G; Bridwell, Keith H; Kim, Yongjung J; Hung, Man; Cheh, Gene; Koester, Linda A

2013-03-15

Retrospective study with prospectively collected outcomes data. Determine the significance of coronal balance on spinal deformity surgery outcomes. Sagittal balance has been confirmed as an important radiographic parameter correlating with adult deformity treatment outcomes. The significance of coronal balance on functional outcomes is less clear. Eighty-five patients with more than 4 cm of coronal imbalance who underwent reconstructive spinal surgery were evaluated to determine the significance of coronal balance on functional outcomes as measured with the Oswestry Disability Index (ODI) and Scoliosis Research Society outcomes questionnaires. Sixty-two patients had combined coronal (>4 cm) and sagittal imbalance (>5 cm), while 23 patients had coronal imbalance alone. Postoperatively, 85% of patients demonstrated improved coronal balance. The mean improvement in the coronal C7 plumb line was 26 mm for a mean correction of 42%. The mean preoperative sagittal C7 plumb line in patients with combined coronal and sagittal imbalance was 118 mm (range, 50-310 mm) and improved to a mean 49 mm. The mean preoperative and postoperative ODI scores were 42 (range, 0-90) and 27 (range, 0-78), for a mean improvement of 15 (36%) (P = 0.00001; 95% CI, 12-20). The mean Scoliosis Research Society scores improved by 17 points (29%) (P = 0.00). Younger age (P = 0.008) and improvement in sagittal balance (P = 0.014) were positive predictors for improved ODI scores. Improvement in sagittal balance (P = 0.010) was a positive predictor for improved Scoliosis Research Society scores. In patients with combined coronal and sagittal imbalance, improvement in sagittal balance was the most significant predictor for improved ODI scores (P = 0.009). In patients with preoperative coronal imbalance alone, improvement in coronal balance trended toward, but was not a significant predictor for improved ODI (P = 0.092). Sagittal balance improvement is the strongest predictor of improved outcomes in

Intrinsic and Extrinsic Contributions to Seated Balance in the Sagittal and Coronal Planes: Implications for Trunk Control After Spinal Cord Injury.

PubMed

Audu, Musa L; Triolo, Ronald J

2015-08-01

The contributions of intrinsic (passive) and extrinsic (active) properties of the human trunk, in terms of the simultaneous actions about the hip and spinal joints, to the control of sagittal and coronal seated balance were examined. Able-bodied (ABD) and spinal-cord-injured (SCI) volunteers sat on a moving platform which underwent small amplitude perturbations in the anterior-posterior (AP) and medial-lateral (ML) directions while changes to trunk orientation were measured. A linear parametric model that related platform movement to trunk angle was fit to the experimental data by identifying model parameters in the time domain. The results showed that spinal cord injury leads to a systematic reduction in the extrinsic characteristics, while most of the intrinsic characteristics were rarely affected. In both SCI and ABD individuals, passive characteristics alone were not enough to maintain seated balance. Passive stiffness in the ML direction was almost 3 times that in the AP direction, making more extrinsic mechanisms necessary for balance in the latter direction. Proportional and derivative terms of the extrinsic model made the largest contribution to the overall output from the active system, implying that a simple proportional plus derivative (PD) controller structure will suffice for restoring seated balance after spinal cord injury.

3D knee segmentation based on three MRI sequences from different planes.

PubMed

Zhou, L; Chav, R; Cresson, T; Chartrand, G; de Guise, J

2016-08-01

In clinical practice, knee MRI sequences with 3.5~5 mm slice distance in sagittal, coronal, and axial planes are often requested for the knee examination since its acquisition is faster than high-resolution MRI sequence in a single plane, thereby reducing the probability of motion artifact. In order to take advantage of the three sequences from different planes, a 3D segmentation method based on the combination of three knee models obtained from the three sequences is proposed in this paper. In the method, the sub-segmentation is respectively performed with sagittal, coronal, and axial MRI sequence in the image coordinate system. With each sequence, an initial knee model is hierarchically deformed, and then the three deformed models are mapped to reference coordinate system defined by the DICOM standard and combined to obtain a patient-specific model. The experimental results verified that the three sub-segmentation results can complement each other, and their integration can compensate for the insufficiency of boundary information caused by 3.5~5 mm gap between consecutive slices. Therefore, the obtained patient-specific model is substantially more accurate than each sub-segmentation results.

Knee joint passive stiffness and moment in sagittal and frontal planes markedly increase with compression.

PubMed

Marouane, H; Shirazi-Adl, A; Adouni, M

2015-01-01

Knee joints are subject to large compression forces in daily activities. Due to artefact moments and instability under large compression loads, biomechanical studies impose additional constraints to circumvent the compression position-dependency in response. To quantify the effect of compression on passive knee moment resistance and stiffness, two validated finite element models of the tibiofemoral (TF) joint, one refined with depth-dependent fibril-reinforced cartilage and the other less refined with homogeneous isotropic cartilage, are used. The unconstrained TF joint response in sagittal and frontal planes is investigated at different flexion angles (0°, 15°, 30° and 45°) up to 1800 N compression preloads. The compression is applied at a novel joint mechanical balance point (MBP) identified as a point at which the compression does not cause any coupled rotations in sagittal and frontal planes. The MBP of the unconstrained joint is located at the lateral plateau in small compressions and shifts medially towards the inter-compartmental area at larger compression forces. The compression force substantially increases the joint moment-bearing capacities and instantaneous angular rigidities in both frontal and sagittal planes. The varus-valgus laxities diminish with compression preloads despite concomitant substantial reductions in collateral ligament forces. While the angular rigidity would enhance the joint stability, the augmented passive moment resistance under compression preloads plays a role in supporting external moments and should as such be considered in the knee joint musculoskeletal models.

The effect of tibiotalar alignment on coronal plane mechanics following total ankle replacement.

PubMed

Grier, A Jordan; Schmitt, Abigail C; Adams, Samuel B; Queen, Robin M

2016-07-01

Gait mechanics following total ankle replacement (TAR) have reported improved ankle motion following surgery. However, no studies have addressed the impact of preoperative radiographic tibiotalar alignment on post-TAR gait mechanics. We therefore investigated whether preoperative tibiotalar alignment (varus, valgus, or neutral) resulted in significantly different coronal plane mechanics or ground reaction forces post-TAR. We conducted a non-randomized study of 93 consecutive end-stage ankle arthritis patients. Standard weight-bearing radiographs were obtained preoperatively to categorize patients as having neutral (±4°), varus (≥5° of varus), or valgus (≥5° of valgus) coronal plane tibiotalar alignment. All patients underwent a standard walking assessment including three-dimensional lower extremity kinetics and kinematics preoperatively, 12 and 24 months postoperatively. A significant group by time interaction was observed for the propulsive vertical ground reaction force (vGRF), coronal plane hip range of motion (ROM) and the peak hip abduction moment. The valgus group demonstrated an increase in the peak knee adduction angle and knee adduction angle at heel strike when compared to the other groups. Coronal plane ankle ROM, knee and hip angles at heel strike, and the peak hip angle exhibited significant increases across time. Peak ankle inversion moment, peak knee abduction moment and the weight acceptance vGRF also exhibited significant increases across time. Neutral ankle alignment was achieved for all patients by 2 years following TAR. Restoration of neutral ankle alignment at the time of TAR in patients with preoperative varus or valgus tibiotalar alignment resulted in biomechanics similar to those of patients with neutral preoperative tibiotalar alignment by 24-month follow-up. Copyright © 2016 Elsevier B.V. All rights reserved.

Relationship between movement time and hip moment impulse in the sagittal plane during sit-to-stand movement: a combined experimental and computer simulation study.

PubMed

Inai, Takuma; Takabayashi, Tomoya; Edama, Mutsuaki; Kubo, Masayoshi

2018-04-27

The association between repetitive hip moment impulse and the progression of hip osteoarthritis is a recently recognized area of study. A sit-to-stand movement is essential for daily life and requires hip extension moment. Although a change in the sit-to-stand movement time may influence the hip moment impulse in the sagittal plane, this effect has not been examined. The purpose of this study was to clarify the relationship between sit-to-stand movement time and hip moment impulse in the sagittal plane. Twenty subjects performed the sit-to-stand movement at a self-selected natural speed. The hip, knee, and ankle joint angles obtained from experimental trials were used to perform two computer simulations. In the first simulation, the actual sit-to-stand movement time obtained from the experiment was entered. In the second simulation, sit-to-stand movement times ranging from 0.5 to 4.0 s at intervals of 0.25 s were entered. Hip joint moments and hip moment impulses in the sagittal plane during sit-to-stand movements were calculated for both computer simulations. The reliability of the simulation model was confirmed, as indicated by the similarities in the hip joint moment waveforms (r = 0.99) and the hip moment impulses in the sagittal plane between the first computer simulation and the experiment. In the second computer simulation, the hip moment impulse in the sagittal plane decreased with a decrease in the sit-to-stand movement time, although the peak hip extension moment increased with a decrease in the movement time. These findings clarify the association between the sit-to-stand movement time and hip moment impulse in the sagittal plane and may contribute to the prevention of the progression of hip osteoarthritis.

Effect of posterior multilevel vertebral osteotomies on coronal and sagittal balance in fused scoliosis deformity caused by previous surgery: preliminary results.

PubMed

Yang, Jae Hyuk; Suh, Seung Woo; Cho, Won Tae; Hwang, Jin Ho; Hong, Jae Young; Modi, Hitesh N

2014-10-15

Prospective case series study. To study the effect of posterior multilevel vertebral osteotomy (posterior crack osteotomy) on coronal and sagittal balance in patients with the fusion mass over the spine caused by previous surgery. Few studies have investigated revisional scoliosis surgery with the fusion mass using osteotomy. Among patients who had a history of prior surgery for scoliosis correction and posterior fusion, those showing progression of the curve postoperatively due to nonunion, implant failure, or adding-on phenomenon were enrolled. All patients were treated using posterior crack osteotomy. For clinical evaluation, the pre- and postoperative Gross Motor Function Classification System score for walking status and the Berg balanced scale were used. For radiological evaluation, pre- and postoperative Cobb angle, and coronal and sagittal balance factors were used. Ten patients (5 males and 5 females) were enrolled. The preoperative diagnosis was neuromuscular scoliosis (3 cases), syndromic scoliosis (1 case), congenital scoliosis (5 cases), and neurofibromatosis (1 case). Osteotomies were performed at 3.3±1.3 levels on average. Pre- and postoperative Cobb angles were 70.8°±30.0° and 28.1°±20.0° (P=0.002 (0.97)), respectively. In pre- and postoperative evaluation of coronal balance, the coronal balance, clavicle angle, and T1-tilt angle were 36.8±27.1 mm and 10.4±8.5 mm, 6.7°±8.0° and 3.3°±1.5°, and 7.8°±19.0° and 4.7°±2.1°, respectively (P=0.002, 0.002, 0.002). In pre- and postoperative evaluation of sagittal balance, the spinal vertical axis, thoracic kyphosis, and lumbar alignments were 25.1±37.8 mm and 14.1±21.8 mm, 33.5°±51.1° and 29.7°±27.4°, and 45.7°±34.8° and 48.9°±23.1° (P=0.002, 0.169, 0.169). The walking and functional statuses did not change (P=0.317, 0.932). Although pulmonary and gastrointestinal complications were noted, the patients were discharged without complications. Posterior crack osteotomy can be

Changing Sagittal-Plane Landing Styles to Modulate Impact and Tibiofemoral Force Magnitude and Directions Relative to the Tibia

PubMed Central

Shimokochi, Yohei; Ambegaonkar, Jatin P.; Meyer, Eric G.

2016-01-01

Context: Ground reaction force (GRF) and tibiofemoral force magnitudes and directions have been shown to affect anterior cruciate ligament loading during landing. However, the kinematic and kinetic factors modifying these 2 forces during landing are unknown. Objective: To clarify the intersegmental kinematic and kinetic links underlying the alteration of the GRF and tibiofemoral force vectors secondary to changes in the sagittal-plane body position during single-legged landing. Design: Crossover study. Setting: Laboratory. Patients or Other Participants: Twenty recreationally active participants (age = 23.4 ± 3.6 years, height = 171.0 ± 9.4 cm, mass = 73.3 ± 12.7 kg). Intervention(s): Participants performed single-legged landings using 3 landing styles: self-selected landing (SSL), body leaning forward and landing on the toes (LFL), and body upright with flat-footed landing (URL). Three-dimensional kinetics and kinematics were recorded. Main Outcome Measure(s): Sagittal-plane tibial inclination and knee-flexion angles, GRF magnitude and inclination angles relative to the tibia, and proximal tibial forces at peak tibial axial forces. Results: The URL resulted in less time to peak tibial axial forces, smaller knee-flexion angles, and greater magnitude and a more anteriorly inclined GRF vector relative to the tibia than did the SSL. These changes led to the greatest peak tibial axial and anterior shear forces in the URL among the 3 landing styles. Conversely, the LFL resulted in longer time to peak tibial axial forces, greater knee-flexion angles, and reduced magnitude and a more posteriorly inclined GRF vector relative to the tibia than the SSL. These changes in LFL resulted in the lowest peak tibial axial and largest posterior shear forces among the 3 landing styles. Conclusions: Sagittal-plane intersegmental kinematic and kinetic links strongly affected the magnitude and direction of GRF and tibiofemoral forces during the impact phase of single-legged landing

[Evaluation of three methods for constructing craniofacial mid-sagittal plane based on the cone beam computed tomography].

PubMed

Wang, S W; Li, M; Yang, H F; Zhao, Y J; Wang, Y; Liu, Y

2016-04-18

To compare the accuracyof interactive closet point (ICP) algorithm, Procrustes analysis (PA) algorithm,and a landmark-independent method to construct the mid-sagittal plane (MSP) of the cone beam computed tomography.To provide theoretical basis for establishing coordinate systemof CBCT images and symmetric analysis. Ten patients were selected and scanned by CBCT before orthodontic treatment.The scan data was imported into Mimics 10.0 to reconstructthree dimensional skulls.And the MSP of each skull was generated by ICP algorithm, PA algorithm and landmark-independent method. MSP extracted by ICP algorithm or PA algorithm involvedthree steps. First, the 3D skull processing was performed by reverse engineering software geomagic studio 2012 to obtain the mirror skull. Then, the original and its mirror skull was registered separately by ICP algorithm in geomagic studio 2012 and PA algorithm in NX Imageware 11.0. Finally, the registered data were united into new data to calculate the MSP of the originaldata in geomagic studio 2012. The mid-sagittal plane was determined by SELLA (S), nasion (N), basion (Ba) as traditional landmark-dependent methodconducted in software InVivoDental 5.0. The distance from 9 pairs of symmetric anatomical marked points to three sagittal plane were measured and calculated to compare the differences of the absolute value. The one-way ANOVA test was used to analyze the variable differences among the 3 MSPs. The pairwise comparison was performed with LSD method. MSPs calculated by the three methods were available for clinic analysis, which could be concluded from the front view.However, there was significant differences among the distances from the 9 pairs of symmetric anatomical marked points to the MSPs (F=10.932,P=0.001).LSD test showed there was no significant difference between the ICP algorithm and landmark-independent method (P=0.11), while there was significant difference between the PA algorithm and landmark-independent methods (P=0

Agreement between fiber optic and optoelectronic systems for quantifying sagittal plane spinal curvature in sitting.

PubMed

Cloud, Beth A; Zhao, Kristin D; Breighner, Ryan; Giambini, Hugo; An, Kai-Nan

2014-07-01

Spinal posture affects how individuals function from a manual wheelchair. There is a need to directly quantify spinal posture in this population to ultimately improve function. A fiber optic system, comprised of an attached series of sensors, is promising for measuring large regions of the spine in individuals sitting in a wheelchair. The purpose of this study was to determine the agreement between fiber optic and optoelectronic systems for measuring spinal curvature, and describe the range of sagittal plane spinal curvatures in natural sitting. Able-bodied adults (n = 26, 13 male) participated. Each participant assumed three sitting postures: natural, slouched (accentuated kyphosis), and extension (accentuated lordosis) sitting. Fiber optic (ShapeTape) and optoelectronic (Optotrak) systems were applied to the skin over spinous processes from S1 to C7 and used to measure sagittal plane spinal curvature. Regions of kyphosis and lordosis were identified. A Cobb angle-like method was used to quantify lordosis and kyphosis. Generalized linear model and Bland-Altman analyses were used to assess agreement. A strong correlation exists between curvature values obtained with Optotrak and ShapeTape (R(2) = 0.98). The mean difference between Optotrak and ShapeTape for kyphosis in natural, extension, and slouched postures was 4.30° (95% LOA: -3.43 to 12.04°), 3.64° (95% LOA: -1.07 to 8.36°), and 4.02° (95% LOA: -2.80 to 10.84°), respectively. The mean difference for lordosis, when present, in natural and extension postures was 2.86° (95% LOA: -1.18 to 6.90°) and 2.55° (95% LOA: -3.38 to 8.48°), respectively. In natural sitting, the mean ± SD of kyphosis values was 35.07 ± 6.75°. Lordosis was detected in 8/26 participants: 11.72 ± 7.32°. The fiber optic and optoelectronic systems demonstrate acceptable agreement for measuring sagittal plane thoracolumbar spinal curvature. Copyright © 2014 Elsevier B.V. All rights reserved.

Agreement between Fiber Optic and Optoelectronic Systems for Quantifying Sagittal Plane Spinal Curvature in Sitting

PubMed Central

Cloud, Beth A.; Zhao, Kristin D.; Breighner, Ryan; Giambini, Hugo; An, Kai-Nan

2014-01-01

Spinal posture affects how individuals function from a manual wheelchair. There is a need to directly quantify spinal posture in this population to ultimately improve function. A fiber optic system, comprised of an attached series of sensors, is promising for measuring large regions of the spine in individuals sitting in a wheelchair. The purpose of this study was to determine the agreement between fiber optic and optoelectronic systems for measuring spinal curvature, and describe the range of sagittal plane spinal curvatures in natural sitting. Able-bodied adults (n=26, 13 male) participated. Each participant assumed three sitting postures: natural, slouched (accentuated kyphosis), and extension (accentuated lordosis) sitting. Fiber optic (ShapeTape) and optoelectronic (Optotrak) systems were applied to the skin over spinous processes from S1 to C7 and used to measure sagittal plane spinal curvature. Regions of kyphosis and lordosis were identified. A Cobb angle-like method was used to quantify lordosis and kyphosis. Generalized linear model and Bland-Altman analyses were used to assess agreement. A strong correlation exists between curvature values obtained with Optotrak and ShapeTape (R2=0.98). The mean difference between Optotrak and ShapeTape for kyphosis in natural, extension, and slouched postures was 4.30° (95%LOA: −3.43-12.04°), 3.64° (95%LOA: −1.07-8.36°), and 4.02° (95%LOA: −2.80-10.84°), respectively. The mean difference for lordosis, when present, in natural and extension postures is 2.86° (95%LOA: −1.18-6.90°) and 2.55° (95%LOA: −3.38-8.48°), respectively. In natural sitting, the mean±SD of kyphosis values was 35.07± 6.75°. Lordosis was detected in 8/26 participants: 11.72±7.32°. The fiber optic and optoelectronic systems demonstrate acceptable agreement for measuring sagittal plane thoracolumbar spinal curvature. PMID:24909579

Reciprocal Changes in Sagittal Alignment in Adolescent Idiopathic Scoliosis Patients Following Strategic Pedicle Screw Fixation.

PubMed

Dumpa, Srikanth Reddy; Shetty, Ajoy Prasad; Aiyer, Siddharth N; Kanna, Rishi Mugesh; Rajasekaran, S

2018-04-01

Retrospective observational study. To analyze the effect of low-density (LD) strategic pedicle screw fixation on the correction of coronal and sagittal parameters in adolescent idiopathic scoliosis (AIS) patients. LD screw fixation achieves favorable coronal correction, but its effect on sagittal parameters is not well established. AIS is often associated with decreased thoracic kyphosis (TK), and the use of multi-level pedicle screws may result in further flattening of the sagittal profile. A retrospective analysis was performed on 92 patients with AIS to compare coronal and sagittal parameters preoperatively and at 2-year follow-up. All patients underwent posterior correction via LD strategic pedicle screw fixation. Radiographs were analyzed for primary Cobb angle (PCA), coronal imbalance, cervical sagittal angle (CSA), TK, lumbar lordosis (LL), pelvic incidence, pelvic tilt (PT), sacral slope (SS), C7 plumb line, spino-sacral angle, curve flexibility, and screw density. PCA changed significantly from 57.6°±13.9° to 19°±8.4° ( p <0.0001) with 67% correction, where the mean curve flexibility was 41% and screw density was 68%. Regional sagittal parameters did not change significantly, including CSA (from 10.76° to 10.56°, p =0.893), TK (from 24.4° to 22.8°, p =0.145), and LL (from 50.3° to 51.1°, p =0.415). However, subgroup analysis of the hypokyphosis group (<10°) and the hyperkyphosis group (>40°) showed significant correction of TK ( p <0.0001 in both). Sacro-pelvic parameters showed a significant decrease of PT and increase of SS, suggesting a reduction in pelvic retroversion SS (from 37° to 40°, p =0.0001) and PT (from 15° to 14°, p =0.025). LD strategic pedicle screw fixation provides favorable coronal correction and improves overall sagittal sacro-pelvic parameters. This technique does not cause significant flattening of TK and results in a favorable restoration of TK in patients with hypokyphosis or hyperkyphosis.

Reciprocal Changes in Sagittal Alignment in Adolescent Idiopathic Scoliosis Patients Following Strategic Pedicle Screw Fixation

PubMed Central

Dumpa, Srikanth Reddy; Aiyer, Siddharth N.; Kanna, Rishi Mugesh; Rajasekaran, S

2018-01-01

Study Design Retrospective observational study. Purpose To analyze the effect of low-density (LD) strategic pedicle screw fixation on the correction of coronal and sagittal parameters in adolescent idiopathic scoliosis (AIS) patients. Overview of Literature LD screw fixation achieves favorable coronal correction, but its effect on sagittal parameters is not well established. AIS is often associated with decreased thoracic kyphosis (TK), and the use of multi-level pedicle screws may result in further flattening of the sagittal profile. Methods A retrospective analysis was performed on 92 patients with AIS to compare coronal and sagittal parameters preoperatively and at 2-year follow-up. All patients underwent posterior correction via LD strategic pedicle screw fixation. Radiographs were analyzed for primary Cobb angle (PCA), coronal imbalance, cervical sagittal angle (CSA), TK, lumbar lordosis (LL), pelvic incidence, pelvic tilt (PT), sacral slope (SS), C7 plumb line, spino-sacral angle, curve flexibility, and screw density. Results PCA changed significantly from 57.6°±13.9° to 19°±8.4° (p <0.0001) with 67% correction, where the mean curve flexibility was 41% and screw density was 68%. Regional sagittal parameters did not change significantly, including CSA (from 10.76° to 10.56°, p =0.893), TK (from 24.4° to 22.8°, p =0.145), and LL (from 50.3° to 51.1°, p =0.415). However, subgroup analysis of the hypokyphosis group (<10°) and the hyperkyphosis group (>40°) showed significant correction of TK (p <0.0001 in both). Sacro-pelvic parameters showed a significant decrease of PT and increase of SS, suggesting a reduction in pelvic retroversion SS (from 37° to 40°, p =0.0001) and PT (from 15° to 14°, p =0.025). Conclusions LD strategic pedicle screw fixation provides favorable coronal correction and improves overall sagittal sacro-pelvic parameters. This technique does not cause significant flattening of TK and results in a favorable restoration of TK in

Sagittal endplate morphology of the lower lumbar spine.

PubMed

Lakshmanan, Palaniappan; Purushothaman, Balaji; Dvorak, Vlasta; Schratt, Walter; Thambiraj, Sathya; Boszczyk, Maximilian

2012-05-01

The sagittal profile of lumbar endplates is discrepant from current simplified disc replacement and fusion device design. Endplate concavity is symmetrical in the coronal plane but shows considerable variability in the sagittal plane, which may lead to implant-endplate mismatch. The aim of this investigation is to provide further analysis of the sagittal endplate morphology of the mid to lower lumbar spine study (L3–S1), thereby identifying the presence of common endplate shape patterns across these levels and providing morphological reference values complementing the findings of previous studies. Observational study. A total of 174 magnetic resonance imaging (MRI) scans of the adult lumbar spine from the digital archive of our centre, which met the inclusion criteria, were studied. Superior (SEP) and inferior (IEP) endplate shape was divided into flat (no concavity), oblong (homogeneous concavity) and ex-centric (inhomogeneous concavity). The concavity depth (ECD) and location of concavity apex (ECA) relative to endplate diameter of the vertebrae L3–S1 were determined. Flat endplates were only predominant at the sacrum SEP (84.5%). The L5 SEP was flat in 24.7% and all other endplates in less than 10%. The majority of endplates were concave with a clear trend of endplate shape becoming more ex-centric from L3 IEP (56.9% oblong vs. 37.4% ex-centric) to L5 IEP (4% oblong vs. 94.3% ex-centric). Ex-centric ECA were always found in the posterior half of the lumbar endplates. Both the oblong and ex-centric ECD was 2-3 mm on average with the IEP of a motion segment regularly possessing the greater depth. A sex- or age-related difference could not be found. The majority of lumbar endplates are concave, while the majority of sacral endplates are flat. An oblong and an ex-centric endplate shape can be distinguished, whereby the latter is more common at the lower lumbar levels. The apex of the concavity of ex-centric discs is located in the posterior half of the endplate

The use of the T1 sagittal angle in predicting overall sagittal balance of the spine.

PubMed

Knott, Patrick T; Mardjetko, Steven M; Techy, Fernando

2010-11-01

A balanced sagittal alignment of the spine has been shown to strongly correlate with less pain, less disability, and greater health status scores. To restore proper sagittal balance, one must assess the position of the occiput relative to the sacrum. The assessment of spinal balance preoperatively can be challenging, whereas predicting postoperative balance is even more difficult. This study was designed to evaluate and quantify multiple factors that influence sagittal balance. Retrospective analysis of existing spinal radiographs. A retrospective review of 52 adult spine patient records was performed. All patients had full-column digital radiographs that showed all the important skeletal landmarks necessary for accurate measurement. The average age of the patient was 53 years. Both genders were equally represented. The radiographs were measured using standard techniques to obtain the following parameters: scoliosis in the coronal plane; lordosis or kyphosis of the cervical, thoracic, and lumbar spine; the T1 sagittal angle (angle between a horizontal line and the superior end plate of T1); the angle of the dens in the sagittal plane; the angle of the dens in relation to the occiput; the sacral slope; the pelvic incidence; the femoral-sacral angle; and finally, the sagittal vertical axis (SVA) measured from both the dens of C2 and from C7. It was found that the SVA when measured from the dens was on average 16 mm farther forward than the SVA measured from C7 (p<.0001). The dens plumb line (SVA(dens)) was then used in the study. An analysis was done to examine the relationship between SVA(dens) and each of the other measurements. The T1 sagittal angle was found to have a moderate positive correlation (r=0.65) with SVA(dens), p<.0001, indicating that the amount of sagittal T1 tilt can be used as a good predictor of overall sagittal balance. When examining the other variables, it was found that cervical lordosis had a weak correlation (r=0.37) with SVA(dens) that was

Navigated total knee arthroplasty: is it error-free?

PubMed

Chua, Kerk Hsiang Zackary; Chen, Yongsheng; Lingaraj, Krishna

2014-03-01

The aim of this study was to determine whether errors do occur in navigated total knee arthroplasty (TKAs) and to study whether errors in bone resection or implantation contribute to these errors. A series of 20 TKAs was studied using computer navigation. The coronal and sagittal alignments of the femoral and tibial cutting guides, the coronal and sagittal alignments of the final tibial implant and the coronal alignment of the final femoral implant were compared with that of the respective bone resections. To determine the post-implantation mechanical alignment of the limb, the coronal alignment of the femoral and tibial implants was combined. The median deviation between the femoral cutting guide and bone resection was 0° (range -0.5° to +0.5°) in the coronal plane and 1.0° (range -2.0° to +1.0°) in the sagittal plane. The median deviation between the tibial cutting guide and bone resection was 0.5° (range -1.0° to +1.5°) in the coronal plane and 1.0° (range -1.0° to +3.5°) in the sagittal plane. The median deviation between the femoral bone resection and the final implant was 0.25° (range -2.0° to 3.0°) in the coronal plane. The median deviation between the tibial bone resection and the final implant was 0.75° (range -3.0° to +1.5°) in the coronal plane and 1.75° (range -4.0° to +2.0°) in the sagittal plane. The median post-implantation mechanical alignment of the limb was 0.25° (range -3.0° to +2.0°). When navigation is used only to guide the positioning of the cutting jig, errors may arise in the manual, non-navigated steps of the procedure. Our study showed increased cutting errors in the sagittal plane for both the femur and the tibia, and following implantation, the greatest error was seen in the sagittal alignment of the tibial component. Computer navigation should be used not only to guide the positioning of the cutting jig, but also to check the bone resection and implant position during TKA. IV.

Evolution of the postoperative sagittal spinal profile in early-onset scoliosis: is there a difference between rib-based and spine-based growth-friendly instrumentation?

PubMed

Chen, Zhonghui; Li, Song; Qiu, Yong; Zhu, Zezhang; Chen, Xi; Xu, Liang; Sun, Xu

2017-12-01

OBJECTIVE Although the vertical expandable prosthetic titanium rib (VEPTR) and growing rod instrumentation (GRI) encourage spinal growth via regular lengthening, they can create different results because of their different fixation patterns and mechanisms in correcting scoliosis. Previous studies have focused comparisons on coronal plane deformity with minimal attention to the sagittal profile. In this retrospective study, the authors aimed to compare the evolution of the sagittal spinal profile in early-onset scoliosis (EOS) treated with VEPTR versus GRI. METHODS The data for 11 patients with VEPTR and 22 with GRI were reviewed. All patients had more than 2 years' follow-up with more than 2 lengthening procedures. Radiographic measurements were performed before and after the index surgery and at the latest follow-up. The complications in both groups were recorded. RESULTS Patients in both groups had similar diagnoses, age at the index surgery, and number of lengthening procedures. The changes in the major coronal Cobb angle and T1-S1 spinal height were not significantly different between the 2 groups. Compared with the GRI group, the VEPTR group had less correction in thoracic kyphosis (23% ± 12% vs 44% ± 16%, p < 0.001) after the index surgery and experienced a greater correction loss in thoracic kyphosis (46% ± 18% vs 11% ± 8%, p < 0.001) at the latest follow-up. Although the increase in the proximal junctional angle was not significantly different (VEPTR: 7° ± 4° vs GRI: 8° ± 5°, p = 0.569), the incidence of proximal junctional kyphosis was relatively lower in the VEPTR group (VEPTR: 18.2% vs GRI: 22.7%). No significant changes in the spinopelvic parameters were observed, while the sagittal vertical axis showed a tendency toward a neutral position in both groups. The overall complication rate was higher in the VEPTR group than in the GRI group (72.7% vs 54.5%). CONCLUSIONS The VEPTR had coronal correction and spinal growth results similar to those

Morphometric differences of nasopalatine canal based on 3D classifications: descriptive analysis on CBCT.

PubMed

Fernández-Alonso, A; Suárez-Quintanilla, J A; Rapado-González, O; Suárez-Cunqueiro, María Mercedes

2015-09-01

This descriptive retrospective study analyzed differences among sagittal, coronal and axial NC groups based on the dimensions of nasopalatine canal (NC), buccal bone plate (BBP) and palatal bone plate (PBP) to canal. Measurements were made on 224 CBCTs for NC, BBP and PBP on the three anatomic planes at three levels: level 1, when the incisive foramen is completely closed on the axial plane; level 2, at the midpoint of NC length (NCL) on the sagittal plane; and level 3, at the foramina of Stenson on the sagittal plane. ANOVA tests with post hoc tests were used. The intraclass correlation coefficient and Kappa test were used for evaluating the intraobserver agreement. Regarding coronal classification, these significant differences were found: BBP length (BL)level 1 was lower for the two parallel canals group; PBP length (PL)level 1 was lower for single canal group; and NCL was lower for Y-type canal group. Regarding axial classification, these significant differences were found: LPlevel 1 was lower for 3.1-3 group; PBP width (PW)level 3 was the greatest for 3.1-3; and LPlevel 3 was lower for 1.1. Presurgical evaluation with CBCT in premaxillae region should include analysis on coronal and axial planes and not only on sagittal plane seeing as morphometric differences were found on coronal and axial planes. Following the morphological coronal classification, two parallel canals presented a higher NCL, a higher LP and a lower LV at inferior edge of alveolar ridge.

The Effects of Frontal- and Sagittal-Plane Plyometrics on Change-of-Direction Speed and Power in Adolescent Female Basketball Players.

PubMed

McCormick, Brian T; Hannon, James C; Newton, Maria; Shultz, Barry; Detling, Nicole; Young, Warren B

2016-01-01

Plyometrics is a popular training modality for basketball players to improve power and change-of-direction speed. Most plyometric training has used sagittal-plane exercises, but improvements in change-of-direction speed have been greater in multi-direction programs. To determine the benefits of a 6-wk frontal-plane plyometric (FPP) training program compared with a 6-wk sagittal-plane plyometric (SPP) training program with regard to power and change-of-direction speed. Fourteen female varsity high school basketball players participated in the study. Multiple 2 × 2 repeated-measures ANOVAs were used to determine differences for the FPP and SPP groups from preintervention to postintervention on 4 tests of power and 2 tests of change-of-direction speed. There was a group main effect for time in all 6 tests. There was a significant group × time interaction effect in 3 of the 6 tests. The SPP improved performance of the countermovement vertical jump more than the FPP, whereas the FPP improved performance of the lateral hop (left) and lateral-shuffle test (left) more than the SPP. The standing long jump, lateral hop (right), and lateral-shuffle test (right) did not show a significant interaction effect. These results suggest that basketball players should incorporate plyometric training in all planes to improve power and change-of-direction speed.

A modified technique to reduce tibial keel cutting errors during an Oxford unicompartmental knee arthroplasty.

PubMed

Inui, Hiroshi; Taketomi, Shuji; Tahara, Keitarou; Yamagami, Ryota; Sanada, Takaki; Tanaka, Sakae

2017-03-01

Bone cutting errors can cause malalignment of unicompartmental knee arthroplasties (UKA). Although the extent of tibial malalignment due to horizontal cutting errors has been well reported, there is a lack of studies evaluating malalignment as a consequence of keel cutting errors, particularly in the Oxford UKA. The purpose of this study was to examine keel cutting errors during Oxford UKA placement using a navigation system and to clarify whether two different tibial keel cutting techniques would have different error rates. The alignment of the tibial cut surface after a horizontal osteotomy and the surface of the tibial trial component was measured with a navigation system. Cutting error was defined as the angular difference between these measurements. The following two techniques were used: the standard "pushing" technique in 83 patients (group P) and a modified "dolphin" technique in 41 patients (group D). In all 123 patients studied, the mean absolute keel cutting error was 1.7° and 1.4° in the coronal and sagittal planes, respectively. In group P, there were 22 outlier patients (27 %) in the coronal plane and 13 (16 %) in the sagittal plane. Group D had three outlier patients (8 %) in the coronal plane and none (0 %) in the sagittal plane. Significant differences were observed in the outlier ratio of these techniques in both the sagittal (P = 0.014) and coronal (P = 0.008) planes. Our study demonstrated overall keel cutting errors of 1.7° in the coronal plane and 1.4° in the sagittal plane. The "dolphin" technique was found to significantly reduce keel cutting errors on the tibial side. This technique will be useful for accurate component positioning and therefore improve the longevity of Oxford UKAs. Retrospective comparative study, Level III.

Three-dimensional reproducibility of natural head position.

PubMed

Weber, Diana W; Fallis, Drew W; Packer, Mark D

2013-05-01

Although natural head position has proven to be reliable in the sagittal plane, with an increasing interest in 3-dimensional craniofacial analysis, a determination of its reproducibility in the coronal and axial planes is essential. This study was designed to evaluate the reproducibility of natural head position over time in the sagittal, coronal, and axial planes of space with 3-dimensional imaging. Three-dimensional photographs were taken of 28 adult volunteers (ages, 18-40 years) in natural head position at 5 times: baseline, 4 hours, 8 hours, 24 hours, and 1 week. Using the true vertical and horizontal laser lines projected in an iCAT cone-beam computed tomography machine (Imaging Sciences International, Hatfield, Pa) for orientation, we recorded references for natural head position on the patient's face with semipermanent markers. By using a 3-dimensional camera system, photographs were taken at each time point to capture the orientation of the reference points. By superimposing each of the 5 photographs on stable anatomic surfaces, changes in the position of the markers were recorded and assessed for parallelism by using 3dMDvultus (3dMD, Atlanta, Ga) and software (Dolphin Imaging & Management Solutions, Chatsworth, Calif). No statistically significant differences were observed between the 5 time points in any of the 3 planes of space. However, a statistically significant difference was observed between the mean angular deviations of 3 reference planes, with a hierarchy of natural head position reproducibility established as coronal > axial > sagittal. Within the parameters of this study, natural head position was found to be reproducible in the sagittal, coronal, and axial planes of space. The coronal plane had the least variation over time, followed by the axial and sagittal planes. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Sagittal MRI often overestimates the degree of cerebellar tonsillar ectopia: a potential for misdiagnosis of the Chiari I malformation.

PubMed

Tubbs, R Shane; Yan, Huang; Demerdash, Amin; Chern, Joshua J; Fries, Fabian N; Oskouian, Rod J; Oakes, W Jerry

2016-07-01

We hypothesized that by using coronal MRI, Chiari I malformation could be more precisely diagnosed, would provide simple anatomic landmarks, would provide information regarding asymmetry of hindbrain herniation, and would be a better method for analyzing the tonsillar herniation postoperatively when the opisthion has been removed. Fifty consecutive pediatric patients diagnosed with Chiari I malformation had comparison between the measurements of their caudally descended cerebellar tonsils on midsagittal and coronal MRI images. On MRI coronal imaging, tonsillar asymmetry was found in 48 patients. Maximal left tonsillar descent was 20.9 mm, and maximal right tonsillar descent was 17.4 mm. On MRI sagittal imaging, tonsillar descent ranged from 5 to 27.4 mm. Fifty-eight % of patients had syringomyelia. Five patients (10 %) on coronal MRI were found to have both cerebellar tonsils that were less than 3 mm below the foramen magnum. However, all of these patients had greater than 3 mm of tonsillar ectopia on sagittal imaging. Nineteen patients (38 %) on coronal MRI were found to have one of the cerebellar tonsils that were less than 3 mm below the foramen magnum. Similarly, each of these had greater than 3 mm of tonsillar ecotpia as measured on midsagittal MRI. Also, based on these findings, Chiari I malformation is almost always an asymmetrical tonsillar ectopia. Sagittal MRI overestimates the degree of tonsillar ectopia in patients with Chiari I malformation. Misdiagnosis may occur if sagittal imaging alone is used. The cerebellar tonsils are paramedian structures, and this should be kept in mind when interpreting midline sagittal MRI.

Femoro-tibial kinematics after TKA in fixed- and mobile-bearing knees in the sagittal plane.

PubMed

Daniilidis, Kiriakos; Höll, Steffen; Gosheger, Georg; Dieckmann, Ralf; Martinelli, Nicolo; Ostermeier, Sven; Tibesku, Carsten O

2013-10-01

Lack of the anterior cruciate ligament in total knee arthroplasty results in paradoxical movement of the femur as opposed to the tibia under deep flexion. Total knee arthroplasty with mobile-bearing inlays has been developed to provide increased physiological movement of the knee joint and to reduce polyethylene abrasion. The aim of this study was to perform an in vitro analysis of the kinematic movement in the sagittal plane in order to show differences between fixed- and mobile-bearing TKA in comparison with the natural knee joint. Seven knee joints of human cadaver material were used in a laboratory experiment. Fixed- and mobile-bearing inlays were tested in sequences under isokinetic extension in so-called kinemator for knee joints, which can simulate muscular traction power by the use of hydraulic cylinders, which crossover the knee joint. As a target parameter, the a.p. translation of the tibio-femoral relative movement was measured in the sagittal plane under ultrasound (Zebris) control. The results show a reduced tibial a.p. translation in relation to the femur in the bearing group compared to the natural joint. In the Z-axis, between 110° and 50° of flexion, linear movement decreases towards caudal movement under extension. Admittedly, the study did not show differences in the movement pattern between "mobile-bearing" and "fixed-bearing" prostheses. Results of this study cannot prove functional advantages of mobile-bearing prostheses for the knee joint kinematic after TKA. Both types of prostheses show typical kinematics of an anterior instability, hence they were incapable of performing physiological movement.

The effects of prosthetic foot stiffness on transtibial amputee walking mechanics and balance control during turning.

PubMed

Shell, Courtney E; Segal, Ava D; Klute, Glenn K; Neptune, Richard R

2017-11-01

Little evidence exists regarding how prosthesis design characteristics affect performance in tasks that challenge mediolateral balance such as turning. This study assesses the influence of prosthetic foot stiffness on amputee walking mechanics and balance control during a continuous turning task. Three-dimensional kinematic and kinetic data were collected from eight unilateral transtibial amputees as they walked overground at self-selected speed clockwise and counterclockwise around a 1-meter circle and along a straight line. Subjects performed the walking tasks wearing three different ankle-foot prostheses that spanned a range of sagittal- and coronal-plane stiffness levels. A decrease in stiffness increased residual ankle dorsiflexion (10-13°), caused smaller adaptations (<5°) in proximal joint angles, decreased residual and increased intact limb body support, increased residual limb propulsion and increased intact limb braking for all tasks. While changes in sagittal-plane joint work due to decreased stiffness were generally consistent across tasks, effects on coronal-plane hip work were task-dependent. When the residual limb was on the inside of the turn and during straight-line walking, coronal-plane hip work increased and coronal-plane peak-to-peak range of whole-body angular momentum decreased with decreased stiffness. Changes in sagittal-plane kinematics and kinetics were similar to those previously observed in straight-line walking. Mediolateral balance improved with decreased stiffness, but adaptations in coronal-plane angles, work and ground reaction force impulses were less systematic than those in sagittal-plane measures. Effects of stiffness varied with the residual limb inside versus outside the turn, which suggests that actively adjusting stiffness to turn direction may be beneficial. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of torso flexion on the lumbar torso extensor muscle sagittal plane moment arms.

PubMed

Jorgensen, Michael J; Marras, William S; Gupta, Purnendu; Waters, Thomas R

2003-01-01

Accurate anatomical inputs for biomechanical models are necessary for valid estimates of internal loading. The magnitude of the moment arm of the lumbar erector muscle group is known to vary as a function of such variables as gender. Anatomical evidence indicates that the moment arms decrease during torso flexion. However, moment arm estimates in biomechanical models that account for individual variability have been derived from imaging studies from supine postures. Quantify the sagittal plane moment arms of the lumbar erector muscle group as a function of torso flexion, and identify individual characteristics that are associated with the magnitude of the moment arms as a function of torso flexion. Utilization of a 0.3 Tesla Open magnetic resonance image (MRI) to image and quantify the moment arm of the right erector muscle group as a function of gender and torso flexion. Axial MRI images through and parallel to each of the lumbar intervertebral discs at four torso flexion angles were obtained from 12 male and 12 female subjects in a lateral recumbent posture. Multivariate analysis of variance was used to investigate the differences in the moment arms at different torso flexion angles, whereas hierarchical linear regression was used to investigate associations with individual anthropometric characteristics and spinal posture. The largest decrease in the lumbar erector muscle group moment arm from neutral to 45-degree flexion occurred at the L5-S1 level (9.7% and 8.9% for men and women, respectively). Measures of spinal curvature (L1-S1 lordosis), body mass and trunk characteristics (depth or circumference) were associated with the varying moment arm at most lumbar levels. The sagittal plane moment arms of the lumbar erector muscle mass decrease as the torso flexes forward. The change in moment arms as a function of torso flexion may have an impact on prediction of spinal loading in biomechanical models.

Biomechanical Comparison of 3 Ankle Braces With and Without Free Rotation in the Sagittal Plane

PubMed Central

Alfuth, Martin; Klein, Dieter; Koch, Raphael; Rosenbaum, Dieter

2014-01-01

Context: Various designs of braces including hinged and nonhinged models are used to provide external support of the ankle. Hinged ankle braces supposedly allow almost free dorsiflexion and plantar flexion of the foot in the sagittal plane. It is unclear, however, whether this additional degree of freedom affects the stabilizing effect of the brace in the other planes of motion. Objective: To investigate the dynamic and passive stabilizing effects of 3 ankle braces, 2 hinged models that provide free plantar flexion–dorsiflexion in the sagittal plane and 1 ankle brace without a hinge. Design: Crossover study. Setting: University Movement Analysis Laboratory. Patients or Other Participants: Seventeen healthy volunteers (5 women, 12 men; age = 25.4 ± 4.8 years; height = 180.3 ± 6.5 cm; body mass = 75.5 ± 10.4 kg). Intervention(s): We dynamically induced foot inversion on a tilting platform and passively induced foot movements in 6 directions via a custom-built apparatus in 3 brace conditions and a control condition (no brace). Main Outcome Measure(s): Maximum inversion was determined dynamically using an in-shoe electrogoniometer. Passively induced maximal joint angles were measured using a torque and angle sensor. We analyzed differences among the 4 ankle-brace conditions (3 braces, 1 control) for each of the dependent variables with Friedman and post hoc tests (P < .05). Results: Each ankle brace restricted dynamic foot-inversion movements on the tilting platform as compared with the control condition, whereas only the 2 hinged ankle braces differed from each other, with greater movement restriction caused by the Ankle X model. Passive foot inversion was reduced with all ankle braces. Passive plantar flexion was greater in the hinged models as compared with the nonhinged brace. Conclusions: All ankle braces showed stabilizing effects against dynamic and passive foot inversion. Differences between the hinged braces and the nonhinged brace did not appear to be

Coronal plane socket stability during gait in persons with transfemoral amputation: Pilot study.

PubMed

Fatone, Stefania; Dillon, Michael; Stine, Rebecca; Tillges, Robert

2014-01-01

Little research describes which transfemoral socket design features are important for coronal plane stability, socket comfort, and gait. Our study objectives were to (1) relate socket comfort during gait to a rank order of changes in ischial containment (IC) and tissue loading and (2) compare socket comfort during gait when tissue loading and IC were systematically manipulated. Six randomly assigned socket conditions (IC and tissue compression) were assessed: (1) IC and high, (2) IC and medium, (3) IC and low, (4) no IC and high, (5) no IC and medium, and (6) no IC and low. For the six subjects in this study, there was a strong, negative relationship between comfort and changes in IC and tissue loading (rho = -0.89). With the ischium contained, tissue loading did not influence socket comfort (p = 0.47). With no IC, the socket was equally comfortable with high tissue loading (p = 0.36) but the medium (p = 0.04) and low (p = 0.02) tissue loading conditions decreased comfort significantly. Coronal plane hip moments, lateral trunk lean, step width, and walking speed were invariant to changes in IC and/or tissue loading. Our results suggest that in an IC socket, medial tissue loading mattered little in terms of comfort. Sockets without IC required high tissue loading to be as comfortable as those with IC, while suboptimal tissue loading compromised comfort.

CT triage for lung malignancy: coronal multiplanar reformation versus images in three orthogonal planes.

PubMed

Kusk, Martin Weber; Karstoft, Jens; Mussmann, Bo Redder

2015-11-01

Generation of multiplanar reformation (MPR) images has become automatic on most modern computed tomography (CT) scanners, potentially increasing the workload of the reporting radiologists. It is not always clear if this increases diagnostic performance in all clinical tasks. To assess detection performance using only coronal multiplanar reformations (MPR) when triaging patients for lung malignancies with CT compared to images in three orthogonal planes, and to evaluate performance comparison of novice and experienced readers. Retrospective study of 63 patients with suspicion of lung cancer, scanned on 64-slice multidetector computed tomography (MDCT) with images reconstructed in three planes. Coronal images were presented to four readers, two novice and two experienced. Readers decided whether the patients were suspicious for malignant disease, and indicated their confidence on a five-point scale. Sensitivity and specificity on per-patient basis was calculated with regards to a reference standard of histological diagnosis, and compared with the original report using McNemar's test. Receiver operating characteristic (ROC) curves were plotted to compare the performance of the four readers, using the area under the curve (AUC) as figure of merit. No statistically significant difference of sensitivity and specificity was found for any of the readers when compared to the original reports. ROC analysis yielded AUCs in the range of 0.92-0.93 for all readers with no significant difference. Inter-rater agreement was substantial (kappa = 0.72). Sensitivity and specificity were comparable to diagnosis using images in three planes. No significant difference was found between experienced and novice readers. © The Foundation Acta Radiologica 2014.

A Dynamic Finite Element Analysis of Human Foot Complex in the Sagittal Plane during Level Walking

PubMed Central

Qian, Zhihui; Ren, Lei; Ding, Yun; Hutchinson, John R.; Ren, Luquan

2013-01-01

The objective of this study is to develop a computational framework for investigating the dynamic behavior and the internal loading conditions of the human foot complex during locomotion. A subject-specific dynamic finite element model in the sagittal plane was constructed based on anatomical structures segmented from medical CT scan images. Three-dimensional gait measurements were conducted to support and validate the model. Ankle joint forces and moment derived from gait measurements were used to drive the model. Explicit finite element simulations were conducted, covering the entire stance phase from heel-strike impact to toe-off. The predicted ground reaction forces, center of pressure, foot bone motions and plantar surface pressure showed reasonably good agreement with the gait measurement data over most of the stance phase. The prediction discrepancies can be explained by the assumptions and limitations of the model. Our analysis showed that a dynamic FE simulation can improve the prediction accuracy in the peak plantar pressures at some parts of the foot complex by 10%–33% compared to a quasi-static FE simulation. However, to simplify the costly explicit FE simulation, the proposed model is confined only to the sagittal plane and has a simplified representation of foot structure. The dynamic finite element foot model proposed in this study would provide a useful tool for future extension to a fully muscle-driven dynamic three-dimensional model with detailed representation of all major anatomical structures, in order to investigate the structural dynamics of the human foot musculoskeletal system during normal or even pathological functioning. PMID:24244500

A dynamic finite element analysis of human foot complex in the sagittal plane during level walking.

PubMed

Qian, Zhihui; Ren, Lei; Ding, Yun; Hutchinson, John R; Ren, Luquan

2013-01-01

The objective of this study is to develop a computational framework for investigating the dynamic behavior and the internal loading conditions of the human foot complex during locomotion. A subject-specific dynamic finite element model in the sagittal plane was constructed based on anatomical structures segmented from medical CT scan images. Three-dimensional gait measurements were conducted to support and validate the model. Ankle joint forces and moment derived from gait measurements were used to drive the model. Explicit finite element simulations were conducted, covering the entire stance phase from heel-strike impact to toe-off. The predicted ground reaction forces, center of pressure, foot bone motions and plantar surface pressure showed reasonably good agreement with the gait measurement data over most of the stance phase. The prediction discrepancies can be explained by the assumptions and limitations of the model. Our analysis showed that a dynamic FE simulation can improve the prediction accuracy in the peak plantar pressures at some parts of the foot complex by 10%-33% compared to a quasi-static FE simulation. However, to simplify the costly explicit FE simulation, the proposed model is confined only to the sagittal plane and has a simplified representation of foot structure. The dynamic finite element foot model proposed in this study would provide a useful tool for future extension to a fully muscle-driven dynamic three-dimensional model with detailed representation of all major anatomical structures, in order to investigate the structural dynamics of the human foot musculoskeletal system during normal or even pathological functioning.

The influence of heel height on sagittal plane knee kinematics during landing tasks in recreationally active and athletic collegiate females.

PubMed

Lindenberg, Kelly M; Carcia, Christopher R; Phelps, Amy L; Martin, Robroy L; Burrows, Anne M

2011-09-01

To determine if heel height alters sagittal plane knee kinematics when landing from a forward hop or drop landing. Knee angles close to extension during landing are theorized to increase ACL injury risk in female athletes. Fifty collegiate females performed two single-limb landing tasks while wearing heel lifts of three different sizes (0, 12 & 24 mm) attached to the bottom of a sneaker. Using an electrogoniometer, sagittal plane kinematics (initial contact [KA(IC)], peak flexion [KA(Peak)], and rate of excursion [RE]) were examined. Repeated measures ANOVAs were used to determine the influence of heel height on the dependent measures. Forward hop task- KA(IC) with 0 mm, 12 mm, and 24 mm lifts were 8.88±6.5, 9.38±5.8 and 11.28±7.0, respectively. Significant differences were noted between 0 and 24 mm lift (p<.001) and 12 and 24 mm lifts (p=.003), but not between the 0 and 12 mm conditions (p=.423). KA(Peak) with 0 mm, 12 mm, and 24 mm lifts were 47.08±10.9, 48.18±10.3 and 48.88±9.7, respectively. A significant difference was noted between 0 and 24 mm lift (p=.004), but not between the 0 and 12 mm or 12 and 24 mm conditions (p=.071 and p=.282, respectively). The RE decreased significantly from 2128/sec±52 with the 12 mm lift to 1958/sec±55 with the 24 mm lift (p=.004). RE did not differ from 0 to 12 or 0 to 24 mm lift conditions (p=.351 and p=.086, respectively). Jump-landing task- No significant differences were found in KA(IC) (p=.531), KA(Peak) (p=.741), or the RE (p=.190) between any of the heel lift conditions. The addition of a 24 mm heel lift to the bottom of a sneaker significantly alters sagittal plane knee kinematics upon landing from a unilateral forward hop but not from a drop jump.

Investigation of sagittal image acquisition for 4D-MRI with body area as respiratory surrogate.

PubMed

Liu, Yilin; Yin, Fang-Fang; Chang, Zheng; Czito, Brian G; Palta, Manisha; Bashir, Mustafa R; Qin, Yujiao; Cai, Jing

2014-10-01

The authors have recently developed a novel 4D-MRI technique for imaging organ respiratory motion employing cine acquisition in the axial plane and using body area (BA) as a respiratory surrogate. A potential disadvantage associated with axial image acquisition is the space-dependent phase shift in the superior-inferior (SI) direction, i.e., different axial slice positions reach the respiratory peak at different respiratory phases. Since respiratory motion occurs mostly in the SI and anterior-posterior (AP) directions, sagittal image acquisition, which embeds motion information in these two directions, is expected to be more robust and less affected by phase-shift than axial image acquisition. This study aims to develop and evaluate a 4D-MRI technique using sagittal image acquisition. The authors evaluated axial BA and sagittal BA using both 4D-CT images (11 cancer patients) and cine MR images (6 healthy volunteers and 1 cancer patient) by comparing their corresponding space-dependent phase-shift in the SI direction (δSPS (SI)) and in the lateral direction (δSPS (LAT)), respectively. To evaluate sagittal BA 4D-MRI method, a motion phantom study and a digital phantom study were performed. Additionally, six patients who had cancer(s) in the liver were prospectively enrolled in this study. For each patient, multislice sagittal MR images were acquired for 4D-MRI reconstruction. 4D retrospective sorting was performed based on respiratory phases. Single-slice cine MRI was also acquired in the axial, coronal, and sagittal planes across the tumor center from which tumor motion trajectories in the SI, AP, and medial-lateral (ML) directions were extracted and used as references from comparison. All MR images were acquired in a 1.5 T scanner using a steady-state precession sequence (frame rate ∼ 3 frames/s). 4D-CT scans showed that δSPS (SI) was significantly greater than δSPS (LAT) (p-value: 0.012); the median phase-shift was 16.9% and 7.7%, respectively. Body surface

Sagittal-Plane Knee Moment During Gait and Knee Cartilage Thickness.

PubMed

Schmitz, Randy J; Harrison, David; Wang, Hsin-Min; Shultz, Sandra J

2017-06-02

  Understanding the factors associated with thicker cartilage in a healthy population is important when developing strategies aimed at minimizing the cartilage thinning associated with knee osteoarthritis progression. Thicker articular cartilage is commonly thought to be healthier cartilage, but whether the sagittal-plane biomechanics important to gait are related to cartilage thickness is unknown.   To determine the relationship of a weight-bearing region of the medial femoral condyle's cartilage thickness to sagittal gait biomechanics in healthy individuals.   Descriptive laboratory study.   Laboratory.   Twenty-eight healthy participants (15 women: age = 21.1 ± 2.1 years, height = 1.63 ± 0.07 m, weight = 64.6 ± 9.9 kg; 13 men: age = 22.1 ± 2.9 years, height = 1.79 ± 0.05 m, weight = 75.2 ± 9.6 kg).   Tibiofemoral angle (°) was obtained via goniometric assessment, thickness of the medial femoral condyle cartilage (mm) was obtained via ultrasound imaging, and peak internal knee-extensor moment (% body weight · height) was measured during 10 trials of over-ground walking at a self-selected pace. We used linear regression to examine the extent to which peak internal knee-extensor moment predicted cartilage thickness after accounting for tibiofemoral angle and sex.   Sex and tibiofemoral angle (12.3° ± 3.2°) were entered in the initial step as control factors (R 2 = 0.01, P = .872). In the final step, internal knee-extensor moment (1.5% ± 1.3% body weight · height) was entered, which resulted in greater knee-extensor moment being related to greater cartilage thickness (2.0 ± 0.3 mm; R 2 Δ = 0.31, PΔ = .003).   Individuals who walked with a greater peak internal knee-extensor moment during gait had a cartilage structure that is generally considered beneficial in a healthy population. Our study offers promising findings that a potentially modifiable biomechanical factor is associated with cartilage status in a healthy population

Sagittal-Plane Knee Moment During Gait and Knee Cartilage Thickness

PubMed Central

Harrison, David; Wang, Hsin-Min; Shultz, Sandra J.

2017-01-01

Context:  Understanding the factors associated with thicker cartilage in a healthy population is important when developing strategies aimed at minimizing the cartilage thinning associated with knee osteoarthritis progression. Thicker articular cartilage is commonly thought to be healthier cartilage, but whether the sagittal-plane biomechanics important to gait are related to cartilage thickness is unknown. Objective:  To determine the relationship of a weight-bearing region of the medial femoral condyle's cartilage thickness to sagittal gait biomechanics in healthy individuals. Design:  Descriptive laboratory study. Setting:  Laboratory. Patients or Other Participants:  Twenty-eight healthy participants (15 women: age = 21.1 ± 2.1 years, height = 1.63 ± 0.07 m, weight = 64.6 ± 9.9 kg; 13 men: age = 22.1 ± 2.9 years, height = 1.79 ± 0.05 m, weight = 75.2 ± 9.6 kg). Main Outcome Measure(s):  Tibiofemoral angle (°) was obtained via goniometric assessment, thickness of the medial femoral condyle cartilage (mm) was obtained via ultrasound imaging, and peak internal knee-extensor moment (% body weight · height) was measured during 10 trials of over-ground walking at a self-selected pace. We used linear regression to examine the extent to which peak internal knee-extensor moment predicted cartilage thickness after accounting for tibiofemoral angle and sex. Results:  Sex and tibiofemoral angle (12.3° ± 3.2°) were entered in the initial step as control factors (R2 = 0.01, P = .872). In the final step, internal knee-extensor moment (1.5% ± 1.3% body weight · height) was entered, which resulted in greater knee-extensor moment being related to greater cartilage thickness (2.0 ± 0.3 mm; R2Δ = 0.31, PΔ = .003). Conclusion:  Individuals who walked with a greater peak internal knee-extensor moment during gait had a cartilage structure that is generally considered beneficial in a healthy population. Our study offers promising findings that a

Two level pedicle substraction osteotomies for the treatment of severe fixed sagittal plane deformity: computer software-assisted preoperative planning and assessing.

PubMed

Atici, Yunus; Akman, Yunus Emre; Balioglu, Mehmet Bulent; Kargin, Deniz; Kaygusuz, Mehmet Akif

2016-08-01

To evaluate the efficacy of two level pedicle substraction osteotomies (PSOs) planned preoperatively with a computer software, in the patients with severe fixed sagittal plane deformities. In the literature, there are studies indicating that two level PSOs may be required in severe cases. However, the results of two level PSOs preoperatively planned with computer software-assistance have not yet been reported in the English literature. Severe fixed sagittal plane deformities of 11 patients are described. Preoperative surgical planning was done with the aid of a computer software. Two level PSOs were indicated after the process. After the application of the indicated surgical technique, clinical and radiological results were evaluated in the preoperative, the early postoperative periods and during the last follow-up. The mean sagittal vertical axis was found as 190.5 (range 161-220) mm in the preoperative period, 23.5 (range -27 to 61) mm in the early postoperative period (P < 0.001) (87.7 % correction) and 34.5 (range -3 to 55) mm during the last follow-up (P < 0.001). The mean pelvic tilt (PT) significantly decreased from 38.3° (range 21°-63°) preoperatively to 23.8° (range 18°-42°) postoperatively (P = 0.008) and to 27.5° (range 17°-42°) during the last follow-up (P = 0.042). The mean lumbar lordosis (LL) was 2.8° (range -29° to 20°) preoperatively, -35.6° (range -54° to 23°) early postoperatively (P < 0.001) and -33.6° (range -52° to 20°) during the last follow-up (P < 0.001). The average amount of bleeding was 5345 (range 2600-7415) ml. Although a statistically significant correction was obtained, the mean PT and PI-LL value could not be restored in physiological limits during the last follow-up. Thus, two level PSOs performed after computer software (surgimap) assisted preoperative planning failed to correct severe fixed sagittal plane deformities. Besides, this procedure is of possible risks for major complications such as a

Which cardiovascular magnetic resonance planes and sequences provide accurate measurements of branch pulmonary artery size in children with right ventricular outflow tract obstruction?

PubMed

Vijarnsorn, Chodchanok; Rutledge, Jennifer M; Tham, Edythe B; Coe, James Y; Quinonez, Luis; Patton, David J; Noga, Michelle

2014-02-01

Children with right ventricular outflow tract obstructive (RVOTO) lesions require precise quantification of pulmonary artery (PA) size for proper management of branch PA stenosis. We aimed to determine which cardiovascular magnetic resonance (CMR) sequences and planes correlated best with cardiac catheterization and surgical measurements of branch PA size. Fifty-five children with RVOTO lesions and biventricular circulation underwent CMR prior to; either cardiac catheterization (n = 30) or surgery (n = 25) within a 6 month time frame. CMR sequences included axial black blood, axial, coronal oblique and sagittal oblique cine balanced steady-state free precession (bSSFP), and contrast-enhanced magnetic resonance angiography (MRA) with multiplanar reformatting in axial, coronal oblique, sagittal oblique, and cross-sectional planes. Maximal branch PA and stenosis (if present) diameter were measured. Comparisons of PA size on CMR were made to reference methods: (1) catheterization measurements performed in the anteroposterior plane at maximal expansion, and (2) surgical measurement obtained from a maximal diameter sound which could pass through the lumen. The mean differences (Δ) and intra class correlation (ICC) were used to determine agreement between different modalities. CMR branch PA measurements were compared to the corresponding cardiac catheterization measurements in 30 children (7.6 ± 5.6 years). Reformatted MRA showed better agreement for branch PA measurement (ICC > 0.8) than black blood (ICC 0.4-0.6) and cine sequences (ICC 0.6-0.8). Coronal oblique MRA and maximal cross sectional MRA provided the best correlation of right PA (RPA) size with ICC of 0.9 (Δ -0.1 ± 2.1 mm and Δ 0.5 ± 2.1 mm). Maximal cross sectional MRA and sagittal oblique MRA provided the best correlate of left PA (LPA) size (Δ 0.1 ± 2.4 and Δ -0.7 ± 2.4 mm). For stenoses, the best correlations were from coronal oblique MRA of right pulmonary artery (RPA) (Δ -0.2 ± 0.8 mm, ICC 0

Transverse forces versus modified ashworth scale for upper limb flexion/extension in para-sagittal plane.

PubMed

Seth, Nitin; Johnson, Denise; Abdullah, Hussein A

2017-07-01

Spasticity is a common impairment following an upper motor neuron lesion in conditions such as stroke and brain injury. A clinical issue is how to best quantify and measure spasticity. Recently, research has been performed to develop new methods of spasticity quantification using various systems. This paper follows up on previous work taking a closer look at the role of transversal forces obtained via rehabilitation robot for motions in the para-sagittal plane. Results from 45 healthy individuals and 40 individuals with acquired brain injury demonstrate that although the passive upper motions are vertical, horizontal forces into and away from the individual's body demonstrate a relationship with the Modified Ashworth Scale. This finding leads the way to new avenues of spasticity quantification and monitoring.

Male and female runners demonstrate different sagittal plane mechanics as a function of static hamstring flexibility.

PubMed

Williams, D S Blaise; Welch, Lee M

2015-01-01

Injuries to runners are common. However, there are many potential contributing factors to injury. While lack of flexibility alone is commonly related to injury, there are clear differences in hamstring flexibility between males and females. To compare the effect of static hamstring length on sagittal plane mechanics between male and female runners. Forty subjects (30.0±6.4 years) participated and were placed in one of 4 groups: flexible males (n=10), inflexible males (n=10), flexible females (n=10), and inflexible females (n=10). All subjects were free of injury at the time of data collection. Three-dimensional kinematics and kinetics were collected while subjects ran over ground across 2 force platforms. Sagittal plane joint angles and moments were calculated at the knee and hip and compared with a 2-way (sex X flexibility) ANOVA (α=0.05). Males exhibited greater peak knee extension moment than females (M=2.80±0.47, F=2.48±0.52 Nm/kg*m, p=0.05) and inflexible runners exhibited greater peak knee extension moment than flexible runners (In=2.83±0.56, Fl=2.44±0.51 Nm/kg*m, p=0.01). For hip flexion at initial contact, a significant interaction existed (p<0.05). Flexible females (36.7±7.4º) exhibited more hip flexion than inflexible females (27.9±4.6º, p<0.01) and flexible males (30.1±9.5º, p<0.05). No differences existed for knee angle at initial contact, peak knee angle, peak hip angle, or peak hip moment. Hamstring flexibility results in different mechanical profiles in males and females. Flexibility in the hamstrings may result in decreased moments via active or passive tension. These differences may have implications for performance and injury in flexible female runners.

Male and female runners demonstrate different sagittal plane mechanics as a function of static hamstring flexibility

PubMed Central

Williams III, D. S. Blaise; Welch, Lee M.

2015-01-01

ABSTRACT Background: Injuries to runners are common. However, there are many potential contributing factors to injury. While lack of flexibility alone is commonly related to injury, there are clear differences in hamstring flexibility between males and females. Objective: To compare the effect of static hamstring length on sagittal plane mechanics between male and female runners. Method: Forty subjects (30.0±6.4 years) participated and were placed in one of 4 groups: flexible males (n=10), inflexible males (n=10), flexible females (n=10), and inflexible females (n=10). All subjects were free of injury at the time of data collection. Three-dimensional kinematics and kinetics were collected while subjects ran over ground across 2 force platforms. Sagittal plane joint angles and moments were calculated at the knee and hip and compared with a 2-way (sex X flexibility) ANOVA (α=0.05). Results: Males exhibited greater peak knee extension moment than females (M=2.80±0.47, F=2.48±0.52 Nm/kg*m, p=0.05) and inflexible runners exhibited greater peak knee extension moment than flexible runners (In=2.83±0.56, Fl=2.44±0.51 Nm/kg*m, p=0.01). For hip flexion at initial contact, a significant interaction existed (p<0.05). Flexible females (36.7±7.4º) exhibited more hip flexion than inflexible females (27.9±4.6º, p<0.01) and flexible males (30.1±9.5º, p<0.05). No differences existed for knee angle at initial contact, peak knee angle, peak hip angle, or peak hip moment. Conclusion: Hamstring flexibility results in different mechanical profiles in males and females. Flexibility in the hamstrings may result in decreased moments via active or passive tension. These differences may have implications for performance and injury in flexible female runners. PMID:26537812

Grizzly bear (Ursus arctos horribilis) locomotion: forelimb joint mechanics across speed in the sagittal and frontal planes.

PubMed

Shine, Catherine L; Robbins, Charles T; Nelson, O Lynne; McGowan, Craig P

2017-04-01

The majority of terrestrial locomotion studies have focused on parasagittal motion and paid less attention to forces or movement in the frontal plane. Our previous research has shown that grizzly bears produce higher medial ground reaction forces (lateral pushing from the animal) than would be expected for an upright mammal, suggesting frontal plane movement may be an important aspect of their locomotion. To examine this, we conducted an inverse dynamics analysis in the sagittal and frontal planes, using ground reaction forces and position data from three high-speed cameras of four adult female grizzly bears. Over the speed range collected, the bears used walks, running walks and canters. The scapulohumeral joint, wrist and the limb overall absorb energy (average total net work of the forelimb joints, -0.97 W kg -1 ). The scapulohumeral joint, elbow and total net work of the forelimb joints have negative relationships with speed, resulting in more energy absorbed by the forelimb at higher speeds (running walks and canters). The net joint moment and power curves maintain similar patterns across speed as in previously studied species, suggesting grizzly bears maintain similar joint dynamics to other mammalian quadrupeds. There is no significant relationship with net work and speed at any joint in the frontal plane. The total net work of the forelimb joints in the frontal plane was not significantly different from zero, suggesting that, despite the high medial ground reaction forces, the forelimb acts as a strut in that plane. © 2017. Published by The Company of Biologists Ltd.

Automatic Recognition of Fetal Facial Standard Plane in Ultrasound Image via Fisher Vector.

PubMed

Lei, Baiying; Tan, Ee-Leng; Chen, Siping; Zhuo, Liu; Li, Shengli; Ni, Dong; Wang, Tianfu

2015-01-01

Acquisition of the standard plane is the prerequisite of biometric measurement and diagnosis during the ultrasound (US) examination. In this paper, a new algorithm is developed for the automatic recognition of the fetal facial standard planes (FFSPs) such as the axial, coronal, and sagittal planes. Specifically, densely sampled root scale invariant feature transform (RootSIFT) features are extracted and then encoded by Fisher vector (FV). The Fisher network with multi-layer design is also developed to extract spatial information to boost the classification performance. Finally, automatic recognition of the FFSPs is implemented by support vector machine (SVM) classifier based on the stochastic dual coordinate ascent (SDCA) algorithm. Experimental results using our dataset demonstrate that the proposed method achieves an accuracy of 93.27% and a mean average precision (mAP) of 99.19% in recognizing different FFSPs. Furthermore, the comparative analyses reveal the superiority of the proposed method based on FV over the traditional methods.

Training intensity and sagittal curvature of the spine in male and female artistic gymnasts.

PubMed

Sanz-Mengibar, Jose M; Sainz-de-Baranda, Pilar; Santonja-Medina, Fernando

2018-04-01

Specific adaptations of the spine in the sagittal plane have been described according to different sports disciplines. The goal of this study was to describe the integrative diagnosis of the sagittal morphotype of the spine in male and female artistic gymnasts. Forty-eight gymnasts were measured with an inclinometer. Thoracic and lumbar curves were quantified in standing position, in Sit and Reach and Slump Sitting in order to assess the sagittal spine posture and analyze if adaptations were related to training intensity. Correlation values of the sagittal plane spine measurements showed significantly increased thoracic kyphosis in men (-0.445, P<0.001). No significant correlations have been found between training hours per year or training volume and any measurements of the spine on the sagittal plane. When data from the two sitting tests were integrated, 62.5% of gymnasts had a functional thoracic kyphosis and 39.6% had lumbar kyphotic attitude. Our hypothesis has only been partially confirmed, because training intensity did not influence the sagittal curvatures in artistic gymnastics; however, this sport seems to cause specific adaptations in postural hypolordosis, functional thoracic kyphosis and lumbar kyphotic attitude during sitting and trunk flexion. The implications of the functional adaptations observed in our results may require a preventive intervention in male and female artistic gymnasts can be assessed with the integrative diagnosis of the sagittal morphotype of the spine.

Does Knee Osteoarthritis Differentially Modulate Proprioceptive Acuity in the Frontal and Sagittal Planes of the Knee?

PubMed Central

Cammarata, Martha L; Schnitzer, Thomas J; Dhaher, Yasin Y

2012-01-01

Objective Impaired proprioception may alter joint loading and contribute to the progression of knee osteoarthritis (OA). Though frontal plane loading at the knee contributes to OA, proprioception and its modulation with OA in this direction have not been examined. The aim of this study was to assess knee proprioceptive acuity in the frontal and sagittal planes in knee OA and healthy participants. We hypothesized that proprioceptive acuity will be decreased in the OA population in both planes of movement. Methods Thirteen persons with knee OA and fourteen healthy age-matched subjects participated. Proprioceptive acuity was assessed in varus, valgus, flexion, and extension using the threshold to detection of passive movement (TDPM). Repeated measures analysis of variance was used to assess differences in TDPM between subject groups and across movement directions. Linear regression analyses were performed to assess the correlation of TDPM between and within planes of movement. Results TDPM was found to be significantly higher (P<0.05), in the knee OA group compared to the control group for all directions tested, indicating reduced proprioceptive acuity. Differences in TDPM between groups were consistent across all movement directions, with mean difference (95% CI) for valgus: 0.94° (0.20°, 1.65°), varus: 0.92° (0.18°, 1.68°), extension: 0.93° (0.19°, 1.66°), and flexion: 1.11° (0.38°, 1.85°). TDPM measures across planes of movement were only weakly correlated, especially in the OA group. Conclusions Consistent differences in TDPM between the OA and control groups across all movement directions suggest a global, not direction-specific, reduction in sensation in knee OA patients. PMID:21547895

Asymmetric C7 pedicle subtraction osteotomy for correction of rigid cervical coronal imbalance secondary to post-traumatic heterotopic ossification: a case report, description of a novel surgical technique, and literature review.

PubMed

Theologis, Alexander A; Bellevue, Kate D; Qamirani, Erion; Ames, Christopher P; Deviren, Vedat

2017-05-01

Deformities of the cervical spine are uncommon in the coronal plane. In this report, a unique case of a 31-year-old male with a fixed, 30° left coronal deformity due to heterotopic ossification 3 years status post poly-trauma was treated with an asymmetric C7 pedicle subtraction osteotomy (PSO). Case report. Pre-operatively, the patient had a fixed 45-degree left tilt of his neck and radiographs demonstrated a rigid 30° scoliosis, 7 cm coronal imbalance, and 4 cm negative sagittal balance, diffuse bridging bone between the spinous processes and the facet joints of C5 to T1 bilaterally. An asymmetric C7 PSO with C2-T3 posterior spinal fusion was completed without complication. There was residual 9° coronal deformity, 2.9 cm left coronal imbalance, and 2.3 cm sagittal imbalance. He had a marked improvement in his function, as assessed by the SF-36 physical component score (pre-op 31.1; post-op 44.7) and mental component score (pre-op 46.0; post-op 66.8). Post-operatively, neck disability index scores also improved (pre-op 38; post-op 16). Although the patient passed away from a drug overdose 14 months post-operatively, he did not report neck pain, he had not sought evaluation from another physician for his neck, and he had not undergone a subsequent neck operation before his passing. In this one patient, an asymmetric C7 PSO was performed safely. While it was effective in addressing a fixed cervical coronal imbalance, its efficacy and safety profile should be confirmed in larger cohorts.

Reliability of tunnel angle in ACL reconstruction: two-dimensional versus three-dimensional guide technique.

PubMed

Leiter, Jeff R S; de Korompay, Nevin; Macdonald, Lindsey; McRae, Sheila; Froese, Warren; Macdonald, Peter B

2011-08-01

To compare the reliability of tibial tunnel position and angle produced with a standard ACL guide (two-dimensional guide) or Howell 65° Guide (three-dimensional guide) in the coronal and sagittal planes. In the sagittal plane, the dependent variables were the angle of the tibial tunnel relative to the tibial plateau and the position of the tibial tunnel with respect to the most posterior aspect of the tibia. In the coronal plane, the dependent variables were the angle of the tunnel with respect to the medial joint line of the tibia and the medial and lateral placement of the tibial tunnel relative to the most medial aspect of the tibia. The position and angle of the tibial tunnel in the coronal and sagittal planes were determined from anteroposterior and lateral radiographs, respectively, taken 2-6 months postoperatively. The two-dimensional and three-dimensional guide groups included 28 and 24 sets of radiographs, respectively. Tibial tunnel position was identified, and tunnel angle measurements were completed. Multiple investigators measured the position and angle of the tunnel 3 times, at least 7 days apart. The angle of the tibial tunnel in the coronal plane using a two-dimensional guide (61.3 ± 4.8°) was more horizontal (P < 0.05) than tunnels drilled with a three-dimensional guide (64.7 ± 6.2°). The position of the tibial tunnel in the sagittal plane was more anterior (P < 0.05) in the two-dimensional (41.6 ± 2.5%) guide group compared to the three-dimensional guide group (43.3 ± 2.9%). The Howell Tibial Guide allows for reliable placement of the tibial tunnel in the coronal plane at an angle of 65°. Tibial tunnels were within the anatomical footprint of the ACL with either technique. Future studies should investigate the effects of tibial tunnel angle on knee function and patient quality of life. Case-control retrospective comparative study, Level III.

Comparison of the trunk-pelvis and lower extremities sagittal plane inter-segmental coordination and variability during walking in persons with and without chronic low back pain.

PubMed

Ebrahimi, Samaneh; Kamali, Fahimeh; Razeghi, Mohsen; Haghpanah, Seyyed Arash

2017-04-01

Inter-segmental coordination can be influenced by chronic low back pain (CLBP). The sagittal plane lower extremities inter-segmental coordination pattern and variability, in conjunction with the pelvis and trunk, were assessed in subjects with and without non-specific CLBP during free-speed walking. Kinematic data were collected from 10 non-specific CLBP and 10 non-CLBP control volunteers while the subjects were walking at their preferred speed. Sagittal plane time-normalized segmental angles and velocities were used to calculate continuous relative phase for each data point. Mean absolute relative phase (MARP) and deviation phase (DP) were derived to quantify the trunk-pelvis and bilateral pelvis-thigh, thigh-shank and shank-foot coordination pattern and variability over the stance and swing phases of gait. Mann-Whitney U test was employed to compare the means of DP and MARP values between two groups (same side comparison). Statistical analysis revealed more in-phase/less variable trunk-pelvis coordination in the CLBP group (P<0.05). CLBP group demonstrated less variable right or left pelvis-thigh coordination pattern (P<0.05). Moreover, the left thigh-shank and left shank-foot MARP values in the CLBP group, were more in-phase than left MARP values in the non-CLBP control group during the swing phase (P<0.05). In conclusion, the sagittal plane lower extremities, pelvis and trunk coordination pattern and variability could be generally affected by CLBP during walking. These changes can be possible compensatory strategies of the motor control system which can be considered in the CLBP subjects. Copyright © 2017 Elsevier B.V. All rights reserved.

Measurement and Finite Element Model Validation of Immature Porcine Brain-Skull Displacement during Rapid Sagittal Head Rotations.

PubMed

Pasquesi, Stephanie A; Margulies, Susan S

2018-01-01

Computational models are valuable tools for studying tissue-level mechanisms of traumatic brain injury, but to produce more accurate estimates of tissue deformation, these models must be validated against experimental data. In this study, we present in situ measurements of brain-skull displacement in the neonatal piglet head ( n  = 3) at the sagittal midline during six rapid non-impact rotations (two rotations per specimen) with peak angular velocities averaging 51.7 ± 1.4 rad/s. Marks on the sagittally cut brain and skull/rigid potting surfaces were tracked, and peak values of relative brain-skull displacement were extracted and found to be significantly less than values extracted from a previous axial plane model. In a finite element model of the sagittally transected neonatal porcine head, the brain-skull boundary condition was matched to the measured physical experiment data. Despite smaller sagittal plane displacements at the brain-skull boundary, the corresponding finite element boundary condition optimized for sagittal plane rotations is far less stiff than its axial counterpart, likely due to the prominent role of the boundary geometry in restricting interface movement. Finally, bridging veins were included in the finite element model. Varying the bridging vein mechanical behavior over a previously reported range had no influence on the brain-skull boundary displacements. This direction-specific sagittal plane boundary condition can be employed in finite element models of rapid sagittal head rotations.

Measurement and Finite Element Model Validation of Immature Porcine Brain–Skull Displacement during Rapid Sagittal Head Rotations

PubMed Central

Pasquesi, Stephanie A.; Margulies, Susan S.

2018-01-01

Computational models are valuable tools for studying tissue-level mechanisms of traumatic brain injury, but to produce more accurate estimates of tissue deformation, these models must be validated against experimental data. In this study, we present in situ measurements of brain–skull displacement in the neonatal piglet head (n = 3) at the sagittal midline during six rapid non-impact rotations (two rotations per specimen) with peak angular velocities averaging 51.7 ± 1.4 rad/s. Marks on the sagittally cut brain and skull/rigid potting surfaces were tracked, and peak values of relative brain–skull displacement were extracted and found to be significantly less than values extracted from a previous axial plane model. In a finite element model of the sagittally transected neonatal porcine head, the brain–skull boundary condition was matched to the measured physical experiment data. Despite smaller sagittal plane displacements at the brain–skull boundary, the corresponding finite element boundary condition optimized for sagittal plane rotations is far less stiff than its axial counterpart, likely due to the prominent role of the boundary geometry in restricting interface movement. Finally, bridging veins were included in the finite element model. Varying the bridging vein mechanical behavior over a previously reported range had no influence on the brain–skull boundary displacements. This direction-specific sagittal plane boundary condition can be employed in finite element models of rapid sagittal head rotations. PMID:29515995

Eccentric Capitellar Ossification Limits the Utility of the Radiocapitellar Line in Young Children.

PubMed

Fader, Lauren M; Laor, Tal; Eismann, Emily A; Cornwall, Roger; Little, Kevin J

2016-03-01

The radiocapitellar line (RCL) has long been used for the radiographic evaluation of elbow alignment. In children, the capitellar ossific nucleus serves as a proxy for the entire capitellum, but this substitution has not been verified. Using magnetic resonance imaging (MRI), we sought to understand how maturation of the ossific nucleus of the capitellum affects the utility of RCL throughout skeletal maturation of the elbow. The RCL was drawn on coronal and sagittal MRIs in 82 children (43 boys, 39 girls; age range, 1 to 13 y) with at least 3 patients in each 1-year interval age group. The perpendicular distance of the RCL from the center of both the cartilaginous capitellum and the capitellar ossific nucleus was measured relative to its total width, and a percent offset for each measurement was calculated. Logarithmic regression analysis was performed to analyze the effect of age and sex on percent offset. The RCL reliably intersected with the central third of the cartilaginous capitellum at all ages in both planes. Although the RCL intersected with the ossified capitellum in all but 3 measurements, it intersected with the central third of the ossified capitellum less often in younger children in both sagittal (B=0.47, P<0.001) and coronal (B=0.31, P=0.002) planes. Percent offset decreased significantly with age in a logarithmic manner in both sagittal (r=0.57, P<0.001) and coronal (r=-0.47, P<0.001) planes. 95% confidence intervals predict that the sagittal plane RCL will accurately intersect the central third of the ossified capitellum by age 10 years in girls and age 11 years in boys but not in the coronal plane. Eccentric ossification of the capitellum explains RCL variability in young children. The RCL does not reliably intersect the central third of the ossified capitellum until ages 10 years in girls and 11 years in boys in the sagittal plane. The RCL should be used within its limitations in skeletally immature children and should be combined with advanced

The path of the superior sagittal sinus in unicoronal synostosis.

PubMed

Russell, Aaron J; Patel, Kamlesh B; Skolnick, Gary; Woo, Albert S; Smyth, Matthew D

2014-10-01

This study investigates the anatomic relationship between the superior sagittal sinus (SSS) and the sagittal suture in infants with uncorrected unicoronal synostosis. The morphology of the SSS is also evaluated postoperatively to assess whether normalization of intracranial structures occurs following reconstruction. The study sample consisted of 20 computed tomography scans (10 preoperative, 6 postoperative, and 4 unaffected controls) obtained between 2001 and 2013. The SSS and the sagittal suture were outlined using Analyze imaging software. These data were used to measure the maximum lateral discrepancy between the SSS and the sagittal suture preoperatively and to assess for postoperative changes in the morphology of the SSS. In children with uncorrected unicoronal synostosis, the SSS deviates to the side of the patent coronal suture posteriorly and tends to follow the path of the sagittal and metopic sutures. The lateral discrepancy between the SSS and the sagittal suture ranged from 5.0 to 11.8 mm, with a 99.9 % upper prediction bound of 14.4 mm. Postoperatively, the curvature of the SSS was statistically decreased following surgical intervention, though it remained significantly greater than in unaffected controls. The SSS follows a predictable course relative to surface landmarks in children with unicoronal synostosis. When creating burr holes for craniotomies, the SSS can be avoided in 99.9 % of cases by remaining at least 14.4 mm from the lateral edge of the sagittal suture. Postoperative changes in the path of the SSS provide indirect evidence for normalization of regional brain morphology following fronto-orbital advancement.

A three-plane architectonic atlas of the rat hippocampal region.

PubMed

Boccara, Charlotte N; Kjonigsen, Lisa J; Hammer, Ingvild M; Bjaalie, Jan G; Leergaard, Trygve B; Witter, Menno P

2015-07-01

The hippocampal region, comprising the hippocampal formation and the parahippocampal region, has been one of the most intensively studied parts of the brain for decades. Better understanding of its functional diversity and complexity has led to an increased demand for specificity in experimental procedures and manipulations. In view of the complex 3D structure of the hippocampal region, precisely positioned experimental approaches require a fine-grained architectural description that is available and readable to experimentalists lacking detailed anatomical experience. In this paper, we provide the first cyto- and chemoarchitectural description of the hippocampal formation and parahippocampal region in the rat at high resolution and in the three standard sectional planes: coronal, horizontal and sagittal. The atlas uses a series of adjacent sections stained for neurons and for a number of chemical marker substances, particularly parvalbumin and calbindin. All the borders defined in one plane have been cross-checked against their counterparts in the other two planes. The entire dataset will be made available as a web-based interactive application through the Rodent Brain WorkBench (http://www.rbwb.org) which, together with this paper, provides a unique atlas resource. © 2014 Wiley Periodicals, Inc.

Sagittal balance and idiopathic scoliosis: does final sagittal alignment influence outcomes, degeneration rate or failure rate?

PubMed

Ilharreborde, Brice

2018-02-01

In the last decade, spine surgeons have been impacted by the "sagittal plane analysis revolution". Significant correlations have been found in adult spinal deformity (ASD) between sagittal lumbo-pelvic parameters and functional outcomes, but most of them do not apply in adolescent idiopathic scoliosis (AIS). Meanwhile, instrumentation and reduction strategies have considerably evolved. This paper aims to describe the preoperative sagittal alignment in AIS, and to report literature evidence regarding the influence of postoperative sagittal balance on complication rates, low back pain incidence and disc degeneration. A bibliographic search in Medline and Google database from 1984 to May 2017 was performed. The keywords included 'adolescent idiopathic scoliosis', 'adult scoliosis', 'sagittal alignment', 'proximal junctional kyphosis', 'distal junctional kyphosis', 'outcomes', 'low back pain' and 'complication', used individually or in combination. Algorithms of sagittal balance analysis and treatment decision have been reported in ASD, but the clinical situation is very different in children. Sagittal alignment greatly varies in AIS among the various Lenke types. Most patients are clinically balanced before surgery, but the spinal harmony is altered, with overgrowth of the anterior column and global sagittal flattening (undersestimated in 2D). The exact role of pelvic incidence and whether or not patients also use pelvic compensation to maintain balance still require further clarification. The incidence of radiological junctional failures remains highly variable, depending on definitions, cohort size and follow-up. Preoperative hyperkyphosis seems to be a consistent and relevant risk factor. Current literature does not support the recent trend to save motion segments (selective fusion), and no significant association was found between the distal level of fusion and the incidence of low back pain. Postoperative sagittal alignment seems to be more important than LIV

Computed tomography of calcaneal fractures: anatomy, pathology, dosimetry, and clinical relevance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guyer, B.H.; Levinsohn, E.M.; Fredrickson, B.E.

1985-11-01

Eighteen CT examinations were performed in 10 patients for the evaluation of acute intraarticular fractures and their follow-up. Fractures comparable to those in the patients were created in cadavers. The normal anatomy and the traumatically altered anatomy of the calcaneus in the axial, coronal, and sagittal planes are demonstrated by CT and corresponding anatomic sections. Scanning was performed in the axial plane, with subsequent reconstruction in the coronal and sagittal planes. The axial scans show disruption of the inferior part of the posterior facet, calcaneocuboid joint involvement, and widening of the calcaneus. The coronal scans show disruption of the superiormore » part of the posterior facet, sustentaculum tali depression (involvement of middle and anterior facets), peroneal and flexor hallucis longus tendon impingement, and widening and height loss of the calcaneus. The sagittal scans show disruption of the posterior facet, calcaneocuboid joint involvement, and height loss of the calcaneus and allow the evaluation of Boehler's and Gissane's angles. All three planes show the position of major fracture fragments. Radiation dose to the foot was measured to be 0.1 rad (0.001 Gy) for plain film radiography (five exposures), 18 rad (0.18 Gy) for conventional tomography (20 cuts), and 2.6 rad (0.026 Gy) for axial CT examination.« less

Correlation between direction and severity of temporomandibular joint disc displacement and reduction ability during mouth opening.

PubMed

Litko, M; Berger, M; Szkutnik, J; Różyło-Kalinowska, I

2017-12-01

The most common temporomandibular joint (TMJ) internal derangement is an abnormal relationship of the disc with respect to the mandibular condyle, articular eminence and glenoid fossa-disc displacement. The aim of our study was to analyse the correlation between partial/complete disc displacement in the intercuspal position (IP) and its reduction in the open-mouth position (OMP) in both oblique sagittal and coronal planes on magnetic resonance imaging (MRI) in patients with temporomandibular disorders. Multisection MRI analysis of 382 TMJs was conducted in 191 patients with disc displacement according to the RDC/TMD criteria (148 women, 43 men; aged 14-60 years). The disc position was evaluated on all oblique sagittal and coronal images in the IP and the OMP. Univariate logistic regression analysis showed that the severity of disc displacement in the sagittal plane is a statistically significant predictor of reduction ability during mouth opening (B = 3.118; P < .001). Moreover, the severity of disc displacement in both planes is also a significant predictor of disc reduction in OMP (B = 2.200; P < .05). In conclusion, reduction ability during mouth opening is associated with the severity of disc displacement in IP, in both sagittal and coronal planes. Multisection analysis of all MR images allows distinguishing the correct disc position from disc displacement and can improve the ability to distinguish between various stages of TMJ internal derangement. © 2017 John Wiley & Sons Ltd.

Identification of Apical and Cervical Curvature Radius of Human Molars.

PubMed

Estrela, Carlos; Bueno, Mike R; Barletta, Fernando B; Guedes, Orlando A; Porto, Olavo C; Estrela, Cyntia R A; Pécora, Jesus Djalma

2015-01-01

To determine the frequency of apical and cervical curvatures in human molars using the radius method and cone-beam computed tomography (CBCT) images. Four hundred images of mandibular and maxillary first and second molars were selected from a database of CBCT exams. The radius of curvature of curved root canals was measured using a circumcenter based on three mathematical points. Radii were classified according to the following scores: 0 - straight line; 1 - large radius (r > 8 mm, mild curvature); 2 - intermediate radius (r > 4 and r < 8 mm, moderate curvature); and 3 - small radius (r ≤ 4 mm, severe curvature). The frequency of curved root canals was analyzed according to root canal, root thirds, and coronal and sagittal planes, and assessed using the chi-square test (significance at α = 0.05). Of the 1,200 evaluated root canals, 92.75% presented curved root canals in the apical third and 73.25% in the cervical third on coronal plane images; sagittal plane analysis yielded 89.75% of curved canals in the apical third and 77% in the cervical third. Root canals with a large radius were significantly more frequent when compared with the other categories, regardless of root third or plane. Most root canals of maxillary and mandibular first and second molars showed some degree of curvature in the apical and cervical thirds, regardless of the analyzed plane (coronal or sagittal).

Case-related factors affecting cutting errors of the proximal tibia in total knee arthroplasty assessed by computer navigation.

PubMed

Tsukeoka, Tadashi; Tsuneizumi, Yoshikazu; Yoshino, Kensuke; Suzuki, Mashiko

2018-05-01

The aim of this study was to determine factors that contribute to bone cutting errors of conventional instrumentation for tibial resection in total knee arthroplasty (TKA) as assessed by an image-free navigation system. The hypothesis is that preoperative varus alignment is a significant contributory factor to tibial bone cutting errors. This was a prospective study of a consecutive series of 72 TKAs. The amount of the tibial first-cut errors with reference to the planned cutting plane in both coronal and sagittal planes was measured by an image-free computer navigation system. Multiple regression models were developed with the amount of tibial cutting error in the coronal and sagittal planes as dependent variables and sex, age, disease, height, body mass index, preoperative alignment, patellar height (Insall-Salvati ratio) and preoperative flexion angle as independent variables. Multiple regression analysis showed that sex (male gender) (R = 0.25 p = 0.047) and preoperative varus alignment (R = 0.42, p = 0.001) were positively associated with varus tibial cutting errors in the coronal plane. In the sagittal plane, none of the independent variables was significant. When performing TKA in varus deformity, careful confirmation of the bone cutting surface should be performed to avoid varus alignment. The results of this study suggest technical considerations that can help a surgeon achieve more accurate component placement. IV.

The effects of the sagittal plane malpositioning of the patella and concomitant quadriceps hypotrophy on the patellofemoral joint: a finite element analysis.

PubMed

Aksahin, Ertugrul; Kocadal, Onur; Aktekin, Cem N; Kaya, Defne; Pepe, Murad; Yılmaz, Serdar; Yuksel, H Yalcin; Bicimoglu, Ali

2016-03-01

Anterior knee pain is a common symptom after intramedullary nailing in tibia shaft fracture. Moreover, patellofemoral malalignment is also known to be a major reason for anterior knee pain. Patellofemoral malalignment predisposes to increased loading in patellar cartilage. In the previous study, we have demonstrated the quadriceps atrophy and patellofemoral malalignment after intramedullary nailing due to tibia shaft fracture. In this study, our aim was to clarify the effects of quadriceps atrophy and patellofemoral malalignment with the pathologic loading on the joint cartilage. Mesh models of patellofemoral joint were constructed with CT images and integrated with soft tissue components such as menisci and ligaments. Physiological and sagittal tilt models during extension and flexion at 15°, 30° and 60° were created generating eight models. All the models were applied with 137 N force to present the effects of normal loading and 115.7 N force for the simulation of quadriceps atrophy. Different degrees of loading were applied to evaluate the joint contact area and pressure value with the finite element analysis. There was increased patellofemoral contact area in patellar tilt models with respect to normal models. The similar loading patterns were diagnosed in all models at 0° and 15° knee flexion when 137 N force was applied. Higher loading values were obtained at 30° and 60° knee flexions in sagittal tilt models. Furthermore, in the sagittal tilt models, in which the quadriceps atrophy was simulated, the loadings at 30° and 60° knee flexion were higher than in the physiological ones. Sagittal malalignment of the patellofemoral joint is a new concept that results in different loading patterns in the patellofemoral joint biomechanics. This malalignment in sagittal plane leads to increased loading values on the patellofemoral joint at 30° and 60° of the knee flexions. This new concept should be kept in mind during the course of diagnosis and treatment

Glenoid deformity in the coronal plane correlates with humeral head changes in osteoarthritis: a radiographic analysis.

PubMed

Hawi, Nael; Magosch, Petra; Tauber, Mark; Lichtenberg, Sven; Martetschläger, Frank; Habermeyer, Peter

2017-02-01

A variety of measurements can be used to assess radiographic osteoarthritic changes of the shoulder. This study aimed to analyze the correlation between the radiographic humeral-sided Samilson and Prieto classification system and 3 different radiographic classifications describing the changes of the glenoid in the coronal plane. The study material included standardized radiographs of 50 patients with idiopathic osteoarthritis before anatomic shoulder replacement. On the basis of radiographic measurements, the cases were evaluated using the Samilson and Prieto grading system, angle β, inclination type, and critical shoulder angle by 2 independent observers. Classification measurements showed an excellent agreement between observers. Our results showed that the humeral-sided Samilson and Prieto grading system had a statistically significant good correlation with angle β (observer 1, r = 0.74; observer 2, r = 0.77; P < .05) and a statistically significant excellent correlation with the inclination type of the glenoid (observer 1, r  = 0.86; observer 2, r = 0.8; P < .05). A poor correlation to the critical shoulder angle was observed (r = -0.14, r = 0.03; P > .05). The grade of humeral-sided osteoarthritis according to Samilson and Prieto correlates with the glenoid-sided osteoarthritic changes of the glenoid in the coronal plane described by the angle β and by the inclination type of the glenoid. Higher glenoid-sided inclination is associated with higher grade of osteoarthritis in primary shoulder osteoarthritis. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Reliability of image-free navigation to monitor lower-limb alignment.

PubMed

Pearle, Andrew D; Goleski, Patrick; Musahl, Volker; Kendoff, Daniel

2009-02-01

Proper alignment of the mechanical axis of the lower limb is the principal goal of a high tibial osteotomy. A well-accepted and relevant technical specification is the coronal plane lower-limb alignment. Target values for coronal plane alignment after high tibial osteotomy include 2 degrees of overcorrection, while tolerances for this specification have been established as 2 degrees to 4 degrees. However, the role of axial plane and sagittal plane realignment after high tibial osteotomy is poorly understood; consequently, targets and tolerance for this technical specification remain undefined. This article reviews the literature concerning the reliability and precision of navigation in monitoring the clinically relevant specification of lower-limb alignment in high tibial osteotomy. We conclude that image-free navigation registration may be clinically useful for intraoperative monitoring of the coronal plane only. Only fair and poor results for the axial and sagittal planes can be obtained by image-free navigation systems. In the future, combined image-based data, such as those from radiographs, magnetic resonance imaging, and gait analysis, may be used to help to improve the accuracy and reproducibility of quantitative intraoperative monitoring of lower-limb alignment.

Sagittal plane gait characteristics in hip osteoarthritis patients with mild to moderate symptoms compared to healthy controls: a cross-sectional study.

PubMed

Eitzen, Ingrid; Fernandes, Linda; Nordsletten, Lars; Risberg, May Arna

2012-12-20

Existent biomechanical studies on hip osteoarthritic gait have primarily focused on the end stage of disease. Consequently, there is no clear consensus on which specific gait parameters are of most relevance for hip osteoarthritis patients with mild to moderate symptoms. The purpose of this study was to explore sagittal plane gait characteristics during the stance phase of gait in hip osteoarthritis patients not eligible for hip replacement surgery. First, compared to healthy controls, and second, when categorized into two subgroups of radiographic severity defined from a minimal joint space of ≤/>2 mm. Sagittal plane kinematics and kinetics of the hip, knee and ankle joint were calculated for total joint excursion throughout the stance phase, as well as from the specific events initial contact, midstance, peak hip extension and toe-off following 3D gait analysis. In addition, the Western Ontario and McMaster Universities Osteoarthritis Index, passive hip range of motion, and isokinetic muscle strength of hip and knee flexion and extension were included as secondary outcomes. Data were checked for normality and differences evaluated with the independent Student's t-test, Welch's t-test and the independent Mann-Whitney U-test. A binary logistic regression model was used in order to control for velocity in key variables. Fourty-eight hip osteoarthritis patients and 22 controls were included in the final material. The patients walked significantly slower than the controls (p=0.002), revealed significantly reduced joint excursions of the hip (p<0.001) and knee (p=0.011), and a reduced hip flexion moment at midstance and peak hip extension (p<0.001). Differences were primarily manifested during the latter 50% of stance, and were persistent when controlling for velocity. Subgroup analyses of patients with minimal joint space ≤/>2 mm suggested that the observed deviations were more pronounced in patients with greater radiographic severity. The biomechanical

Patient-specific instrumentation for total knee arthroplasty.

PubMed

Nabavi, Arash; Olwill, Caroline M; Do, Mike; Wanasawage, Tanya; Harris, Ian A

2017-01-01

To assess the accuracy of total knee replacements (TKRs) performed using CT-based patient-specific instrumentation by postoperative CT scan. Approval from the Ethics Committee was granted prior to commencement of this study. Fifty prospective and consecutive patients who had undergone TKR (Evolis, Medacta International) using CT-based patient-specific instrumentation (MY KNEE, Medacta International) were assessed postoperatively using a CT scan and the validated Perth protocol measurement technique. The hip-knee-ankle (HKA) angle of the lower limb in the coronal plane; the coronal, sagittal, and rotational orientation of the femoral component; and the coronal and sagittal orientation of the tibial component were measured. These results were then compared to each patient's preoperative planning. The percentage of patients found to be less than or equal to 3° of planned alignment was calculated. One patient was excluded as the femoral cutting block did not fit the femur as predicted by planning and therefore underwent a conventional TKR. Ninety-eight percent of patients were within 3° of planned alignment in the coronal plane reproducing the predicted HKA angle. Predicted coronal plane orientation of the tibial and femoral component was achieved in 100% and 96% of patients, respectively. The sagittal orientation of the femoral component was within 3° in 98% of patients. The planned sagittal positioning of the tibial component was achieved in 92% of patients. Furthermore, 90% of patients were found to have a femoral rotation within 3° of planning. Eighty-six percent of patients achieved good-to-excellent outcome at 12 months (Oxford Knee Score > 34). We have found that TKR using this patient-specific instrumentation accurately reproduces preoperative planning in all six of the parameters measured in this study.

Sagittal plane bending moments acting on the lower leg during running.

PubMed

Haris Phuah, Affendi; Schache, Anthony G; Crossley, Kay M; Wrigley, Tim V; Creaby, Mark W

2010-02-01

Sagittal bending moments acting on the lower leg during running may play a role in tibial stress fracture development. The purpose of this study was to evaluate these moments at nine equidistant points along the length of the lower leg (10% point-90% point) during running. Kinematic and ground reaction force data were collected for 20 male runners, who each performed 10 running trials. Inverse dynamics and musculoskeletal modelling techniques were used to estimate sagittal bending moments due to reaction forces and muscle contraction. The muscle moment was typically positive during stance, except at the most proximal location (10% point) on the lower leg. The reaction moment was predominantly negative throughout stance and greater in magnitude than the muscle moment. Hence, the net sagittal bending moment acting on the lower leg was principally negative (indicating tensile loads on the posterior tibia). Peak moments typically occurred around mid-stance, and were greater in magnitude at the distal, compared with proximal, lower leg. For example, the peak reaction moment at the most distal point was -9.61+ or - 2.07%Bw.Ht., and -2.73 + or - 1.18%Bw.Ht. at the most proximal point. These data suggest that tensile loads on the posterior tibia are likely to be higher toward the distal end of the bone. This finding may explain the higher incidence of stress fracture in the distal aspect of the tibia, observed by some authors. Stress fracture susceptibility will also be influenced by bone strength and this should also be accounted for in future studies. Copyright 2009 Elsevier B.V. All rights reserved.

Quantification of shoulder and elbow passive moments in the sagittal plane as a function of adjacent angle fixations.

PubMed

Kodek, Timotej; Munih, Marko

2003-01-01

The goal of this study was an assessment of the shoulder and elbow joint passive moments in the sagittal plane for six healthy individuals. Either the shoulder or elbow joints were moved at a constant speed, very slowly throughout a large portion of their range by means of an industrial robot. During the whole process the arm was held fully passively, while the end point force data and the shoulder, elbow and wrist angle data were collected. The presented method unequivocally reveals a large passive moment adjacent angle dependency in the central angular range, where most everyday actions are performed. It is expected to prove useful in the future work when examining subjects with neuromuscular disorders. Their passive moments may show a fully different pattern than the ones obtained in this study.

Increased conformity offers diminishing returns for reducing total knee replacement wear.

PubMed

Fregly, Benjamin J; Marquez-Barrientos, Carlos; Banks, Scott A; DesJardins, John D

2010-02-01

Wear remains a significant problem limiting the lifespan of total knee replacements (TKRs). Though increased conformity between TKR components has the potential to decrease wear, the optimal amount and planes of conformity have not been investigated. Furthermore, differing conformities in the medial and lateral compartments may provide designers the opportunity to address both wear and kinematic design goals simultaneously. This study used a computational model of a Stanmore knee simulator machine and a previously validated wear model to investigate this issue for simulated gait. TKR geometries with different amounts and planes of conformity on the medial and lateral sides were created and tested in two phases. The first phase utilized a wide range of sagittal and coronal conformity combinations to blanket a physically realistic design space. The second phase performed a focused investigation of the conformity conditions from the first phase to which predicted wear volume was sensitive. For the first phase, sagittal but not coronal conformity was found to have a significant effect on predicted wear volume. For the second phase, increased sagittal conformity was found to decrease predicted wear volume in a nonlinear fashion, with reductions gradually diminishing as conformity increased. These results suggest that TKR geometric design efforts aimed at minimizing wear should focus on sagittal rather than coronal conformity and that at least moderate sagittal conformity is desirable in both compartments.

Sagittal Balance in Adolescent Idiopathic Scoliosis

PubMed Central

Xu, Xi-Ming; Wang, Fei; Zhou, Xiao-Yi; Liu, Zi-Xuan; Wei, Xian-Zhao; Bai, Yu-Shu; Li, Ming

2015-01-01

Abstract The relationship between spinal sagittal alignment and pelvic parameters is well known in adolescent idiopathic scoliosis. However, few studies have reported the sagittal spinopelvic relationship after selective posterior fusion of thoracolumbar/lumbar (TL/L) curves. We evaluated the relationship between spinal sagittal alignment and the pelvis, and analyzed how the pelvic sagittal state is adjusted in Lenke type 5C patients. We conducted a retrospective study of 36 patients with Lenke type 5C curves who received selective posterior TL/L curve fusion. Coronal and spinopelvic sagittal parameters were pre and postoperatively compared. Pearson coefficients were used to analyze the correlation between all spinopelvic sagittal parameters before and after surgery. We also evaluated 3 pelvic morphologies (anteverted, normal, and retroverted) before and after surgery. Preoperatively, the mean pelvic incidence was 46.0°, with a pelvic tilt and sacral slope (SS) of 8.2° and 37.8°, respectively, and 25% (9/36) of patients had an anteverted pelvis, whereas the other 75% had a normal pelvis. Postoperatively, 42% (15/36) of patients had a retroverted pelvis, 53% (19/36) had a normal pelvis, and 2 patients had an anteverted pelvis. Logistic regression analyses yielded 2 factors that were significantly associated with the risk for a postoperative unrecovered anteverted pelvis, including increased lumbar lordosis (LL) (odds ratio [OR] 4.8, P = 0.029) and increased SS (OR 5.6, P = 0.018). Four factors were significantly associated with the risk of a postoperative newly anteverted pelvis, including LL at the final follow-up (OR 6.9, P = 0.009), increased LL (OR 8.9, P = 0.003), LL below fusion (OR 9.4, P = 0.002), and increased SS (OR 11.5, P = 0.001). The pelvic state may be adjusted after selective posterior TL/L curve fusion in Lenke 5C adolescent idiopathic scoliosis patients. It is difficult to improve an anteverted pelvis in patients who have

Transforaminal Anterior Release for the Treatment of Fixed Sagittal Imbalance and Segmental Kyphosis, Minimum 2-Year Follow-Up Study.

PubMed

Sweet, Fred A; Sweet, Andrea

2015-09-01

Retrospective review of prospectively accrued patient cohort. To report minimum 2 years' follow-up after a single-surgeon series of 47 consecutive patients in whom fixed sagittal imbalance or segmental kyphosis was treated with a novel unilateral transforaminal annular release. Fixed sagittal imbalance has been treated most recently with pedicle subtraction osteotomy with great success but is associated with significant blood loss and neurologic risk. Forty-seven consecutive patients with fixed sagittal imbalance (n = 29) or segmental kyphosis (n = 18) were treated by a single surgeon with a single-level transforaminal anterior release (TFAR) to effect an opening wedge correction. Sagittal and coronal correction was performed with in situ rod contouring. An interbody cage was captured in the disc space with rod compression. Radiographic and clinical outcome analysis was performed with a minimum 2-year follow-up (range 2-7.8 years). The average increase in lordosis was 36° (range 24°-56°) in the fixed sagittal deformity group. Coronal corrections averaged 34° (range 18°-48°). The average improvement in plumb line was 13.6 cm. There were four pseudarthroses, one at the TFAR. Average blood loss was 578 mL (range 200-1,200). One patient had a transient grade 4/5 anterior tibialis weakness. There were no vascular injuries or permanent neurologic deficits. There were significant improvements in the Oswestry Disability Index (p < .001) and Scoliosis Research Society Questionnaire scores (p = .003). Eighty-four percent of patients reported improvement in pain, self-image, and satisfaction with the procedure. TFAR is a useful procedure for correcting segmental kyphosis and fixed sagittal imbalance with relatively low blood loss and was found to be neurologically safe in this single-surgeon series. Therapeutic study, Level IV (case series, no control group). Copyright © 2015 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

Analysis of the Pelvic Functional Orientation in the Sagittal Plane: A Radiographic Study With EOS 2D/3D Technology.

PubMed

Loppini, Mattia; Longo, Umile Giuseppe; Ragucci, Pasquala; Trenti, Nicoletta; Balzarini, Luca; Grappiolo, Guido

2017-03-01

We investigated the relationship between pelvic incidence (PI) with anterior pelvic plane angle (APPA), pelvic tilt (PT) angle, and sacral slope (SS) in standing and sitting positions to identify the best parameter expressing the pelvic functional orientation in the sagittal plane. We enrolled 109 consecutive patients (M:F = 43:66) eligible for a primary total hip arthroplasty (THA) with an average age of 63.4 years (15-85). EOS 2D/3D radiography was performed in standing and sitting positions before THA to evaluate the functional pelvic orientation. 3D images took into account the patient-specific sagittal balance measuring APPA, PT, SS, and PI. In standing position, functional parameters measured 5° ± 7.1 for APPA, 11° ± 8.3 for PT, 43° ± 8.5 for SS, and 53° ± 10.9 for PI. In sitting position, they were -18° ± 10.4 for APPA, 34° ± 11.8 for PT, 20° ± 12.6 for SS, and 54° ± 10.9 for PI. There was no significant difference between men and women in terms of the functional parameters in both positions. No relationship was found between APPA and PI in both positions. SS correlated with PI in standing (r = 0.66; P < .0001; R 2  = 0.44) and sitting (r = 0.51; P < .0001; R 2  = 0.26). PT correlated with PI in standing (r = 0.65; P < .0001; R 2  = 0.42) and sitting (r = 0.38; P < .0001; R 2  = 0.14). SS shows the highest correlation with functional pelvic tilt. The study suggests that adjustments in acetabular anteversion during primary THA should be based on SS. Copyright © 2016 Elsevier Inc. All rights reserved.

Sinus anatomy associated with inadvertent cerebrospinal fluid leak during functional endoscopic sinus surgery.

PubMed

Heaton, Chase M; Goldberg, Andrew N; Pletcher, Steven D; Glastonbury, Christine M

2012-07-01

Anatomic variations in skull base anatomy may predispose the surgeon to inadvertent skull base injury with resultant cerebrospinal fluid (CSF) leak during functional endoscopic sinus surgery (ESS). Our objective was to compare preoperative sinus imaging of patients who underwent FESS with and without CSF leak to elucidate these variations. In this retrospective case-control study, 18 patients with CSF leak following FESS for chronic rhinosinusitis (CRS) from 2000 to 2011 were compared to 18 randomly selected patients who underwent preoperative imaging for FESS for CRS. Measurements were obtained from preoperative computed tomography images with specific attention to anatomic differences in cribriform plate and ethmoid roof heights in the coronal plane, and the skull base angle in the sagittal plane. Mean values of measured variables were compared using a nonparametric Mann-Whitney test. When compared to controls, patients with CSF leak demonstrated a greater angle of the skull base in the sagittal plane (P < .001) and a greater slope of the skull base in the coronal plane (P < .006). A lower cribriform height relative to ethmoid roof height was also noted in cases of CSF leak as compared to controls (P < .04). A steep skull base angle in the sagittal plane, a greater slope of the skull base in the coronal plane, and a low cribriform height relative to the ethmoid roof predispose the patient to CSF leak during FESS. Preoperative review of imaging with specific attention paid to these anatomic variations may help to prevent iatrogenic CSF leak. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

What is the optimal cutoff value of the axis-line-angle technique for evaluating trunk imbalance in coronal plane?

PubMed

Zhang, Rui-Fang; Fu, Yu-Chuan; Lu, Yi; Zhang, Xiao-Xia; Hu, Yu-Min; Zhou, Yong-Jin; Tian, Nai-Feng; He, Jia-Wei; Yan, Zhi-Han

2017-02-01

Accurately evaluating the extent of trunk imbalance in the coronal plane is significant for patients before and after treatment. We preliminarily practiced a new method, axis-line-angle technique (ALAT), for evaluating coronal trunk imbalance with excellent intra-observer and interobserver reliability. Radiologists and surgeons were encouraged to use this method in clinical practice. However, the optimal cutoff value of the ALAT for determination of the extent of coronal trunk imbalance has not been calculated up to now. The purpose of this study was to identify the cutoff value of the ALAT that best predicts a positive measurement point to assess coronal balance or imbalance. A retrospective study at a university affiliated hospital was carried out. A total of 130 patients with C7-central sacral vertical line (CSVL) >0 mm and aged 10-18 years were recruited in this study from September 2013 to December 2014. Data were analyzed to determine the optimal cutoff value of the ALAT measurement. The C7-CSVL and ALAT measurements were conducted respectively twice on plain film within a 2-week interval by two radiologists. The optimal cutoff value of the ALAT was analyzed via receiver operating characteristic (ROC) curve. Comparison variables were performed with chi-square test between the C7-CSVL and ALAT measurements for evaluating trunk imbalance. Kappa agreement coefficient method was used to test the intra-observer and interobserver agreement of C7-CSVL and ALAT. The ROC curve area for the ALAT was 0.82 (95% confidence interval: 0.753-0.894, p<.001). The maximum Youden index was 0.51, and the corresponding cutoff point was 2.59°. No statistical difference was found between the C7-CSVL and ALAT measurements for evaluating trunk imbalance (p>.05). Intra-observer agreement values for the C7-CSVL measurements by observers 1 and 2 were 0.79 and 0.91 (p<.001), respectively, whereas intra-observer agreement values for the ALAT measurements were both 0.89 by observers 1

Supra-acetabular line is better than supra-iliac line for coronal balance referencing-a study of perioperative whole spine X-rays in degenerative lumbar scoliosis and ankylosing spondylitis patients.

PubMed

Hey, Hwee Weng Dennis; Kim, Cheung-Kue; Lee, Won-Gyu; Juh, Hyung-Suk; Kim, Ki-Tack

2017-12-01

The aim of spinal deformity correction is to restore the spine's functional alignment by balancing it in both the sagittal and coronal planes. Regardless of posture, the ideal coronal profile is straight, and therefore readily assessable. This study compares two radiological methods to determine which better predicts postoperative standing coronal balance. We conducted a single-center, radiographic comparative study between 2011 and 2015. A total of 199 patients with a mean age of 55.1 years were studied. Ninety patients with degenerative lumbar scoliosis (DLS) and 109 ankylosing spondylitis (AS) were treated with posterior surgery during this period. Baseline clinical and radiographic parameters (sagittal and coronal) were recorded. Comparison was performed between the new supra-acetabular line (central sacral vertical line [CSVL1]) and conventional supra-iliac line (CSVL2) perpendicular methods of coronal balance assessment. These methods were also compared with the gold standard standing C7 plumb line. Each patient underwent standardized operative procedures and had perioperative spine X-rays obtained for assessment of spinal balance. Adjusted multivariate analysis was used to determine predictors of coronal balance. Significant differences in baseline characteristics (age, gender, and radiographic parameters) were found between patients with DLS and AS. CSVL1, CSVL2, and C7 plumb line differed in all the perioperative measurements. These three radiological methods showed a mean right coronal imbalance for both diagnoses in all pre-, intra-, and postoperative radiographs. The magnitude of imbalance was the greatest for CSVL2 followed by CSVL1 and subsequently the C7 plumb line. A larger discrepancy between CSVL and C7 plumb line measurements intraoperatively than those postoperatively suggests a postural effect on these parameters, which is greater for CSVL2. Multivariate analysis identified that in DLS, the preoperative C7 plumb line was predictive of its

Correction Capability in the 3 Anatomic Planes of Different Pedicle Screw Designs in Scoliosis Instrumentation.

PubMed

Wang, Xiaoyu; Aubin, Carl-Eric; Coleman, John; Rawlinson, Jeremy

2017-05-01

Computer simulations to compare the correction capabilities of different pedicle screws in adolescent idiopathic scoliosis (AIS) instrumentations. To compare the correction and resulting bone-screw forces associated with different pedicle screws in scoliosis instrumentations. Pedicle screw fixation is widely used in surgical instrumentation for spinal deformity treatment. Screw design, correction philosophies, and surgical techniques are constantly evolving to achieve better control of the vertebrae and correction of the spinal deformity. Yet, there remains a lack of biomechanical studies that quantify the effects and advantages of different screw designs in terms of correction kinematics. The correction capabilities of fixed-angle, multiaxial, uniaxial, and saddle axial screws were kinematically analyzed, simulated, and compared. These simulations were based on the screw patterns and correction techniques proposed by 2 experienced surgeons for 2 AIS cases. Additional instrumentations were assessed to compare the correction and resulting bone-screw forces associated with each type of screw. The fixed-angle, uniaxial and saddle axial screws had similar kinematic behavior and performed better than multiaxial screws in the coronal and transverse planes (8% and 30% greater simulated corrections, respectively). Uniaxial and multiaxial screws were less effective than fixed-angle and saddle axial screws in transmitting compression/distraction to the anterior spine because of their sagittal plane mobility between the screw head and shank. Only the saddle axial screws allow vertebra angle in the sagittal plane to be independently adjusted. Pedicle screws of different designs performed differently for deformity corrections or for compensating screw placement variations in different anatomic planes. For a given AIS case, screw types should be determined based on the particular instrumentation objectives, the deformity's stiffness and characteristics so as to make the best of

Twice cutting method reduces tibial cutting error in unicompartmental knee arthroplasty.

PubMed

Inui, Hiroshi; Taketomi, Shuji; Yamagami, Ryota; Sanada, Takaki; Tanaka, Sakae

2016-01-01

Bone cutting error can be one of the causes of malalignment in unicompartmental knee arthroplasty (UKA). The amount of cutting error in total knee arthroplasty has been reported. However, none have investigated cutting error in UKA. The purpose of this study was to reveal the amount of cutting error in UKA when open cutting guide was used and clarify whether cutting the tibia horizontally twice using the same cutting guide reduced the cutting errors in UKA. We measured the alignment of the tibial cutting guides, the first-cut cutting surfaces and the second cut cutting surfaces using the navigation system in 50 UKAs. Cutting error was defined as the angular difference between the cutting guide and cutting surface. The mean absolute first-cut cutting error was 1.9° (1.1° varus) in the coronal plane and 1.1° (0.6° anterior slope) in the sagittal plane, whereas the mean absolute second-cut cutting error was 1.1° (0.6° varus) in the coronal plane and 1.1° (0.4° anterior slope) in the sagittal plane. Cutting the tibia horizontally twice reduced the cutting errors in the coronal plane significantly (P<0.05). Our study demonstrated that in UKA, cutting the tibia horizontally twice using the same cutting guide reduced cutting error in the coronal plane. Copyright © 2014 Elsevier B.V. All rights reserved.

Mid-callosal plane determination using preferred directions from diffusion tensor images

NASA Astrophysics Data System (ADS)

Costa, André L.; Rittner, Letícia; Lotufo, Roberto A.; Appenzeller, Simone

2015-03-01

The corpus callosum is the major brain structure responsible for inter{hemispheric communication between neurons. Many studies seek to relate corpus callosum attributes to patient characteristics, cerebral diseases and psychological disorders. Most of those studies rely on 2D analysis of the corpus callosum in the mid-sagittal plane. However, it is common to find conflicting results among studies, once many ignore methodological issues and define the mid-sagittal plane based on precary or invalid criteria with respect to the corpus callosum. In this work we propose a novel method to determine the mid-callosal plane using the corpus callosum internal preferred diffusion directions obtained from diffusion tensor images. This plane is analogous to the mid-sagittal plane, but intended to serve exclusively as the corpus callosum reference. Our method elucidates the great potential the directional information of the corpus callosum fibers have to indicate its own referential. Results from experiments with five image pairs from distinct subjects, obtained under the same conditions, demonstrate the method effectiveness to find the corpus callosum symmetric axis relative to the axial plane.

Design and clinical use of a rotational phantom for dosimetric verification of IMRT/VMAT treatments.

PubMed

Grams, Michael P; de Los Santos, Luis E Fong

2018-06-01

To describe the design and clinical use of a rotational phantom for dosimetric verification of IMRT/VMAT treatment plans using radiochromic film. A solid water cylindrical phantom was designed with separable upper and lower halves and rests on plastic bearings allowing for 360° rotation about its central axis. The phantom accommodates a half sheet of radiochromic film, and by rotating the cylinder, the film can be placed in any plane between coronal and sagittal. Calculated dose planes coinciding with rotated film measurements are exported by rotating the CT image and dose distribution within the treatment planning system. The process is illustrated with 2 rotated film measurements of an SRS treatment plan involving 4 separate targets. Additionally, 276 patient specific QA measurements were obtained with the phantom and analyzed with a 2%/2 mm gamma criterion. The average 2%/2 mm gamma passing rate for all 276 plans was 99.3%. Seventy-two of the 276 plans were measured with the plane of the film rotated between the coronal and sagittal planes and had an average passing rate of 99.4%. The rotational phantom allows for accurate film measurements in any plane. With this technique, regions of a dose distribution which might otherwise require multiple sagittal or coronal measurements can be verified with as few as a single measurement. This increases efficiency and, in combination with the high spatial resolution inherent to film dosimetry, makes the rotational technique an attractive option for patient-specific QA. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Patients with proximal junctional kyphosis requiring revision surgery have higher postoperative lumbar lordosis and larger sagittal balance corrections.

PubMed

Kim, Han Jo; Bridwell, Keith H; Lenke, Lawrence G; Park, Moon Soo; Song, Kwang Sup; Piyaskulkaew, Chaiwat; Chuntarapas, Tapanut

2014-04-20

Case control study. To evaluate risk factors in patients in 3 groups: those without proximal junctional kyphosis (PJK) (N), with PJK but not requiring revision (P), and then those with PJK requiring revision surgery (S). It is becoming clear that some patients maintain stable PJK angles, whereas others progress and develop severe PJK necessitating revision surgery. A total of 206 patients at a single institution from 2002 to 2007 with adult scoliosis with 2-year minimum follow-up (average 3.5 yr) were analyzed. Inclusion criteria were age more than 18 years and primary fusions greater than 5 levels from any thoracic upper instrumented vertebra to any lower instrumented vertebrae. Revisions were excluded. Radiographical assessment included Cobb measurements in the coronal/sagittal plane and measurements of the PJK angle at postoperative time points: 1 to 2 months, 2 years, and final follow-up. PJK was defined as an angle greater than 10°. The prevalence of PJK was 34%. The average age in N was 49.9 vs. 51.3 years in P and 60.1 years in S. Sex, body mass index, and smoking status were not significantly different between groups. Fusions extending to the pelvis were 74%, 85%, and 91% of the cases in groups N, P, and S. Instrumentation type was significantly different between groups N and S, with a higher number of upper instrumented vertebra hooks in group N. Radiographical parameters demonstrated a higher postoperative lumbar lordosis and a larger sagittal balance change, with surgery in those with PJK requiring revision surgery. Scoliosis Research Society postoperative pain scores were inferior in group N vs. P and S, and Oswestry Disability Index scores were similar between all groups. Patients with PJK requiring revision were older, had higher postoperative lumbar lordosis, and larger sagittal balance corrections than patients without PJK. Based on these data, it seems as though older patients with large corrections in their lumbar lordosis and sagittal balance

Comparing preseason frontal and sagittal plane plyometric programs on vertical jump height in high-school basketball players.

PubMed

King, Jeffrey A; Cipriani, Daniel J

2010-08-01

The primary purpose of this study was to evaluate whether frontal plane (FP) plyometrics, which are defined as plyometrics dominated with a lateral component, would produce similar increases in vertical jump height (VJH) compared to sagittal plane (SP) Plyometrics. Thirty-two junior varsity and varsity high-school basketball players participated in 6 weeks of plyometric training. Players participated in either FP or SP plyometrics for the entire study. Vertical jump height was measured on 3 occasions: preintervention (baseline), at week 3 of preparatory training, and at week 6 of training. Descriptive statistics were calculated for VJH. A 2-way analysis of variance (ANOVA) with repeated measures was used to test the difference in mean vertical jump scores using FP and SP training modalities. Results showed a significant effect over time for vertical jump (p < 0.001). Moreover, a significant time by protocol interaction was noted (p < 0.032). A 1-way ANOVA demonstrated that only the SP group demonstrated improvements over time, in VJH, p < 0.05. The FP group did not improve statistically. The data from this study suggest that FP plyometric training did not have a significant effect on VJH and significant improvement in VJH was seen in subjects participating in SP plyometrics thus reinforcing the specificity principle of training. However, coaches should implement both types of plyometrics because both training modalities can improve power and quickness among basketball players.

Effect of Acute Alterations in Foot Strike Patterns during Running on Sagittal Plane Lower Limb Kinematics and Kinetics

PubMed Central

Valenzuela, Kevin A.; Lynn, Scott K.; Mikelson, Lisa R.; Noffal, Guillermo J.; Judelson, Daniel A.

2015-01-01

The purpose of this study was to determine the effect of foot strike patterns and converted foot strike patterns on lower limb kinematics and kinetics at the hip, knee, and ankle during a shod condition. Subjects were videotaped with a high speed camera while running a 5km at self-selected pace on a treadmill to determine natural foot strike pattern on day one. Preferred forefoot group (PFFG, n = 10) and preferred rear foot group (PRFG, n = 11) subjects were identified through slow motion video playback (n = 21, age = 22.8±2.2 years, mass = 73.1±14.5 kg, height 1.75 ± 0.10 m). On day two, subjects performed five overground run trials in both their natural and unnatural strike patterns while motion and force data were collected. Data were collected over two days so that foot strike videos could be analyzed for group placement purposes. Several 2 (Foot Strike Pattern –forefoot strike [FFS], rearfoot strike [RFS]) x 2 (Group – PFFG, PRFG) mixed model ANOVAs (p < 0.05) were run on speed, active peak vertical ground reaction force (VGRF), peak early stance and mid stance sagittal ankle moments, sagittal plane hip and knee moments, ankle dorsiflexion ROM, and sagittal plane hip and knee ROM. There were no significant interactions or between group differences for any of the measured variables. Within subject effects demonstrated that the RFS condition had significantly lower (VGRF) (RFS = 2.58 ± .21 BW, FFS = 2.71 ± 0.23 BW), dorsiflexion moment (RFS = -2.6 1± 0.61 Nm·kg-1, FFS = -3.09 ± 0.32 Nm·kg-1), and dorsiflexion range of motion (RFS = 17.63 ± 3.76°, FFS = 22.10 ± 5.08°). There was also a significantly higher peak plantarflexion moment (RFS = 0.23 ± 0.11 Nm·kg-1, FFS = 0.01 ± 0.01 Nm·kg-1), peak knee moment (RFS = 2.61 ± 0.54 Nm·kg-1, FFS = 2.39 ± 0.61 Nm·kg-1), knee ROM (RFS = 31.72 ± 2.79°, FFS = 29.58 ± 2.97°), and hip ROM (RFS = 42.72 ± 4.03°, FFS = 41.38 ± 3.32°) as compared with the FFS condition. This research suggests that

Effect of Acute Alterations in Foot Strike Patterns during Running on Sagittal Plane Lower Limb Kinematics and Kinetics.

PubMed

Valenzuela, Kevin A; Lynn, Scott K; Mikelson, Lisa R; Noffal, Guillermo J; Judelson, Daniel A

2015-03-01

The purpose of this study was to determine the effect of foot strike patterns and converted foot strike patterns on lower limb kinematics and kinetics at the hip, knee, and ankle during a shod condition. Subjects were videotaped with a high speed camera while running a 5km at self-selected pace on a treadmill to determine natural foot strike pattern on day one. Preferred forefoot group (PFFG, n = 10) and preferred rear foot group (PRFG, n = 11) subjects were identified through slow motion video playback (n = 21, age = 22.8±2.2 years, mass = 73.1±14.5 kg, height 1.75 ± 0.10 m). On day two, subjects performed five overground run trials in both their natural and unnatural strike patterns while motion and force data were collected. Data were collected over two days so that foot strike videos could be analyzed for group placement purposes. Several 2 (Foot Strike Pattern -forefoot strike [FFS], rearfoot strike [RFS]) x 2 (Group - PFFG, PRFG) mixed model ANOVAs (p < 0.05) were run on speed, active peak vertical ground reaction force (VGRF), peak early stance and mid stance sagittal ankle moments, sagittal plane hip and knee moments, ankle dorsiflexion ROM, and sagittal plane hip and knee ROM. There were no significant interactions or between group differences for any of the measured variables. Within subject effects demonstrated that the RFS condition had significantly lower (VGRF) (RFS = 2.58 ± .21 BW, FFS = 2.71 ± 0.23 BW), dorsiflexion moment (RFS = -2.6 1± 0.61 Nm·kg(-1), FFS = -3.09 ± 0.32 Nm·kg(-1)), and dorsiflexion range of motion (RFS = 17.63 ± 3.76°, FFS = 22.10 ± 5.08°). There was also a significantly higher peak plantarflexion moment (RFS = 0.23 ± 0.11 Nm·kg(-1), FFS = 0.01 ± 0.01 Nm·kg(-1)), peak knee moment (RFS = 2.61 ± 0.54 Nm·kg(-1), FFS = 2.39 ± 0.61 Nm·kg(-1)), knee ROM (RFS = 31.72 ± 2.79°, FFS = 29.58 ± 2.97°), and hip ROM (RFS = 42.72 ± 4.03°, FFS = 41.38 ± 3.32°) as compared with the FFS condition. This research suggests

Role of MRI in Diagnosis of Ruptured Intracranial Dermoid Cyst

PubMed Central

Muçaj, Sefedin; Ugurel, Mehmet Sahin; Dedushi, Kreshnike; Ramadani, Naser; Jerliu, Naim

2017-01-01

Introduction: Intracranial dermoid cystic tumors account for <1% of all intracranial masses. Case report: A 52-year-old male, having headaches, nausea and is presented with a history of 2 episodes of new onset seizures. On presentation, the patient had a normal physical exam, including a complete neurological and cranial nerve exam. Methods: Precontrast MRI; TSE/T2Wsequence in axial/coronal planes; 3D – HI-resolution T1W sagittal; FLAIR/T2W axial; FLAIR/T2W, Flash/T2W oblique coronal plane, GRE/T2W axial. Post-contrast TSE/T1W sequence in axial, coronal and sagittal planes. Diffusion weighted and ADC mapping, postcontrast: TSE/T1W sequence in axial, coronal and sagittal planes. Results: Subsequent MRI of the brain revealed an oval and lobulated 47x34x30mm (TRxAPxCC) non-enhancing T1-hyperintense mass in right cavernous sinus, with compression of surrounding mesial temporal lobe and right anterolateral aspect of mesencephalon. Findings are consistent with ruptured dermoid cyst, given the evacuated sebum content at its lower half. Sebum particles in millimetric sizes are seen within right Sylvian fissure, anterior horns of lateral ventricles and to a lesser extent within left Sylvian fissure, right parietal sulci, cerebral aqueduct, and basal cisterns. No restricted diffusion is seen, eliminating the possibility of epidermoid. A shunt catheter is evident traversing between right lateral ventricle and right parietal bone; besides, slit-like right lateral ventricle is noted (likely secondary to over-draining shunt catheter). Conclusion: Intracranial dermoid cysts are benign rare slow-growing tumors that upon rupture, however, widespread presence of T1 hyperintense droplets and leptomeningeal enhancement can be noted–making MRI the best imaging modality for diagnosis of this rare entity. PMID:28883682

Role of MRI in Diagnosis of Ruptured Intracranial Dermoid Cyst.

PubMed

Muçaj, Sefedin; Ugurel, Mehmet Sahin; Dedushi, Kreshnike; Ramadani, Naser; Jerliu, Naim

2017-06-01

Intracranial dermoid cystic tumors account for <1% of all intracranial masses. A 52-year-old male, having headaches, nausea and is presented with a history of 2 episodes of new onset seizures. On presentation, the patient had a normal physical exam, including a complete neurological and cranial nerve exam. Precontrast MRI; TSE/T2Wsequence in axial/coronal planes; 3D - HI-resolution T1W sagittal; FLAIR/T2W axial; FLAIR/T2W, Flash/T2W oblique coronal plane, GRE/T2W axial. Post-contrast TSE/T1W sequence in axial, coronal and sagittal planes. Diffusion weighted and ADC mapping, postcontrast: TSE/T1W sequence in axial, coronal and sagittal planes. Subsequent MRI of the brain revealed an oval and lobulated 47x34x30mm (TRxAPxCC) non-enhancing T1-hyperintense mass in right cavernous sinus, with compression of surrounding mesial temporal lobe and right anterolateral aspect of mesencephalon. Findings are consistent with ruptured dermoid cyst, given the evacuated sebum content at its lower half. Sebum particles in millimetric sizes are seen within right Sylvian fissure, anterior horns of lateral ventricles and to a lesser extent within left Sylvian fissure, right parietal sulci, cerebral aqueduct, and basal cisterns. No restricted diffusion is seen, eliminating the possibility of epidermoid. A shunt catheter is evident traversing between right lateral ventricle and right parietal bone; besides, slit-like right lateral ventricle is noted (likely secondary to over-draining shunt catheter). Intracranial dermoid cysts are benign rare slow-growing tumors that upon rupture, however, widespread presence of T1 hyperintense droplets and leptomeningeal enhancement can be noted-making MRI the best imaging modality for diagnosis of this rare entity.

[Evaluation of the resolving power of different angles in MPR images of 16DAS-MDCT].

PubMed

Kimura, Mikio; Usui, Junshi; Nozawa, Takeo

2007-03-20

In this study, we evaluated the resolving power of three-dimensional (3D) multiplanar reformation (MPR) images with various angles by using 16 data acquisition system multi detector row computed tomography (16DAS-MDCT) . We reconstructed the MPR images using data with a 0.75 mm slice thickness of the axial image in this examination. To evaluate resolving power, we used an original new phantom (RC phantom) that can be positioned at any slice angle in MPR images. We measured the modulation transfer function (MTF) by using the methods of measuring pre-sampling MTF, and used Fourier transform of image data of the square wave chart. The scan condition and image reconstruction condition that were adopted in this study correspond to the condition that we use for three-dimensional computed tomographic angiography (3D-CTA) examination of the head in our hospital. The MTF of MPR images showed minimum values at slice angles in parallel with the axial slice, and showed maximum values at the sagittal slice and coronal slice angles that are parallel to the Z-axis. With an oblique MPR image, MTF did not change with angle changes in the oblique sagittal slice plane, but in the oblique coronal slice plane, MTF increased as the tilt angle increased from the axial plane to the Z plane. As a result, we could evaluate the resolving power of a head 3D image by measuring the MTF of the axial image and sagittal image or the coronal image.

Reliable sagittal plane kinematic gait assessments are feasible using low-cost webcam technology.

PubMed

Saner, Robert J; Washabaugh, Edward P; Krishnan, Chandramouli

2017-07-01

Three-dimensional (3-D) motion capture systems are commonly used for gait analysis because they provide reliable and accurate measurements. However, the downside of this approach is that it is expensive and requires technical expertise; thus making it less feasible in the clinic. To address this limitation, we recently developed and validated (using a high-precision walking robot) a low-cost, two-dimensional (2-D) real-time motion tracking approach using a simple webcam and LabVIEW Vision Assistant. The purpose of this study was to establish the repeatability and minimal detectable change values of hip and knee sagittal plane gait kinematics recorded using this system. Twenty-one healthy subjects underwent two kinematic assessments while walking on a treadmill at a range of gait velocities. Intraclass correlation coefficients (ICC) and minimal detectable change (MDC) values were calculated for commonly used hip and knee kinematic parameters to demonstrate the reliability of the system. Additionally, Bland-Altman plots were generated to examine the agreement between the measurements recorded on two different days. The system demonstrated good to excellent reliability (ICC>0.75) for all the gait parameters tested on this study. The MDC values were typically low (<5°) for most of the parameters. The Bland-Altman plots indicated that there was no systematic error or bias in kinematic measurements and showed good agreement between measurements obtained on two different days. These results indicate that kinematic gait assessments using webcam technology can be reliably used for clinical and research purposes. Copyright © 2017 Elsevier B.V. All rights reserved.

Lower extremity energy absorption and biomechanics during landing, part II: frontal-plane energy analyses and interplanar relationships.

PubMed

Norcross, Marc F; Lewek, Michael D; Padua, Darin A; Shultz, Sandra J; Weinhold, Paul S; Blackburn, J Troy

2013-01-01

Greater sagittal-plane energy absorption (EA) during the initial impact phase (INI) of landing is consistent with sagittal-plane biomechanics that likely increase anterior cruciate ligament (ACL) loading, but it does not appear to influence frontal-plane biomechanics. We do not know whether frontal-plane INI EA is related to high-risk frontal-plane biomechanics. To compare biomechanics among INI EA groups, determine if women are represented more in the high group, and evaluate interplanar INI EA relationships. Descriptive laboratory study. Research laboratory. Participants included 82 (41 men, 41 women; age = 21.0 ± 2.4 years, height = 1.74 ± 0.10 m, mass = 70.3 ± 16.1 kg) healthy, physically active volunteers. We assessed landing biomechanics with an electromagnetic motion-capture system and force plate. We calculated frontal- and sagittal-plane total, hip, knee, and ankle INI EA. Total frontal-plane INI EA was used to create high, moderate, and low tertiles. Frontal-plane knee and hip kinematics, peak vertical and posterior ground reaction forces, and peak internal knee-varus moment (pKVM) were identified and compared across groups using 1-way analyses of variance. We used a χ (2) analysis to evaluate male and female allocation to INI EA groups. We used simple, bivariate Pearson product moment correlations to assess interplanar INI EA relationships. The high-INI EA group exhibited greater knee valgus at ground contact, hip adduction at pKVM, and peak hip adduction than the low-INI EA group (P < .05) and greater peak knee valgus, pKVM, and knee valgus at pKVM than the moderate- (P < .05) and low- (P < .05) INI EA groups. Women were more likely than men to be in the high-INI EA group (χ(2) = 4.909, P = .03). Sagittal-plane knee and frontal-plane hip INI EA (r = 0.301, P = .006) and sagittal-plane and frontal-plane ankle INI EA were associated (r = 0.224, P = .04). No other interplanar INI EA relationships were found (P > .05). Greater frontal-plane INI EA was

Lower Extremity Energy Absorption and Biomechanics During Landing, Part II: Frontal-Plane Energy Analyses and Interplanar Relationships

PubMed Central

Norcross, Marc F.; Lewek, Michael D.; Padua, Darin A.; Shultz, Sandra J.; Weinhold, Paul S.; Blackburn, J. Troy

2013-01-01

Context: Greater sagittal-plane energy absorption (EA) during the initial impact phase (INI) of landing is consistent with sagittal-plane biomechanics that likely increase anterior cruciate ligament (ACL) loading, but it does not appear to influence frontal-plane biomechanics. We do not know whether frontal-plane INI EA is related to high-risk frontal-plane biomechanics. Objective: To compare biomechanics among INI EA groups, determine if women are represented more in the high group, and evaluate interplanar INI EA relationships. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: Participants included 82 (41 men, 41 women; age = 21.0 ± 2.4 years, height = 1.74 ± 0.10 m, mass = 70.3 ± 16.1 kg) healthy, physically active volunteers. Intervention(s): We assessed landing biomechanics with an electromagnetic motion-capture system and force plate. Main Outcome Measure(s): We calculated frontal- and sagittal-plane total, hip, knee, and ankle INI EA. Total frontal-plane INI EA was used to create high, moderate, and low tertiles. Frontal-plane knee and hip kinematics, peak vertical and posterior ground reaction forces, and peak internal knee-varus moment (pKVM) were identified and compared across groups using 1-way analyses of variance. We used a χ2 analysis to evaluate male and female allocation to INI EA groups. We used simple, bivariate Pearson product moment correlations to assess interplanar INI EA relationships. Results: The high–INI EA group exhibited greater knee valgus at ground contact, hip adduction at pKVM, and peak hip adduction than the low–INI EA group (P < .05) and greater peak knee valgus, pKVM, and knee valgus at pKVM than the moderate– (P < .05) and low– (P < .05) INI EA groups. Women were more likely than men to be in the high–INI EA group (χ2 = 4.909, P = .03). Sagittal-plane knee and frontal-plane hip INI EA (r = 0.301, P = .006) and sagittal-plane and frontal-plane ankle INI EA were

Task-level strategies for human sagittal-plane running maneuvers are consistent with robotic control policies.

PubMed

Qiao, Mu; Jindrich, Devin L

2012-01-01

The strategies that humans use to control unsteady locomotion are not well understood. A "spring-mass" template comprised of a point mass bouncing on a sprung leg can approximate both center of mass movements and ground reaction forces during running in humans and other animals. Legged robots that operate as bouncing, "spring-mass" systems can maintain stable motion using relatively simple, distributed feedback rules. We tested whether the changes to sagittal-plane movements during five running tasks involving active changes to running height, speed, and orientation were consistent with the rules used by bouncing robots to maintain stability. Changes to running height were associated with changes to leg force but not stance duration. To change speed, humans primarily used a "pogo stick" strategy, where speed changes were associated with adjustments to fore-aft foot placement, and not a "unicycle" strategy involving systematic changes to stance leg hip moment. However, hip moments were related to changes to body orientation and angular speed. Hip moments could be described with first order proportional-derivative relationship to trunk pitch. Overall, the task-level strategies used for body control in humans were consistent with the strategies employed by bouncing robots. Identification of these behavioral strategies could lead to a better understanding of the sensorimotor mechanisms that allow for effective unsteady locomotion.

Task-Level Strategies for Human Sagittal-Plane Running Maneuvers Are Consistent with Robotic Control Policies

PubMed Central

Qiao, Mu; Jindrich, Devin L.

2012-01-01

The strategies that humans use to control unsteady locomotion are not well understood. A “spring-mass” template comprised of a point mass bouncing on a sprung leg can approximate both center of mass movements and ground reaction forces during running in humans and other animals. Legged robots that operate as bouncing, “spring-mass” systems can maintain stable motion using relatively simple, distributed feedback rules. We tested whether the changes to sagittal-plane movements during five running tasks involving active changes to running height, speed, and orientation were consistent with the rules used by bouncing robots to maintain stability. Changes to running height were associated with changes to leg force but not stance duration. To change speed, humans primarily used a “pogo stick” strategy, where speed changes were associated with adjustments to fore-aft foot placement, and not a “unicycle” strategy involving systematic changes to stance leg hip moment. However, hip moments were related to changes to body orientation and angular speed. Hip moments could be described with first order proportional-derivative relationship to trunk pitch. Overall, the task-level strategies used for body control in humans were consistent with the strategies employed by bouncing robots. Identification of these behavioral strategies could lead to a better understanding of the sensorimotor mechanisms that allow for effective unsteady locomotion. PMID:23284804

Validation, repeatability and reproducibility of a noninvasive instrument for measuring thoracic and lumbar curvature of the spine in the sagittal plane.

PubMed

Chaise, Fabiana O; Candotti, Cláudia T; Torre, Marcelo L; Furlanetto, Tássia S; Pelinson, Patricia P T; Loss, Jefferson F

2011-01-01

The need for early identification of postural abnormalities without exposing patients to constant radiation has stimulated the development of instruments aiming to measure the spinal curvatures. To verify the validity, repeatability and reproducibility of angular measures of sagittal curvatures of the spine obtained using an adapted arcometer, by comparing them with Cobb angles of the respective curvatures obtained by using X-rays. 52 participants were submitted to two procedures designed to evaluate the thoracic and lumbar curvatures: (1) X-ray examination from which the Cobb angles (CA) of both curvatures were obtained, and (2) measuring the angles with the arcometer (AA). Two evaluators collected the data using the arcometer, with the rods placed at T1, T12, L1 and L5 spinous processes levels in a way as to permit linear measurements which, with aid of trigonometry, supplied the AA. There was a very strong and significant correlation between AA and CA (r=0.94; p<0.01), with no-significant difference (p=0.32), for the thoracic curvature. There was a strong and significant correlation for the lumbar curvature (r=0.71; p<0.01) between AA and CA, with no-significant difference (p=0.30). There is a very strong correlation between intra-evaluator and inter-evaluator AA. It was possible to quantify reliably the thoracic and lumbar curvatures with the arcometer and it can thus be considered valid and reliable and for use in evaluating spinal curvatures in the sagittal plane.

Asymmetry of the leg alignment affects trunk bending in the coronal plane after unilateral total knee arthroplasty.

PubMed

Harato, Kengo; Yoshida, Hiroki; Otani, Toshiro

2013-08-01

Unilateral total knee arthroplasty (TKA) would produce asymmetric changes of lower extremity in patients with bilateral varus deformity. Our purpose was to investigate whether asymmetry of the leg alignment would affect trunk bending in the coronal plane after unilateral TKA. Twenty patients (mean 76 years old) with bilateral end-stage knee osteoarthritis (OA) participated. Spine images during relaxed standing were obtained on pre- and postoperative day 21. As a result, the shoulder tilted more to the TKA side and the pelvis inclined more to the contralateral OA side. These results suggested that the trunk would bend away from the contralateral OA side after unilateral TKA in patients with bilateral end-stage knee OA and varus deformity. Asymmetry of the leg alignment led to asymmetric trunk bending. Copyright © 2013 Elsevier Inc. All rights reserved.

Computer-assisted design and finite element simulation of braces for the treatment of adolescent idiopathic scoliosis using a coronal plane radiograph and surface topography.

PubMed

Pea, Rany; Dansereau, Jean; Caouette, Christiane; Cobetto, Nikita; Aubin, Carl-Éric

2018-05-01

Orthopedic braces made by Computer-Aided Design and Manufacturing and numerical simulation were shown to improve spinal deformities correction in adolescent idiopathic scoliosis while using less material. Simulations with BraceSim (Rodin4D, Groupe Lagarrigue, Bordeaux, France) require a sagittal radiograph, not always available. The objective was to develop an innovative modeling method based on a single coronal radiograph and surface topography, and assess the effectiveness of braces designed with this approach. With a patient coronal radiograph and a surface topography, the developed method allowed the 3D reconstruction of the spine, rib cage and pelvis using geometric models from a database and a free form deformation technique. The resulting 3D reconstruction converted into a finite element model was used to design and simulate the correction of a brace. The developed method was tested with data from ten scoliosis cases. The simulated correction was compared to analogous simulations performed with a 3D reconstruction built using two radiographs and surface topography (validated gold standard reference). There was an average difference of 1.4°/1.7° for the thoracic/lumbar Cobb angle, and 2.6°/5.5° for the kyphosis/lordosis between the developed reconstruction method and the reference. The average difference of the simulated correction was 2.8°/2.4° for the thoracic/lumbar Cobb angles and 3.5°/5.4° the kyphosis/lordosis. This study showed the feasibility to design and simulate brace corrections based on a new modeling method with a single coronal radiograph and surface topography. This innovative method could be used to improve brace designs, at a lesser radiation dose for the patient. Copyright © 2018 Elsevier Ltd. All rights reserved.

Occlusal plane rotation: aesthetic enhancement in mandibular micrognathia.

PubMed

Rosen, H M

1993-06-01

Patients afflicted with extreme degrees of mandibular micrognathia typically have vertically deficient rami as well as sagittally deficient mandibular bodies. This results in deficient posterior facial height, an obtuse gonial angle, excessively steep occlusal and mandibular planes, and a compensatory increase in anterior facial height. The entire maxillomandibular complex is overrotated in a clockwise direction. Standard orthognathic surgical correction fails to address this rotational deformity. As a consequence, the achieved projection of the lower face is inadequate, posterior facial height is further reduced, and occlusal and mandibular planes remain steep. Eleven patients with severe mandibular micrognathia underwent a surgical correction involving occlusal plane rotation to its normal orientation relative to Frankfort horizontal. This was accomplished by Le Fort I osteotomy to shorten the anterior maxilla (creating open bites in seven patients and making preexisting open bites worse in four patients) and sagittal split ramus osteotomies to advance and rotate the mandibular body counterclockwise, thus closing the surgically produced open bite. Counterclockwise rotation of the mandible afforded significantly greater sagittal displacement at the B point (mean 17 mm) than at the first molar (mean 10 mm) and produced adequate degrees of projection of the lower face when accompanied by a modest sliding genioplasty (mean 6.9 mm). Total advancement at the pogonion was a mean of 25.2 mm. In addition, posterior facial height was preserved, and mandibular and occlusal planes were normalized to mean angles of 27 and 10 degrees, respectively. At follow-up, which ranged from 9 to 24 months with a mean of 14.1 months, the mean sagittal relapse at the B point was 1.9 mm. Although heretofore considered unstable and therefore not clinically accepted, maxillomandibular counterclockwise rotation to normalize the occlusal plane rotational deformity provides stable, aesthetically

The effect of ankle distraction on arthroscopic evaluation of syndesmotic instability: A cadaveric study.

PubMed

Lubberts, Bart; Guss, Daniel; Vopat, Bryan G; Wolf, Jonathon C; Moon, Daniel K; DiGiovanni, Christopher W

2017-12-01

To assist with visualization, orthopaedic surgeons often apply ankle distraction during arthroscopic procedures. The study aimed to investigate whether ankle distraction suppresses fibular motion in cadaveric specimens with an unstable syndesmotic injury. Fourteen fresh-frozen above knee specimens underwent arthroscopic assessment with 1) intact ligaments, 2) after sectioning of the anterior inferior tibiofibular ligament, the interosseous ligament, and the posterior inferior tibiofibular ligament, and 3) after sectioning of the deep and superficial deltoid ligament. In all scenarios, the lateral hook test, anterior-posterior hook test, and posterior-anterior hook test were applied. Each test was performed with and without ankle distraction. Coronal plane anterior and posterior tibiofibular diastasis as well as sagittal plane tibiofibular translation due to the applied load were arthroscopically measured. Tibiofibular diastasis in the coronal plane, as measured at both the anterior and posterior third of the incisura, was found to be significantly less when ankle distraction was applied, as compared to arthroscopic evaluation in the absence of distraction. In contrast, measurement of sagittal plane tibiofibular translation was not affected by ankle distraction. Since arthroscopic findings of syndesmotic instability are subtle the differential values of the syndesmotic measurements taken on and off distraction are clinically relevant. To optimally assess syndesmotic instability one should evaluate the syndesmosis without distraction or focus on fibular motion in the sagittal plane when distraction is required. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sagittal Plane Hip, Knee, and Ankle Biomechanics and the Risk of Anterior Cruciate Ligament Injury: A Prospective Study

PubMed Central

Leppänen, Mari; Pasanen, Kati; Krosshaug, Tron; Kannus, Pekka; Vasankari, Tommi; Kujala, Urho M.; Bahr, Roald; Perttunen, Jarmo; Parkkari, Jari

2017-01-01

Background: Stiff landings with less knee flexion and high vertical ground-reaction forces have been shown to be associated with an increased risk of anterior cruciate ligament (ACL) injury. The literature on the association between other sagittal plane measures and the risk of ACL injuries with a prospective study design is lacking. Purpose: To investigate the relationship between selected sagittal plane hip, knee, and ankle biomechanics and the risk of ACL injury in young female team-sport athletes. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 171 female basketball and floorball athletes (age range, 12-21 years) participated in a vertical drop jump test using 3-dimensional motion analysis. All new ACL injuries, as well as match and training exposure data, were recorded for 1 to 3 years. Biomechanical variables, including hip and ankle flexion at initial contact (IC), hip and ankle ranges of motion (ROMs), and peak external knee and hip flexion moments, were selected for analysis. Cox regression models were used to calculate hazard ratios (HRs) with 95% CIs. The combined sensitivity and specificity of significant test variables were assessed using a receiver operating characteristic (ROC) curve analysis. Results: A total of 15 noncontact ACL injuries were recorded during follow-up (0.2 injuries/1000 player-hours). Of the variables investigated, landing with less hip flexion ROM (HR for each 10° increase in hip ROM, 0.61 [95% CI, 0.38-0.99]; P < .05) and a greater knee flexion moment (HR for each 10-N·m increase in knee moment, 1.21 [95% CI, 1.04-1.40]; P = .01) was significantly associated with an increased risk of ACL injury. Hip flexion at IC, ankle flexion at IC, ankle flexion ROM, and peak external hip flexion moment were not significantly associated with the risk of ACL injury. ROC curve analysis for significant variables showed an area under the curve of 0.6, indicating a poor combined sensitivity and specificity of the test

The Impact of Imaging Modality on the Measurement of Coronal Plane Alignment After Total Knee Arthroplasty.

PubMed

Nam, Denis; Vajapey, Sravya; Nunley, Ryan M; Barrack, Robert L

2016-10-01

The optimal coronal alignment after total knee arthroplasty (TKA) has become an area of increased debate. Sources of variability among investigations include the radiographic technique used for both preoperative surgical planning and postoperative alignment assessments. This study's purpose was to assess the impact of the imaging modality used on the measurement of coronal plane alignment after TKA. A consecutive series of patients undergoing TKA using the same cruciate-retaining prosthesis were included for analysis. Postoperatively, all patients received both a rotationally controlled, scout computed tomography scan and a hip-knee-ankle (HKA) image using the EOS Imaging system (EOS Inc., Paris, France). Two, independent observers measured the HKA angle, and femoral and tibial component alignment from each image. After classifying overall and component alignment as neutral, varus, or valgus, 40.6% (65 of 160) of knees had a discordant alignment classification for HKA, 28.1% (45 of 160) for femoral component alignment, and 26.9% (43 of 160) for tibial component alignment between their computed tomography and EOS images. Overall, 24.4% (39 of 160) of patients had a HKA difference of ≥3° between the 2 images, whereas 18.8% (30 of 160) and 20.0% (32 of 160) of patients had a femoral and tibial component alignment difference of ≥2°, respectively. Significant differences are present when comparing 2 measurement techniques of mechanical alignment after TKA. The impact of imaging modality on postoperative assessments must be accounted for and be consistent when comparing the results of different investigations. Copyright © 2016 Elsevier Inc. All rights reserved.

Standardized way for imaging of the sagittal spinal balance.

PubMed

Morvan, Gérard; Mathieu, Philippe; Vuillemin, Valérie; Guerini, Henri; Bossard, Philippe; Zeitoun, Frédéric; Wybier, Marc

2011-09-01

Nowadays, conventional or digitalized teleradiography remains the most commonly used tool for the study of the sagittal balance, sometimes with secondary digitalization. The irradiation given by this technique is important and the photographic results are often poor. Some radiographic tables allow the realization of digitalized spinal radiographs by simultaneous translation of X-ray tube and receptor. EOS system is a new, very low dose system which gives good quality images, permits a simultaneous acquisition of upright frontal and sagittal views, is able to cover in the same time the spine and the lower limbs and study the axial plane on 3D envelope reconstructions. In the future, this low dose system should take a great place in the study of the pelvispinal balance. On the lateral view, several pelvic (incidence, pelvic tilt, sacral slope) and spinal (lumbar lordosis, thoracic kyphosis, Th9 sagittal offset, C7 plumb line) parameters are drawn to define the pelvispinal balance. All are interdependent. Pelvic incidence is an individual anatomic characteristic that corresponds to the "thickness" of the pelvis and governs the spinal balance. Pelvis and spine, in a harmonious whole, can be compared to an accordion, more or less compressed or stretched.

Determination of a sagittal plane axis of rotation for a dynamic office chair.

PubMed

Bauer, C M; Rast, F M; Böck, C; Kuster, R P; Baumgartner, D

2018-10-01

This study investigated the location of the axis of rotation in sagittal plane movement of the spine in a free sitting condition to adjust the kinematics of a mobile seat for a dynamic chair. Dynamic office chairs are designed to avoid continuous isometric muscle activity, and to facilitate increased mobility of the back during sitting. However, these chairs incorporate increased upper body movement which could distract office workers from the performance of their tasks. A chair with an axis of rotation above the seat would facilitate a stable upper back during movements of the lower back. The selection of a natural kinematic pattern is of high importance in order to match the properties of the spine. Twenty-one participants performed four cycles of flexion and extension of the spine during an upper arm hang on parallel bars. The location of the axis of rotation relative to the seat was estimated using infrared cameras and reflective skin markers. The median axis of rotation across all participants was located 36 cm above the seat for the complete movement and 39 cm for both the flexion and extension phases, each with an interquartile range of 20 cm. There was no significant effect of the movement direction on the location of the axis of rotation and only a weak, non-significant correlation between body height and the location of the axis of rotation. Individual movement patterns explained the majority of the variance. The axis of rotation for a spinal flexion/extension movement is located above the seat. The recommended radius for a guide rail of a mobile seat is between 36 cm and 39 cm. Copyright © 2018 Elsevier Ltd. All rights reserved.

A clinico-radiographic analysis of sagittal condylar guidance determined by protrusive interocclusal registration and panoramic radiographic images in humans

PubMed Central

Prasad, Krishna D.; Shah, Namrata; Hegde, Chethan

2012-01-01

Purpose: To evaluate the correlation between sagittal condylar guidance obtained by protrusive interocclusal records and panoramic radiograph tracing methods in human dentulous subjects. Materials and Methods: The sagittal condylar guidance was determined in 75 dentulous subjects by protrusive interocclusal records using Aluwax through a face bow transfer (HANAU™ Spring Bow, Whip Mix Corporation, USA) to a semi-adjustable articulator (HANAU™ Wide-Vue Articulator, Whip Mix Corporation, USA). In the same subjects, the sagittal outline of the articular eminence and glenoid fossa was traced in panoramic radiographs. The sagittal condylar path inclination was constructed by joining the heights of curvature in the glenoid fossa and the corresponding articular eminence. This was then related to the constructed Frankfurt's horizontal plane to determine the radiographic angle of sagittal condylar guidance. Results: A strong positive correlation existed between right and left condylar guidance by the protrusive interocclusal method (P 0.000) and similarly by the radiographic method (P 0.013). The mean difference between the condylar guidance obtained using both methods were 1.97° for the right side and 3.18° for the left side. This difference between the values by the two methods was found to be highly significant for the right (P 0.003) and left side (P 0.000), respectively. The sagittal condylar guidance obtained from both methods showed a significant positive correlation on right (P 0.000) and left side (P 0.015), respectively. Conclusion: Panoramic radiographic tracings of the sagittal condylar path guidance may be made relative to the Frankfurt's horizontal reference plane and the resulting condylar guidance angles used to set the condylar guide settings of semi-adjustable articulators. PMID:23633793

Kinematic gait deficits at the trunk and pelvis: characteristic features in children with hereditary spastic paraplegia.

PubMed

Adair, Brooke; Rodda, Jillian; McGinley, Jennifer L; Graham, H Kerr; Morris, Meg E

2016-08-01

To examine the kinematic gait deviations at the trunk and pelvis of children with hereditary spastic paraplegia (HSP). This exploratory observational study quantified gait kinematics for the trunk and pelvis from 11 children with HSP (7 males, 4 females) using the Gait Profile Score and Gait Variable Scores (GVS), and compared the kinematics to data from children with typical development using a Mann-Whitney U test. Children with HSP (median age 11y 4mo, interquartile range 4y) demonstrated large deviations in the GVS for the trunk and pelvis in the sagittal and coronal planes when compared to the gait patterns of children with typical development (p=0.010-0.020). Specific deviations included increased range of movement for the trunk in the coronal plane and increased excursion of the trunk and pelvis in the sagittal plane. In the transverse plane, children with HSP demonstrated later peaks in posterior pelvic rotation. The kinematic gait deviations identified in this study raise questions about the contribution of muscle weakness in HSP. Further research is warranted to determine contributing factors for gait dysfunction in HSP, especially the relative influence of spasticity and weakness. © 2016 Mac Keith Press.

Location of Osteochondritis Dissecans Lesions of the Capitellum.

PubMed

Johnson, Christine C; Roberts, Susanne; Mintz, Douglas; Fabricant, Peter D; Hotchkiss, Robert N; Daluiski, Aaron

2018-04-17

The location of capitellar osteochondritis dissecans (OCD) lesions in the sagittal plane guides the surgical approach, and lesion location in the coronal plane influences surgical management. Although most lesions have been reported to occur between 4 o'clock and 4:30 (120° to 135° anterior to the humerus), some lesions are located elsewhere in the capitellum. The primary aim was to define the region of the capitellum affected by OCD lesions using a novel clock-face localization system. We reviewed 104 magnetic resonance imaging examinations diagnosing a nontraumatic capitellar OCD lesion. In the sagittal plane, lesion margins were recorded as degrees on the capitellum and converted into a clock-face format in which 0° corresponds to 12:00 with the forearm facing to the right. The 0° axis (12-o'clock axis) was defined as a line parallel to the anterior humeral line that intersects the capitellum center. The following coronal measurements were recorded: lesion width, capitellar width, and distance between the lateral capitellum and lateral lesion. Two independent observers took measurements. In the sagittal plane, average lesion location was 92° to 150° (3:04-5:00, clock face) and ranged from 52.1° to 249.5° (1:44-8:19, clock face). Average lesion dimensions were 10.7 mm (mediolateral width) and 5.2 mm (anteroposterior depth). Interrater reliability was high (intraclass correlation coefficient = 0.98). Using a magnetic resonance imaging-based clock-face localization system, we found that capitellar OCD lesions affect a broad region of the capitellum in the sagittal plane. The clock-face localization system allows for precise description of capitellar OCD lesion location, which may facilitate intraoperative decision and longitudinal monitoring. Copyright © 2018 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Assessment of geometrical accuracy of magnetic resonance images for radiation therapy of lung cancers

PubMed Central

Liu, H. H.; Olsson, L. E.; Jackson, E. F.

2003-01-01

The purpose of this research was to investigate the geometrical accuracy of magnetic resonance (MR) images used in the radiation therapy treatment planning for lung cancer. In this study, the capability of MR imaging to acquire dynamic two‐dimensional images was explored to access the motion of lung tumors. Due to a number of factors, including the use of a large field‐of‐view for the thorax, MR images are particularly subject to geometrical distortions caused by the inhomogeneity and gradient nonlinearity of the magnetic field. To quantify such distortions, we constructed a phantom, which approximated the dimensions of the upper thorax and included two air cavities. Evenly spaced vials containing contrast agent could be held in three directions with their cross‐sections in the coronal, sagittal, and axial planes, respectively, within the air cavities. MR images of the phantom were acquired using fast spin echo (FSE) and fast gradient echo (fGRE) sequences. The positions of the vials according to their centers of mass were measured from the MR images and registered to the corresponding computed tomography images for comparison. Results showed the fGRE sequence exhibited no errors >2.0 mm in the sagittal and coronal planes, whereas the FSE sequence produced images with errors between 2.0 and 4.0 mm along the phantom's perimeter in the axial plane. On the basis of these results, the fGRE sequence was considered to be clinically acceptable in acquiring images in all sagittal and coronal planes tested. However, the spatial accuracy in periphery of the axial FSE images exceeded the acceptable criteria for the acquisition parameters used in this study. PACS number(s): 87.57.–s, 87.61.–c PMID:14604425

An Audit to Evaluate the Image Quality of Magnetic Resonance of Knee at Radiology Department of a Tertiary Care Hospital.

PubMed

Mansoor, Ali; Ramzan, Amaila; Chaudhary, Aamer Nadeem

2017-04-01

light of recommendations of ACR. Aclinical audit. Department of Radiology, Jinnah Hospital, Lahore, from August 2015 to February 2016. Scans of 20 patients who underwent MRI of knee in August 2015 were studied retrospectively to assess the quality of images obtained in the first audit. Based on the findings of this audit, recommendations were made and re audit was done 6 months later in February 2016 to look for improvement in local practice. In the first audit, images were acquired in all the three necessary planes and the sagittal and coronal images had appropriate slice thickness, interslice gap as well as adequate anatomical coverage in all the patients. However, FOV (field of view) was appropriately set in 66% of cases in axial plane, 5% in sagittal plane, and 0% in coronal plane. Also, the anatomical coverage was not upto the mark in axial plane with 13 studies (66%) having adequate superior coverage, and 16 cases (80%) having recommended inferior anatomical coverage. The re audit performed 6 months later showed improvement with 100% compliance to standards. The first audit showed many shortcomings in acquiring of MRI data in patients undergoing knee MRI with FOV requiring a decrease in all planes and anatomical coverage increase in axial plane. These recommendations were made in departmental meetings and re-audit was done after 6 months. This second audit showed 100 % compliance.

[Degenerative adult scoliosis].

PubMed

García-Ramos, C L; Obil-Chavarría, C A; Zárate-Kalfópulos, B; Rosales-Olivares, L M; Alpizar-Aguirre, A; Reyes-Sánchez, A A

2015-01-01

Adult scoliosis is a complex three-dimensional rotational deformity of the spine, resulting from the progressive degeneration of the vertebral elements in middle age, in a previously straight spine; a Cobb angle greater than 10° in the coronal plane, which also alters the sagittal and axial planes. It originates an asymmetrical degenerative disc and facet joint, creating asymmetrical loads and subsequently deformity. The main symptom is axial, radicular pain and neurological deficit. Conservative treatment includes drugs and physical therapy. The epidural injections and facet for selectively blocking nerve roots improves short-term pain. Surgical treatment is reserved for patients with intractable pain, radiculopathy and/ or neurological deficits. There is no consensus for surgical indications, however, it must have a clear understanding of the symptoms and clinical signs. The goal of surgery is to decompress neural elements with restoration, modification of the three-dimensional shape deformity and stabilize the coronal and sagittal balance.

High-resolution 3T Magnetic Resonance Imaging of the Triangular Fibrocartilage Complex in Chinese Wrists: Correlation with Cross-sectional Anatomy.

PubMed

Zhan, Hui-Li; Li, Wen-Ting; Bai, Rong-Jie; Wang, Nai-Li; Qian, Zhan-Hua; Ye, Wei; Yin, Yu-Ming

2017-04-05

The injury of the triangular fibrocartilage complex (TFCC) is a common cause of ulnar-sided wrist pain. The aim of this study was to investigate if the high-resolution 3T magnetic resonance imaging (MRI) could demonstrate the detailed complex anatomy of TFCC in Chinese. Fourteen Chinese cadaveric wrists (from four men and three women; age range at death from 30 to 60 years; mean age at 46 years) and forty healthy Chinese wrists (from 20 healthy volunteers, male/female: 10/10; age range from 21 to 53 years with a mean age of 32 years) in Beijing Jishuitan Hospital from March 2014 to March 2016 were included in this study. All cadavers and volunteers had magnetic resonance (MR) examination of the wrist with coronal T1-weighted and proton density-weighted imaging with fat suppression in three planes, respectively. MR arthrography (MRAr) was performed on one of the cadaveric wrists. Subsequently, all 14 cadaveric wrists were sliced into 2 mm thick slab with band saw (six in coronal plane, four in sagittal plane, and four in axial plane). The MRI features of normal TFCC were analyzed in these specimens and forty healthy wrists. Triangular fibrocartilage, the ulnar collateral ligament, and the meniscal homolog could be best observed on images in coronal plane. The palmar and dorsal radioulnar ligaments were best evaluated in transverse plane. The ulnotriquetral and ulnolunate ligaments were best visualized in sagittal plane. The latter two structures and the volar and dorsal capsules were better demonstrated on MRAr. High-resolution 3T MRI is capable to show the detailed complex anatomy of the TFCC and can provide valuable information for the clinical diagnosis in Chinese.

Geometry of solar coronal rays

NASA Astrophysics Data System (ADS)

Filippov, B. P.; Martsenyuk, O. V.; Platov, Yu. V.; Den, O. E.

2016-02-01

Coronal helmet streamers are the most prominent large-scale elements of the solar corona observed in white light during total solar eclipses. The base of the streamer is an arcade of loops located above a global polarity inversion line. At an altitude of 1-2 solar radii above the limb, the apices of the arches sharpen, forming cusp structures, above which narrow coronal rays are observed. Lyot coronagraphs, especially those on-board spacecrafts flying beyond the Earth's atmosphere, enable us to observe the corona continuously and at large distances. At distances of several solar radii, the streamers take the form of fairly narrow spokes that diverge radially from the Sun. This radial direction displays a continuous expansion of the corona into the surrounding space, and the formation of the solar wind. However, the solar magnetic field and solar rotation complicate the situation. The rotation curves radial streams into spiral ones, similar to water streams flowing from rotating tubes. The influence of the magnetic field is more complex and multifarious. A thorough study of coronal ray geometries shows that rays are frequently not radial and not straight. Coronal streamers frequently display a curvature whose direction in the meridional plane depends on the phase of the solar cycle. It is evident that this curvature is related to the geometry of the global solar magnetic field, which depends on the cycle phase. Equatorward deviations of coronal streamers at solar minima and poleward deviations at solar maxima can be interpreted as the effects of changes in the general topology of the global solar magnetic field. There are sporadic temporal changes in the coronal rays shape caused by remote coronal mass ejections (CMEs) propagating through the corona. This is also a manifestation of the influence of the magnetic field on plasma flows. The motion of a large-scale flux rope associated with a CME away from the Sun creates changes in the structure of surrounding field

A comparison of short term radiological alignment outcomes of the patient specific and standard instrumentation for primary total knee arthroplasty: A systematic review and meta-analysis.

PubMed

Alcelik, Ilhan; Blomfield, Mark; Öztürk, Cenk; Soni, Ashish; Charity, Richard; Acornley, Alex

2017-05-01

The aim of this study was to review the radiological alignment outcomes of patient Specific (PS) cutting blocks and Standard Instrumentation in Primary Total Knee Arthroplasty. We hypothesized that the use of PS techniques would significantly improve sagittal, coronal and rotational alignment of the prosthesis on short term. We performed a systematic review and a meta-analysis including all the randomised controlled trials (RCT) using PS and standard (ST) total knee arthroplasty to date. A total of 538 PS TKA and 549 ST TKA were included in the study. Statistical analysis of the outliers for femoral component sagittal, coronal and rotational positioning, tibial component sagittal and coronal positioning and the overall mechanical axis were assessed. We found that there was no significant benefit from using PS instrumentation in primary knee arthroplasty to aid in the positioning of either the tibial or femoral components. Furthermore sagittal plane tibial component positioning was worse in the PS than the traditional ST group. Our results suggest that at present PS instrumentation is not superior to ST instrumentation in primary total knee arthroplasty. Level 1, Systematic review of therapeutic studies. Copyright © 2017 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

Permeability of canine vocal fold lamina propria.

PubMed

Meyer, Jacob P; Kvit, Anton A; Devine, Erin E; Jiang, Jack

2015-04-01

Determine the permeability of excised canine vocal fold lamina propria. Basic science. Vocal folds were excised from canine larynges and mounted within a device to measure the flow of 0.9% saline through the tissue over time. The resultant fluid volume displaced over time was then used in a variation of Darcy's law to calculate the permeability of the tissue. Permeability was found through each anatomical plane of the vocal fold, with five samples per plane. Permeability was also found for lamina propria stretched to 10%, 20%, and 30% of its initial length to determine the effects of tensile strain on permeability, with five samples per level of strain. Permeability was found to be 1.40 × 10(-13) m(3) s/kg through the sagittal plane, 1.00 × 10(-13) m(3) s/kg through the coronal plane, and 4.02 × 10(-13) m(3) s/kg through the axial plane. It was significantly greater through the axial plane than both the sagittal (P = .025) and coronal (P = .009) planes. Permeability under strain through the sagittal plane was found to be 1.94 × 10(-13) m(3) s/kg under 10% strain, 3.35 × 10(-13) m(3) s/kg under 20% strain, and 4.80 × 10(-13) m(3) s/kg under 30% strain. The permeability significantly increased after 20% strain (P < .05). Permeability in canine vocal fold lamina propria was found to be increased along the anterior-posterior axis, following the length of the vocal folds. This may influence fluid distribution within the lamina propria during and after vibration. Similarly, permeability increased after 20% strain was imposed on the lamina propria, and may influence vocal fold dynamics during certain phonation tasks. NA Laryngoscope, 125:941-945, 2015. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

REDEFINING THE BOUNDARIES OF INTERPLANETARY CORONAL MASS EJECTIONS FROM OBSERVATIONS AT THE ECLIPTIC PLANE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cid, C.; Palacios, J.; Saiz, E.

2016-09-01

On 2015 January 6–7, an interplanetary coronal mass ejection (ICME) was observed at L1. This event, which can be associated with a weak and slow coronal mass ejection, allows us to discuss the differences between the boundaries of the magnetic cloud and the compositional boundaries. A fast stream from a solar coronal hole surrounding this ICME offers a unique opportunity to check the boundaries’ process definition and to explain differences between them. Using Wind and ACE data, we perform a complementary analysis involving compositional, magnetic, and kinematic observations providing relevant information regarding the evolution of the ICME as travelling awaymore » from the Sun. We propose erosion, at least at the front boundary of the ICME, as the main reason for the difference between the boundaries, and compositional signatures as the most precise diagnostic tool for the boundaries of ICMEs.« less

Influence of malalignment on socket reaction moments during gait in amputees with transtibial prostheses.

PubMed

Boone, David A; Kobayashi, Toshiki; Chou, Teri G; Arabian, Adam K; Coleman, Kim L; Orendurff, Michael S; Zhang, Ming

2013-04-01

Alignment - the process and measured orientation of the prosthetic socket relative to the foot - is important for proper function of a transtibial prosthesis. Prosthetic alignment is performed by prosthetists using visual gait observation and amputees' feedback. The aim of this study was to investigate the effect of transtibial prosthesis malalignment on the moments measured at the base of the socket: the socket reaction moments. Eleven subjects with transtibial amputation were recruited from the community. An instrumented prosthesis alignment component was used to measure socket reaction moments during ambulation under 17 alignment conditions, including nominally aligned using conventional clinical methods, and angle perturbations of 3° and 6° (flexion, extension, abduction, and adduction) and translation perturbations of 5mm and 10mm (anterior, posterior, lateral, and medial) referenced from the nominal alignment. Coronal alignment perturbations caused systematic changes in the coronal socket reaction moments. All angle and translation perturbations revealed statistically significant differences on coronal socket reaction moments compared to the nominal alignment at 30% and 75% of stance phase (P<0.05). The effect of sagittal alignment perturbations on sagittal socket reaction moments was not as responsive as that of the coronal perturbations. The sagittal angle and translation perturbations of the socket led to statistically significant changes in minimum moment, maximum moment, and moments at 45% of stance phase in the sagittal plane. Therefore, malalignment affected the socket reaction moments in amputees with transtibial prostheses. Copyright © 2012 Elsevier B.V. All rights reserved.

Perception of socket alignment perturbations in amputees with transtibial prostheses.

PubMed

Boone, David A; Kobayashi, Toshiki; Chou, Teri G; Arabian, Adam K; Coleman, Kim L; Orendurff, Michael S; Zhang, Ming

2012-01-01

A person with amputation's subjective perception is the only tool available to describe fit and comfort to a prosthetist. However, few studies have investigated the effect of alignment on this perception. The aim of this article is to determine whether people with amputation could perceive the alignment perturbations of their prostheses and effectively communicate them. A randomized controlled perturbation of angular (3 and 6 degrees) and translational (5 and 10 mm) alignments in the sagittal (flexion, extension, and anterior and posterior translations) and coronal (abduction, adduction, and medial and lateral translations) planes were induced from an aligned condition in 11 subjects with transtibial prostheses. The perception was evaluated when standing (static) and immediately after walking (dynamic) using software that used a visual analog scale under each alignment condition. In the coronal plane, Friedman test demonstrated general statistical differences in static (p < 0.001) and dynamic (p < 0.001) measures of perceptions with angular perturbations. In the sagittal plane, it also demonstrated general statistical differences in late-stance dynamic measures of perceptions (p < 0.001) with angular perturbations, as well as in early-stance dynamic measures of perceptions (p < 0.05) with translational perturbations. Fisher exact test suggested that people with amputation's perceptions were good indicators for coronal angle malalignments but less reliable when defining other alignment conditions.

[An automatic system for anatomophysiological correlation in three planes simultaneously during functional neurosurgery].

PubMed

Teijeiro, E J; Macías, R J; Morales, J M; Guerra, E; López, G; Alvarez, L M; Fernández, F; Maragoto, C; Seijo, F; Alvarez, E

The Neurosurgical Deep Recording System (NDRS) using a personal computer takes the place of complex electronic equipment for recording and processing deep cerebral electrical activity, as a guide in stereotaxic functional neurosurgery. It also permits increased possibilities of presenting information in direct graphic form with automatic management and sufficient flexibility to implement different analyses. This paper describes the possibilities of automatic simultaneous graphic representation in three almost orthogonal planes, available with the new 5.1 version of NDRS so as to facilitate the analysis of anatomophysiological correlation in the localization of deep structures of the brain during minimal access surgery. This new version can automatically show the spatial behaviour of signals registered throughout the path of the electrode inside the brain, superimposed simultaneously on sagittal, coronal and axial sections of an anatomical atlas of the brain, after adjusting the scale automatically according to the dimensions of the brain of each individual patient. This may also be shown in a tridimensional representation of the different planes themselves intercepting. The NDRS system has been successfully used in Spain and Cuba in over 300 functional neurosurgery operations. The new version further facilitates analysis of spatial anatomophysiological correlation for the localization of brain structures. This system has contributed to increase the precision and safety in selecting surgical targets in the control of Parkinson s disease and other disorders of movement.

Remodeling of angulation deformities in diaphyseal femoral fracture in children.

PubMed

Kamegaya, Makoto; Saisu, Takashi; Segawa, Yuko; Kakizaki, Jun; Sakamoto, Yuko; Hagiwara, Shigeo

2012-11-01

The purpose of this study was to reconsider the factors influencing the remodeling effects in diaphyseal femoral fractures in children based on radiological results. We reviewed 39 patients with more than a 5° residual angulation deformity at the fracture site on anteroposterior and/or lateral views at the primary healing stage. The average follow-up period was 30.4 months. Angulation deformity was measured on plain radiographs both at the primary healing stage and the final follow-up. The correction rate (A - B/A × 100, A angulation deformities at the primary healing, B the angulation at the final follow-up) between at the primary healing stage and final follow-up was analyzed in terms of age at injury (0-5, 6-9, and ≥10 years), fracture site (proximal one third, middle one third, and distal one third) and direction of the deformities (coronal and sagittal planes). The remodeling effect significantly appeared on the coronal plane (correction rate 66.7 %) rather than on the sagittal plane (correction rate 31.6 %) in the 0- to 5-year age group (P < 0.05). There was a statistically significant difference in the correction rate between the 0- to 5-year age group (66.7 %) and the 6- to 9-year group (30.6 %) on the coronal plane (P < 0.05), with no significance between any other two groups on both planes. No statistical difference of remodeling effect appeared among the three fracture sites. The average leg-length discrepancy was 4.7 mm longer. We suggest that a patient ≤5 years at injury could expect more sufficient remodeling on the coronal plane compared with the other age groups on both planes. However, a patient >5 years at injury should be encouraged to undergo the maximum possible correction of the angulation deformity at the initial treatment. Surgical intervention might be considered for that purpose.

Chevron osteotomy in patients with scheduled osteotomy of the medial malleolus.

PubMed

Gül, Murat; Yavuz, Umut; Çetinkaya, Engin; Aykut, Ümit Selçuk; Özkul, Barış; Kabukçuoğlu, Yavuz Selim

2015-01-01

The aim of the present study was to evaluate intermediate-term outcomes of Chevron osteotomy for treatment of osteochondral lesions of the talus with mosaicplasty and to assess its effect on surgery and whether it reduces complications that might occur intraoperatively. The present study included a total of 42 patients (31 men, 11 women) who underwent Chevron osteotomy of the medial malleolus and who had been followed for more than 2 years. Mean age of the patients was 34 years (range: 18-54 years). Preoperatively, size of the lesions was measured in millimeters in the coronal and sagittal planes using magnetic resonance imaging (MRI). The angle between the osteotomy with the long axis of the tibia was measured on the coronal plane, the angle between the arms and the angle for the screws to be directed to the osteotomy line were measured on the sagittal plane on the postoperative images. Nonunion, malunion, and complications from the screws were evaluated from X-ray images taken at the final follow-up. Mean duration for follow-up was 31.4 years (range: 24-46). On the X-ray images taken at the final follow-up, no distraction, migration of the distal part, or rotation was observed. Only 1 patient experienced radiological non-union. Mean duration to union was 5.8 weeks (range: 4-14 weeks). Screws of 8 patients were removed at an average of 7.4 months (range: 5-11 months). The angle between the osteotomy line and long axis of the tibia was 29.0°±6.5°, the angel between the osteotomy arms on the sagittal plane was 74.7°±8.3°, and the direction angle of the screws on the coronal plane was 85.7°±5.9°. Chevron osteotomy is an assistive surgical method used for treatment of osteochondral lesions located in the medial talar joint surface (TOL) which provides fast anatomical healing because it allows efficient fixation due to its geometry.

Influence of implant rod curvature on sagittal correction of scoliosis deformity.

PubMed

Salmingo, Remel Alingalan; Tadano, Shigeru; Abe, Yuichiro; Ito, Manabu

2014-08-01

Deformation of in vivo-implanted rods could alter the scoliosis sagittal correction. To our knowledge, no previous authors have investigated the influence of implanted-rod deformation on the sagittal deformity correction during scoliosis surgery. To analyze the changes of the implant rod's angle of curvature during surgery and establish its influence on sagittal correction of scoliosis deformity. A retrospective analysis of the preoperative and postoperative implant rod geometry and angle of curvature was conducted. Twenty adolescent idiopathic scoliosis patients underwent surgery. Average age at the time of operation was 14 years. The preoperative and postoperative implant rod angle of curvature expressed in degrees was obtained for each patient. Two implant rods were attached to the concave and convex side of the spinal deformity. The preoperative implant rod geometry was measured before surgical implantation. The postoperative implant rod geometry after surgery was measured by computed tomography. The implant rod angle of curvature at the sagittal plane was obtained from the implant rod geometry. The angle of curvature between the implant rod extreme ends was measured before implantation and after surgery. The sagittal curvature between the corresponding spinal levels of healthy adolescents obtained by previous studies was compared with the implant rod angle of curvature to evaluate the sagittal curve correction. The difference between the postoperative implant rod angle of curvature and normal spine sagittal curvature of the corresponding instrumented level was used to evaluate over or under correction of the sagittal deformity. The implant rods at the concave side of deformity of all patients were significantly deformed after surgery. The average degree of rod deformation Δθ at the concave and convex sides was 15.8° and 1.6°, respectively. The average preoperative and postoperative implant rod angle of curvature at the concave side was 33.6° and 17.8�

Reliability of sagittal plane hip, knee, and ankle joint angles from a single frame of video data using the GAITRite camera system.

PubMed

Ross, Sandy A; Rice, Clinton; Von Behren, Kristyn; Meyer, April; Alexander, Rachel; Murfin, Scott

2015-01-01

The purpose of this study was to establish intra-rater, intra-session, and inter-rater, reliability of sagittal plane hip, knee, and ankle angles with and without reflective markers using the GAITRite walkway and single video camera between student physical therapists and an experienced physical therapist. This study included thirty-two healthy participants age 20-59, stratified by age and gender. Participants performed three successful walks with and without markers applied to anatomical landmarks. GAITRite software was used to digitize sagittal hip, knee, and ankle angles at two phases of gait: (1) initial contact; and (2) mid-stance. Intra-rater reliability was more consistent for the experienced physical therapist, regardless of joint or phase of gait. Intra-session reliability was variable, the experienced physical therapist showed moderate to high reliability (intra-class correlation coefficient (ICC) = 0.50-0.89) and the student physical therapist showed very poor to high reliability (ICC = 0.07-0.85). Inter-rater reliability was highest during mid-stance at the knee with markers (ICC = 0.86) and lowest during mid-stance at the hip without markers (ICC = 0.25). Reliability of a single camera system, especially at the knee joint shows promise. Depending on the specific type of reliability, error can be attributed to the testers (e.g. lack of digitization practice and marker placement), participants (e.g. loose fitting clothing) and camera systems (e.g. frame rate and resolution). However, until the camera technology can be upgraded to a higher frame rate and resolution, and the software can be linked to the GAITRite walkway, the clinical utility for pre/post measures is limited.

Coronal CT scan measurements and hearing evolution in enlarged vestibular aqueduct syndrome.

PubMed

Saliba, Issam; Gingras-Charland, Marie-Eve; St-Cyr, Karine; Décarie, Jean-Claude

2012-04-01

To assess the correlation between the enlarged vestibular aqueduct (EVA) diameter and (1) the hearing loss level (mild, moderate, severe and profound and (2) the hearing evolution. The secondary objective was to obtain measurement limits on the coronal plane of the temporal bone CT scan for the diagnosis of EVA. Retrospective study in a tertiary pediatric center. Mastoid CT scans were reviewed to measure the VA diameter at its midpoint and operculum on axial and coronal planes in a pathologic and normal population. We used their serial audiograms to assess the evolution of hearing. 101 EVA was identified out of 1812 temporal bones CT scan from our radiologic database in 8 years. Bone conduction was stable after a mean follow-up of 40.9 ± 32.9 months. PTA has been the most affected in time by the EVA (p=0.006). No correlation was identified between impedancemetry and the diameter of the EVA. On the diagnostic audiogram, 61% of hearing loss were in the mild and moderate hearing levels; at the end of the follow-up 64% of hearing loss are still in the mild and moderate hearing levels. The cut-off values for the coronal midpoint and operculum planes on the CT scan to diagnose an EVA are 2.4 mm and 4.34 mm respectively. Conductive or mixed hearing loss might be the first manifestation of EVA. Coronal CT scan cuts can provide additional information to evaluate EVA especially when axial cuts are not conclusive. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

High-resolution 3T Magnetic Resonance Imaging of the Triangular Fibrocartilage Complex in Chinese Wrists: Correlation with Cross-sectional Anatomy

PubMed Central

Zhan, Hui-Li; Li, Wen-Ting; Bai, Rong-Jie; Wang, Nai-Li; Qian, Zhan-Hua; Ye, Wei; Yin, Yu-Ming

2017-01-01

Background: The injury of the triangular fibrocartilage complex (TFCC) is a common cause of ulnar-sided wrist pain. The aim of this study was to investigate if the high-resolution 3T magnetic resonance imaging (MRI) could demonstrate the detailed complex anatomy of TFCC in Chinese. Methods: Fourteen Chinese cadaveric wrists (from four men and three women; age range at death from 30 to 60 years; mean age at 46 years) and forty healthy Chinese wrists (from 20 healthy volunteers, male/female: 10/10; age range from 21 to 53 years with a mean age of 32 years) in Beijing Jishuitan Hospital from March 2014 to March 2016 were included in this study. All cadavers and volunteers had magnetic resonance (MR) examination of the wrist with coronal T1-weighted and proton density-weighted imaging with fat suppression in three planes, respectively. MR arthrography (MRAr) was performed on one of the cadaveric wrists. Subsequently, all 14 cadaveric wrists were sliced into 2 mm thick slab with band saw (six in coronal plane, four in sagittal plane, and four in axial plane). The MRI features of normal TFCC were analyzed in these specimens and forty healthy wrists. Results: Triangular fibrocartilage, the ulnar collateral ligament, and the meniscal homolog could be best observed on images in coronal plane. The palmar and dorsal radioulnar ligaments were best evaluated in transverse plane. The ulnotriquetral and ulnolunate ligaments were best visualized in sagittal plane. The latter two structures and the volar and dorsal capsules were better demonstrated on MRAr. Conclusion: High-resolution 3T MRI is capable to show the detailed complex anatomy of the TFCC and can provide valuable information for the clinical diagnosis in Chinese. PMID:28345546

Neuromuscular strategies for lumbopelvic control during frontal and sagittal plane movement challenges differ between people with and without low back pain.

PubMed

Nelson-Wong, E; Poupore, K; Ingvalson, S; Dehmer, K; Piatte, A; Alexander, S; Gallant, P; McClenahan, B; Davis, A M

2013-12-01

Observation-based assessments of movement are a standard component in clinical assessment of patients with non-specific low back pain. While aberrant motion patterns can be detected visually, clinicians are unable to assess underlying neuromuscular strategies during these tests. The purpose of this study was to compare coordination of the trunk and hip muscles during 2 commonly used assessments for lumbopelvic control in people with low back pain (LBP) and matched control subjects. Electromyography was recorded from hip and trunk muscles of 34 participants (17 with LBP) during performance of the Active Hip Abduction (AHAbd) and Active Straight Leg Raise (ASLR) tests. Relative muscle timing was calculated using cross-correlation. Participants with LBP demonstrated a variable strategy, while control subjects used a consistent proximal to distal activation strategy during both frontal and sagittal plane movements. Findings from this study provide insight into underlying neuromuscular control during commonly used assessment tests for patients with LBP that may help to guide targeted intervention approaches. Copyright © 2013 Elsevier Ltd. All rights reserved.

Computer-assisted oblique single-cut rotation osteotomy to reduce a multidirectional tibia deformity: case report.

PubMed

Dobbe, J G G; du Pré, K J; Blankevoort, L; Streekstra, G J; Kloen, P

2017-08-01

The correction of multiplanar deformity is challenging. We describe preoperative 3-D planning and treatment of a complex tibia malunion using an oblique single-cut rotation osteotomy to correct deformity parameters in the sagittal, coronal and transverse plane. At 5 years postoperatively, the patient ambulates without pain with a well-aligned leg.

Sagittal fresh blood imaging with interleaved acquisition of systolic and diastolic data for improved robustness to motion.

PubMed

Atanasova, Iliyana P; Kim, Daniel; Storey, Pippa; Rosenkrantz, Andrew B; Lim, Ruth P; Lee, Vivian S

2013-02-01

To improve robustness to patient motion of "fresh blood imaging" (FBI) for lower extremity noncontrast MR angiography. In FBI, two sets of three-dimensional fast spin echo images are acquired at different cardiac phases and subtracted to generate bright-blood angiograms. Routinely performed with a single coronal slab and sequential acquisition of systolic and diastolic data, FBI is prone to subtraction errors due to patient motion. In this preliminary feasibility study, FBI was implemented with two sagittal imaging slabs, and the systolic and diastolic acquisitions were interleaved to minimize sensitivity to motion. The proposed technique was evaluated in volunteers and patients. In 10 volunteers, imaged while performing controlled movements, interleaved FBI demonstrated better tolerance to subject motion than sequential FBI. In one patient with peripheral arterial disease, interleaved FBI offered better depiction of collateral flow by reducing sensitivity to inadvertent motion. FBI with interleaved acquisition of diastolic and systolic data in two sagittal imaging slabs offers improved tolerance to patient motion. Copyright © 2013 Wiley Periodicals, Inc.

Magnetic Resonance Imaging of a Case of Central Neurocytoma.

PubMed

Dedushi, Kreshnike; Kabashi, Serbeze; Ugurel, Mehmet Sahin; Ramadani, Naser; Mucaj, Sefedin; Zeqiraj, Kamber

2016-12-01

The purpose of this study is to investigate the MRI features of central neurocytoma. A 45 year old man with 3 months of worsening daily headaches. These headaches were diffuse, lasted for several hours, and mostly occurred in the morning. She was initially diagnosed and treated for migraines but later he had epileptic attack and diplopia and neurolog recomaded MRI. precontrast MRI; TSE/T2Wsequence in axial/coronal planes; 3D-Hi-resolution T1W sagittal; FLAIR/T2W axial; FLAIR/T2W and Flash/T2W oblique coronal plane (perpendicular to temporal lobes) GRE/T2W axial plane for detection of heme products. Post-contrast TSE/T1W sequence in axial, coronal and sagittal planes. Diffusion weighted and ADC mapping MRI images for EPI sequence in axial plane. A 23x12mm heterogeneous mass within aqueductus cerebri, with calcified and hemorrhagic foci and extending downwards till fourth ventricle. It's originating from the right paramedian posterior aqueductal wall (tectum), and also extending to and involving the tegmentum of mesencephalon at its right paramedian aspect. CSF flow obstruction secondary to described aqueductal mass, with resultant triventricular hydrocephalus). Marked transependymal CSF leak can be noted at periventricular white matter, secondary to severe hydrocephalus. After IV injection of contrast media, this mass shows mild-to-moderate heterogenous speckled enhancement. MRI is helpful in defining tumor extension, which is important in preoperative planning. Although IN is a relatively rare lesion, it should be considered in the differential diagnosis of intraventricular lesions in the presence of such typical MR findings. However, a definitive diagnosis requires immunochemical study and electron microscopy.

Current concepts and controversies on adolescent idiopathic scoliosis: Part I.

PubMed

Sud, Alok; Tsirikos, Athanasios I

2013-03-01

Adolescent idiopathic scoliosis is the most common spinal deformity encountered by General Orthopaedic Surgeons. Etiology remains unclear and current research focuses on genetic factors that may influence scoliosis development and risk of progression. Delayed diagnosis can result in severe deformities which affect the coronal and sagittal planes, as well as the rib cage, waistline symmetry, and shoulder balance. Patient's dissatisfaction in terms of physical appearance and mechanical back pain, as well as the risk for curve deterioration are usually the reasons for treatment. Conservative management involves mainly bracing with the aim to stop or slow down scoliosis progression during growth and if possible prevent the need for surgical treatment. This is mainly indicated in young compliant patients with a large amount of remaining growth and progressive curvatures. Scoliosis correction is indicated for severe or progressive curves which produce significant cosmetic deformity, muscular pain, and patient discontent. Posterior spinal arthrodesis with Harrington instrumentation and bone grafting was the first attempt to correct the coronal deformity and replace in situ fusion. This was associated with high pseudarthrosis rates, need for postoperative immobilization, and flattening of sagittal spinal contour. Segmental correction techniques were introduced along with the Luque rods, Harri-Luque, and Wisconsin systems. Correction in both coronal and sagittal planes was not satisfactory and high rates of nonunion persisted until Cotrel and Dubousset introduced the concept of global spinal derotation. Development of pedicle screws provided a powerful tool to correct three-dimensional vertebral deformity and opened a new era in the treatment of scoliosis.

Low coronal signatures of coronal mass ejections

NASA Astrophysics Data System (ADS)

Attrill, Gemma Diana Ruth

Coronal mass ejections (CMEs) are vast eruptions of magnetised plasma that explode from the solar atmosphere. This thesis focuses on understanding the nascent stages of CMEs, and their magnetic development as they expand into the interplanetary space of our solar system. This is an important part of our effort to understand the space weather environment that we live in, and increasingly interact with through satellite communications technologies. Predominantly through combining extreme ultra-violet imaging and magnetogram data, two low coronal signatures of CMEs, namely coronal waves and dimmings, are studied. A comprehensive list of observational properties of EIT coronal waves is compiled and potential counterparts in radio, Ha, soft X-rays and He n wavelengths are also discussed. New observational constraints on EIT coronal waves are presented, most notably diffuse coronal waves are shown to have a magnetic nature. Finding that many observational constraints are not satisfactorily explained by current theories, a new model for understanding the physical nature of diffuse coronal waves is developed. The new model interprets diffuse coronal "wave" bright fronts to be the low coronal magnetic footprint of CMEs. Implications for developing our understanding of how CMEs become large-scale in the low corona are discussed. Application of the model demonstrates how an understanding of the formation of complex global-scale coronal dimmings can be derived. For the first time it is shown that study of the evolution and magnetic nature of coronal dimming regions can be used to probe the post-eruptive evolution of the CME. Finally, a study is presented regarding why and how CME-related dimmings recover, despite the "open" magnetic connectivity of the ejecta to the Sun being maintained as indicated by electron heat flux measurements at 1 AU.

Application of Ni-Ti Alloy connector for the treatment of comminuted coronal plane supracondylar-condylar femoral fractures: a retrospective review of 21 patients

PubMed Central

2013-01-01

Background Our preliminary retrospective study assessed outcomes after the use of Ni-Ti arched shape-memory connector (ASC) combined with partially threaded cancellous screws (PTCS) to repair coronal plane supracondylar-condylar femoral fractures. Methods Twenty-one patients (16 men and 5 women) with a mean age of 34.1 years (range, 28 to 44 years) with coronal plane supracondylar and condylar fractures of the distal femur were included in this study. Each patient underwent open reduction and internal fixation using the ASC and PTCS. Active functional exercises with restricted weight bearing were initiated the first postoperative day. A gradual increase in weight bearing status and range of motion was permitted and subjects progressed to full weight bearing by 8 weeks. Surgical time, blood loss, postoperative knee range of motion, American Knee Society Scores (KSS), and postoperative complications were assessed. Results The mean surgical time was 75 mins (range, 45 to 100 mins) and average blood loss was 105 ml (range, 35 to 130 ml). Mean follow-up was 65 months (range, 22 to 90 months). No subjects demonstrated evidence of osteonecrosis or arthritis at the final follow-up. The mean KSS was excellent (≥85) in 8 subjects, good (70-84) in 11 subjects, and fair (60-69) in 2 subjects. The mean active range of motion of knee flexion at final follow-up was 100 degrees (range, 85 to 110 degrees). Conclusions ASC combined with PTCS can serve as an effective means for managing comminuted femoral fractures that extend from the condyle to the supracondylar region. However, further prospective comparative studies and biomechanical analyses are needed to evaluate long-term outcomes using these materials. PMID:24341860

No Differences Identified in Transverse Plane Biomechanics Between Medial Pivot and Rotating Platform Total Knee Implant Designs.

PubMed

Papagiannis, Georgios I; Roumpelakis, Ilias M; Triantafyllou, Athanasios I; Makris, Ioannis N; Babis, George C

2016-08-01

Total knee arthroplasties (TKAs) using well-designed, fixed bearing prostheses, such as medial pivot (MP), have produced good long-term results. Rotating-platform, posterior-stabilized (RP-PS) mobile bearing implants were designed to decrease polyethylene wear. Sagittal and coronal plane TKA biomechanics are well examined and correlated to polyethylene wear. However, limited research findings describe this relationship in transverse plane. We assumed that although axial plane biomechanics might not be the most destructive parameters on polyethylene wear, it is important to clarify their role because both joint kinematics and kinetics in all 3 planes are important input parameters for TKA wear testing (International Organization for Standardization 14243-1 and 14343-3). Our hypothesis was that transverse plane overall range of motion (ROM) and/or peak moment show differences that reflect on wear advantages when compared RP-PS implants to MP designs. Two groups (MPs = 24 and RP-PSs = 22 subjects) were examined by using 3D gait analysis. The variables were total internal-external rotation (IER) ROM and peak IER moments. No statistically significant difference was demonstrated between the 2 groups in kinetics (P = .389) or kinematics (P = .275). In the present study, no wear advantages were found between 2 TKAs. Both designs showed identical kinetics at the transverse plane in level-ground walking. Kinematic analysis could not illustrate any statistically significant difference in terms of overall IER ROM. Nevertheless, kinematic gait pattern differences observed possibly reflect different patterns of joint surface motion or abnormal gait patterns. Thus, wear testing with various input waveforms combined with functional data analysis will be necessary to identify the actual effects of gait variability on polyethylene wear. Copyright © 2016 Elsevier Inc. All rights reserved.

Two-plane symmetry in the structural organization of man.

PubMed

Ermolenko, A E

2005-01-01

Manifestations of symmetry in the human structural organization in ontogenesis and phylogenetic development are analysed. A concept of macrobiocrystalloid with inherent complex symmetry is proposed for the description of the human organism in its integrity. The symmetry can be characterized as two-plane radial (quadrilateral), where the planar symmetry is predominant while the layout of organs of radial symmetry is subordinated to it. Out of the two planes of symmetry (sagittal and horizontal), the sagittal plane is predominant: (a) the location of the organs is governed by two principles: in compliance with the symmetry planes and in compliance with the radial symmetry around cavities; (b) the location of the radial symmetry organs is also governed by the principle of two-plane symmetry; (c) out of the four antimeres of two-plane symmetry, two are paired while the other two have merged into one organ; (d) some organs which are antimeres relative to the horizontal plane are located at the cranial end of the organism (sensory organs, cerebrum-cerebellum, heart-spleen and others). The two-plane symmetry is formed by two mechanisms--(a) the impact of morphogenetic fields of the whole crystalloid organism during embriogenesis and (b) genetic mechanisms of the development of chromosomes having two-plane symmetry. When comparing mineral and biological entities we should consider not the whole immobile crystal but only the active superficial part of a growing or dissolving crystal, the interface between the crystal surface and the crystal-forming environment which directly controls crystal growth and adapts itself to it, as well as crystal feed stock expressed in the structure of concentration flows. The symmetry of the chromosome, of the embrion at the early stages of cell cleavage as well as of some organs and systems in their phylogenetic development is described.

Associations between lower extremity muscle mass and multiplanar knee laxity and stiffness: a potential explanation for sex differences in frontal and transverse plane knee laxity.

PubMed

Shultz, Sandra J; Pye, Michele L; Montgomery, Melissa M; Schmitz, Randy J

2012-12-01

Compared with men, women have disproportionally greater frontal (varus-valgus) and transverse (internal-external) plane laxity and lower stiffness, despite having similar sagittal (anterior-posterior) plane laxity and stiffness. While the underlying cause is unclear, the amount of lower extremity lean mass (LELM) may be a contributing factor. Lower extremity lean mass would be a stronger predictor of frontal and transverse plane laxity and incremental stiffness than the sagittal plane. Associations between LELM and stiffness would be stronger at lower force increments. Descriptive laboratory study. Sixty-three women and 30 men with no history of ligament injury were measured for knee laxity and incremental stiffness in the sagittal (-90- to 130-N posterior-to-anterior directed loads), frontal (±10-N·m varus-valgus torques), and transverse (±5-N·m internal-external rotation torques) planes and underwent dual-energy X-ray absorptiometry scans to measure LELM. Linear regressions examined the extent to which LELM predicted each laxity and stiffness value, while also accounting for a person's sex. Females (vs males) had greater laxity and less stiffness in the frontal and transverse planes but not the sagittal plane. Lower extremity lean mass was a poor predictor of sagittal laxity and stiffness (R (2) range = .021-.081; P > .06) but was a stronger predictor of frontal (R (2) range = .215-.567; P < .01) and transverse (R (2) range = .224-.356; P < .01) plane laxity and stiffness. Associations were stronger for low (R (2) = .495-.504) versus high (R (2) = .215-.435) frontal plane stiffness but were similar for low (R (2) = .233-.293) versus high (R (2) = .224-.356) transverse plane stiffness. Once we accounted for a person's LELM, sex had little effect on laxity and stiffness (change in R (2) after removal = .01-.08; P = .027-.797). Less LELM was associated with greater laxity and less stiffness in frontal and transverse planes, which may contribute to the

Sagittal plane analysis of selective posterior thoracic spinal fusion in adolescent idiopathic scoliosis: a comparison study of all pedicle screw and hybrid instrumentation.

PubMed

Liu, Tie; Hai, Yong

2014-07-01

To compare sagittal profiles of selective posterior thoracic instrumentation with segmental pedicle screws instrumentation and hybrid (hook and pedicle screw). Nowadays, thoracic screws are considered more effective than other constructs in spinal deformity correction and have become the treatment in adolescent idiopathic scoliosis surgery. However, recent research found that this enhanced correction ability may sacrifice sagittal balance. As lumbar lordosis is dependent upon thoracic kyphosis (TK), it has been important to maintain TK magnitude in selective thoracic fusions to keep balance. There is no sagittal measurement analysis between the hybrid and all-screw constructs type in cases of selective thoracic fusion. All adolescent idiopathic scoliosis (Lenke1) patients surgically treated in our department between 2003 and 2008 were reviewed. Radiographs of these patients, whose preoperative, immediately postoperative, and minimum 2-year follow-up after selective thoracic fusion (lower instrumented vertebrae not lower than L1, hybrid group the pedicle screw instrumentation not higher than T10) were evaluated, 21 patients underwent posterior hybrid instrumentation and 21 underwent pedicle screw instrumentation. No significant difference in sagittal profiles was observed between the 2 groups. At final follow-up, the proximal junctional measurement has a minor increase in both the groups. TK (T5-T12) also increased (+2.0 degrees of increase in hybrid group vs. +3.9 degrees of increase in the pedicle screw group). The effect of different instrumentation in changing TK at various time points between 2 groups was statistic different (P=0.004). Lumbar lordosis (L1-L5) was increased in both the groups. No significant changes in distal junctional measurement and thoracolumbar junction were noted. The C7 sagittal plumbline remained negative in both the groups at the final follow-up. There was no statistically significant difference comparing the sagittal alignment

Evaluation of Blalock-Taussig shunts in newborns: value of oblique MRI planes.

PubMed

Kastler, B; Livolsi, A; Germain, P; Zöllner, G; Dietemann, J L

1991-01-01

Eight infants with systemic-pulmonary Blalock-Taussig shunts were evaluated by spin-echo ECG-gated MRI. Contrary to Echocardiography, MRI using coronal oblique projections successfully visualized all palliative shunts entirely in one single plane (including one carried out on a right aberrant subclavian artery). MRI allowed assessment of size, course and patency of the shunt, including pulmonary and subclavian insertion. The proximal portion of the pulmonary and subclavian arteries were also visualized. We conclude that MRI with axial scans completed by coronal oblique planes is a promising, non invasive method for imaging the anatomical features of Blalock-Taussig shunts.

Oblique Sagittal Images Prevent Underestimation of the Neuroforaminal Stenosis Grade Caused by Disc Herniation in Cervical Spine MRI.

PubMed

Kintzelé, Laurent; Rehnitz, Christoph; Kauczor, Hans-Ulrich; Weber, Marc-André

2018-06-06

 To identify whether standard sagittal MRI images result in underestimation of the neuroforaminal stenosis grade compared to oblique sagittal MRI images in patients with cervical spine disc herniation.  74 patients with a total of 104 cervical disc herniations compromising the corresponding nerve root were evaluated. Neuroforaminal stenosis grades were evaluated in standard and oblique sagittal images by one senior and one resident radiologist experienced in musculoskeletal imaging. Oblique images were angled 30° towards the standard sagittal plane. Neuroforaminal stenosis grades were classified from 0 (no stenosis) to 3 (high grade stenosis).  Average neuroforaminal stenosis grades of both readers were significantly lower in standard compared to oblique sagittal images (p < 0.001). For 47.1 % of the cases, one or both readers reported a stenosis grade, which was at least 1 grade lower in standard compared to oblique sagittal images. There was also a significant difference when looking at patients who had neurological symptoms (p = 0.002) or underwent cervical spine surgery subsequently (p = 0.004). Interreader reliability, as measured by kappa value, and accordance rates were better for oblique sagittal images (0.94 vs. 0.88 and 99 % vs. 93 %).  Standard sagittal images tend to underestimate neuroforaminal stenosis grades compared to oblique sagittal images and are less reliable in the evaluation of disc herniations within the cervical spine MRI. In order to assess the potential therapeutic consequence, oblique images should therefore be considered as a valuable adjunct to the standard MRI protocol for patients with a radiculopathy.   · Neuroforaminal stenosis grades are underestimated in standard compared to oblique sagittal images. · Interreader reliability is higher for oblique sagittal images. · Oblique sagittal images should be performed in patients with a cervical radiculopathy. · Kintzele L, Rehnitz C, Kauczor H et�

Standardising the clinical assessment of coronal knee laxity.

PubMed

Clarke, Jon V; Wilson, William T; Wearing, Scott C; Picard, Frederic; Riches, Philip E; Deakin, Angela H

2012-09-01

Clinical laxity tests are used for assessing knee ligament injuries and for soft tissue balancing in total knee arthroplasty. This study reports the development and validation of a quantitative technique of assessing collateral knee laxity through accurate measurement of potential variables during routine clinical examination. The hypothesis was that standardisation of a clinical stress test would result in a repeatable range of laxity measurements. Non-invasive infrared tracking technology with kinematic registration of joint centres gave real-time measurement of both coronal and sagittal mechanical tibiofemoral alignment Knee flexion, moment arm and magnitude of the applied force were all measured and standardised. Three clinicians then performed six knee laxity examinations on a single volunteer using a target moment of 18 Nm. Standardised laxity measurements had small standard deviations (within 1. 1 degree) for each clinician and similar mean values between clinicians, with the valgus laxity assessment (mean of 3 degrees) being slightly more consistent than varus (means of 4 degrees or 5 degrees). The manual technique of coronal knee laxity assessment was successfully quantified and standardised, leading to a narrow range of measurements (within the accuracy of the measurement system). Minimising the subjective variables of clinical examination could improve current knowledge of soft tissue knee behaviour.

“Soft that molds the hard:” Geometric morphometry of lateral atlantoaxial joints focusing on the role of cartilage in changing the contour of bony articular surfaces

PubMed Central

Prasad, Prashant Kumar; Salunke, Pravin; Sahni, Daisy; Kalra, Parveen

2017-01-01

Purpose: The existing literature on lateral atlantoaxial joints is predominantly on bony facets and is unable to explain various C1-2 motions observed. Geometric morphometry of facets would help us in understanding the role of cartilages in C1-2 biomechanics/kinematics. Objective: Anthropometric measurements (bone and cartilage) of the atlantoaxial joint and to assess the role of cartilages in joint biomechanics. Materials and Methods: The authors studied 10 cadaveric atlantoaxial lateral joints with the articular cartilage in situ and after removing it, using three-dimensional laser scanner. The data were compared using geometric morphometry with emphasis on surface contours of articulating surfaces. Results: The bony inferior articular facet of atlas is concave in both sagittal and coronal plane. The bony superior articular facet of axis is convex in sagittal plane and is concave (laterally) and convex medially in the coronal plane. The bony articulating surfaces were nonconcordant. The articular cartilages of both C1 and C2 are biconvex in both planes and are thicker than the concavities of bony articulating surfaces. Conclusion: The biconvex structure of cartilage converts the surface morphology of C1-C2 bony facets from concave on concavo-convex to convex on convex. This reduces the contact point making the six degrees of freedom of motion possible and also makes the joint gyroscopic. PMID:29403249

Cone Beam Computed Tomography Analysis in 3D Position of Maxillary Denture

PubMed Central

Jia, Ying; Yang, Hua; Li, Ping; Xiong, Jiangyan; Chen, Bo

2017-01-01

Abstract The dynamic correlation between teeth and denture morphology as well as the morphological positions needs to be explored. Methodology 63 adult patients with skeletal class III malocclusions that met the inclusion criteria were enrolled and imaged with Cone Beam Computed Tomography (CBCT), and Digital Imaging and Communications in Medicine (DICOM) data were collected. The torque angle and axial inclination were measured and analyzed for the corona, root, and entire body of every tooth on the maxilla. Results There is a statistically significant difference between the coronal axial inclination/coronal torque angle for the skeletal class III malocclusion cases and Andrew’s six keys of occlusion. On the sagittal plane of the maxillary denture (except that the secondary molar is inclined medial-distally), the remaining teeth are inclined towards the labia with slightly larger angles compared to the normal occlusion. In the coronal direction, the maxillary anterior teeth tend to have a corona that inclines medial-distally, whereas the posterior teeth have a buccal inclination compared to the normal occlusion. Conclusion Sagittal and transversal compensations prevail in maxillary dentures; for the camouflaged treatment design for skeletal class III, there is limited scope of sagittal and transversal movements on the maxillary denture. PMID:29104942

The relation between knee flexion angle and anterior cruciate ligament femoral tunnel characteristics: a cadaveric study comparing a standard and a far anteromedial portal.

PubMed

Alavekios, Damon; Peterson, Alexander; Patton, John; McGarry, Michelle H; Lee, Thay Q

2014-11-01

The purpose of this study was to compare the anterior cruciate ligament (ACL) femoral tunnel characteristics between 2 common arthroscopic portals used for ACL reconstruction, a standard anteromedial portal and a far anteromedial portal. Seven cadaveric knees were used. A 1.25-mm Kirschner wire was drilled through the center of the ACL femoral footprint and through the distal femur from the standard anteromedial and far anteromedial portals at knee flexion angles of 100°, 120°, and 140°. No formal tunnels were drilled. Each tunnel exit point was marked with a colored pin. After all tunnels were created, the specimens were digitized with a MicroScribe device (Revware, Raleigh, NC) to measure the tunnel length; distance to the posterior femoral cortical wall (posterior cortical margin); and tunnel orientation in the sagittal, coronal, and axial planes. The standard anteromedial portal resulted in a longer tunnel length, a less horizontal tunnel in the coronal plane, and a greater posterior cortical margin compared with the far anteromedial portal at all knee flexion angles. For both portal locations, the tunnel length and posterior cortical margin increased, and the tunnel position became more horizontal in the coronal plane, more anterior in the sagittal plane, and less horizontal in the transverse plane as knee flexion increased. Portal position affects femoral tunnel characteristics, with results favoring the more laterally positioned standard anteromedial portal at all flexion angles. Increasing the knee flexion angle leads to a longer femoral tunnel length and posterior femoral cortical margin with either portal position. Understanding how portal positioning and knee flexion angle affect femoral tunnel orientation and characteristics may lead to improved surgical outcomes after ACL reconstruction. Published by Elsevier Inc.

Magnetic Resonance Imaging of a Case of Central Neurocytoma

PubMed Central

Dedushi, Kreshnike; Kabashi, Serbeze; Ugurel, Mehmet Sahin; Ramadani, Naser; Mucaj, Sefedin; Zeqiraj, Kamber

2016-01-01

Background: The purpose of this study is to investigate the MRI features of central neurocytoma. Case report: A 45 year old man with 3 months of worsening daily headaches. These headaches were diffuse, lasted for several hours, and mostly occurred in the morning. She was initially diagnosed and treated for migraines but later he had epileptic attack and diplopia and neurolog recomaded MRI. Methods: precontrast MRI; TSE/T2Wsequence in axial/coronal planes; 3D–Hi-resolution T1W sagittal; FLAIR/T2W axial; FLAIR/T2W and Flash/T2W oblique coronal plane (perpendicular to temporal lobes) GRE/T2W axial plane for detection of heme products. Post-contrast TSE/T1W sequence in axial, coronal and sagittal planes. Diffusion weighted and ADC mapping MRI images for EPI sequence in axial plane. Results: A 23x12mm heterogeneous mass within aqueductus cerebri, with calcified and hemorrhagic foci and extending downwards till fourth ventricle. It’s originating from the right paramedian posterior aqueductal wall (tectum), and also extending to and involving the tegmentum of mesencephalon at its right paramedian aspect. CSF flow obstruction secondary to described aqueductal mass, with resultant triventricular hydrocephalus). Marked transependymal CSF leak can be noted at periventricular white matter, secondary to severe hydrocephalus. After IV injection of contrast media, this mass shows mild-to-moderate heterogenous speckled enhancement. Conclusion: MRI is helpful in defining tumor extension, which is important in preoperative planning. Although IN is a relatively rare lesion, it should be considered in the differential diagnosis of intraventricular lesions in the presence of such typical MR findings. However, a definitive diagnosis requires immunochemical study and electron microscopy. PMID:28077908

The contribution of two ears to the perception of vertical angle in sagittal planes.

PubMed

Morimoto, M

2001-04-01

Because the input signals to the left and right ears are not identical, it is important to clarify the role of these signals in the perception of the vertical angle of a sound source at any position in the upper hemisphere. To obtain basic findings on upper hemisphere localization, this paper investigates the contribution of each pinna to the perception of vertical angle. Tests measured localization of the vertical angle in five planes parallel to the median plane. In the localization tests, the pinna cavities of one or both ears were occluded. Results showed that pinna cavities of both the near and far ears play a role in determining the perceived vertical angle of a sound source in any plane, including the median plane. As a sound source shifts laterally away from the median plane, the contribution of the near ear increases and, conversely, that of the far ear decreases. For saggital planes at azimuths greater than 60 degrees from midline, the far ear no longer contributes measurably to the determination of vertical angle.

Sagittal Fresh Blood Imaging with Interleaved Acquisition of Systolic and Diastolic Data for Improved Robustness to Motion

PubMed Central

Atanasova, Iliyana P.; Kim, Daniel; Storey, Pippa; Rosenkrantz, Andrew B; Lim, Ruth P.; Lee, Vivian S.

2012-01-01

Purpose To improve robustness to patient motion of ‘fresh blood imaging’ (FBI) for lower extremity non-contrast MRA. Methods In FBI, two sets of 3D fast spin echo images are acquired at different cardiac phases and subtracted to generate bright-blood angiograms. Routinely performed with a single coronal slab and sequential acquisition of systolic and diastolic data, FBI is prone to subtraction errors due to patient motion. In this preliminary feasibility study, FBI was implemented with two sagittal imaging slabs, and the systolic and diastolic acquisitions were interleaved to minimize sensitivity to motion. The proposed technique was evaluated in volunteers and patients. Results In ten volunteers, imaged while performing controlled movements, interleaved FBI demonstrated better tolerance to subject motion than sequential FBI. In one patient with peripheral arterial disease, interleaved FBI offered better depiction of collateral flow by reducing sensitivity to inadvertent motion. Conclusions FBI with interleaved acquisition of diastolic and systolic data in two sagittal imaging slabs offers improved tolerance to patient motion. PMID:23300129

A Biomechanical Investigation of Selected Lumbopelvic Hip Tests: Implications for the Examination of Walking.

PubMed

Bailey, Robert Walter; Richards, Jim; Selfe, James

2016-01-01

The purpose of this study was to compare lumbopelvic hip ranges of motion during the Trendelenburg, Single Leg Squat, and Corkscrew Tests to walking and to describe the 3-dimensional lumbopelvic hip motion during the tests. This may help clinicians to select appropriate tests when examining gait. An optoelectronic movement analysis tracking system was used to assess the lumbopelvic hip region of 14 healthy participants while performing Trendelenburg, Single Leg Squat, and Corkscrew Tests and walking. The lumbopelvic hip 3-dimensional ranges of movement for the clinical tests were compared with walking using a repeated-measures analysis of variance with pairwise comparisons. No significant differences were found between the pelvic obliquity during the Trendelenburg Test and walking (Trendelenburg Test: L, 11.3° ± 4.8°, R, 10.8° ± 5.0° vs walk: L, 8.3° ± 4.8°, R 8.3° ± 5.1°, L, P = .143, R, P = .068). Significant differences were found between the hip sagittal plane range of movement during the Single Leg Squat and walking (Single Leg Squat: L, 44.2° ±13.7°, R, 41.7° ±10.9° vs walk: 38.6° ±7.0°, R 37.8° ±5.1°, P < .05), the hip coronal plane range of movement (Single Leg Squat: L, 9.1° ±5.8°, R, 9.0° ± 4.6° vs walk: L, 9.4° ± 2.3°, R 9.5° ± 2.0°, P < .05), and the hip coronal plane range of movement during the Corkscrew Test and walking (Corkscrew: L, 5.7° ±3.3°, R, 5.7° ±3.2° vs walk: L, 9.4° ± 2.3°, R 9.5° ± 2.0°, P < .05). The results of the present study showed that, in young asymptomatic participants with no known lumbopelvic hip pathology, the pelvic obliquity during the Trendelenburg Test and walking is similar. During the Single Leg Squat, the hip moved more in the sagittal plane and less in the coronal plane when compared with walking. There was more movement in the hip transverse plane movement during the Corkscrew Test than during walking. These results suggest that for the Trendelenburg Test to be

The Photospheric Footprints of Coronal Hole Jets

NASA Astrophysics Data System (ADS)

Muglach, Karin

2016-10-01

Coronal jets are transient, collimated ejections of plasma that are a common feature of solar X-ray and EUV image sequences. Of special interest are jets in coronal holes due to their possible contribution to the solar wind outflow. From a sample of 35 jet events I will investigate the photospheric signatures at the footpoints of these jets. White light images from the HMI on board SDO are used to derive the plane-of-sky flow field using local correlation tracking, and HMI magnetograms show the development of the magnetic flux. Both the evolution of the magnetic field and flows allow one to study the photospheric driver of these jets. One particularly interesting example demonstrates that the untwisting jet involves a tiny filament whose eruption is most likely triggered by the emergence of a small magnetic bipole close to one of its legs.

Determining the sagittal relationship between the maxilla and the mandible: a cephalometric analysis to clear up the confusion.

PubMed

Davis, Glen S; Cannon, James L; Messersmith, Marion L

2013-01-01

Establishing the sagittal jaw relationship is a key component to developing a diagnosis when treating an orthodontic patient. Several measurements, including the Wits Appraisal, ANB angle and nasion perpendicular have been and are currently used by practitioners to diagnose the sagittal jaw relationship. Unfortunately, all of these measurements have their limitations. The Cannon Analysis was created in an attempt to help overcome these limitations. One hundred untreated patients from the Vanderbilt University Medical Center database were selected, and their initial lateral cephalometric radiographs were digitally traced utilizing the Cannon Cephalometric Analysis. All of these patients had an orthognathic profile, a Class I occlusion and a good skeletal balance as judged by the authors. Normative values were established for the Cannon Analysis and then broken down by sex and age (8-11, 12-18, 19 and over). An example case was analyzed using the Cannon Analysis and several diagnostic scenarios were reviewed. The variance or difference between Porion to A Point (Po-A) and Porion to B Point (Po-B) was found to be 12.6 mm. This value remained relatively constant throughout life, with only slightly higher values for males versus females. The Cannon Analysis is an effective way to accurately establish the sagittal jaw relationship since it is not affected by the anterior / posterior position of nasion, the steepness of the mandibular plane angle, nor an improperly drawn occlusal plane.

Geometrical Properties of Coronal Mass Ejections

NASA Astrophysics Data System (ADS)

Cremades, Hebe; Bothmer, Volker

Based on the SOHO/LASCO dataset, a collection of "structured" coronal mass ejections (CMEs) has been compiled within the period 1996-2002, in order to analyze their three-dimensional configuration. These CME events exhibit white-light fine structures, likely indicative of their possible 3D topology. From a detailed investigation of the associated low coronal and photospheric source regions, a generic scheme has been deduced, which considers the white-light topology of a CME projected in the plane of the sky as being primarily dependent on the orientation and position of the source region's neutral line on the solar disk. The obtained results imply that structured CMEs are essentially organized along a symmetry axis, in a cylindrical manner. The measured dimensions of the cylinder's base and length yield a ratio of 1.6. These CMEs seem to be better approximated by elliptic cones, rather than by the classical ice cream cone, characterized by a circular cross section.

Analysis of sagittal spinopelvic parameters in achondroplasia.

PubMed

Hong, Jae-Young; Suh, Seung-Woo; Modi, Hitesh N; Park, Jong-Woong; Park, Jung-Ho

2011-08-15

Prospective radiological analysis of patients with achondroplasia. To analyze sagittal spinal alignment and pelvic orientation in achondroplasia patients. Knowledge of sagittal spinopelvic parameters is important for the treatment of achondroplasia, because they differ from those of the normal population and can induce pain. The study and control groups were composed of 32 achondroplasia patients and 24 healthy volunteers, respectively. All underwent lateral radiography of the whole spine including hip joints. The radiographic parameters examined were sacral slope (SS), pelvic tilt, pelvic incidence (PI), S1 overhang, thoracic kyphosis, T10-L2 kyphosis, lumbar lordosis (LL1, LL2), and sagittal balance. Statistical analysis was performed to identify significant differences between the two groups. In addition, correlations between parameters and symptoms were sought. Sagittal spinopelvic parameters, namely, pelvic tilt, pelvic incidence, S1 overhang, thoracic kyphosis, T10-L2 kyphosis, lumbar lordosis 1 and sagittal balance were found to be significantly different in the patient and control groups (P < 0.05). In addition, sagittal parameters were found to be related to each other in the patient group (P < 0.05), that is, PI was related to SS and pelvic tilt, and LL was related to thoracic kyphosis. Furthermore, in terms of relations between spinal and pelvic parameters, LL was related to SS and PI, and sagittal balance was related to SS and PI. Furthermore, LL and T10-L2 kyphosis were found to be related to pain (P < 0.05), whereas no other parameter was found to be related to VAS scores. Sagittal parameters and possible relationships between sagittal parameters and symptoms were found to be significantly different in achondroplasia patients and normal healthy controls. The present study shows that sagittal spinal and pelvic parameters can assist the treatment of spinal disorders in achondroplasia patients.

Modification of the sagittal split osteotomy of the mandibular ramus: mobilizing vertical osteotomy of the internal ramus segment.

PubMed

Ricard, Daniel; Ferri, Joël

2009-08-01

We describe a new surgical procedure to improve stability when counterclockwise rotation of the maxillomandibular complex and the occlusal plane is intended. This preliminary prospective study evaluated 10 patients (8 female patients and 2 male patients) who each underwent maxillomandibular surgical advancement with counterclockwise rotation of the occlusal plane. A mandibular counterclockwise rotation was done in all cases with bilateral ramus sagittal split osteotomy. After the split of the ramus had been completed, a vertical osteotomy was done distally to the second molar on the internal ramus segment. With the completion of this vertical osteotomy, the internal ramus segment became completely mobile. All osteotomies were stabilized with rigid internal fixation by use of plates with monocortical screws. Ten patients have been treated with the "mobilizing vertical osteotomy of the internal ramus segment." The mean reduction of the occlusal plane angle was 10.1 degrees , showing a substantial counterclockwise rotation of the maxillomandibular complex. All patients had significant improvement of their facial balance. After a 1-year follow-up period, all cases but 1 showed very good stability of their occlusion and occlusal plane angle. An 11.4% relapse of the forward movement of the mandible was noted. On the basis of this prospective study, we conclude that when performing a counterclockwise rotation of the maxillomandibular complex, the mobilizing vertical osteotomy of the internal ramus segment combined with the sagittal split osteotomy of the mandible potentially enhances the occlusal plane angle and occlusal stability after a 1-year period.

Temporal lobe anatomy: eight imaging signs to facilitate interpretation of MRI.

PubMed

Lehman, Vance T; Black, David F; Bernstein, Matt A; Welker, Kirk M

2016-05-01

The temporal lobe is anatomically and functionally complex. However, relatively few radiologic signs are described to facilitate recognition of temporal lobe sulci and gyri in clinical practice. We devised and tested 8 radiologic signs of temporal lobe anatomy. Images from volumetric magnetization-prepared rapid gradient-echo imaging were analyzed of 100 temporal lobes from 26 female and 24 male patients. Patient age ranged from 1 to 79 years (mean 19 years; standard deviation 16 years). Standardized axial, coronal, and sagittal planes were evaluated and cross-referenced. Eight signs to delineate the superior temporal gyrus, Heschl gyrus (HG), parahippocampal gyrus, rhinal sulcus, collateral sulcus proper, or the occipitotemporal sulcus, or a combination, were evaluated in the sagittal or axial plane. Two neuroradiologists independently evaluated each sign; the sign was considered present only with positive reader agreement. All 8 signs were present in most patients. The most frequent signs were the posterior insular corner to identify HG in the axial plane (100 %), pointed STG to identify STG in the axial plane (98 %), and parahippocampal Y to identify the posterior parahippocampal gyrus in the sagittal plane (98 %). The frequencies were similar between the right and left cerebral hemispheres. Temporal lobe gyri and sulci can be reliably identified in multiple planes using anatomic signs.

Sagittal crest formation in great apes and gibbons.

PubMed

Balolia, Katharine L; Soligo, Christophe; Wood, Bernard

2017-06-01

The frequency of sagittal crest expression and patterns of sagittal crest growth and development have been documented in hominoids, including some extinct hominin taxa, and the more frequent expression of the sagittal crest in males has been traditionally linked with the need for larger-bodied individuals to have enough attachment area for the temporalis muscle. In the present study, we investigate sagittal cresting in a dentally mature sample of four hominoid taxa (Pan troglodytes schweinfurthii, Gorilla gorilla gorilla, Pongo pygmaeus pygmaeus and Hylobates lar). We investigate whether sagittal crest size increases with age beyond dental maturity in males and females of G. g. gorilla and Po. pyg. pygmaeus, and whether these taxa show sex differences in the timing of sagittal crest development. We evaluate the hypothesis that the larger sagittal crest of males may not be solely due to the requirement for a larger surface area than the un-crested cranial vault can provide for the attachment of the temporalis muscle, and present data on sex differences in temporalis muscle attachment area and sagittal crest size relative to cranial size. Gorilla g. gorilla and Po. pyg. pygmaeus males show significant relationships between tooth wear rank and sagittal crest size, and they show sagittal crest size differences between age groups that are not found in females. The sagittal crest emerges in early adulthood in the majority of G. g. gorilla males, whereas the percentage of G. g. gorilla females possessing a sagittal crest increases more gradually. Pongo pyg. pygmaeus males experience a three-fold increase in the number of specimens exhibiting a sagittal crest in mid-adulthood, consistent with a secondary growth spurt. Gorilla g. gorilla and Po. pyg. pygmaeus show significant sex differences in the size of the temporalis muscle attachment area, relative to cranial size, with males of both taxa showing positive allometry not shown in females. Gorilla g

LIMITED HIP AND KNEE FLEXION DURING LANDING IS ASSOCIATED WITH INCREASED FRONTAL PLANE KNEE MOTION AND MOMENTS

PubMed Central

Pollard, Christine D.; Sigward, Susan M.; Powers, Christopher M.

2009-01-01

Background It has been proposed that female athletes who limit knee and hip flexion during athletic tasks rely more on the passive restraints in the frontal plane to deceleration their body center of mass. This biomechanical pattern is thought to increase the risk for anterior cruciate ligament injury. To date, the relationship between sagittal plane kinematics and frontal plane knee motion and moments has not been explored. Methods Subjects consisted of fifty-eight female club soccer players (age range: 11 to 20 years) with no history of knee injury. Kinematics, ground reaction forces, and surface electromyography were collected while each subject performed a drop landing task. Subjects were divided into two groups based on combined sagittal plane knee and hip flexion angles during the deceleration phase of landing (high flexion and low flexion). Findings Subjects in the low flexion group demonstrated increased knee valgus angles (P = 0.02, effect size 0.27), increased knee adductor moments (P = 0.03, effect size 0.24), decreased energy absorption at the knee and hip (P = 0.02, effect size 0.25; and P< 0.001, effect size 0.59), and increased vastus lateralis EMG when compared to subjects in the high flexion group (P = 0.005, effect size 0.35). Interpretation Female athletes with limited sagittal plane motion during landing exhibit a biomechanical profile that may put these individuals at greater risk for anterior cruciate ligament injury. PMID:19913961

The effect of age on sagittal plane profile of the lumbar spine according to standing, supine, and various sitting positions

PubMed Central

2014-01-01

Background The sagittal alignment of the spine changes depending on body posture and degenerative changes. This study aimed to observe changes in sagittal alignment of the lumbar spine with different positions (standing, supine, and various sitting postures) and to verify the effect of aging on lumbar sagittal alignment. Methods Whole-spine lateral radiographs were obtained for young volunteers (25.4 ± 2.3 years) and elderly volunteers (66.7 ± 1.7 years). Radiographs were obtained in standing, supine, and sitting (30°, 60°, and 90°) positions respectively. We compared the radiological changes in the lordotic and segmental angles in different body positions and at different ages. Upper and lower lumbar lordosis were defined according to differences in anatomical sagittal mobility and kinematic behavior. Results Lumbar lordosis was greater in a standing position (52.79° and 53.90° in young and old groups, respectively) and tended to decrease as position changed from supine to sitting. Compared with the younger group, the older group showed significantly more lumbar lordosis in supine and 60° and 90° sitting positions (P = 0.043, 0.002, 0.011). Upper lumbar lordosis in the younger group changed dynamically in all changed positions compared with the old group (P = 0.019). Lower lumbar lordosis showed a decreasing pattern in both age groups, significantly changing as position changed from 30° to 60° (P = 0.007, 0.007). Conclusions Lumbar lordosis decreases as position changes from standing to 90°sitting. The upper lumbar spine is more flexible in individuals in their twenties compared to those in their sixties. Changes in lumbar lordosis were concentrated in the lower lumbar region in the older group in sitting positions. PMID:24571953

Effects of myofascial release leg pull and sagittal plane isometric contract-relax techniques on passive straight-leg raise angle.

PubMed

Hanten, W P; Chandler, S D

1994-09-01

Experimental evidence does not currently exist to support the claims of clinical effectiveness for myofascial release techniques. This presents an obvious need to document the effects of myofascial release. The purpose of this study was to compare the effects of two techniques, sagittal plane isometric contract-relax and myofascial release leg pull for increasing hip flexion range of motion (ROM) as measured by the angle of passive straight-leg raise. Seventy-five nondisabled, female subjects 18-29 years of age were randomly assigned to contract-relax, leg pull, or control groups. Pretest hip flexion ROM was measured for each subject's right hip with a passive straight-leg raise test using a fluid-filled goniometer. Subjects in the treatment groups received either contract-relax or leg pull treatment applied to the right lower extremity; subjects in the control group remained supine quietly for 5 minutes. Following treatment, posttest straight-leg raise measurements were performed. A one-way analysis of variance followed by a Newman-Keuls post hoc comparison of mean gain scores showed that subjects receiving contract-relax treatment increased their ROM significantly more than those who received leg pull treatment, and the increase in ROM of subjects in both treatment groups was significantly higher than those of the control group. The results suggest that while both contract-relax and leg pull techniques can significantly increase hip flexion ROM in normal subjects, contract-relax treatment may be more effective and efficient than leg pull treatment.

Fast cine-magnetic resonance imaging point tracking for prostate cancer radiation therapy planning

NASA Astrophysics Data System (ADS)

Dowling, J.; Dang, K.; Fox, Chris D.; Chandra, S.; Gill, Suki; Kron, T.; Pham, D.; Foroudi, F.

2014-03-01

The analysis of intra-fraction organ motion is important for improving the precision of radiation therapy treatment delivery. One method to quantify this motion is for one or more observers to manually identify anatomic points of interest (POIs) on each slice of a cine-MRI sequence. However this is labour intensive and inter- and intra- observer variation can introduce uncertainty. In this paper a fast method for non-rigid registration based point tracking in cine-MRI sagittal and coronal series is described which identifies POIs in 0.98 seconds per sagittal slice and 1.35 seconds per coronal slice. The manual and automatic points were highly correlated (r>0.99, p<0.001) for all organs and the difference generally less than 1mm. For prostate planning peristalsis and rectal gas can result in unpredictable out of plane motion, suggesting the results may require manual verification.

CORONAL FOURIER POWER SPECTRA: IMPLICATIONS FOR CORONAL SEISMOLOGY AND CORONAL HEATING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ireland, J.; McAteer, R. T. J.; Inglis, A. R., E-mail: jack.ireland@nasa.gov

The dynamics of regions of the solar corona are investigated using Atmospheric Imaging Assembly 171 Å and 193 Å data. The coronal emission from the quiet Sun, coronal loop footprints, coronal moss, and from above a sunspot is studied. It is shown that the mean Fourier power spectra in these regions can be described by a power law at lower frequencies that tails to a flat spectrum at higher frequencies, plus a Gaussian-shaped contribution that varies depending on the region studied. This Fourier spectral shape is in contrast to the commonly held assumption that coronal time series are well describedmore » by the sum of a long timescale background trend plus Gaussian-distributed noise, with some specific locations also showing an oscillatory signal. The implications of the observed spectral shape on the fields of coronal seismology and the automated detection of oscillations in the corona are discussed. The power-law contribution to the shape of the Fourier power spectrum is interpreted as being due to the summation of a distribution of exponentially decaying emission events along the line of sight. This is consistent with the idea that the solar atmosphere is heated everywhere by small energy deposition events.« less

Computer-assisted shape descriptors for skull morphology in craniosynostosis.

PubMed

Shim, Kyu Won; Lee, Min Jin; Lee, Myung Chul; Park, Eun Kyung; Kim, Dong Seok; Hong, Helen; Kim, Yong Oock

2016-03-01

Our aim was to develop a novel method for characterizing common skull deformities with high sensitivity and specificity, based on two-dimensional (2D) shape descriptors in computed tomography (CT) images. Between 2003 and 2014, 44 normal subjects and 39 infants with craniosynostosis (sagittal, 29; bicoronal, 10) enrolled for analysis. Mean age overall was 16 months (range, 1-120 months), with a male:female ratio of 56:29. Two reference planes, sagittal (S-plane: through top of lateral ventricle) and coronal (C-plane: at maximum dimension of fourth ventricle), were utilized to formulate three 2D shape descriptors (cranial index [CI], cranial radius index [CR], and cranial extreme spot index [CES]), which were then applied to S- and C-plane target images of both groups. In infants with sagittal craniosynostosis, CI in S-plane (S-CI) usually was <1.0 (mean, 0.78; range, 0.67-0.95), with CR consistently at 3 and a characteristic CES pattern of two discrete hot spots oriented diagonally. In the bicoronal craniosynostosis subset, CI was >1.0 (mean 1.11; range, 1.04-1.25), with CR at -3 and a CES pattern of four discrete diagonally oriented hot spots. Scatter plots underscored the highly intuitive joint performance of CI and CES in distinguishing normal and deformed states. Altogether, these novel 2D shape descriptors enabled effective discrimination of sagittal and bicoronal skull deformities. Newly developed 2D shape descriptors for cranial CT imaging enabled recognition of common skull deformities with statistical significance, perhaps providing impetus for automated CT-based diagnosis of craniosynostosis.

The size of the supraspinatus outlet during elevation of the arm in the frontal and sagittal plane: a 3-D model study.

PubMed

Meskers, Carel G M; van der Helm, Frans C T; Rozing, Piet M

2002-05-01

To quantify the size of the supraspinatus outlet as it is dictated by both the three-dimensional geometry of the shoulder and the relative orientation of the humerus with respect to the scapula during motions of the arm. Previously obtained data of shoulder kinematics were brought into a geometrical model of the shoulder, derived from a cadaver study. Knowledge of the parameters dictating the size of the supraspinatus outlet is essential for a better understanding of the impingement syndrome of the shoulder. A geometrical model, based on fitting spheres to various anatomical items of the shoulder was derived from three-dimensional position data of the gleno-humeral joint and coraco-acromial arch of 32 cadaver shoulders. Kinematical data were collected from 10 healthy volunteers. The geometrical and kinematical data were combined to study the supraspinatus outlet during elevation of the humerus in the frontal and sagittal plane. No single geometry parameter correlated significantly with the initial size of the outlet. During arm elevation, the greater tuberosity was moved away from the coraco-acromial arch quite effectively resulting in narrowing of the outlet during elevation in the frontal plane from 60 degrees to 120 degrees only. Deviations from the average were quite substantial. This was caused by kinematical and especially geometrical variability. The size of the outlet is dictated by both the geometry and kinematics of the gleno-humeral joint. Assessment of the individual susceptibility to impingement requires three-dimensional viewing techniques including three-dimensional movements of both the scapula and humerus. Little is known about etiology and pathogenesis of various shoulder disorders such as the impingement syndrome. The supraspinatus outlet plays probably a key role. More knowledge on the architecture of the outlet is required for a better understanding.

CT of facet distraction in flexion injuries of the thoracolumbar spine: the "naked" facet.

PubMed

O'Callaghan, J P; Ullrich, C G; Yuan, H A; Kieffer, S A

1980-03-01

Vertical distraction of the articular processes is an important sign of ligamentous disruption due to flexion injuries of the thoracolumbar spine. In addition to illustrating this finding in cross section (the "naked" facet), computed tomography in the transaxial plane allows assessment of the presence and position of fracture fragments that may encroach on the spinal canal. Image reconstruction in sagittal and coronal planes provides a clear demonstration of the degree of bony compression, facet distraction, and kyphosis associated with flexion injuries without additional patient manipulation or radiation exposure.

Improved access and visibility during stapling of the ultra-low rectum: a comparative human cadaver study between two curved staplers

PubMed Central

2012-01-01

Background The purpose of this study was to compare in human cadavers the applicability of a commonly used stapling device, the CONTOUR® curved cutter (CC) (Ethicon Endo-Surgery, Cincinnati, OH) to a newly released, curved stapler, the Endo GIA™ Radial Reload with Tri-Staple™ Technology (RR) (Covidien, New Haven, CT) Methods Four experienced surgeons performed deep pelvic dissection with total mesorectal excision (TME) of the rectum in twelve randomized male cadavers. Both stapling devices were applied to the ultra-low rectum in coronal and sagittal configurations. Extensive measurements were recorded of anatomic landmarks for each cadaver pelvis along with various aspects of access, visibility, and ease of placement for each device. Results The RR reached significantly lower into the pelvis in both the coronal and sagittal positions compared to the CC. The median distance from the pelvic floor was 1.0 cm compared to 2.0 cm in the coronal position, and 1.0 cm versus 3.3 cm placed sagitally, p < 0.0001. Surgeons gave a higher visibility rating with less visual impediment in the sagittal plane using the RR Stapler. Impediment of visibility occurred in only 10% (5/48) of RR applications in the coronal position, compared to a rate of 48% (23/48) using the CC, p = 0.0002. Conclusions The RR device performed significantly better when compared to the CC stapler in regards to placing the stapler further into the deep pelvis and closer to the pelvic floor, while causing less obstructing of visualization. PMID:23148602

Super-resolution reconstruction in frequency, image, and wavelet domains to reduce through-plane partial voluming in MRI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gholipour, Ali, E-mail: ali.gholipour@childrens.harvard.edu; Afacan, Onur; Scherrer, Benoit

Purpose: To compare and evaluate the use of super-resolution reconstruction (SRR), in frequency, image, and wavelet domains, to reduce through-plane partial voluming effects in magnetic resonance imaging. Methods: The reconstruction of an isotropic high-resolution image from multiple thick-slice scans has been investigated through techniques in frequency, image, and wavelet domains. Experiments were carried out with thick-slice T2-weighted fast spin echo sequence on the Academic College of Radiology MRI phantom, where the reconstructed images were compared to a reference high-resolution scan using peak signal-to-noise ratio (PSNR), structural similarity image metric (SSIM), mutual information (MI), and the mean absolute error (MAE) ofmore » image intensity profiles. The application of super-resolution reconstruction was then examined in retrospective processing of clinical neuroimages of ten pediatric patients with tuberous sclerosis complex (TSC) to reduce through-plane partial voluming for improved 3D delineation and visualization of thin radial bands of white matter abnormalities. Results: Quantitative evaluation results show improvements in all evaluation metrics through super-resolution reconstruction in the frequency, image, and wavelet domains, with the highest values obtained from SRR in the image domain. The metric values for image-domain SRR versus the original axial, coronal, and sagittal images were PSNR = 32.26 vs 32.22, 32.16, 30.65; SSIM = 0.931 vs 0.922, 0.924, 0.918; MI = 0.871 vs 0.842, 0.844, 0.831; and MAE = 5.38 vs 7.34, 7.06, 6.19. All similarity metrics showed high correlations with expert ranking of image resolution with MI showing the highest correlation at 0.943. Qualitative assessment of the neuroimages of ten TSC patients through in-plane and out-of-plane visualization of structures showed the extent of partial voluming effect in a real clinical scenario and its reduction using SRR. Blinded expert evaluation of image

Super-resolution reconstruction in frequency, image, and wavelet domains to reduce through-plane partial voluming in MRI

PubMed Central

Gholipour, Ali; Afacan, Onur; Aganj, Iman; Scherrer, Benoit; Prabhu, Sanjay P.; Sahin, Mustafa; Warfield, Simon K.

2015-01-01

Purpose: To compare and evaluate the use of super-resolution reconstruction (SRR), in frequency, image, and wavelet domains, to reduce through-plane partial voluming effects in magnetic resonance imaging. Methods: The reconstruction of an isotropic high-resolution image from multiple thick-slice scans has been investigated through techniques in frequency, image, and wavelet domains. Experiments were carried out with thick-slice T2-weighted fast spin echo sequence on the Academic College of Radiology MRI phantom, where the reconstructed images were compared to a reference high-resolution scan using peak signal-to-noise ratio (PSNR), structural similarity image metric (SSIM), mutual information (MI), and the mean absolute error (MAE) of image intensity profiles. The application of super-resolution reconstruction was then examined in retrospective processing of clinical neuroimages of ten pediatric patients with tuberous sclerosis complex (TSC) to reduce through-plane partial voluming for improved 3D delineation and visualization of thin radial bands of white matter abnormalities. Results: Quantitative evaluation results show improvements in all evaluation metrics through super-resolution reconstruction in the frequency, image, and wavelet domains, with the highest values obtained from SRR in the image domain. The metric values for image-domain SRR versus the original axial, coronal, and sagittal images were PSNR = 32.26 vs 32.22, 32.16, 30.65; SSIM = 0.931 vs 0.922, 0.924, 0.918; MI = 0.871 vs 0.842, 0.844, 0.831; and MAE = 5.38 vs 7.34, 7.06, 6.19. All similarity metrics showed high correlations with expert ranking of image resolution with MI showing the highest correlation at 0.943. Qualitative assessment of the neuroimages of ten TSC patients through in-plane and out-of-plane visualization of structures showed the extent of partial voluming effect in a real clinical scenario and its reduction using SRR. Blinded expert evaluation of image resolution in

Super-resolution reconstruction in frequency, image, and wavelet domains to reduce through-plane partial voluming in MRI.

PubMed

Gholipour, Ali; Afacan, Onur; Aganj, Iman; Scherrer, Benoit; Prabhu, Sanjay P; Sahin, Mustafa; Warfield, Simon K

2015-12-01

To compare and evaluate the use of super-resolution reconstruction (SRR), in frequency, image, and wavelet domains, to reduce through-plane partial voluming effects in magnetic resonance imaging. The reconstruction of an isotropic high-resolution image from multiple thick-slice scans has been investigated through techniques in frequency, image, and wavelet domains. Experiments were carried out with thick-slice T2-weighted fast spin echo sequence on the Academic College of Radiology MRI phantom, where the reconstructed images were compared to a reference high-resolution scan using peak signal-to-noise ratio (PSNR), structural similarity image metric (SSIM), mutual information (MI), and the mean absolute error (MAE) of image intensity profiles. The application of super-resolution reconstruction was then examined in retrospective processing of clinical neuroimages of ten pediatric patients with tuberous sclerosis complex (TSC) to reduce through-plane partial voluming for improved 3D delineation and visualization of thin radial bands of white matter abnormalities. Quantitative evaluation results show improvements in all evaluation metrics through super-resolution reconstruction in the frequency, image, and wavelet domains, with the highest values obtained from SRR in the image domain. The metric values for image-domain SRR versus the original axial, coronal, and sagittal images were PSNR = 32.26 vs 32.22, 32.16, 30.65; SSIM = 0.931 vs 0.922, 0.924, 0.918; MI = 0.871 vs 0.842, 0.844, 0.831; and MAE = 5.38 vs 7.34, 7.06, 6.19. All similarity metrics showed high correlations with expert ranking of image resolution with MI showing the highest correlation at 0.943. Qualitative assessment of the neuroimages of ten TSC patients through in-plane and out-of-plane visualization of structures showed the extent of partial voluming effect in a real clinical scenario and its reduction using SRR. Blinded expert evaluation of image resolution in resampled out-of-plane

Image-based reconstruction of the Newtonian dynamics of solar coronal ejecta

NASA Astrophysics Data System (ADS)

Uritsky, Vadim M.; Thompson, Barbara J.

2016-10-01

We present a new methodology for analyzing rising and falling dynamics of unstable coronal material as represented by high-cadence SDO AIA images. The technique involves an adaptive spatiotemporal tracking of propagating intensity gradients and their characterization in terms of time-evolving areas swept out by the position vector originated from the Sun disk center. The measured values of the areal velocity and acceleration are used to obtain quantitative information on the angular momentum and acceleration along the paths of the rising and falling coronal plasma. In the absence of other forces, solar gravitation results in purely ballistic motions consistent with the Kepler's second law; non-central forces such as the Lorentz force introduce non-zero torques resulting in more complex motions. The developed algorithms enable direct evaluation of the line-of-sight component of the net torque applied to a unit mass of the ejected coronal material which is proportional to the image-plane projection of the observed areal acceleration. The current implementation of the method cannot reliably distinguish torque modulations caused by the coronal force field from those imposed by abrupt changes of plasma mass density and nontrivial projection effects. However, it can provide valid observational constraints on the evolution of large-scale unstable magnetic topologies driving major solar-coronal eruptions as demonstrated in the related talk by B. Thompson et al.

Spinal sagittal imbalance in patients with lumbar disc herniation: its spinopelvic characteristics, strength changes of the spinal musculature and natural history after lumbar discectomy.

PubMed

Liang, Chen; Sun, Jianmin; Cui, Xingang; Jiang, Zhensong; Zhang, Wen; Li, Tao

2016-07-22

Spinal sagittal imbalance is a widely acknowledged problem, but there is insufficient knowledge regarding its occurrence. In some patients with lumbar disc herniation (LDH), their symptom is similar to spinal sagittal imbalance. The aim of this study is to illustrate the spinopelvic sagittal characteristics and identity the role of spinal musculature in the mechanism of sagittal imbalance in patients with LDH. Twenty-five adults with spinal sagittal imbalance who initially came to our clinic for treatment of LDH, followed by posterior discectomy were reviewed. The horizontal distance between C7 plumb line-sagittal vertical axis (C7PL-SVA) greater than 5 cm anteriorly with forward bending posture is considered as spinal sagittal imbalance. Radiographic parameters including thoracic kyphotic angle (TK), lumbar lordotic angle (LL), pelvic tilting angle (PT), sacral slope angle (SS) and an electromyography(EMG) index 'the largest recruitment order' were recorded and compared. All patients restored coronal and sagittal balance immediately after lumbar discectomy. The mean C7PL-SVA and trunk shift value decreased from (11.6 ± 6.6 cm, and 2.9 ± 6.1 cm) preoperatively to (-0.5 ± 2.6 cm and 0.2 ± 0.5 cm) postoperatively, while preoperative LL and SS increased from (25.3° ± 14.0° and 25.6° ± 9.5°) to (42.4° ± 10.2° and 30.4° ± 8.7°) after surgery (P < 0.05). The preoperative mean TK and PT (24.7° ± 11.3° and 20.7° ± 7.8°) decreased to (22.0° ± 9.8° and 15.8 ± 5.5°) postoperatively (P < 0.05). The largest recruitment order on the level of T7-T8, T12-L1 and the herniated level all improved compared with before and after surgery (P < 0.05). All patients have been followed up for more than 2 years. The mean ODI was 77.8 % before surgery to 4.2 % at the final follow-up. Spinal sagittal imbalance caused by LDH is one type of compensatory sagittal imbalance. Compensatory mechanism of

Length and Geometric Patterns of the Greater Palatine Canal Observed in Cone Beam Computed Tomography

PubMed Central

Howard-Swirzinski, Karen; Edwards, Paul C.; Saini, Tarnjit S.; Norton, Neil S.

2010-01-01

The greater palatine canal is an important anatomical structure that is often utilized as a pathway for infiltration of local anesthesia to affect sensation and hemostasis. Increased awareness of the length and anatomic variation in the anatomy of this structure is important when performing surgical procedures in this area (e.g., placement of osseointegrated dental implants). We examined the anatomy of the greater palatine canal using data obtained from CBCT scans of 500 subjects. Both right and left canals were viewed (N = 1000) in coronal and sagittal planes, and their paths and lengths determined. The average length of the greater palatine canal was 29 mm (±3 mm), with a range from 22 to 40 mm. Coronally, the most common anatomic pattern consisted of the canal traveling inferior-laterally for a distance then directly inferior for the remainder (43.3%). In the sagittal view, the canal traveled most frequently at an anterior-inferior angle (92.9%). PMID:20871845

[Usefulness of curved coronal MPR imaging for the diagnosis of cervical radiculopathy].

PubMed

Inukai, Chikage; Inukai, Takashi; Matsuo, Naoki; Shimizu, Ikuo; Goto, Hisaharu; Takagi, Teruhide; Takayasu, Masakazu

2010-03-01

In surgical treatment of cervical radiculopathy, localization of the responsible lesions by various imaging modalities is essential. Among them, MRI is non-invasive and plays a primary role in the assessment of spinal radicular symptoms. However, demonstration of nerve root compression is sometimes difficult by the conventional methods of MRI, such as T1 weighted (T1W) and T2 weighted (T2W) sagittal or axial images. We have applied a new technique of curved coronal multiplanar reconstruction (MPR) imaging for the diagnosis of cervical radiculopathy. Ten patients (4 male, 6 female) with ages between 31 and 79 year-old, who had clinical diagnosis of cervical radiculopathy, were included in this study. Seven patients underwent anterior key-hole foraminotomy to decompress the nerve root with successful results. All the patients had 3D MRI studies, such as true fast imaging with steady-state precession (FISP), 3DT2W sampling perfection with application optimized contrasts using different fillip angle evolution (SPACE), and 3D multi-echo data image combination (MEDIC) imagings in addition to the routine MRI (1.5 T Avanto, Siemens, Germany) with a phased array coil. The curved coronal MPR images were produced from these MRI data using a workstation. The nerve root compression was diagnosed by curved coronal MPR images in all the patients. The compression sites were compatible with those of the operative findings in 7 patients, who underwent surgical treatment. The MEDIC imagings were the most demonstrable to visualize the nerve root, while the 3D-space imagings were the next. The curved coronal MPR imaging is useful for the diagnosis of accurate localization of the compressing lesions in patients with cervical radiculopathy.

Effect of scaling and root planing on alveolar bone as measured by subtraction radiography.

PubMed

Hwang, You-Jeong; Fien, Matthew Jonas; Lee, Sam-Sun; Kim, Tae-Il; Seol, Yang-Jo; Lee, Yong-Moo; Ku, Young; Rhyu, In-Chul; Chung, Chong-Pyoung; Han, Soo-Boo

2008-09-01

Scaling and root planing of diseased periodontal pockets is fundamental to the treatment of periodontal disease. Although various clinical parameters have been used to assess the efficacy of this therapy, radiographic analysis of changes in bone density following scaling and root planing has not been extensively researched. In this study, digital subtraction radiography was used to analyze changes that occurred in the periodontal hard tissues following scaling and root planing. Thirteen subjects with a total of 39 sites that presented with >3 mm of vertical bone loss were included in this study. Clinical examinations were performed and radiographs were taken prior to treatment and were repeated 6 months following scaling and root planing. Radiographic analysis was performed with computer-assisted radiographic evaluation software. Three regions of interest (ROI) were defined as the most coronal, middle, and apical portions of each defect. A fourth ROI was used for each site as a control region and was placed at a distant, untreated area. Statistical analysis was carried out to evaluate changes in the mean gray level at the coronal, middle, and apical region of each treated defect. Digital subtraction radiography revealed an increase in radiographic density in 101 of the 117 test regions (83.3%). A 256 gray level was used, and a value >128 was assumed to represent a density gain in the ROI. The average gray level increase was 18.65. Although the coronal, middle, and apical regions displayed increases in bone density throughout this study, the bone density of the apical ROI (gray level = 151.27 +/- 20.62) increased significantly more than the bone density of the coronal ROI (gray level = 139.19 +/- 21.78). A significant increase in bone density was seen in probing depths >5 mm compared to those <5 mm in depth. No significant difference was found with regard to bone-density changes surrounding single- versus multiple-rooted teeth. Scaling and root planing of diseased

Evaluating Uncertainties in Coronal Electron Temperature and Radial Speed Measurements Using a Simulation of the Bastille Day Eruption

NASA Astrophysics Data System (ADS)

Reginald, Nelson; St. Cyr, Orville; Davila, Joseph; Rastaetter, Lutz; Török, Tibor

2018-05-01

Obtaining reliable measurements of plasma parameters in the Sun's corona remains an important challenge for solar physics. We previously presented a method for producing maps of electron temperature and speed of the solar corona using K-corona brightness measurements made through four color filters in visible light, which were tested for their accuracies using models of a structured, yet steady corona. In this article we test the same technique using a coronal model of the Bastille Day (14 July 2000) coronal mass ejection, which also contains quiet areas and streamers. We use the coronal electron density, temperature, and flow speed contained in the model to determine two K-coronal brightness ratios at (410.3, 390.0 nm) and (423.3, 398.7 nm) along more than 4000 lines of sight. Now assuming that for real observations, the only information we have for each line of sight are these two K-coronal brightness ratios, we use a spherically symmetric model of the corona that contains no structures to interpret these two ratios for electron temperature and speed. We then compare the interpreted (or measured) values for each line of sight with the true values from the model at the plane of the sky for that same line of sight to determine the magnitude of the errors. We show that the measured values closely match the true values in quiet areas. However, in locations of coronal structures, the measured values are predictably underestimated or overestimated compared to the true values, but can nevertheless be used to determine the positions of the structures with respect to the plane of the sky, in front or behind. Based on our results, we propose that future white-light coronagraphs be equipped to image the corona using four color filters in order to routinely create coronal maps of electron density, temperature, and flow speed.

Ambulant adults with spastic cerebral palsy: the validity of lower limb joint angle measurements from sagittal video recordings.

PubMed

Larsen, Kerstin L; Maanum, Grethe; Frøslie, Kathrine F; Jahnsen, Reidun

2012-02-01

In the development of a clinical program for ambulant adults with cerebral palsy (CP), we investigated the validity of joint angles measured from sagittal video recordings and explored if movements in the transversal plane identified with three-dimensional gait analysis (3DGA) affected the validity of sagittal video joint angle measurements. Ten observers, and 10 persons with spastic CP (19-63 years), Gross Motor Function Classification System I-II, participated in the study. Concurrent criterion validity between video joint angle measurements and 3DGA was assessed by Bland-Altman plots with mean differences and 95% limits of agreement (LoA). Pearson's correlation coefficients (r) and scatter plots were used supplementary. Transversal kinematics ≥2 SD from our reference band were defined as increased movement in the transversal plane. The overall mean differences in degrees between joint angles measured by 3DGA and video recordings (3°, 5° and -7° for the hip, knee and ankle respectively) and corresponding LoA (18°, 10° and 15° for the hip, knee and ankle, respectively) demonstrated substantial discrepancies between the two methods. The correlations ranged from low (r=0.39) to moderate (r=0.68). Discrepancy between the two measurements was seen both among persons with and without the presence of deviating transversal kinematics. Quantifying lower limb joint angles from sagittal video recordings in ambulant adults with spastic CP demonstrated low validity, and should be conducted with caution. This gives implications for selecting evaluation method of gait. Copyright © 2011 Elsevier B.V. All rights reserved.

Does Tibial Slope Affect Perception of Coronal Alignment on a Standing Anteroposterior Radiograph?

PubMed

Schwartz, Adam J; Ravi, Bheeshma; Kransdorf, Mark J; Clarke, Henry D

2017-07-01

A standing anteroposterior (AP) radiograph is commonly used to evaluate coronal alignment following total knee arthroplasty (TKA). The impact of coronal alignment on TKA outcomes is controversial, perhaps due to variability in imaging and/or measurement technique. We sought to quantify the effect of image rotation and tibial slope on coronal alignment. Using a standard extramedullary tibial alignment guide, 3 cadaver legs were cut to accept a tibial tray at 0°, 3°, and 7° of slope. A computed tomography scan of the entire tibia was obtained for each specimen to confirm neutral coronal alignment. Images were then obtained at progressive 10° intervals of internal and external rotation up to 40° maximum in each direction. Images were then randomized and 5 blinded TKA surgeons were asked to determine coronal alignment. Continuous data values were transformed to categorical data (neutral [0], valgus [L], and varus [R]). Each 10° interval of external rotation of a 7° sloped tibial cut (or relative internal rotation of a tibial component viewed in the AP plane) resulted in perception of an additional 0.75° of varus. The slope of the proximal tibia bone cut should be taken into account when measuring coronal alignment on a standing AP radiograph. Copyright © 2017 Elsevier Inc. All rights reserved.

Image-optimized Coronal Magnetic Field Models

NASA Astrophysics Data System (ADS)

Jones, Shaela I.; Uritsky, Vadim; Davila, Joseph M.

2017-08-01

We have reported previously on a new method we are developing for using image-based information to improve global coronal magnetic field models. In that work, we presented early tests of the method, which proved its capability to improve global models based on flawed synoptic magnetograms, given excellent constraints on the field in the model volume. In this follow-up paper, we present the results of similar tests given field constraints of a nature that could realistically be obtained from quality white-light coronagraph images of the lower corona. We pay particular attention to difficulties associated with the line-of-sight projection of features outside of the assumed coronagraph image plane and the effect on the outcome of the optimization of errors in the localization of constraints. We find that substantial improvement in the model field can be achieved with these types of constraints, even when magnetic features in the images are located outside of the image plane.

Image-optimized Coronal Magnetic Field Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Shaela I.; Uritsky, Vadim; Davila, Joseph M., E-mail: shaela.i.jones-mecholsky@nasa.gov, E-mail: shaela.i.jonesmecholsky@nasa.gov

We have reported previously on a new method we are developing for using image-based information to improve global coronal magnetic field models. In that work, we presented early tests of the method, which proved its capability to improve global models based on flawed synoptic magnetograms, given excellent constraints on the field in the model volume. In this follow-up paper, we present the results of similar tests given field constraints of a nature that could realistically be obtained from quality white-light coronagraph images of the lower corona. We pay particular attention to difficulties associated with the line-of-sight projection of features outsidemore » of the assumed coronagraph image plane and the effect on the outcome of the optimization of errors in the localization of constraints. We find that substantial improvement in the model field can be achieved with these types of constraints, even when magnetic features in the images are located outside of the image plane.« less

Image-Optimized Coronal Magnetic Field Models

NASA Technical Reports Server (NTRS)

Jones, Shaela I.; Uritsky, Vadim; Davila, Joseph M.

2017-01-01

We have reported previously on a new method we are developing for using image-based information to improve global coronal magnetic field models. In that work we presented early tests of the method which proved its capability to improve global models based on flawed synoptic magnetograms, given excellent constraints on the field in the model volume. In this follow-up paper we present the results of similar tests given field constraints of a nature that could realistically be obtained from quality white-light coronagraph images of the lower corona. We pay particular attention to difficulties associated with the line-of-sight projection of features outside of the assumed coronagraph image plane, and the effect on the outcome of the optimization of errors in localization of constraints. We find that substantial improvement in the model field can be achieved with this type of constraints, even when magnetic features in the images are located outside of the image plane.

A gait retraining system using augmented-reality to modify footprint parameters: Effects on lower-limb sagittal-plane kinematics.

PubMed

Bennour, Sami; Ulrich, Baptiste; Legrand, Thomas; Jolles, Brigitte M; Favre, Julien

2018-01-03

Improving lower-limb flexion/extension angles during walking is important for the treatment of numerous pathologies. Currently, these gait retraining procedures are mostly qualitative, often based on visual assessment and oral instructions. This study aimed to propose an alternative method combining motion capture and display of target footprints on the floor. The second objectives were to determine the error in footprint modifications and the effects of footprint modifications on lower-limb flexion/extension angles. An augmented-reality system made of an optoelectronic motion capture device and video projectors displaying target footprints on the floor was designed. 10 young healthy subjects performed a series of 27 trials, consisting of increased and decreased amplitudes in stride length, step width and foot progression angle. 11 standard features were used to describe and compare lower-limb flexion/extension angles among footprint modifications. Subjects became accustomed to walk on target footprints in less than 10 min, with mean (± SD) precision of 0.020 ± 0.002 m in stride length, 0.022 ± 0.006 m in step width, and 2.7 ± 0.6° in progression angle. Modifying stride length had significant effects on 3/3 hip, 2/4 knee and 4/4 ankle features. Similarly, step width and progression angle modifications affected 2/3 and 1/3 hip, 2/4 and 1/4 knee as well as 3/4 and 2/4 ankle features, respectively. In conclusion, this study introduced an augmented-reality method allowing healthy subjects to modify their footprint parameters rapidly and precisely. Walking with modified footprints changed lower-limb sagittal-plane kinematics. Further research is needed to design rehabilitation protocols for specific pathologies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Coronal and Prominence Plasmas

NASA Technical Reports Server (NTRS)

Poland, Arthur I. (Editor)

1986-01-01

Various aspects of solar prominences and the solar corona are discussed. The formation of prominences, prominence diagnostics and structure, prominence dissappearance, large scale coronal structure, coronal diagnostics, small scale coronal structure, and non-equilibrium/coronal heating are among the topics covered.

Comparison of Precision between Optical and Electromagnetic Navigation Systems in Total Knee Arthroplasty

PubMed Central

Rhee, Seung Joon; Park, Shi Hwan; Cho, He Myung

2014-01-01

Purpose The purpose of this study is to compare and analyze the precision of optical and electromagnetic navigation systems in total knee arthroplasty (TKA). Materials and Methods We retrospectively reviewed 60 patients who underwent TKA using an optical navigation system and 60 patients who underwent TKA using an electromagnetic navigation system from June 2010 to March 2012. The mechanical axis that was measured on preoperative radiographs and by the intraoperative navigation systems were compared between the groups. The postoperative positions of the femoral and tibial components in the sagittal and coronal plane were assessed. Results The difference of the mechanical axis measured on the preoperative radiograph and by the intraoperative navigation systems was 0.6 degrees more varus in the electromagnetic navigation system group than in the optical navigation system group, but showed no statistically significant difference between the two groups (p>0.05). The positions of the femoral and tibial components in the sagittal and coronal planes on the postoperative radiographs also showed no statistically significant difference between the two groups (p>0.05). Conclusions In TKA, both optical and electromagnetic navigation systems showed high accuracy and reproducibility, and the measurements from the postoperative radiographs showed no significant difference between the two groups. PMID:25505703

Three dimensional ultrasonography for advanced neurosonography (Neurosofe-3d). Analysis of acquisition-related factors influencing the quality of the brain volumes.

PubMed

Maiz, Nerea; Alonso, Ignacio; Belar, María; Burgos, Jorge; Irasarri, Ana; Molina, Francisca S; de Paco, Catalina; Pijoan, José I; Plasencia, Walter; Rodó, Carlota; Rodríguez, M Angeles; Tajada, Mauricio; Tubau, Albert

2016-11-01

To evaluate the acquisition-related factors influencing the quality of the brain volumes for further study of advanced neurosonography. This was a prospective multicentre study. Five centres were asked to include five cases each, acquiring two volumes per case, at different gestational ages. Ten operators performed an advanced neurosonography per case. The potential influence of the following factors on the number of evaluable structures was assessed: vaginal/ abdominal acquisition, position of the head, gestational age, subjective quality of the volume and the acquiring operator itself. Four hundred and thirty-two evaluations were included in the study. A total of 80% of the structures were evaluated satisfactorily in the axial plane, 67.1% and 55.1% in the coronal and sagittal plane, respectively. Sagittal volumes acquired transvaginally had a better quality than those acquired transabdominally. Gestational age affected the quality of axial and sagittal volumes (p < 0.001), and the best quality was obtained between 20 and 27 weeks. In axial and sagittal volumes, the head position influenced the percentage of structures visualized (p < 0.001, p < 0.001). Factors affecting the quality of the volume for advanced neurosonography are gestational age, fetal head position, transvaginal acquisition in sagittal volumes, the acquiring operator and the subjective quality of the volume. © 2016 John Wiley & Sons, Ltd. © 2016 John Wiley & Sons, Ltd.

Retrograde lag screw placement in anterior acetabular column with regard to the anterior pelvic plane and midsagittal plane -- virtual mapping of 260 three-dimensional hemipelvises for quantitative anatomic analysis.

PubMed

Ochs, Bjoern Gunnar; Stuby, Fabian Maria; Ateschrang, Atesch; Stoeckle, Ulrich; Gonser, Christoph Emanuel

2014-10-01

Percutaneous screw placement can be used for minimally invasive treatment of none or minimally displaced fractures of the anterior column. The complex pelvic geometry can pose a major challenge even for experienced surgeons. The present study examined the preformed bone stock of the anterior column in 260 hemipelvises (130 male and 130 female). Screws were virtually implanted using iPlan(®) CMF (BrainLAB AG, Feldkirchen, Germany); the maximal implant length and the maximal implant diameter were assessed. The study showed, that 6.5mm can generally be used in men; in women however individual planning is essential in regard to the maximal implant diameter since we found that in 15.4% of women, screws with a diameter less than 6.5mm were necessary. The virtual analysis of the preformed bone stock corridor of the anterior column showed two constrictions of crucial clinical importance. These can be found after 18% and 55% (men) respectively 16% and 55% (women) measured from the entry point along the axis of the implant. The entry point of the retrograde anterior column screw in our collective was located lateral of tuberculum pubicum at the level of the superior-medial margin of foramen obturatum. In female patients, the entry point was located significantly more lateral of symphysis and closer to the cranial margin of ramus superior ossis pubis. The mean angle between the screw trajectory and the anterior pelvic plane in sagittal section was 31.6 ± 5.5°, the mean angle between the screw trajectory and the midsagittal plane in axial section was 55.9 ± 4.6° and the mean angle between the screw trajectory and the midsagittal plane in coronal section was 42.1 ± 3.9° with no significant deviation between both sexes. The individual angles formed by the screw trajectory and the anterior pelvic and midsagittal plane are independent from anthropometric parameters sex, age, body length and weight. Therefore, they can be used for orientation in lag screw placement keeping

Handheld Navigation Device and Patient-Specific Cutting Guides Result in Similar Coronal Alignment for Primary Total Knee Arthroplasty: a Retrospective Matched Cohort Study.

PubMed

Steinhaus, Michael E; McLawhorn, Alexander S; Richardson, Shawn S; Maher, Patrick; Mayman, David J

2016-10-01

Proper alignment of total knee arthroplasty (TKA) is essential for TKA function and may reduce the risk of aseptic failure. Technologies that prevent malalignment may reduce the risk of revision surgery. The purpose of this study was to compare two competing TKA systems that purport improved alignment: patient-specific instrumentation (PSI), and a handheld portable navigation device (NAV). After IRB approval, 49 consecutive PSI TKAs (40 patients) were matched based on preoperative characteristics to 49 NAV TKAs (40 patients) performed by a single surgeon. A blinded observer measured alignment on digital radiographs. Operating room records were reviewed for procedure times. Two-tailed paired sample t tests and McNemar's test were used as appropriate. Alpha level was 0.05 for all tests. Preoperative cohort characteristics were not different. Mean postoperative long-leg mechanical alignment was within ±1° of neutral for both groups, although statistically different ( p  = 0.026). There were no other significant differences in coronal alignment. PSI exhibited significantly greater posterior tibial slope (4.4°) compared to NAV (2.7°) ( p  = 0.004); PSI resulted in significantly more outliers (>6°; p  = 0.004). Procedure time for unilateral TKAs was lower for PSI (74.4 min) compared to that for NAV (80.6 min; p  = 0.023). NAV and PSI technologies provided excellent coronal plane alignment. NAV was better for sagittal tibial slope, while PSI procedure times were shorter for unilateral TKA. The impact of these technologies on patient-reported outcomes and TKA survivorship is controversial and should be the focus of future research.

Is the sagittal postural alignment different in normal and dysphonic adult speakers?

PubMed

Franco, Débora; Martins, Fernando; Andrea, Mário; Fragoso, Isabel; Carrão, Luís; Teles, Júlia

2014-07-01

Clinical research in the field of voice disorders, in particular functional dysphonia, has suggested abnormal laryngeal posture due to muscle adaptive changes, although specific evidence regarding body posture has been lacking. The aim of our study was to verify if there were significant differences in sagittal spine alignment between normal (41 subjects) and dysphonic speakers (33 subjects). Cross-sectional study. Seventy-four adults, 35 males and 39 females, were submitted to sagittal plane photographs so that spine alignment could be analyzed through the Digimizer-MedCalc Software Ltd program. Perceptual and acoustic evaluation and nasoendoscopy were used for dysphonic judgments: normal and dysphonic speakers. For thoracic length curvature (TL) and for the kyphosis index (KI), a significant effect of dysphonia was observed with mean TL and KI significantly higher for the dysphonic speakers than for the normal speakers. Concerning the TL variable, a significant effect of sex was found, in which the mean of the TL was higher for males than females. The interaction between dysphonia and sex did not have a significant effect on TL and KI variables. For the lumbar length curvature variable, a significant main effect of sex was demonstrated; there was no significant main effect of dysphonia or significant sex×dysphonia interaction. Findings indicated significant differences in some sagittal spine posture measures between normal and dysphonic speakers. Postural measures can add useful information to voice assessment protocols and should be taken into account when considering particular treatment strategies. Copyright © 2014 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Effects of mid-foot contact area ratio on lower body kinetics/kinematics in sagittal plane during stair descent in women.

PubMed

Lee, Jinkyu; Hong, Yoon No Gregory; Shin, Choongsoo S

2016-07-01

The mid-foot contact area relative to the total foot contact area can facilitate foot arch structure evaluation. A stair descent motion consistently provides initial fore-foot contact and utilizes the foot arch more actively for energy absorption. The purpose of this study was to compare ankle and knee joint angle, moment, and work in sagittal plane during stair descending between low and high Mid-Foot-Contact-Area (MFCA) ratio group. The twenty-two female subjects were tested and classified into two groups (high MFCA and low MFCA) using their static MFCA ratios. The ground reaction force (GRF) and kinematics of ankle and knee joints were measured while stair descending. During the period between initial contact and the first peak in vertical GRF (early absorption phase), ankle negative work for the low MFCA ratio group was 33% higher than that for the high MFCA ratio group (p<0.05). However, ankle negative work was not significantly different between the two groups during the period between initial contact and peak dorsiflexion angle (early absorption phase+late absorption phase). The peak ankle dorsiflexion angle was smaller in the low MFCA ratio group (p<0.05). Our results suggest that strategy of energy absorption at the ankle and foot differs depending upon foot arch types classified by MFCA. The low MFCA ratio group seemed to absorb more impact energy using strain in the planar fascia during early absorption phase, whereas the high MFCA ratio group absorbed more impact energy using increased dorsiflexion during late absorption phase. Copyright © 2016 Elsevier B.V. All rights reserved.

The influence of different sets of surgical instrumentation in Oxford UKA on bearing size and component position.

PubMed

Walker, Tilman; Heinemann, Pascal; Bruckner, Thomas; Streit, Marcus R; Kinkel, Stefan; Gotterbarm, Tobias

2017-07-01

The Oxford unicompartmental knee arthroplasty (OUKA) has been proven to be an effective treatment for anteromedial osteoarthritis of the knee joint. New instrumentation has been introduced to improve the reproducibility of implant positioning and to minimize bone loss during tibial resection (Oxford Microplasty; Zimmer Biomet, Warsaw, Indiana, USA). To assess the effect of the new instrumentation, we retrospectively evaluated the postoperative radiographs and surgical records of 300 OUKAs in three consecutive cohorts of patients. The first cohort consists of the first 100 minimal invasive implantations of the OUKA using the conventional phase III instrumentation, the second cohort consists of the 100 most recent minimal invasive OUKA with the conventional phase III instrumentation and the third cohort consists of the first 100 minimal invasive OUKA using the new Oxford Microplasty instrumentation. Mean bearing thickness was statistically significant and lower in OUKA with use of the updated instrumentation than with the conventional instrumentation (p = 0.01 and p = 0.04). Additionally, statistically significant and more femoral components were aligned within the accepted range of tolerance in both the coronal and the sagittal plane with use of the updated instrumentation compared to the conventional phase III instrumentation in group A (p = 0.029 and p = 0.038) and in the sagittal plane with use of the updated instrumentation compared to the conventional phase III instrumentation in group B (p = 0.002). The new modified instrumentation seems to be an effective tool to reduce the risk of malalignment of the femoral component in the coronal and in the sagittal plane compared to the conventional phase III instrumentation. Furthermore, the instrumentation is also effective in determining an adequate level of tibial resection and thus avoiding unnecessary bone loss.

FIBRE AND INTEGRATED OPTICS. OPTICAL PROCESSING OF INFORMATION: Intrafibre rotation of the plane of polarisation

NASA Astrophysics Data System (ADS)

Zel'dovich, Boris Ya; Kundikova, N. D.

1995-02-01

Rotation of the plane of polarisation during propagation of sagittal rays in a rectilinear multimode fibre was observed experimentally. The angle of rotation was in good agreement with the results predicted on the basis of the Rytov—Vladimirskii—Berry theory.

Knee joint changes in patients with neglected developmental hip dysplasia: a prospective case-control study.

PubMed

Li, Qiwei; Kadhim, Muayad; Zhang, Lijun; Cheng, Xiangjun; Zhao, Qun; Li, Lianyong

2014-12-01

Few reports are available describing knee changes in neglected developmental dysplasia of the hip (DDH). The purpose of this study was to assess the radiographic morphology of knee joints in adults with neglected DDH. Thirty-seven patients (35 females and two males) with neglected DDH were prospectively recruited with an average age of 32.6 years. Twenty-three patients had unilateral and 14 patients had bilateral neglected DDH. Thirty-seven healthy individuals were recruited to form a matched control group. Three groups of knee joints were examined: affected knees (on the same side of the neglected DDH), unaffected knees (contralateral to the neglected DDH in patients with unilateral involvement), and control knees. A series of radiographic parameters of the knee joint were measured in the coronal and sagittal plane, and they were compared between patients and normal controls. In the coronal plane, the affected knees had increased valgus angulation related to increased height of the medial femoral condyle, decreased height of the lateral femoral condyle and decreased lateral distal femoral angle compared to control knees. In the sagittal plane, both distal femoral and proximal tibial joints of the affected knees developed a decrease in posterior angles. Additionally, the unaffected knees also developed radiographic changes compared to control knees. Patients with neglected DDH may develop changes in both knee joints. These changes should be considered during surgery to the hip, femur and knee to prevent potential complications. Level 2. Copyright © 2014 Elsevier B.V. All rights reserved.

Clinical Evaluation of positioning verification using digital tomosynthesis (DTS) based on bony anatomy and soft tissues for prostate image-guided radiation therapy (IGRT)

PubMed Central

Yoo, Sua; Wu, Q. Jackie; Godfrey, Devon; Yan, Hui; Ren, Lei; Das, Shiva; Lee, William R.; Yin, Fang-Fang

2008-01-01

Purpose To evaluate on-board digital tomosynthesis (DTS) for patient positioning in comparison with 2D-radiographs and 3D-CBCT. Methods and Materials A total of 92 image sessions from 9 prostate cancer patients were analyzed. An on-board image set was registered to a corresponding reference image set. Four pairs of image sets were used; DRR vs. on-board orthogonal paired radiograph for the 2D method, coronal-reference-DTS (RDTS) vs. on-board coronal-DTS for the coronal-DTS method, sagittal-RDTS vs. on-board sagittal-DTS for the sagittal-DTS method, and planning CT vs. CBCT for the CBCT method. Registration results were compared. Results The systematic errors in all methods were less than 1 mm/1°. When registering bony anatomy, the mean vector differences were 0.21±0.11 cm between 2D and CBCT, 0.11±0.08 cm between CBCT and coronal-DTS, and 0.14±0.07 cm between CBCT and sagittal-DTS. The correlation of CBCT to DTS was stronger (coefficients=0.92–0.95) than the correlation between 2D and CBCT or DTS (coefficients=0.81–0.83). When registering soft tissue, the mean vector differences were 0.18±0.11 cm between CBCT and coronal-DTS and 0.29±0.17 cm between CBCT and sagittal-DTS. The correlation coefficients of CBCT to sagittal-DTS and to coronal-DTS were 0.84 and 0.92, respectively. Conclusions DTS could provide equivalent results to CBCT when bony anatomy is used as landmarks for prostate IGRT. For soft tissue-based positioning verification, coronal-DTS produced equivalent results to CBCT and sagittal-DTS alone was insufficient. DTS could allow comparable soft tissue-based target localization with faster scanning time and less imaging dose compared to CBCT. PMID:19100923

Can coronal hole spicules reach coronal temperatures?

NASA Astrophysics Data System (ADS)

Madjarska, M. S.; Vanninathan, K.; Doyle, J. G.

2011-08-01

Aims: The present study aims to provide observational evidence of whether coronal hole spicules reach coronal temperatures. Methods: We combine multi-instrument co-observations obtained with the SUMER/SoHO and with the EIS/SOT/XRT/Hinode. Results: The analysed three large spicules were found to be comprised of numerous thin spicules that rise, rotate, and descend simultaneously forming a bush-like feature. Their rotation resembles the untwisting of a large flux rope. They show velocities ranging from 50 to 250 kms-1. We clearly associated the red- and blue-shifted emissions in transition region lines not only with rotating but also with rising and descending plasmas. Our main result is that these spicules although very large and dynamic, are not present in the spectral lines formed at temperatures above 300 000 K. Conclusions: In this paper we present the analysis of three Ca ii H large spicules that are composed of numerous dynamic thin spicules but appear as macrospicules in lower resolution EUV images. We found no coronal counterpart of these and smaller spicules. We believe that the identification of phenomena that have very different origins as macrospicules is due to the interpretation of the transition region emission, and especially the He ii emission, wherein both chromospheric large spicules and coronal X-ray jets are present. We suggest that the recent observation of spicules in the coronal AIA/SDO 171 Å and 211 Å channels probably comes from the existence of transition region emission there. Movie is available in electronic form at http://www.aanda.org

Does a minimally invasive approach affect positioning of components in unicompartmental knee arthroplasty? Early results with survivorship analysis.

PubMed

Cool, Steve; Victor, Jan; De Baets, Thierry

2006-12-01

Fifty unicompartmental knee arthroplasties (UKAs) were performed through a minimally invasive approach and were reviewed with an average follow-up of 3.7 years. This technique leads to reduced access to surgical landmarks. The purpose of this study was to evaluate whether correct component positioning is possible through this less invasive approach. Component positioning, femorotibial alignment and early outcomes were evaluated. We observed perfect tibial component position, but femoral component position was less consistent, especially in the sagittal plane. Femorotibial alignment in the coronal plane was within 2.5 degrees of the desired axis for 80% of the cases. Femoral component position in the sagittal plane was within a 10 degrees range of the ideal for 70% of the cases. The mean IKS Knee Function Score and Knee Score were 89/100 and 91/100 respectively. We observed two polyethylene dislocations, and one revision was performed for progressive patellofemoral arthrosis. According to our data, minimally invasive UKA does not conflict with component positioning although a learning curve needs to be respected, with femoral component positioning as the major obstacle.

Correction of antebrachial angulation-rotation deformities in dogs with oblique plane inclined osteotomies.

PubMed

Franklin, Samuel P; Dover, Ryan K; Andrade, Natalia; Rosselli, Desiree; M Clarke, Kevin

2017-11-01

To describe oblique plane inclined osteotomies and report preliminary data on outcomes in dogs treated for antebrachial angulation-rotation deformities. Retrospective clinical study. Six antebrachii from 5 dogs. Records of dogs with antebrachial angulation-rotation deformities treated with oblique plane inclined osteotomies were reviewed. Postoperative frontal, sagittal, and transverse plane alignments were assessed subjectively, and alignment in the frontal and sagittal planes was quantified on radiographs. Outcomes were classified based on owner's and veterinarian's evaluation as full, acceptable, and unacceptable function. Complications were classified as minor, major, or catastrophic. Limb alignment was subjectively considered excellent in 1 case, good in 3 cases, and fair in 2 cases. Osseous union was achieved in all cases (mean 10.5 weeks; range, 6-13 weeks). Outcomes were assessed by the veterinarian as return to full function in 5 cases and acceptable function in 1 case at the final in-hospital follow-up (mean 44 weeks; range, 6-124 weeks). All owners classified their dogs as returning to full function at the final phone/email interview (mean 107 weeks; range, 72-153 weeks). Implants were removed due to infection or irritation in 3/6 limbs, while the other 3 limbs had minor dermatitis secondary to postoperative external coaptation. No catastrophic complications occurred. Oblique plane inclined osteotomies led to a successful outcome in all 6 limbs, but the technique can be challenging and does not always lead to optimal alignment. Future refinement of this technique could focus on the development of patient-specific osteotomy guides to improve accuracy and precision. © 2017 The American College of Veterinary Surgeons.

Influence of meniscus shape in the cross sectional plane on the knee contact mechanics.

PubMed

Łuczkiewicz, Piotr; Daszkiewicz, Karol; Witkowski, Wojciech; Chróścielewski, Jacek; Zarzycki, Witold

2015-06-01

We present a three dimensional finite element analysis of stress distribution and menisci deformation in the human knee joint. The study is based on the Open Knee model with the geometry of the lateral meniscus which shows some degenerative disorders. The nonlinear analysis of the knee joint under compressive axial load is performed. We present results for intact knee, knee with complete radial posterior meniscus root tear and knee with total meniscectomy of medial or lateral meniscus. We investigate how the meniscus shape in the cross sectional plane influences knee-joint mechanics by comparing the results for flat (degenerated) lateral and normal medial meniscus. Specifically, the deformation of the menisci in the coronal plane and the corresponding stress values in cartilages are studied. By analysing contact resultant force acting on the menisci in axial plane we have shown that restricted extrusion of the torn lateral meniscus can be attributed to small slope of its cross section in the coronal plane. Additionally, the change of the contact area and the resultant force acting on the menisci as the function of compressive load are investigated. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biomechanical evaluation of sagittal maxillary internal distraction osteogenesis in unilateral cleft lip and palate patient and noncleft patients: a three-dimensional finite element analysis.

PubMed

Olmez, Sultan; Dogan, Servet; Pekedis, Mahmut; Yildiz, Hasan

2014-09-01

To compare the pattern and amount of stress and displacement during maxillary sagittal distraction osteogenesis (DO) between a patient with unilateral cleft lip and palate (UCLP) and a noncleft patient. Three-dimensional finite element models for both skulls were constructed. Displacements of the surface landmarks and stress distributions in the circummaxillary sutures were analyzed after an anterior displacement of 6 mm was loaded to the elements where the inferior plates of the distractor were assumed to be fixed and were below the Le Fort I osteotomy line. In sagittal plane, more forward movement was found on the noncleft side in the UCLP model (-6.401 mm on cleft side and -6.651 mm on noncleft side for the central incisor region). However, similar amounts of forward movement were seen in the control model. In the vertical plane, a clockwise rotation occurred in the UCLP model, whereas a counterclockwise rotation was seen in the control model. The mathematical UCLP model also showed higher stress values on the sutura nasomaxillaris, frontonasalis, and zygomatiomaxillaris on the cleft side than on the normal side. Not only did the sagittal distraction forces produce advancement forces at the intermaxillary sutures, but more stress was also present on the sutura nasomaxillaris, sutura frontonasalis, and sutura zygomaticomaxillaris on the cleft side than on the noncleft side.

Does Medial Meniscal Allograft Transplantation With the Bone-Plug Technique Restore the Anatomic Location of the Native Medial Meniscus?

PubMed

Kim, Nam-Ki; Bin, Seong-Il; Kim, Jong-Min; Lee, Chang-Rack

2015-12-01

position as the native meniscus, the anatomic locations of both horns were shifted posteromedially compared with those of the native medial meniscus. There were significant differences, attributed to several limitations in the bone-plug technique, between the preoperative and postoperative values of both horns. However, the posterior horn showed a location change of <5 mm, on average, in both the coronal and sagittal planes, whereas the anterior horn showed a location change of ≥ 5 mm in the coronal plane but <5 mm in the sagittal plane. © 2015 The Author(s).

Influence of intentional femoral component flexion in navigated TKA on gap balance and sagittal anatomy.

PubMed

Roßkopf, J; Singh, P K; Wolf, P; Strauch, M; Graichen, H

2014-03-01

Navigation has proven its ability to accurately restore coronal leg axis; however, for a good clinical outcome, other factors such as sagittal anatomy and balanced gaps are at least as important. In a gap-balanced technique, the size of the flexion gap is equalled to that of the extension gap. Flexion of the femoral component has been described as a theoretical possibility to balance flexion and extension gap. Aim of this study was to assess whether intentional femoral component flexion is helpful in balancing TKA gaps and in restoring sagittal anatomy. One hundred and thirty-one patients with TKA were included in this study. Implantation was performed in a navigated, gap-balanced, tibia-first technique. The femoral component flexion needed to equal flexion to extension gap was calculated based upon the navigation data. The sagittal diameter, the anterior and posterior offset were measured pre- and postoperatively based on the lateral radiographs. Medial and lateral gaps in extension and flexion as well as flexion/extension gap differences pre- and postoperatively were analysed. Additionally range of motion (ROM) and patient satisfaction (SF 12) were obtained. To achieve equal flexion and extension gap, the femoral component was flexed in 120 out of 131 patients showing mean flexion of 2.9° (SD 2.2°; navigation data) and 3.1° (SD 2.0°; radiological analysis), respectively. Based on this technique, it was possible to balance the extension gap (<2 mm difference) in 130 out of 131 patients (99%) and the flexion gap in 119 out of 131 (91%). The difference between extension and flexion gap was reduced from 39 to 24 out of 131 patients (81%) on the medial side and from 69 to 28 on the lateral side (79%). The sagittal diameter was restored in 114 out of 131 cases (87%); however, anterior offset was significantly reduced by 1.3 mm (SD 3.9°), and posterior offset was significantly increased by 1.6 mm (SD 3.3°). No correlation between any navigation and radiological

Coronal View Ultrasound Imaging of Movement in Different Segments of the Tongue during Paced Recital: Findings from Four Normal Speakers and a Speaker with Partial Glossectomy

ERIC Educational Resources Information Center

Bressmann, Tim; Flowers, Heather; Wong, Willy; Irish, Jonathan C.

2010-01-01

The goal of this study was to quantitatively describe aspects of coronal tongue movement in different anatomical regions of the tongue. Four normal speakers and a speaker with partial glossectomy read four repetitions of a metronome-paced poem. Their tongue movement was recorded in four coronal planes using two-dimensional B-mode ultrasound…

The Coronal Monsoon: Thermal Nonequilibrium Revealed by Periodic Coronal Rain

NASA Astrophysics Data System (ADS)

Auchère, Frédéric; Froment, Clara; Soubrié, Elie; Antolin, Patrick; Oliver, Ramon; Pelouze, Gabriel

2018-02-01

We report on the discovery of periodic coronal rain in an off-limb sequence of Solar Dynamics Observatory/Atmospheric Imaging Assembly images. The showers are co-spatial and in phase with periodic (6.6 hr) intensity pulsations of coronal loops of the sort described by Auchère et al. and Froment et al. These new observations make possible a unified description of both phenomena. Coronal rain and periodic intensity pulsations of loops are two manifestations of the same physical process: evaporation/condensation cycles resulting from a state of thermal nonequilibrium. The fluctuations around coronal temperatures produce the intensity pulsations of loops, and rain falls along their legs if thermal runaway cools the periodic condensations down and below transition-region temperatures. This scenario is in line with the predictions of numerical models of quasi-steadily and footpoint heated loops. The presence of coronal rain—albeit non-periodic—in several other structures within the studied field of view implies that this type of heating is at play on a large scale.

Self-Inflicted Drywall Screws in the Sagittal Sinus.

PubMed

Guppy, Kern H; Ochi, Calvin

2018-02-01

A 30-year-old right-handed man with a history of schizophrenia presented with 2 self-inflicted drywall screws in the skull. The patient was sleepy but easily arousable; blood tests showed he had taken methamphetamines. Computed tomography and computed tomography angiography of the head showed the frontal screw abutted left of the superior sagittal sinus, and the posterior screw went through the superior sagittal sinus with no extravasation of contrast material at either site. Both screws were removed with exposure of the sagittal sinus using U-shaped craniectomies. There was no bleeding on the removal of the screws. It appears the posterior screw entered between the leaflets of the sagittal sinus dura mater. The patient had returned to work without any sequelae 1 month after injury. Copyright © 2017 Elsevier Inc. All rights reserved.

Biodegradable screw versus a press-fit bone plug fixation for hamstring anterior cruciate ligament reconstruction: a prospective randomized study.

PubMed

Jagodzinski, Michael; Geiges, Bjoern; von Falck, Christian; Knobloch, Karsten; Haasper, Carl; Brand, Juergen; Hankemeier, Stefan; Krettek, Christian; Meller, Rupert

2010-03-01

Press-fit fixation of a tendon graft has been advocated to achieve tendon-to-bone healing. Fixation of hamstring tendon grafts with a porous bone scaffold limits bone tunnel enlargement compared with a biodegradable interference screw fixation. Randomized controlled trial; Level of evidence, 1. Methods Between 2005 and 2006, 20 patients (17 men, 3 women) with a primary reconstruction of the anterior cruciate ligament (ACL) were enrolled in this study. Patients were randomized to obtain graft fixation in the tibial tunnel either by means of an interference screw (I) or a press-fit fixation with a porous bone cylinder (P). At 3 months after surgery, a computed tomography (CT) scan of the knee was performed, and tunnel enlargement was analyzed in the coronal and sagittal planes for the proximal, middle, and distal thirds of the tunnel. After 6 months and 1 and 2 years, radiographs of the knee in the sagittal and coronal plane were analyzed for bone tunnel widening. The International Knee Documentation Committee (IKDC), Tegner, and Lysholm scores of both groups were compared after 1 and 2 years. The bone tunnel enlargement determined by CT was 106.9% + or - 10.9% for group P and 121.9% + or - 9.0% for group I (P < .02) in the anteroposterior (AP) plane and 102.8% + or - 15.2% versus 121.5% + or - 10.1% in the coronal plane (P <.01). The IKDC, Tegner, and Lysholm scores improved in both groups from preoperatively to postoperatively without significant differences between the 2 groups. There was a trend to higher knee stability in group P after 3 months (0.6 + or - 1.4 mm vs 1.8 + or - 1.5 mm; P = .08). Both interference screw and a press-fit fixation lead to a high number of good or very good outcomes after ACL reconstruction. Tibial press-fit fixation decreases the amount of proximal bone tunnel enlargement.

Coronal ``Wave'': Magnetic Footprint of a Coronal Mass Ejection?

NASA Astrophysics Data System (ADS)

Attrill, Gemma D. R.; Harra, Louise K.; van Driel-Gesztelyi, Lidia; Démoulin, Pascal

2007-02-01

We investigate the properties of two ``classical'' EUV Imaging Telescope (EIT) coronal waves. The two source regions of the associated coronal mass ejections (CMEs) possess opposite helicities, and the coronal waves display rotations in opposite senses. We observe deep core dimmings near the flare site and also widespread diffuse dimming, accompanying the expansion of the EIT wave. We also report a new property of these EIT waves, namely, that they display dual brightenings: persistent ones at the outermost edge of the core dimming regions and simultaneously diffuse brightenings constituting the leading edge of the coronal wave, surrounding the expanding diffuse dimmings. We show that such behavior is consistent with a diffuse EIT wave being the magnetic footprint of a CME. We propose a new mechanism where driven magnetic reconnections between the skirt of the expanding CME magnetic field and quiet-Sun magnetic loops generate the observed bright diffuse front. The dual brightenings and the widespread diffuse dimming are identified as innate characteristics of this process.

Coronal partings

NASA Astrophysics Data System (ADS)

Nikulin, Igor F.; Dumin, Yurii V.

2016-02-01

The basic observational properties of "coronal partings"-the special type of quasi-one-dimensional magnetic structures, identified by a comparison of the coronal X-ray and EUV images with solar magnetograms-are investigated. They represent the channels of opposite polarity inside the unipolar large-scale magnetic fields, formed by the rows of magnetic arcs directed to the neighboring sources of the background polarity. The most important characteristics of the partings are discussed. It can be naturally assumed that-from the evolutionary and spatial points of view-the partings can transform into the coronal holes and visa versa. The classes of global, intersecting, and complex partings are identified.

Plasma Evolution within an Erupting Coronal Cavity

NASA Astrophysics Data System (ADS)

Long, David M.; Harra, Louise K.; Matthews, Sarah A.; Warren, Harry P.; Lee, Kyoung-Sun; Doschek, George A.; Hara, Hirohisa; Jenkins, Jack M.

2018-03-01

Coronal cavities have previously been observed to be associated with long-lived quiescent filaments and are thought to correspond to the associated magnetic flux rope. Although the standard flare model predicts a coronal cavity corresponding to the erupting flux rope, these have only been observed using broadband imaging data, restricting an analysis to the plane-of-sky. We present a unique set of spectroscopic observations of an active region filament seen erupting at the solar limb in the extreme ultraviolet. The cavity erupted and expanded rapidly, with the change in rise phase contemporaneous with an increase in nonthermal electron energy flux of the associated flare. Hot and cool filamentary material was observed to rise with the erupting flux rope, disappearing suddenly as the cavity appeared. Although strongly blueshifted plasma continued to be observed flowing from the apex of the erupting flux rope, this outflow soon ceased. These results indicate that the sudden injection of energy from the flare beneath forced the rapid eruption and expansion of the flux rope, driving strong plasma flows, which resulted in the eruption of an under-dense filamentary flux rope.

Screw-Home Movement of the Tibiofemoral Joint during Normal Gait: Three-Dimensional Analysis

PubMed Central

Kim, Ha Yong; Yang, Dae Suk; Jeung, Sang Wook; Choi, Han Gyeol; Choy, Won Sik

2015-01-01

Background The purpose of this study was to evaluate the screw-home movement at the tibiofemoral joint during normal gait by utilizing the 3-dimensional motion capture technique. Methods Fifteen young males and fifteen young females (total 60 knee joints) who had no history of musculoskeletal disease or a particular gait problem were included in this study. Two more markers were attached to the subject in addition to the Helen-Hayes marker set. Thus, two virtual planes, femoral coronal plane (Pf) and tibial coronal plane (Pt), were created by Skeletal Builder software. This study measured the 3-dimensional knee joint movement in the sagittal, coronal, and transverse planes of these two virtual planes (Pf and Pt) during normal gait. Results With respect to kinematics and kinetics, both males and females showed normal adult gait patterns, and the mean difference in the temporal gait parameters was not statistically significant (p > 0.05). In the transverse plane, the screw-home movement occurred as expected during the pre-swing phase and the late-swing phase at an angle of about 17°. However, the tibia rotated externally with respect to the femur, rather than internally, while the knee joint started to flex during the loading response (paradoxical screw-home movement), and the angle was 6°. Conclusions Paradoxical screw-home movement may be an important mechanism that provides stability to the knee joint during the remaining stance phase. Obtaining the kinematic values of the knee joint during gait can be useful in diagnosing and treating the pathological knee joints. PMID:26330951

Screw-Home Movement of the Tibiofemoral Joint during Normal Gait: Three-Dimensional Analysis.

PubMed

Kim, Ha Yong; Kim, Kap Jung; Yang, Dae Suk; Jeung, Sang Wook; Choi, Han Gyeol; Choy, Won Sik

2015-09-01

The purpose of this study was to evaluate the screw-home movement at the tibiofemoral joint during normal gait by utilizing the 3-dimensional motion capture technique. Fifteen young males and fifteen young females (total 60 knee joints) who had no history of musculoskeletal disease or a particular gait problem were included in this study. Two more markers were attached to the subject in addition to the Helen-Hayes marker set. Thus, two virtual planes, femoral coronal plane (P f ) and tibial coronal plane (P t ), were created by Skeletal Builder software. This study measured the 3-dimensional knee joint movement in the sagittal, coronal, and transverse planes of these two virtual planes (P f and P t ) during normal gait. With respect to kinematics and kinetics, both males and females showed normal adult gait patterns, and the mean difference in the temporal gait parameters was not statistically significant (p > 0.05). In the transverse plane, the screw-home movement occurred as expected during the pre-swing phase and the late-swing phase at an angle of about 17°. However, the tibia rotated externally with respect to the femur, rather than internally, while the knee joint started to flex during the loading response (paradoxical screw-home movement), and the angle was 6°. Paradoxical screw-home movement may be an important mechanism that provides stability to the knee joint during the remaining stance phase. Obtaining the kinematic values of the knee joint during gait can be useful in diagnosing and treating the pathological knee joints.

Localizing Circuits of Atrial Macro-Reentry Using ECG Planes of Coherent Atrial Activation

PubMed Central

Kahn, Andrew M.; Krummen, David E.; Feld, Gregory K.; Narayan, Sanjiv M.

2007-01-01

Background The complexity of ablation for atrial macro-reentry (AFL) varies significantly depending upon the circuit location. Presently, surface ECG analysis poorly separates left from right atypical AFL and from some cases of typical AFL, delaying diagnosis until invasive study. Objective To differentiate and localize the intra-atrial circuits of left atypical AFL, right atypical, and typical AFL using quantitative ECG analysis. Methods We studied 66 patients (54 M, age 59±14 years) with typical (n=35), reverse typical (n=4) and atypical (n=27) AFL. For each, we generated filtered atrial waveforms from ECG leads V5 (X-axis), aVF (Y) and V1 (Z) by correlating a 120 ms F-wave sample to successive ECG regions. Atrial spatial loops were plotted for 3 orthogonal planes (frontal, XY=V5/aVF; sagittal, YZ=aVF/V1; axial, XZ=V5/V1), then cross-correlated to measure spatial regularity (‘coherence’: range −1 to 1). Results Mean coherence was greatest in the XY plane (p<10−3 vs XZ or YZ). Atypical AFL showed lower coherence than typical AFL in XY (p<10−3), YZ (p<10−6) and XZ (p<10−5) planes. Atypical left AFL could be separated from atypical right AFL by lower XY coherence (p=0.02); for this plane coherence < 0.69 detected atypical left AFL with 84% specificity and 75% sensitivity. F-wave amplitude did not separate typical, atypical right or atypical left AFL (p=NS). Conclusions Atypical AFL shows lower spatial coherence than typical AFL, particularly in sagittal and axial planes. Coherence in the Cartesian frontal plane separated left and right atypical AFL. Such analyses may be used to plan ablation strategy from the bedside. PMID:17399632

Shoulder motor performance assessment in the sagittal plane in children with hemiplegia during single joint pointing tasks.

PubMed

Formica, Domenico; Petrarca, Maurizio; Rossi, Stefano; Zollo, Loredana; Guglielmelli, Eugenio; Cappa, Paolo

2014-07-29

Pointing is a motor task extensively used during daily life activities and it requires complex visuo-motor transformation to select the appropriate movement strategy. The study of invariant characteristics of human movements has led to several theories on how the brain solves the redundancy problem, but the application of these theories on children affected by hemiplegia is limited. This study aims at giving a quantitative assessment of the shoulder motor behaviour in children with hemiplegia during pointing tasks. Eight children with hemiplegia were involved in the study and were asked to perform movements on the sagittal plane with both arms, at low and high speed. Subject movements were recorded using an optoelectronic system; a 4-DOF model of children arm has been developed to calculate kinematic and dynamic variables. A set of evaluation indexes has been extracted in order to quantitatively assess whether and how children modify their motor control strategies when perform movements with the more affected or less affected arm. In low speed movements, no differences can be seen in terms of movement duration and peak velocity between the More Affected arm (MA) and the Less Affected arm (LA), as well as in the main characteristics of movement kinematics and dynamics. As regards fast movements, remarkable differences in terms of strategies of motor control can be observed: while movements with LA did not show any significant difference in Dimensionless Jerk Index (JI) and Dimensionless Torque-change Cost index (TC) between the elevation and lowering phases, suggesting that motor control optimization is similar for movements performed with or against gravity, movements with MA showed a statistically significant increase of both JI and TC during lowering phase. Results suggest the presence of a different control strategy for fast movements in particular during lowering phase. Results suggest that motor control is not able to optimize Jerk and Torque-change cost

The triple PCL sign: bucket handle tears of both medial and lateral menisci in a chronically ACL-deficient knee.

PubMed

Kakel, Rafid; Russell, Robert; VanHeerden, Pieter

2010-10-11

Bucket handle tears of both menisci in the setting of acute or chronic anterior cruciate ligament (ACL) tears of the same knee have rarely been reported in the literature. This article presents a case of a bucket handle tear affecting both the medial and lateral menisci in a patient with chronic ACL rupture. Both bucket handle tears were displaced and locked in the intercondylar notch. A new magnetic resonance image (MRI) sign suggested on sagittal view is called the triple PCL sign, comprising the intact posterior cruciate ligament (PCL) and the 2 displaced fragments in the intercondylar notch from the two bucket handle tears. The precise diagnosis of this condition is of obvious importance for optimal operative planning. While finding the displaced fragment from the medial meniscus is expected to cause the double PCL sign, the torn ACL may have made it easier to visualize the bucket handle tear of the lateral meniscus in the same sagittal plane as the PCL. Only 5 other reports mention bimeniscal bucket handle tears of both the medial and lateral menisci in association with an ACL tear. None have shown the suggested triple PCL sign because of lack of overlap between the 2 bucket handle tears in the coronal plane while lying in the intercondylar notch causing them not to fall in the same sagittal plane. Our patient showed some overlap between the 2 meniscal fragments while lying in the notch to create the triple PCL sign on sagittal MRI. Copyright 2010, SLACK Incorporated.

Effect of Trunk Sagittal Attitude on Shoulder, Thorax and Pelvis Three-Dimensional Kinematics in Able-Bodied Subjects during Gait

PubMed Central

Leardini, Alberto; Berti, Lisa; Begon, Mickaël; Allard, Paul

2013-01-01

It has been shown that an original attitude in forward or backward inclination of the trunk is maintained at gait initiation and during locomotion, and that this affects lower limb loading patterns. However, no studies have shown the extent to which shoulder, thorax and pelvis three-dimensional kinematics are modified during gait due to this sagittal inclination attitude. Thirty young healthy volunteers were analyzed during level walking with video-based motion analysis. Reflecting markers were mounted on anatomical landmarks to form a two-marker shoulder line segment, and a four-marker thorax and pelvis segments. Absolute and relative spatial rotations were calculated, for a total of 11 degrees of freedom. The subjects were divided into two groups of 15 according to the median of mean thorax inclination angle over the gait cycle. Preliminary MANOVA analysis assessed whether gender was an independent variable. Then two-factor nested ANOVA was used to test the possible effect of thorax inclination on body segments, planes of motion and gait periods, separately. There was no significant difference in all anthropometric and spatio-temporal parameters between the two groups, except for subject mass. The three-dimensional kinematics of the thorax and pelvis were not affected by gender. Nested ANOVA revealed group effect in all segment rotations apart those at the pelvis, in the sagittal and frontal planes, and at the push-off. Attitudes in sagittal thorax inclination altered trunk segments kinematics during gait. Subjects with a backward thorax showed less thorax-to-pelvis motion, but more shoulder-to-thorax and thorax-to-laboratory motion, less motion in flexion/extension and in lateral bending, and also less motion during push-off. This contributes to the understanding of forward propulsion and sideways load transfer mechanisms, fundamental for the maintenance of balance and the risk of falling. PMID:24204763

Effect of trunk sagittal attitude on shoulder, thorax and pelvis three-dimensional kinematics in able-bodied subjects during gait.

PubMed

Leardini, Alberto; Berti, Lisa; Begon, Mickaël; Allard, Paul

2013-01-01

It has been shown that an original attitude in forward or backward inclination of the trunk is maintained at gait initiation and during locomotion, and that this affects lower limb loading patterns. However, no studies have shown the extent to which shoulder, thorax and pelvis three-dimensional kinematics are modified during gait due to this sagittal inclination attitude. Thirty young healthy volunteers were analyzed during level walking with video-based motion analysis. Reflecting markers were mounted on anatomical landmarks to form a two-marker shoulder line segment, and a four-marker thorax and pelvis segments. Absolute and relative spatial rotations were calculated, for a total of 11 degrees of freedom. The subjects were divided into two groups of 15 according to the median of mean thorax inclination angle over the gait cycle. Preliminary MANOVA analysis assessed whether gender was an independent variable. Then two-factor nested ANOVA was used to test the possible effect of thorax inclination on body segments, planes of motion and gait periods, separately. There was no significant difference in all anthropometric and spatio-temporal parameters between the two groups, except for subject mass. The three-dimensional kinematics of the thorax and pelvis were not affected by gender. Nested ANOVA revealed group effect in all segment rotations apart those at the pelvis, in the sagittal and frontal planes, and at the push-off. Attitudes in sagittal thorax inclination altered trunk segments kinematics during gait. Subjects with a backward thorax showed less thorax-to-pelvis motion, but more shoulder-to-thorax and thorax-to-laboratory motion, less motion in flexion/extension and in lateral bending, and also less motion during push-off. This contributes to the understanding of forward propulsion and sideways load transfer mechanisms, fundamental for the maintenance of balance and the risk of falling.

Elongated Coronal Hole

NASA Image and Video Library

2016-03-24

NASA Solar Dynamics Observatory shows a long coronal hole has rotated so that was temporarily facing right towards Earth Mar. 23-25, 2016. Coronal holes appear dark when viewed in some wavelengths of extreme ultraviolet light.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ball, J.B. Jr.

Direct oblique sagittal CT was used to evaluate trauma to 77 orbits. Sixty-seven orbital wall fractures with intact orbital rims (36 floor, 22 medial wall, nine roof) were identified in 47 orbits. Since persistent diplopia and/or enophthalmos may warrant surgical repair of orbital floor fractures, optimal imaging should include an evaluation of extraocular muscle status, the nature and amount of displaced orbital contents, and an accurate definition of fracture margins. For orbital floor fractures, a combination of the direct oblique sagittal and direct coronal projections optimally displayed all fracture margins, the fracture's relationship to the inferior orbital rim and medialmore » orbital wall, and the amount of displacement into the maxillary sinus. Inferior rectus muscle status with 36 floor fractures was best seen on the direct oblique sagittal projection in 30 fractures (83.3%) and was equally well seen on sagittal and coronal projections in two fractures (5.5%). Floor fractures were missed on 100% of axial, 5.5% of sagittal, and 0% of coronal projections. Since the direct oblique sagittal projection complements the direct coronal projection in evaluating orbital floor fractures, it should not be performed alone. A technical approach to the CT evaluation or orbital wall fractures is presented.« less

USING RUNNING DIFFERENCE IMAGES TO TRACK PROPER MOTIONS OF XUV CORONAL INTENSITY ON THE SUN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheeley, N. R. Jr.; Warren, H. P.; Lee, J., E-mail: neil.sheeley@nrl.navy.mil, E-mail: harry.warren@nrl.navy.mil

2014-12-20

We have developed a procedure for observing and tracking proper motions of faint XUV coronal intensity on the Sun and have applied this procedure to study the collective motions of cellular plumes and the shorter-period waves in sunspots. Our space/time maps of cellular plumes show a series of tracks with the same 5-8 minute repetition times and ∼100 km s{sup –1} sky-plane speeds found previously in active-region fans and in coronal hole plumes. By synchronizing movies and space/time maps, we find that the tracks are produced by elongated ejections from the unipolar flux concentrations at the bases of the cellular plumes and thatmore » the phases of these ejections are uncorrelated from cell to cell. Thus, the large-scale motion is not a continuous flow, but is more like a system of independent conveyor belts all moving in the same direction along the magnetic field. In contrast, the proper motions in sunspots are clearly waves resulting from periodic disturbances in the sunspot umbras. The periods are ∼2.6 minutes, but the sky-plane speeds and wavelengths depend on the heights of the waves above the sunspot. In the chromosphere, the waves decelerate from 35-45 km s{sup –1} in the umbra to 7-8 km s{sup –1} toward the outer edge of the penumbra, but in the corona, the waves accelerate to ∼60-100 km s{sup –1}. Because chromospheric and coronal tracks originate from the same space/time locations, the coronal waves must emerge from the same umbral flashes that produce the chromospheric waves.« less

Acute proximal junctional failure in patients with preoperative sagittal imbalance.

PubMed

Smith, Micah W; Annis, Prokopis; Lawrence, Brandon D; Daubs, Michael D; Brodke, Darrel S

2015-10-01

Proximal junctional failure (PJF) is a recognized complication of spinal deformity surgery. Acute PJF (APJF) has recently been demonstrated to be 5.6% in the adult spinal deformity (ASD) population. The incidence and rate of return to the operating room for APJF have not been specifically investigated in individuals with sagittal imbalance. The purpose of this study was to report the incidence of APJF in patients with preoperative sagittal imbalance and the rate of return to the operating room for APJF. This study is based on a retrospective review of prospectively collected database of ASD patients. One hundred seventy-three consecutive patients were included with preoperative sagittal imbalance according to one of the following common parameters: sagittal vertical axis (SVA) greater than 50 mm, global sagittal alignment greater than 45°, or pelvic incidence minus lumbar lordosis greater than 10°. Outcome measure was presence and/or absence of APJF defined as fracture at the upper instrumented vertebra (UIV) or UIV+1, failure of UIV fixation, 15° or more proximal junctional kyphosis, or need for extension of instrumentation within 6 months of surgery. We performed radiographic measurements on X-rays at preoperative, immediate postoperative, and 6-month follow-up visits. The APJF rate was reported for the entire patient population with preoperative sagittal imbalance. Acute PJF incidence was calculated postoperatively for each of the accepted sagittal balance parameters and/or formulas. Patients with persistent postoperative sagittal imbalance were compared with the sagittally balanced group. We also assessed for threshold values. Acute PJF was observed in 60 of 173 patients (35%) and was least common in fusions with the UIV in the upper thoracic (UT) spine (p=.035). Of those who developed APJF, 21.7% required surgery. Proximal junctional kyphosis 15° or more was the most common form of APJF in fusions to the UT spine but least likely to need revision (p=.014

Comprehensive Analysis of Mandibular Residual Asymmetry after Bilateral Sagittal Split Ramus Osteotomy Correction of Menton Point Deviation

PubMed Central

Lin, Qiuping; Huang, Xiaoqiong; Xu, Yue; Yang, Xiaoping

2016-01-01

Purpose Facial asymmetry often persists even after mandibular deviation corrected by the bilateral sagittal split ramus osteotomy (BSSRO) operation, since the reference facial sagittal plane for the asymmetry analysis is usually set up before the mandibular menton (Me) point correction. Our aim is to develop a predictive and quantitative method to assess the true asymmetry of the mandible after a midline correction performed by a virtual BSSRO, and to verify its availability by evaluation of the post-surgical improvement. Patients and Methods A retrospective cohort study was conducted at the Hospital of Stomatology, Sun Yat-sen University (China) of patients with pure hemi-mandibular elongation (HE) from September 2010 through May 2014. Mandibular models were reconstructed from CBCT images of patients with pre-surgical orthodontic treatment. After mandibular de-rotation and midline alignment with virtual BSSRO, the elongation hemi-mandible was virtually mirrored along the facial sagittal plane. The residual asymmetry, defined as the superimposition and boolean operation of the mirrored elongation side on the normal side, was calculated, including the volumetric differences and the length of transversal and vertical asymmetry discrepancy. For more specific evaluation, both sides of the hemi-mandible were divided into the symphysis and parasymphysis (SP), mandibular body (MB), and mandibular angle (MA) regions. Other clinical variables include deviation of Me point, dental midline and molar relationship. The measurement of volumetric discrepancy between the two sides of post-surgical hemi-mandible were also calculated to verify the availability of virtual surgery. Paired t-tests were computed and the P value was set at .05. Results This study included 45 patients. The volume differences were 407.8±64.8 mm3, 2139.1±72.5 mm3, and 422.5±36.9 mm3; residual average transversal discrepancy, 1.9 mm, 1.0 mm, and 2.2 mm; average vertical discrepancy, 1.1 mm, 2.2 mm, and 2

Comprehensive Analysis of Mandibular Residual Asymmetry after Bilateral Sagittal Split Ramus Osteotomy Correction of Menton Point Deviation.

PubMed

Lin, Han; Zhu, Ping; Lin, Qiuping; Huang, Xiaoqiong; Xu, Yue; Yang, Xiaoping

2016-01-01

Facial asymmetry often persists even after mandibular deviation corrected by the bilateral sagittal split ramus osteotomy (BSSRO) operation, since the reference facial sagittal plane for the asymmetry analysis is usually set up before the mandibular menton (Me) point correction. Our aim is to develop a predictive and quantitative method to assess the true asymmetry of the mandible after a midline correction performed by a virtual BSSRO, and to verify its availability by evaluation of the post-surgical improvement. A retrospective cohort study was conducted at the Hospital of Stomatology, Sun Yat-sen University (China) of patients with pure hemi-mandibular elongation (HE) from September 2010 through May 2014. Mandibular models were reconstructed from CBCT images of patients with pre-surgical orthodontic treatment. After mandibular de-rotation and midline alignment with virtual BSSRO, the elongation hemi-mandible was virtually mirrored along the facial sagittal plane. The residual asymmetry, defined as the superimposition and boolean operation of the mirrored elongation side on the normal side, was calculated, including the volumetric differences and the length of transversal and vertical asymmetry discrepancy. For more specific evaluation, both sides of the hemi-mandible were divided into the symphysis and parasymphysis (SP), mandibular body (MB), and mandibular angle (MA) regions. Other clinical variables include deviation of Me point, dental midline and molar relationship. The measurement of volumetric discrepancy between the two sides of post-surgical hemi-mandible were also calculated to verify the availability of virtual surgery. Paired t-tests were computed and the P value was set at .05. This study included 45 patients. The volume differences were 407.8±64.8 mm3, 2139.1±72.5 mm3, and 422.5±36.9 mm3; residual average transversal discrepancy, 1.9 mm, 1.0 mm, and 2.2 mm; average vertical discrepancy, 1.1 mm, 2.2 mm, and 2.2 mm (before virtual surgery). The

Thoracic Idiopathic Scoliosis Severity Is Highly Correlated with 3D Measures of Thoracic Kyphosis.

PubMed

Sullivan, T Barrett; Reighard, Fredrick G; Osborn, Emily J; Parvaresh, Kevin C; Newton, Peter O

2017-06-07

between scoliosis severity and loss of 3D kyphosis that was absent in the 2D analysis. A similarly strong correlation between curve magnitude and apical axial rotation was evident. These findings lend further credence to the concept that scoliosis progresses in the coronal, sagittal, and axial planes simultaneously. The findings of this study suggest that 3D assessment is critical for adequate characterization of the multiplanar deformity of idiopathic scoliosis and deformity in the sagittal plane is linked to deformity in the coronal plane. Increasing severity of coronal plane curvature is associated with a progressive loss of thoracic kyphosis that should be anticipated so that the appropriate intraoperative techniques for correction of idiopathic scoliosis can be applied in all 3 planes.

Evaluation of failing hemodialysis fistulas with multidetector CT angiography: comparison of different 3D planes.

PubMed

Karadeli, E; Tarhan, N C; Ulu, E M Kayahan; Tutar, N U; Basaran, O; Coskun, M; Niron, E A

2009-01-01

To evaluate failing hemodialysis fistula complications using 16-detector MDCTA, and to assess the accuracies of different 3D planes. Thirty patients (16 men, 14 women, aged 27-79 years) were referred for hemodialysis access dysfunction. Thirty-one MDCTA exams were done prior to fistulography. For MDCTA, contrast was administered (2mL/kg at 5mL/s) via a peripheral vein in the contralateral arm. Axial MIP, coronal MIP, and VRT images were constructed. Venous complications were evaluated on axial source images, on each 3D plane, and on all-planes together. Results were analyzed using McNemar test. Axial MIP, VRT and all-planes evaluations were most sensitive for fistula site detection (93%). Coronal MIP had the highest sensitivity, specificity and accuracy (35%, 96%, and 85%, respectively) for detecting venous stenosis. VRT and all-planes had the highest sensitivity and accuracy for detecting aneurysms (100%). All-planes and axial MIP were most sensitive for detecting venous occlusion (61% and 54%). Comparisons of detection frequencies for each venous pathology between the five categories of MDCTA revealed no significant differences (P>0.05). MDCTA additionally showed 3 partially thrombosed aneurysms, 4 anastomosis site stenosis and 12 arterial complications. MDCTA overall gives low sensitivity for detection of central vein stenosis and moderate sensitivity for occlusion. For most pathology, all-planes evaluation of MDCTA gives highest sensitivity and accuracy rates when compared to other planes. For venous stenosis and occlusion, MDCTA should be considered when ultrasonography and fistulography are inconclusive. MDCTA is helpful in identifying aneurysms, collaterals, partial venous thromboses and additional arterial, anastomosis site pathologies.

Returning Coronal Hole

NASA Image and Video Library

2017-02-06

A substantial coronal hole rotated across the face of the sun this past week and is again streaming solar wind towards Earth (Jan. 30 - Feb. 2, 2017). This same coronal hole was facing Earth about a month ago and has rotated into a similar position again. Coronal holes are areas of open magnetic field from which solar wind particles stream into space. In this wavelength of extreme ultraviolet light it appears as a dark area near the center and lower portion of the sun. Movies are available at http://photojournal.jpl.nasa.gov/catalog/PIA11177

Disruption of a coronal streamer by an eruptive prominence and coronal mass ejection

NASA Technical Reports Server (NTRS)

Illing, R. M. E.; Hundhausen, A. J.

1986-01-01

The coronal mass ejection of August 18, 1980 is analyzed using images from the coronagraph on the Solar Maximum Mission (SMM) satellite. The event occurred at the site of a large coronal helmet streamer and evolved into the three-part structure of a bright frontal shell, followed by a relatively dark space surrounding a bright filamentary core as seen in many mass ejections of the SMM epoch. The bright core can be identified as material from a prominence whose eruption was observed from the ground. The mass of the frontal shell is equal to that of the coronal helmet streamer, indicating that the shell is the coronal material previously in the helmet streamer, displaced and set into motion by the erupting prominence and surrounding cavity. The mass ejected in the bright core (or prominences) is estimated to be 50 percent larger than the 'coronal' material in the front loop.

Multiplanar lumbopelvic control in patients with low back pain: is multiplanar assessment better than single plane assessment in discriminating between patients and healthy controls?

PubMed

Nelson-Wong, E; Gallant, P; Alexander, S; Dehmer, K; Ingvalson, S; McClenahan, B; Piatte, A; Poupore, K; Davis, A M

2016-02-01

Patients with low back pain (LBP) commonly have lumbopelvic control deficits. Lumbopelvic assessment during sagittal motion is incorporated into commonly used clinical examination algorithms for Treatment Based Classification. The purpose of this study was to investigate whether combined assessment of lumbopelvic control during sagittal and frontal plane motion discriminates between people with and without LBP better than single plane assessment alone. Nineteen patients with LBP and 18 healthy control participants volunteered for this study. The active straight leg raise (ASLR) and active hip abduction (AHAbd) tests were used to assess lumbopelvic control during sagittal and frontal plane motion, respectively. The tests were scored as positive or negative using published scoring criteria. Contingency tables were created for each test alone and for the combined tests (both positive/both negative) with presence/absence of LBP as the reference standard to calculate accuracy statistics of sensitivity (sn), specificity (sp), likelihood (+LR and -LR), and diagnostic odds ratios (OR). Active straight leg raise and AHAbd tests alone had sn of 0·63, 0·74, respectively, sp of 0·61, 0·50, respectively, and OR of 2·7, 2·8, respectively. The combined tests had sn = 0·89, sp = 0·60, and OR = 12·0. Forty percent of patients with LBP had control deficits in both planes of motion. The AHAbd and ALSR tests appear to have greater diagnostic discrimination when used in combination than when used independently. A percentage of patients with LBP had control deficits in both planes, while others demonstrated uniplanar deficits only. These findings highlight the importance of multiplanar assessment in patients with LBP.

Using coronal seismology to estimate the magnetic field strength in a realistic coronal model

NASA Astrophysics Data System (ADS)

Chen, F.; Peter, H.

2015-09-01

Aims: Coronal seismology is used extensively to estimate properties of the corona, e.g. the coronal magnetic field strength is derived from oscillations observed in coronal loops. We present a three-dimensional coronal simulation, including a realistic energy balance in which we observe oscillations of a loop in synthesised coronal emission. We use these results to test the inversions based on coronal seismology. Methods: From the simulation of the corona above an active region, we synthesise extreme ultraviolet emission from the model corona. From this, we derive maps of line intensity and Doppler shift providing synthetic data in the same format as obtained from observations. We fit the (Doppler) oscillation of the loop in the same fashion as done for observations to derive the oscillation period and damping time. Results: The loop oscillation seen in our model is similar to imaging and spectroscopic observations of the Sun. The velocity disturbance of the kink oscillation shows an oscillation period of 52.5 s and a damping time of 125 s, which are both consistent with the ranges of periods and damping times found in observations. Using standard coronal seismology techniques, we find an average magnetic field strength of Bkink = 79 G for our loop in the simulation, while in the loop the field strength drops from roughly 300 G at the coronal base to 50 G at the apex. Using the data from our simulation, we can infer what the average magnetic field derived from coronal seismology actually means. It is close to the magnetic field strength in a constant cross-section flux tube, which would give the same wave travel time through the loop. Conclusions: Our model produced a realistic looking loop-dominated corona, and provides realistic information on the oscillation properties that can be used to calibrate and better understand the result from coronal seismology. A movie associated with Fig. 1 is available in electronic form at http://www.aanda.org

Radius morphology and its effects on rotation with contoured and noncontoured plating of the proximal radius.

PubMed

Rupasinghe, Shavantha L; Poon, Peter C

2012-05-01

The radius has a sagittal bow and a coronal bow. Fractures are often treated with volar anterior plating. However, the sagittal bow is often overlooked when plating. This study looks at radial morphology and the effect of plating the proximal radius with straight plates and then contoured plates bowed in the sagittal plane. We report our findings and their effect on forearm rotation. Morphology was investigated in 14 radii. Attention was paid to the proximal shaft of the radius and its sagittal bow; from this, 6-, 7-, and 8-hole plates were contoured to fit this bow. A simple transverse fracture was then made at the apex of this bow in 23 cadaver arms. Supination and pronation were compared when plating with a straight plate and a contoured plate. Ten cadavers underwent ulna plating at the same level. The effect on rotation of fractures plated in the distal-third shaft was also measured. A significant reduction in rotation was found when a proximal radius fracture was plated with a straight plate compared with a contoured plate: 10.8°, 12.8°, and 21.7° for 6-, 7-, and 8-hole plates, respectively (P < .05). Forearm rotation was decreased further when a longer plate was used. Ulna or distal shaft plating did not reduce rotation. This study has shown a significant sagittal bow of the proximal shaft of the radius. Plating this with contoured plates in the sagittal plane improves rotation when compared with straight plates. Additional ulna plating is not a source of reduced forearm rotation. Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Development of synthetic simulators for endoscope-assisted repair of metopic and sagittal craniosynostosis.

PubMed

Eastwood, Kyle W; Bodani, Vivek P; Haji, Faizal A; Looi, Thomas; Naguib, Hani E; Drake, James M

2018-06-01

OBJECTIVE Endoscope-assisted repair of craniosynostosis is a safe and efficacious alternative to open techniques. However, this procedure is challenging to learn, and there is significant variation in both its execution and outcomes. Surgical simulators may allow trainees to learn and practice this procedure prior to operating on an actual patient. The purpose of this study was to develop a realistic, relatively inexpensive simulator for endoscope-assisted repair of metopic and sagittal craniosynostosis and to evaluate the models' fidelity and teaching content. METHODS Two separate, 3D-printed, plastic powder-based replica skulls exhibiting metopic (age 1 month) and sagittal (age 2 months) craniosynostosis were developed. These models were made into consumable skull "cartridges" that insert into a reusable base resembling an infant's head. Each cartridge consists of a multilayer scalp (skin, subcutaneous fat, galea, and periosteum); cranial bones with accurate landmarks; and the dura mater. Data related to model construction, use, and cost were collected. Eleven novice surgeons (residents), 9 experienced surgeons (fellows), and 5 expert surgeons (attendings) performed a simulated metopic and sagittal craniosynostosis repair using a neuroendoscope, high-speed drill, rongeurs, lighted retractors, and suction/irrigation. All participants completed a 13-item questionnaire (using 5-point Likert scales) to rate the realism and utility of the models for teaching endoscope-assisted strip suturectomy. RESULTS The simulators are compact, robust, and relatively inexpensive. They can be rapidly reset for repeated use and contain a minimal amount of consumable material while providing a realistic simulation experience. More than 80% of participants agreed or strongly agreed that the models' anatomical features, including surface anatomy, subgaleal and subperiosteal tissue planes, anterior fontanelle, and epidural spaces, were realistic and contained appropriate detail. More

The Coronal Solar Magnetism Observatory

NASA Astrophysics Data System (ADS)

Tomczyk, S.; Landi, E.; Zhang, J.; Lin, H.; DeLuca, E. E.

2015-12-01

Measurements of coronal and chromospheric magnetic fields are arguably the most important observables required for advances in our understanding of the processes responsible for coronal heating, coronal dynamics and the generation of space weather that affects communications, GPS systems, space flight, and power transmission. The Coronal Solar Magnetism Observatory (COSMO) is a proposed ground-based suite of instruments designed for routine study of coronal and chromospheric magnetic fields and their environment, and to understand the formation of coronal mass ejections (CME) and their relation to other forms of solar activity. This new facility will be operated by the High Altitude Observatory of the National Center for Atmospheric Research (HAO/NCAR) with partners at the University of Michigan, the University of Hawaii and George Mason University in support of the solar and heliospheric community. It will replace the current NCAR Mauna Loa Solar Observatory (http://mlso.hao.ucar.edu). COSMO will enhance the value of existing and new observatories on the ground and in space by providing unique and crucial observations of the global coronal and chromospheric magnetic field and its evolution. The design and current status of the COSMO will be reviewed.

PROPELLER technique to improve image quality of MRI of the shoulder.

PubMed

Dietrich, Tobias J; Ulbrich, Erika J; Zanetti, Marco; Fucentese, Sandro F; Pfirrmann, Christian W A

2011-12-01

The purpose of this article is to evaluate the use of the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) technique for artifact reduction and overall image quality improvement for intermediate-weighted and T2-weighted MRI of the shoulder. One hundred eleven patients undergoing MR arthrography of the shoulder were included. A coronal oblique intermediate-weighted turbo spin-echo (TSE) sequence with fat suppression and a sagittal oblique T2-weighted TSE sequence with fat suppression were obtained without (standard) and with the PROPELLER technique. Scanning time increased from 3 minutes 17 seconds to 4 minutes 17 seconds (coronal oblique plane) and from 2 minutes 52 seconds to 4 minutes 10 seconds (sagittal oblique) using PROPELLER. Two radiologists graded image artifacts, overall image quality, and delineation of several anatomic structures on a 5-point scale (5, no artifact, optimal diagnostic quality; and 1, severe artifacts, diagnostically not usable). The Wilcoxon signed rank test was used to compare the data of the standard and PROPELLER images. Motion artifacts were significantly reduced in PROPELLER images (p < 0.001). Observer 1 rated motion artifacts with diagnostic impairment in one patient on coronal oblique PROPELLER images compared with 33 patients on standard images. Ratings for the sequences with PROPELLER were significantly better for overall image quality (p < 0.001). Observer 1 noted an overall image quality with diagnostic impairment in nine patients on sagittal oblique PROPELLER images compared with 23 patients on standard MRI. The PROPELLER technique for MRI of the shoulder reduces the number of sequences with diagnostic impairment as a result of motion artifacts and increases image quality compared with standard TSE sequences. PROPELLER sequences increase the acquisition time.

Posterior tibial slope in medial opening-wedge high tibial osteotomy: 2-D versus 3-D navigation.

PubMed

Yim, Ji Hyeon; Seon, Jong Keun; Song, Eun Kyoo

2012-10-01

Although opening-wedge high tibial osteotomy (HTO) is used to correct deformities, it can simultaneously alter tibial slope in the sagittal plane because of the triangular configuration of the proximal tibia, and this undesired change in tibial slope can influence knee kinematics, stability, and joint contact pressure. Therefore, medial opening-wedge HTO is a technically demanding procedure despite the use of 2-dimensional (2-D) navigation. The authors evaluated the posterior tibial slope pre- and postoperatively in patients who underwent navigation-assisted opening-wedge HTO and compared posterior slope changes for 2-D and 3-dimensional (3-D) navigation versions. Patients were randomly divided into 2 groups based on the navigation system used: group A (2-D guidance for coronal alignment; 17 patients) and group B (3-D guidance for coronal and sagittal alignments; 17 patients). Postoperatively, the mechanical axis was corrected to a mean valgus of 2.81° (range, 1°-5.4°) in group A and 3.15° (range, 1.5°-5.6°) in group B. A significant intergroup difference existed for the amount of posterior tibial slope change (Δ slope) pre- and postoperatively (P=.04).Opening-wedge HTO using navigation offers accurate alignment of the lower limb. In particular, the use of 3-D navigation results in significantly less change in the posterior tibial slope postoperatively than does the use of 2-D navigation. Accordingly, the authors recommend the use of 3-D navigation systems because they provide real-time intraoperative information about coronal, sagittal, and transverse axes and guide the maintenance of the native posterior tibial slope. Copyright 2012, SLACK Incorporated.

Intravertebral deformation in idiopathic scoliosis: a transverse plane computer tomographic study.

PubMed

Kotwicki, Tomasz; Napiontek, Marek

2008-03-01

The scoliotic vertebrae are submitted to (1) the displacement in the 3-dimensional space and (2) the bone remodeling, which results in a 3-dimensional intrinsic vertebral deformation. Both phenomena are most expressed inside the apical zone of the curve and can be measured in a computer tomographic (CT) scan. A comparative study of CT thoracic scans in scoliotic and normal children was performed to provide a better description of the altered anatomy with respect to patomechanism of scoliosis. Twenty-three scoliotic girls, aged 14.3 +/- 2.1 years, a case of a right thoracic curve with a Cobb angle of 60.6 +/- 19.3 degrees, and 24 controls, free of spinal deformity, sex- and age-matched, underwent CT examination of the thorax at the level of Th8 to Th9 vertebra. The rotation angle of the apical vertebra and the sagittal to coronal rib cage diameters ratio were measured. The intravertebral deformation was assessed by measuring the angles between the axis of the whole vertebra and the axes of the spinous or transverse processes. The ratio of sagittal to coronal chest diameter was reduced in scoliosis patients (P < 0.001) and correlated with the Cobb angle. The angle between the axis of vertebra and the spinous process increased (P = 0.008), and its value was positively correlated with the rotation angle of the vertebra (r = 0.78, P < 0.05); however, the rotation was oriented clockwise, whereas the spinous process deviation was counterclockwise. The angle between the spinous and the transverse process revealed greater values on the concave side (P < 0.001), whereas the transverse processes were not deviated from the axis of vertebra (P = 0.469). A constant pattern, previously not described, of the alteration of morphology of the apical vertebra due to the intravertebral bone remodeling was identified. The intravertebral deformation accompanied the displacement of the vertebra with a linear correlation; however, the 2 phenomena were developing in the opposite directions

Individual responses to alignment perturbations in socket reaction moments while walking in transtibial prostheses.

PubMed

Kobayashi, Toshiki; Orendurff, Michael S; Zhang, Ming; Boone, David A

2014-05-01

The alignment of transtibial prostheses has a systematic effect on the mean socket reaction moments in amputees. However, understanding their individual differences in response to alignment perturbations is also important for prosthetists to fully utilize the socket reaction moments for dynamic alignment in each unique patient. The aim of this study was to investigate individual responses to alignment perturbations in transtibial prostheses with solid-ankle-cushion-heel feet. A custom instrumented prosthesis alignment component was used to measure the socket reaction moments while walking in 11 amputees with transtibial prostheses under 17 alignment conditions, including 3° and 6° of flexion, extension, abduction, and adduction of the socket, 5mm and 10mm of anterior, posterior, lateral, and medial translation of the socket, and an initial baseline alignment. Coronal moments at 30% of stance and maximum sagittal moments were extracted for comparisons from each amputee. In the coronal plane, varus moment at 30% of stance was generally reduced by adduction or medial translation of the socket in all the amputees. In the sagittal plane, extension moment was generally increased by posterior translation or flexion of the socket; however, this was not necessarily the case for all the amputees. Individual responses to alignment perturbations are not always consistent, and prosthetists would need to be aware of this variance when addressing individual socket reaction moments during dynamic alignment in clinical setting. Copyright © 2014 Elsevier Ltd. All rights reserved.

Accuracy of external ventricular drainage catheter placement.

PubMed

Abdoh, Mohammad Ghazi; Bekaert, Olivier; Hodel, Jérôme; Diarra, Salia Mamadou; Le Guerinel, Caroline; Nseir, Rémi; Bastuji-Garin, Sylvie; Decq, Philippe

2012-01-01

External ventricular drainage (EVD) is a freehand neurosurgical procedure performed routinely using the anatomical landmarks. The aim of this study was to determine the accuracy of EVD catheter freehand placement. Pre-operative and post-operative computed tomography scans for 66 consecutive EVDs performed in 56 adult patients (26 men, 30 women) in 2008 were retrospectively reviewed. Etiologies of acute hydrocephalus were subarachnoid or intraventricular haemorrhage (43 cases) or miscellaneous (13 cases). Pre-operative lateral ventricular volume, position of the burr hole, length of the catheter and its sagittal and coronal angular variations from a theoretical trajectory were measured. The EVD was placed on the right (53 cases) or left (13 cases) side. The mean pre-operative lateral ventricular volume was 51 cc (10-118 cc). The average distance from the burr hole to the midline was 28 mm (10-49 mm) and to the supra-orbital ridge was 101 mm (75-125 mm). The mean intracranial catheter length was 60 mm (from 39-102 mm). Only 50% of the EVDs in the coronal plane and 40% in the sagittal plane were placed with an angular variation of ±5° to the target. The tip was placed outside of the ventricles in three cases; 13 catheters crossed the midline, and five intracranial minor haemorrhages were detected. Freehand placement of EVDs does not have sufficient accuracy and may lead to drainage dysfunctions. This data suggests that a guidance system for EVD's would be required.

Drilling the femoral tunnel during ACL reconstruction: transtibial versus anteromedial portal techniques.

PubMed

Tudisco, Cosimo; Bisicchia, Salvatore

2012-08-01

Incorrect bone tunnel position, particularly on the femoral side, is a frequent cause of failed anterior cruciate ligament reconstruction. Several studies have reported that drilling the femoral tunnel through the anteromedial portal allows a more anatomical placement on the lateral femoral condyle and higher knee stability than does transtibial reconstruction.In the current study, the femoral tunnel was drilled with transtibial (n=6) and anteromedial (n=6) portal techniques in 12 cadaveric knees. With appropriate landmarks inserted into bone tunnels, the direction and length of the tunnels were determined on anteroposterior and lateral radiographs. Knee stability was evaluated with a KT1000 arthrometer (MEDmetric Corporation, San Diego, California) and pivot shift test, comparing the pre- and postoperative values of both techniques. Finally, all knees were dissected to enhance vision of the insertion of the reconstructed ligament. The anteromedial portal technique led to better placement of the femoral tunnel in the coronal and sagittal planes, with higher knee stability according to the pivot shift test but not the KT1000 arthrometer. Anatomical and clinical results reported in the literature on transtibial and anteromedial portal techniques are controversial, but most of studies report better results with the anteromedial portal technique, especially regarding rotational stability. The current cadaveric study showed that the anteromedial portal technique provided better tunnel placement on the lateral femoral condyle in the coronal and sagittal planes, with an improvement in the rotational stability of the knee. Copyright 2012, SLACK Incorporated.

EUV Waves Driven by the Sudden Expansion of Transequatorial Loops Caused by Coronal Jets

NASA Astrophysics Data System (ADS)

Shen, Yuandeng; Tang, Zehao; Miao, Yuhu; Su, Jiangtao; Liu, Yu

2018-06-01

We present two events to study the driving mechanism of extreme-ultraviolet (EUV) waves that are not associated with coronal mass ejections (CMEs), by using high-resolution observations taken by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. Observational results indicate that the observed EUV waves were accompanied by flares and coronal jets, but not the CMEs that were regarded as drivers of most EUV waves in previous studies. In the first case, it is observed that a coronal jet is ejected along a transequatorial loop system at a plane-of-the-sky (POS) speed of 335 ± 22 km s{}-1; in the meantime, an arc-shaped EUV wave appeared on the eastern side of the loop system. In addition, the EUV wave further interacted with another interconnecting loop system and launched a fast propagating (QFP) magnetosonic wave along the loop system, which had a period of 200 s and a speed of 388 ± 65 km s{}-1, respectively. In the second case, we observed a coronal jet that ejected at a POS speed of 282 ± 44 km s{}-1 along a transequatorial loop system as well as the generation of bright EUV waves on the eastern side of the loop system. Based on the observational results, we propose that the observed EUV waves on the eastern side of the transequatorial loop systems are fast-mode magnetosonic waves and that they are driven by the sudden lateral expansion of the transequatorial loop systems due to the direct impingement of the associated coronal jets, while the QFP wave in the fist case formed due to the dispersive evolution of the disturbance caused by the interaction between the EUV wave and the interconnecting coronal loops. It is noted that EUV waves driven by sudden loop expansions have shorter lifetimes than those driven by CMEs.

Vertebral coplanar alignment: a standardized technique for three dimensional correction in scoliosis surgery: technical description and preliminary results in Lenke type 1 curves.

PubMed

Vallespir, Gabriel Pizà; Flores, Jesús Burgos; Trigueros, Ignacio Sanpera; Sierra, Eduardo Hevia; Fernández, Pedro Doménech; Olaverri, Juan Carlos Rodríguez; Alonso, Manuel García; Galea, Rafael Ramos; Francisco, Antonio Pérez; Rodríguez de Paz, Beatriz; Carbonell, Pedro Gutiérrez; Thomas, Javier Vicente; López, José Luís González; Paulino, José Ignacio Maruenda; Pitarque, Carlos Barrios; García, Oscar Riquelme

2008-06-15

Prospective multicentric study. To present the preliminary results of an innovative method for standardized correction of scoliosis, vertebral coplanar alignment (VCA), based on a novel concept: the relocation of vertebral axis in a single plane. Normal standing spine has no rotation in coronal or transverse planes, therefore X and Z axis of vertebrae are in the same plane: they are coplanar. VCA intends to relocate these axis in one plane, correcting rotation and translation, while X axis are returned to its normal posterior divergence in sagittal plane in thoracic spine. Twenty-five consecutive adolescent idiopathic scoliosis patients (Lenke type 1) underwent posterior surgery with segmental pedicle screw fixation. Slotted tubes were attached to convex side screws. Two longitudinal rods were inserted through the end of tubes. Then, they were separated along the slots, driving the tubes into one plane, making the axis of the vertebrae coplanar and thus correcting transverse rotation and coronal translation. To obtain kyphosis, distal ends of the tubes were spread in thoracic spine. Correction was maintained by locking a definitive rod in the concave side, then tubes were retrieved and the convex side rod, inserted and tightened. Correction was assessed on preoperative and postoperative full-spine standing radiograph. Vertebral rotation was measured on computed tomography-scan and magnetic resonance imaging. Preoperative average thoracic curves of 61 degrees were corrected to 16 degrees (73%). Preoperative average thoracolumbar curves of 39 degrees were corrected to 12 degrees (70%). Preoperative average thoracic apical rotation of 24 degrees was corrected to 11 degrees (56%). Preoperative average thoracic kyphosis of 18 degrees remained unchanged after surgery; however, no patients had kyphosis <10 degrees after surgery. Rib hump improved from 30 to 11 mm (65%). There were no perioperative complications. VCA provided excellent correction of coronal and transverse

Walking sagittal balance correction by pedicle subtraction osteotomy in adults with fixed sagittal imbalance.

PubMed

Yagi, Mitsuru; Kaneko, Shinjiro; Yato, Yoshiyuki; Asazuma, Takashi; Machida, Masafumi

2016-08-01

Pedicle subtraction osteotomy (PSO) is widely used to treat severe fixed sagittal imbalance. However, the effect of PSO on balance has not been fully documented. The aim of this study was to assess dynamic walking balance after PSO to treat fixed sagittal imbalance. Gait and balance were assessed in 15 consecutive adult female patients who had been treated by PSO for a fixed sagittal imbalance and compare patients' preop and postop dynamic walking balance with that of 15 age- and gender-matched healthy volunteers (HV). Each patient's chart, X-rays, pre and postop SRS22 outcome scores, and ODI were reviewed. Means were compared by Mann-Whitney U test and Chi-square test. The mean age was 66.3 years (51-74 years). The mean follow-up was 2.7 years (2-3.5 years). The C7PL and GL, measured on the force platform, were both improved from 24.2 ± 7.3 cm and 27.6 ± 9.4 to 5.4 ± 2.6 cm and 7.2 ± 3.4 cm, respectively. The baseline hip ROM was significantly smaller in patients compared to HV, whereas no significant difference was observed in the knee or ankle ROM. The pelvic tilt (preop -0.4° ± 1.4°, postop 8.9° ± 1.0°), and maximum hip-extension angle (preop -1.2° ± 14.2°, postop -11.2° ± 7.2°) were also improved after surgery. Cadence (116 s/min), stance-swing ratio (stance 63.2 % vs. swing 36.8 %), and stride (98.0 cm) were all increased after surgery. On the other hand, gait velocity was significantly slower in the PSO group at both pre and postop than in HV (PSO 53.3 m/min at preop and 58.8 m/min at postop vs. HV 71.1 m/min, p = 0.04). Despite a mild residual spinal-pelvic malalignment, PSO restored sagittal alignment and balance satisfactorily and has improved the gait pattern.

Coronal Structures in Cool Stars: XMM-NEWTON Hybrid Stars and Coronal Evolution

NASA Technical Reports Server (NTRS)

Dupree, Andrea K.; Mushotzky, Richard (Technical Monitor)

2003-01-01

This program addresses the evolution of stellar coronas by comparing a solar-like corona in the supergiant Beta Dra (G2 Ib-IIa) to the corona in the allegedly more evolved state of a hybrid star, alpha TrA (K2 II-III). Because the hybrid star has a massive wind, it appears likely that the corona will be cooler and less dense as the magnetic loop structures are no longer closed. By analogy with solar coronal holes, when the topology of the magnetic field is configured with open magnetic structures, both the coronal temperature and density are lower than in atmospheres dominated by closed loops. The hybrid stars assume a pivotal role in the definition of coronal evolution, atmospheric heating processes and mechanisms to drive winds of cool stars. We are attempting to determine if this model of coronal evolution is correct by using XMM-NEWTON RGS spectra for the 2 targets we were allocated through the Guest Observer program.

Coronal Hole Coming Around

NASA Image and Video Library

2016-12-06

A substantial coronal hole began to rotate into view over the past few days (Dec. 1-2, 2016). Coronal holes are magnetically open areas of the sun's magnetic field structure that spew streams of high speed solar wind into space. In about a week or so that coronal hole might send streams of particles in the direction of Earth. Often times these streams can interact with Earth's magnetosphere and generate aurora. The images were taken in a wavelength of extreme ultraviolet light. Movies are available at http://photojournal.jpl.nasa.gov/catalog/PIA21208

Characterizing head motion in three planes during combined visual and base of support disturbances in healthy and visually sensitive subjects.

PubMed

Keshner, E A; Dhaher, Y

2008-07-01

Multiplanar environmental motion could generate head instability, particularly if the visual surround moves in planes orthogonal to a physical disturbance. We combined sagittal plane surface translations with visual field disturbances in 12 healthy (29-31 years) and 3 visually sensitive (27-57 years) adults. Center of pressure (COP), peak head angles, and RMS values of head motion were calculated and a three-dimensional model of joint motion was developed to examine gross head motion in three planes. We found that subjects standing quietly in front of a visual scene translating in the sagittal plane produced significantly greater (p<0.003) head motion in yaw than when on a translating platform. However, when the platform was translated in the dark or with a visual scene rotating in roll, head motion orthogonal to the plane of platform motion significantly increased (p<0.02). Visually sensitive subjects having no history of vestibular disorder produced large, delayed compensatory head motion. Orthogonal head motions were significantly greater in visually sensitive than in healthy subjects in the dark (p<0.05) and with a stationary scene (p<0.01). We concluded that motion of the visual field could modify compensatory response kinematics of a freely moving head in planes orthogonal to the direction of a physical perturbation. These results suggest that the mechanisms controlling head orientation in space are distinct from those that control trunk orientation in space. These behaviors would have been missed if only COP data were considered. Data suggest that rehabilitation training can be enhanced by combining visual and mechanical perturbation paradigms.

Can a single isotropic 3D fast spin echo sequence replace three-plane standard proton density fat-saturated knee MRI at 1.5 T?

PubMed Central

Robinson, P; Hodgson, R; Grainger, A J

2015-01-01

Objective: To assess whether a single isotropic three-dimensional (3D) fast spin echo (FSE) proton density fat-saturated (PD FS) sequence reconstructed in three planes could replace the three PD (FS) sequences in our standard protocol at 1.5 T (Siemens Avanto, Erlangen, Germany). Methods: A 3D FSE PD water excitation sequence was included in the protocol for 95 consecutive patients referred for routine knee MRI. This was used to produce offline reconstructions in axial, sagittal and coronal planes. Two radiologists independently assessed each case twice, once using the standard MRI protocol and once replacing the standard PD (FS) sequences with reconstructions from the 3D data set. Following scoring, the observer reviewed the 3D data set and performed multiplanar reformats to see if this altered confidence. The menisci, ligaments and cartilage were assessed, and statistical analysis was performed using the standard sequence as the reference standard. Results: The reporting accuracy was as follows: medial meniscus (MM) = 90.9%, lateral meniscus (LM) = 93.7%, anterior cruciate ligament (ACL) = 98.9% and cartilage surfaces = 85.8%. Agreement among the readers was for the standard protocol: MM kappa = 0.91, LM = 0.89, ACL = 0.98 and cartilage = 0.84; and for the 3D protocol: MM = 0.86, LM = 0.77, ACL = 0.94 and cartilage = 0.64. Conclusion: A 3D PD FSE sequence reconstructed in three planes gives reduced accuracy and decreased concordance among readers compared with conventional sequences when evaluating the menisci and cartilage with a 1.5-T MRI scanner. Advances in knowledge: Using the existing 1.5-T MR systems, a 3D FSE sequence should not replace two-dimensional sequences. PMID:26067920

Large-Scale Coronal Heating, Clustering of Coronal Bright Points, and Concentration of Magnetic Flux

NASA Technical Reports Server (NTRS)

Falconer, D. A.; Moore, R. L.; Porter, J. G.; Hathaway, D. H.

1998-01-01

By combining quiet-region Fe XII coronal images from SOHO/EIT with magnetograms from NSO/Kitt Peak and from SOHO/MDI, we show that on scales larger than a supergranule the population of network coronal bright points and the magnetic flux content of the network are both markedly greater under the bright half of the quiet corona than under the dim half. These results (1) support the view that the heating of the entire corona in quiet regions and coronal holes is driven by fine-scale magnetic activity (microflares, explosive events, spicules) seated low in the magnetic network, and (2) suggest that this large-scale modulation of the magnetic flux and coronal heating is a signature of giant convection cells.

Sagittal alignment of the cervical spine after neck injury.

PubMed

Beltsios, Michail; Savvidou, Olga; Mitsiokapa, Evanthia A; Mavrogenis, Andreas F; Kaspiris, Angelos; Efstathopoulos, Nikolaos; Papagelopoulos, Panayiotis J

2013-07-01

The normal sagittal alignment of the cervical spine is lordotic and is affected by the posture of the head and neck. The question of whether loss of cervical lordosis is the result of muscle spasm after injury or a normal variation, and the clinical significance of such changes in sagittal profile of the cervical spine has been an issue of several studies. The purpose of this paper is to study the incidence of normal cervical lordosis and its changes after neck injury compared to the healthy population. We studied the lateral radiographs of the cervical spine of 60 patients with neck injury compared to 100 patients without a neck injury. Lateral radiographs were obtained in the standing or sitting position, and the curvature of the cervical spine was measured using the angle formed between the inferior end plates of the C2 and C7 vertebrae. In the patients without neck injury, lordotic and straight cervical spine sagittal alignment was observed in 36.5% each, double curvature in 17%, and kyphotic in 10%. In the patients with neck injury, lordotic sagittal alignment was observed in 36%, straight in 34%, double curvature in 26% and kyphotic in 4%. No significant difference between the two groups regarding all types of sagittal alignment of the cervical spine was found (p > 0.100). The alterations in normal cervical lordosis in patients with neck injury must be considered coincidental. These alterations should not be associated with muscle spasm caused by neck pain.

Coroners and death certification law reform: the Coroners and Justice Act 2009 and its aftermath.

PubMed

Luce, Tom

2010-10-01

After considering various different options for half a decade, the last Government legislated in 2009 to reform the England and Wales coroner and death certification systems. The Coroners and Justice Act 2009 provides for the creation of a new Chief Coroner post to lead the jurisdiction and for local medical examiners to oversee a new death certification scheme applicable equally to burial and cremation cases. In October 2010 the new Government announced that it judges the main coroner reform to be unaffordable, will not proceed with it and plans to repeal the provisions. It intends to implement the new death certification arrangements, which is welcome. The decision to abort the main coroner reform in spite of longstanding and widespread recognition of the need for major change is deplorable though in line with other failures over the last century to properly modernise this neglected service.

Key aspects of coronal heating

PubMed Central

Klimchuk, James A.

2015-01-01

We highlight 10 key aspects of coronal heating that must be understood before we can consider the problem to be solved. (1) All coronal heating is impulsive. (2) The details of coronal heating matter. (3) The corona is filled with elemental magnetic stands. (4) The corona is densely populated with current sheets. (5) The strands must reconnect to prevent an infinite build-up of stress. (6) Nanoflares repeat with different frequencies. (7) What is the characteristic magnitude of energy release? (8) What causes the collective behaviour responsible for loops? (9) What are the onset conditions for energy release? (10) Chromospheric nanoflares are not a primary source of coronal plasma. Significant progress in solving the coronal heating problem will require coordination of approaches: observational studies, field-aligned hydrodynamic simulations, large-scale and localized three-dimensional magnetohydrodynamic simulations, and possibly also kinetic simulations. There is a unique value to each of these approaches, and the community must strive to coordinate better. PMID:25897094

Coronal Hole Faces Earth

NASA Image and Video Library

2017-08-14

A substantial coronal hole rotated into a position where it is facing Earth (Aug. 9-11, 2017). Coronal holes are areas of open magnetic field that spew out charged particles as solar wind that spreads into space. If that solar wind interacts with our own magnetosphere it can generate aurora. In this view of the sun in extreme ultraviolet light, the coronal hole appears as the dark stretch near the center of the sun. It was the most distinctive feature on the sun over the past week. Movies are available at https://photojournal.jpl.nasa.gov/catalog/PIA21874

Transverse Oscillations of Coronal Loops

NASA Astrophysics Data System (ADS)

Ruderman, Michael S.; Erdélyi, Robert

2009-12-01

On 14 July 1998 TRACE observed transverse oscillations of a coronal loop generated by an external disturbance most probably caused by a solar flare. These oscillations were interpreted as standing fast kink waves in a magnetic flux tube. Firstly, in this review we embark on the discussion of the theory of waves and oscillations in a homogeneous straight magnetic cylinder with the particular emphasis on fast kink waves. Next, we consider the effects of stratification, loop expansion, loop curvature, non-circular cross-section, loop shape and magnetic twist. An important property of observed transverse coronal loop oscillations is their fast damping. We briefly review the different mechanisms suggested for explaining the rapid damping phenomenon. After that we concentrate on damping due to resonant absorption. We describe the latest analytical results obtained with the use of thin transition layer approximation, and then compare these results with numerical findings obtained for arbitrary density variation inside the flux tube. Very often collective oscillations of an array of coronal magnetic loops are observed. It is natural to start studying this phenomenon from the system of two coronal loops. We describe very recent analytical and numerical results of studying collective oscillations of two parallel homogeneous coronal loops. The implication of the theoretical results for coronal seismology is briefly discussed. We describe the estimates of magnetic field magnitude obtained from the observed fundamental frequency of oscillations, and the estimates of the coronal scale height obtained using the simultaneous observations of the fundamental frequency and the frequency of the first overtone of kink oscillations. In the last part of the review we summarise the most outstanding and acute problems in the theory of the coronal loop transverse oscillations.

Higher-speed coronal mass ejections and their geoeffectiveness

NASA Astrophysics Data System (ADS)

Singh, A. K.; Bhargawa, Asheesh; Tonk, Apeksha

2018-06-01

We have attempted to examine the ability of coronal mass ejections to cause geoeffectiveness. To that end, we have investigated total 571 cases of higher-speed (> 1000 km/s) coronal mass ejection events observed during the years 1996-2012. On the basis of angular width (W) of observance, events of coronal mass ejection were further classified as front-side or halo coronal mass ejections (W = 360°); back-side halo coronal mass ejections (W = 360°); partial halo (120°< W < 360°) and non-halo (W < 120°). From further analysis, we found that front halo coronal mass ejections were much faster and more geoeffective in comparison of partial halo and non-halo coronal mass ejections. We also inferred that the front-sided halo coronal mass ejections were 67.1% geoeffective while geoeffectiveness of partial halo coronal mass ejections and non-halo coronal mass ejections were found to be 44.2% and 56.6% respectively. During the same period of observation, 43% of back-sided CMEs showed geoeffectiveness. We have also investigated some events of coronal mass ejections having speed > 2500 km/s as a case study. We have concluded that mere speed of coronal mass ejection and their association with solar flares or solar activity were not mere criterion for producing geoeffectiveness but angular width of coronal mass ejections and their originating position also played a key role.

Diffraction crystal for sagittally focusing x-rays

DOEpatents

Ice, Gene E.; Sparks, Jr., Cullie J.

1984-01-01

The invention is a new type of diffraction crystal designed for sagittally focusing photons of various energies. The invention is based on the discovery that such focusing is not obtainable with conventional crystals because of distortion resulting from anticlastic curvature. The new crystal comprises a monocrystalline base having a front face contoured for sagittally focusing photons and a back face provided with rigid, upstanding, stiffening ribs restricting anticlastic curvature. When mounted in a suitable bending device, the reflecting face of the crystal can be adjusted to focus photons having any one of a range of energies.

Diffraction crystals for sagittally focusing x-rays

DOEpatents

Ice, G.E.; Sparks, C.J. Jr.

1982-06-07

The invention is a new type of diffraction crystal designed for sagittally focusing photons of various energies. The invention is based on the discovery that such focusing is not obtainable with conventional crystals because of distortion resulting from anticlastic curvature. The new crystal comprises a monocrystalline base having a front face contoured for sagittally focusing photons and a back face provided with rigid, upstanding, stiffening ribs restricting anticlastic curvature. When mounted in a suitable bending device, the reflecting face of the crystal can be adjusted to focus photons having any one of a range of energies.

Dynamic simulation of coronal mass ejections

NASA Technical Reports Server (NTRS)

Steinolfson, R. S.; Wu, S. T.

1980-01-01

A model is developed for the formation and propagation through the lower corona of the loop-like coronal transients in which mass is ejected from near the solar surface to the outer corona. It is assumed that the initial state for the transient is a coronal streamer. The initial state for the streamer is a polytropic, hydrodynamic solution to the steady-state radial equation of motion coupled with a force-free dipole magnetic field. The numerical solution of the complete time-dependent equations then gradually approaches a stationary coronal streamer configuration. The streamer configuration becomes the initial state for the coronal transient. The streamer and transient simulations are performed completely independent of each other. The transient is created by a sudden increase in the pressure at the base of the closed-field region in the streamer configuration. Both coronal streamers and coronal transients are calculated for values of the plasma beta (the ratio of thermal to magnetic pressure) varying from 0.1 to 100.

How is sagittal balance acquired during bipedal gait acquisition? Comparison of neonatal and adult pelves in three dimensions. Evolutionary implications.

PubMed

Tardieu, Christine; Bonneau, Noémie; Hecquet, Jérôme; Boulay, Christophe; Marty, Catherine; Legaye, Jean; Duval-Beaupère, Geneviève

2013-08-01

We compare adult and intact neonatal pelves, using a pelvic sagittal variable, the angle of sacral incidence, which presents significant correlations with vertebral curvature in adults and plays an important role in sagittal balance of the trunk on the lower limbs. Since the lumbar curvature develops in the child in association with gait acquisition, we expect a change in this angle during growth which could contribute to the acquisition of sagittal balance. To understand the mechanisms underlying the sagittal balance in the evolution of human bipedalism, we also measure the angle of incidence of hominid fossils. Fourty-seven landmarks were digitized on 50 adult and 19 intact neonatal pelves. We used a three-dimensional model of the pelvis (DE-VISU program) which calculates the angle of sacral incidence and related functional variables. Cross-sectional data from newborns and adults show that the angle of sacral incidence increases and becomes negatively correlated with the sacro-acetabular distance. During ontogeny the sacrum becomes curved, tends to sink down between the iliac blades as a wedge and moves backward in the sagittal plane relative to the acetabula, thus contributing to the backwards displacement of the center of gravity of the trunk. A chain of correlations links the degree of the sacral slope and of the angle of incidence, which is tightly linked with the lumbar lordosis. We sketch a model showing the coordinated changes occurring in the pelvis and vertebral column during the acquisition of bipedalism in infancy. In the australopithecine pelves, Sts 14 and AL 288-1, and in the Homo erectus Gona pelvis the angle of sacral incidence reaches the mean values of humans. Discussing the incomplete pelves of Ardipithecus ramidus, Australopithecus sediba and the Nariokotome Boy, we suggest how the functional linkage between pelvis and spine, observed in humans, could have emerged during hominid evolution. Copyright © 2013 Elsevier Ltd. All rights reserved.

Radio Studies of Coronal Holes.

DTIC Science & Technology

1981-03-01

Withbroe (1978) has pointed out, "The transport of energy by thermal conduction into the transition zone is a primary coronal cooling mechanism." Thus, the...temperature and particle density gradients in the transition zone are of critical importance in understanding the energy balance of a coronal hole. The...coronal hole has been provided by Konp and Orrall (1977), but a quantitative understanding requires a detailed knowledge of the energy balance in the

An equatorial coronal hole at solar minimum

NASA Technical Reports Server (NTRS)

Bromage, B. J. I.; DelZanna, G.; DeForest, C.; Thompson, B.; Clegg, J. R.

1997-01-01

The large transequatorial coronal hole that was observed in the solar corona at the end of August 1996 is presented. It consists of a north polar coronal hole called the 'elephant's trunk or tusk'. The observations of this coronal hole were carried out with the coronal diagnostic spectrometer onboard the Solar and Heliospheric Observatory (SOHO). The magnetic field associated with the equatorial coronal hole is strongly connected to that of the active region at its base, resulting in the two features rotating at almost the same rate.

Alignment and component position after patient-matched instrumentation versus conventional total knee arthroplasty.

PubMed

Pourgiezis, N; Reddy, S P; Nankivell, M; Morrison, G; VanEssen, J

2016-08-01

To compare patient-matched instrumentation (PMI) with conventional total knee arthroplasty (TKA) in terms of limb alignment and component position. Nine men and 36 women (mean age, 69.5 years) who underwent PMI TKA were compared with 20 men and 25 women (mean age, 69.3 years) who underwent conventional TKA by the same team of surgeons with the same prosthesis and protocols in terms of limb alignment and component position using the Perth protocol computed tomography, as well as bone resection measurements, operating time, and the number of trays used. The PMI and conventional TKA groups were comparable in terms of age, body mass index, tourniquet time, operating time, and the number of trays used. For limb alignment and component position, the 2 groups differed significantly in sagittal femoral component position (2.4º vs. 0.9º, p=0.0008) and the percentage of knees with femoral component internally rotated ≥1° with respect to the transepicondylar axis (20% vs. 55%, p=0.001). The difference was not significant in terms of limb alignment, coronal and rotational femoral component position, or coronal and sagittal tibial component position. Intra-operatively, all patient-matched cutting blocks demonstrated acceptable fit and stability. No instrument-related adverse events or complications were encountered. One (2.2%) femur and 6 (13.3%) tibiae were recut 2 mm for optimal ligament balancing. Two femoral components were upsized to the next size, and 2 tibial components were upsized and 2 downsized to the next size. PMI was as accurate as conventional instrumentation in TKA. There was no significant difference in limb alignment or femoral and tibial component position in the coronal and sagittal planes between PMI and conventional TKA. PMI had a higher tendency to achieve correct femoral component rotation.

Solar radio bursts of spectral type II, coronal shocks, and optical coronal transients

NASA Technical Reports Server (NTRS)

Maxwell, A.; Dryer, M.

1981-01-01

An examination is presented of the association of solar radio bursts of spectral type II and coronal shocks with solar flare ejecta observed in H-alpha, the green coronal line, and white-light coronagraphs. It is suggested that fast-moving optical coronal transients should for the most part be identified with piston-type phenomena well behind the outward-traveling shock waves that generate type II radio bursts. A general model is presented which relates type II radio bursts and coronal shocks to optically observed ejecta and consists of three main velocity regimes: (1) a quasi-hemispherical shock wave moving outward from the flare at speeds of 1000-2000 km/sec and Alfven Mach number of about 1.5; (2) the velocity of the piston driving the shock, on the order of 0.8 that of the shock; and (3) the regime of the slower-moving H-alpha ejecta, with velocities of 300-500 km/sec.

Sagittal band, boutonniere, and pulley injuries in the athlete.

PubMed

Grandizio, Louis Christopher; Klena, Joel Christian

2017-03-01

While hand injuries occur frequently in the athletic population, sagittal band ruptures, boutonniere deformities, and pulley ruptures are infrequently encountered. These injuries represent diagnostic challenges and can result in significant impairment. Early recognition with appropriate treatment is necessary to maximize recovery and minimize return to athletic competition. This review will focus on the underlying mechanism, pathophysiology of injury, diagnosis, and treatment of each of these injuries. With respect to sagittal band ruptures, boutonniere deformities, and pulley ruptures, the recent literature has been limited in scope. For sagittal band injuries, current efforts have focused on alternative techniques for sagittal band reconstruction. Little progress has been made in recent years with respect to boutonniere injuries in the athletic population; prevention of fixed deformities remains the backbone of treatment. The exact contribution from individual and combined pulley injuries in the creation of bowstringing remains controversial. Recent anatomical studies have failed to definitively answer the question of what degree of rupture is necessary to create symptomatic bowstringing. Favorable outcomes, with respect to both preventing bowstringing and returning to full athletic participation, have been newly reported following pulley reconstruction in rock climbers. Due to the infrequent nature of sagittal band ruptures, boutonniere deformities, and pulley ruptures, current treatment is mostly guided by historically established methods, limited case series, and case reports. Nonsurgical treatment remains the mainstay for most injuries and, if employed early, often precludes the need for surgery. Further anatomical and clinical research, including outcome studies, is necessary in guiding treatment algorithms.

Interceptive orthopedics for the correction of maxillary transverse and sagittal deficiency in the early mixed dentition period

PubMed Central

Talapaneni, Ashok Kumar; Kumar, Karnati Praveen; Kommi, Pradeep Babu; Nuvvula, Sivakumar

2011-01-01

Dentofacial Orthopedics directed to a hypoplastic maxilla in the prepubertal period redirects growth of the maxilla in the vertical, transverse and sagittal planes of space. The orthopedic correction of maxillary hypoplasia in the early mixed dentition period thus intercepts the establishment of permanent structural asymmetry in the mandible and helps in the achievement of optimal dentofacial esthetics. This paper presents the growth redirection in a hypoplastic maxilla of an 8-year-old girl with simultaneous rapid maxillary expansion and protraction headgear therapy for a period of 11 months which corrected the posterior unilateral cross-bite, the positional asymmetry of the mandible and established an orthognathic profile in the individual. PMID:22346162

Coronal Seismology -- Achievements and Perspectives

NASA Astrophysics Data System (ADS)

Ruderman, Michael

Coronal seismology is a new and fast developing branch of the solar physics. The main idea of coronal seismology is the same as of any branches of seismology: to determine basic properties of a medium using properties of waves propagating in this medium. The waves and oscillations in the solar corona are routinely observed in the late space missions. In our brief review we concentrate only on one of the most spectacular type of oscillations observed in the solar corona - the transverse oscillations of coronal magnetic loops. These oscillations were first observed by TRACE on 14 July 1998. At present there are a few dozens of similar observations. Shortly after the first observation of the coronal loop transverse oscillations they were interpreted as kink oscillations of magnetic tubes with the ends frozen in the dense photospheric plasma. The frequency of the kink oscillation is proportional to the magnetic field magnitude and inversely proportional to the tube length times the square root of the plasma density. This fact was used to estimate the magnetic field magnitude in the coronal loops. In 2004 the first simultaneous observation of the fundamental mode and first overtone of the coronal loop transverse oscillation was reported. If we model a coronal loop as a homogeneous magnetic tube, then the ratio of the frequencies of the first overtone and the fundamental mode should be equal to 2. However, the ratio of the observed frequencies was smaller than 2. This is related to the density variation along the loop. If we assume that the corona is isothermal and prescribe the loop shape (usually it is assumed that it has the shape of half-circle), then, using the ratio of the two frequencies, we can determine the temperature of the coronal plasma. The first observation of transverse oscillations of the coronal loops showed that they were strongly damped. This phenomenon was confirmed by the subsequent observations. At present, the most reliable candidate for the

Characterizing Head Motion in 3 Planes during Combined Visual and Base of Support Disturbances in Healthy and Visually Sensitive Subjects

PubMed Central

Keshner, E.A.; Dhaher, Y.

2008-01-01

Multiplanar environmental motion could generate head instability, particularly if the visual surround moves in planes orthogonal to a physical disturbance. We combined sagittal plane surface translations with visual field disturbances in 12 healthy (29–31 years) and 3 visually sensitive (27–57 years) adults. Center of pressure (COP), peak head angles, and RMS values of head motion were calculated and a 3-dimensional model of joint motion11 was developed to examine gross head motion in 3 planes. We found that subjects standing quietly in front of a visual scene translating in the sagittal plane produced significantly greater (p<0.003) head motion in yaw than when on a translating platform. However, when the platform was translated in the dark or with a visual scene rotating in roll, head motion orthogonal to the plane of platform motion significantly increased (p<0.02). Visually sensitive subjects having no history of vestibular disorder produced large, delayed compensatory head motion. Orthogonal head motions were significantly greater in visually sensitive than in healthy subjects in the dark (p<0.05) and with a stationary scene (p<0.01). We concluded that motion of the visual field can modify compensatory response kinematics of a freely moving head in planes orthogonal to the direction of a physical perturbation. These results suggest that the mechanisms controlling head orientation in space are distinct from those that control trunk orientation in space. These behaviors would have been missed if only COP data were considered. Data suggest that rehabilitation training can be enhanced by combining visual and mechanical perturbation paradigms. PMID:18162402

Multidimensional Modeling of Coronal Rain Dynamics

NASA Astrophysics Data System (ADS)

Fang, X.; Xia, C.; Keppens, R.

2013-07-01

We present the first multidimensional, magnetohydrodynamic simulations that capture the initial formation and long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host a chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes of physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into V-shaped features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views of blobs that evaporate in situ or are siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys of coronal rain showers in true multidimensional settings to connect parameterized heating prescriptions with rain statistics, ultimately allowing us to quantify the coronal heating input.

Level-dependent coronal and axial moment-rotation corridors of degeneration-free cervical spines in lateral flexion.

PubMed

Yoganandan, Narayan; Pintar, Frank A; Stemper, Brian D; Wolfla, Christopher E; Shender, Barry S; Paskoff, Glenn

2007-05-01

Aging, trauma, or degeneration can affect intervertebral kinematics. While in vivo studies can determine motions, moments are not easily quantified. Previous in vitro studies on the cervical spine have largely used specimens from older individuals with varying levels of degeneration and have shown that moment-rotation responses under lateral bending do not vary significantly by spinal level. The objective of the present in vitro biomechanical study was, therefore, to determine the coronal and axial moment-rotation responses of degeneration-free, normal, intact human cadaveric cervicothoracic spinal columns under the lateral bending mode. Nine human cadaveric cervical columns from C2 to T1 were fixed at both ends. The donors had ranged from twenty-three to forty-four years old (mean, thirty-four years) at the time of death. Retroreflective targets were inserted into each vertebra to obtain rotational kinematics in the coronal and axial planes. The specimens were subjected to pure lateral bending moment with use of established techniques. The range-of-motion and neutral zone metrics for the coronal and axial rotation components were determined at each level of the spinal column and were evaluated statistically. Statistical analysis indicated that the two metrics were level-dependent (p < 0.05). Coronal motions were significantly greater (p < 0.05) than axial motions. Moment-rotation responses were nonlinear for both coronal and axial rotation components under lateral bending moments. Each segmental curve for both rotation components was well represented by a logarithmic function (R(2) > 0.95). Range-of-motion metrics compared favorably with those of in vivo investigations. Coronal and axial motions of degeneration-free cervical spinal columns under lateral bending showed substantially different level-dependent responses. The presentation of moment-rotation corridors for both metrics forms a normative dataset for the degeneration-free cervical spines.

DIRECT OBSERVATION OF SOLAR CORONAL MAGNETIC FIELDS BY VECTOR TOMOGRAPHY OF THE CORONAL EMISSION LINE POLARIZATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kramar, M.; Lin, H.; Tomczyk, S., E-mail: kramar@cua.edu, E-mail: lin@ifa.hawaii.edu, E-mail: tomczyk@ucar.edu

We present the first direct “observation” of the global-scale, 3D coronal magnetic fields of Carrington Rotation (CR) Cycle 2112 using vector tomographic inversion techniques. The vector tomographic inversion uses measurements of the Fe xiii 10747 Å Hanle effect polarization signals by the Coronal Multichannel Polarimeter (CoMP) and 3D coronal density and temperature derived from scalar tomographic inversion of Solar Terrestrial Relations Observatory (STEREO)/Extreme Ultraviolet Imager (EUVI) coronal emission lines (CELs) intensity images as inputs to derive a coronal magnetic field model that best reproduces the observed polarization signals. While independent verifications of the vector tomography results cannot be performed, wemore » compared the tomography inverted coronal magnetic fields with those constructed by magnetohydrodynamic (MHD) simulations based on observed photospheric magnetic fields of CR 2112 and 2113. We found that the MHD model for CR 2112 is qualitatively consistent with the tomography inverted result for most of the reconstruction domain except for several regions. Particularly, for one of the most noticeable regions, we found that the MHD simulation for CR 2113 predicted a model that more closely resembles the vector tomography inverted magnetic fields. In another case, our tomographic reconstruction predicted an open magnetic field at a region where a coronal hole can be seen directly from a STEREO-B/EUVI image. We discuss the utilities and limitations of the tomographic inversion technique, and present ideas for future developments.« less

Measurement of Malrotation on Direct Radiography in Pediatric Distal Radius Fractures

PubMed Central

Duymus, Tahir Mutlu; Mutlu, Serhat; Komur, Baran; Mutlu, Harun; Yucel, Bulent; Parmaksizoglu, Atilla Sancar

2016-01-01

Abstract The aim of this prospective study was to test a mathematical method of measuring the malrotation of pediatric distal radius fractures (PDRFs) from direct radiographs. A total of 70 pediatric patients who presented at the Emergency Department with a distal radius fracture were evaluated. For 38 selected patients conservative treatment for PDRF was planned. Anteroposterior and lateral radiographs were taken of all of the patients for comparison before and after reduction. Radius bone diameters were measured in the coronal and sagittal planes on the healthy and fractured sides. Using the diameter values on the healthy side and the new diameter values on the fractured side in the rotation formula, the degree of malrotation between the fracture ends was calculated. The mean follow-up period was 13.5 months. Patients’ mean age was 10.00 ± 3.19 years (range, 4–12 years). The rotation degree in the sagittal plane significantly differed between the proximal (26.52°±2.84°) and distal fracture ends (20.96°±2.73°) (P = 0.001). The rotation degree in the coronal plane significantly differed between the proximal (26.70°±2.38°) and distal fracture ends (20.26°±2.86°) (P = 0.001). The net rotation deformity of the fracture line was determined to be 5.55°± 3.54° on lateral radiographs and 5.44°± 3.35° on anteroposterior radiographs, no significant difference was observed between measurements (P >0.05). The malrotation deformity in PDRF occurs with greater rotation in the proximal fragment than in the distal fragment. The net rotation deformity created between the fracture ends can be calculated on direct radiographs. Level of Evidence: Diagnostic, Level II PMID:27149480

Three Coronal Holes

NASA Image and Video Library

2018-04-16

For much of this week the sun featured three substantial coronal holes (Apr. 3-6, 2018). Coronal holes appear as large dark areas which are identified with arrows in the still image. These are areas of open magnetic field from which high speed solar wind rushes out into space. This wind, if it interacts with Earth's magnetosphere, can cause aurora to appear near the poles. They are not at all uncommon. Animations are available at https://photojournal.jpl.nasa.gov/catalog/PIA22414

The effect of sagittal rotation of the glenoid on axial glenoid width and glenoid version in computed tomography scan imaging.

PubMed

Gross, Daniel J; Golijanin, Petar; Dumont, Guillaume D; Parada, Stephen A; Vopat, Bryan G; Reinert, Steven E; Romeo, Anthony A; Provencher, C D R Matthew T

2016-01-01

Computed tomography (CT) scans of the shoulder are often not well aligned to the axis of the scapula and glenoid. The purpose of this paper was to determine the effect of sagittal rotation of the glenoid on axial measurements of anterior-posterior (AP) glenoid width and glenoid version attained by standard CT scan. In addition, we sought to define the angle of rotation required to correct the CT scan to optimal positioning. A total of 30 CT scans of the shoulder were reformatted using OsiriX software multiplanar reconstruction. The uncorrected (UNCORR) and corrected (CORR) CT scans were compared for measurements of both (1) axial AP glenoid width and (2) glenoid version at 5 standardized axial cuts. The mean difference in glenoid version was 2.6% (2° ± 0.1°; P = .0222) and the mean difference in AP glenoid width was 5.2% (1.2 ± 0.42 mm; P = .0026) in comparing the CORR and UNCORR scans. The mean angle of correction required to align the sagittal plane was 20.1° of rotation (range, 9°-39°; standard error of mean, 1.2°). These findings demonstrate that UNCORR CT scans of the glenohumeral joint do not correct for the sagittal rotation of the glenoid, and this affects the characteristics of the axial images. Failure to align the sagittal image to the 12-o'clock to 6-o'clock axis results in measurement error in both glenoid version and AP glenoid width. Use of UNCORR CT images may have notable implications for decision-making and surgical treatment. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Effect of alignment changes on socket reaction moments while walking in transtibial prostheses with energy storage and return feet

PubMed Central

Kobayashi, Toshiki; Arabian, Adam K.; Orendurff, Michael S.; Rosenbaum-Chou, Teri G.; Boone, David A.

2014-01-01

Background Energy storage and return feet are designed for active amputees. However, little is known about the socket reaction moments in transtibial prostheses with energy storage and return feet. The aim of this study was to investigate the effect of alignment changes on the socket reaction moments during gait while using the energy storage and return feet. Methods A Smart Pyramid™ was used to measure the socket reaction moments in 10 subjects with transtibial prostheses while walking under 25 alignment conditions, including a nominal alignment (as defined by conventional clinical methods), as well as angle malalignments of 2°, 4° and 6° (flexion, extension, abduction, and adduction) and translation malalignments of 5mm, 10mm and 15mm (anterior, posterior, lateral, and medial) referenced from the nominal alignment. The socket reaction moments of the nominal alignment were compared with each malalignment. Findings Both coronal and sagittal alignment changes demonstrated systematic effects on the socket reaction moments. In the sagittal plane, angle and translation alignment changes demonstrated significant differences (P<0.05) in the minimum moment, the moment at 45% of stance and the maximum moment for some comparisons. In the coronal plane, angle and translation alignment changes demonstrated significant differences (P<0.05) in the moment at 30% and 75% of stance for all comparisons. Interpretation The alignment may have systematic effects on the socket reaction moments in transtibial prostheses with energy storage and return feet. The socket reaction moments could potentially be a useful biomechanical parameter to evaluate the alignment of the transtibial prostheses. PMID:24315709

Effect of alignment changes on socket reaction moments while walking in transtibial prostheses with energy storage and return feet.

PubMed

Kobayashi, Toshiki; Arabian, Adam K; Orendurff, Michael S; Rosenbaum-Chou, Teri G; Boone, David A

2014-01-01

Energy storage and return feet are designed for active amputees. However, little is known about the socket reaction moments in transtibial prostheses with energy storage and return feet. The aim of this study was to investigate the effect of alignment changes on the socket reaction moments during gait while using the energy storage and return feet. A Smart Pyramid™ was used to measure the socket reaction moments in 10 subjects with transtibial prostheses while walking under 25 alignment conditions, including a nominal alignment (as defined by conventional clinical methods), as well as angle malalignments of 2°, 4° and 6° (flexion, extension, abduction, and adduction) and translation malalignments of 5mm, 10mm and 15mm (anterior, posterior, lateral, and medial) referenced from the nominal alignment. The socket reaction moments of the nominal alignment were compared with each malalignment. Both coronal and sagittal alignment changes demonstrated systematic effects on the socket reaction moments. In the sagittal plane, angle and translation alignment changes demonstrated significant differences (P<0.05) in the minimum moment, the moment at 45% of stance and the maximum moment for some comparisons. In the coronal plane, angle and translation alignment changes demonstrated significant differences (P<0.05) in the moment at 30% and 75% of stance for all comparisons. The alignment may have systematic effects on the socket reaction moments in transtibial prostheses with energy storage and return feet. The socket reaction moments could potentially be a useful biomechanical parameter to evaluate the alignment of the transtibial prostheses. Copyright © 2013 Elsevier Ltd. All rights reserved.

Observational features of equatorial coronal hole jets

NASA Astrophysics Data System (ADS)

Nisticò, G.; Bothmer, V.; Patsourakos, S.; Zimbardo, G.

2010-03-01

Collimated ejections of plasma called "coronal hole jets" are commonly observed in polar coronal holes. However, such coronal jets are not only a specific features of polar coronal holes but they can also be found in coronal holes appearing at lower heliographic latitudes. In this paper we present some observations of "equatorial coronal hole jets" made up with data provided by the STEREO/SECCHI instruments during a period comprising March 2007 and December 2007. The jet events are selected by requiring at least some visibility in both COR1 and EUVI instruments. We report 15 jet events, and we discuss their main features. For one event, the uplift velocity has been determined as about 200 km s-1, while the deceleration rate appears to be about 0.11 km s-2, less than solar gravity. The average jet visibility time is about 30 min, consistent with jet observed in polar regions. On the basis of the present dataset, we provisionally conclude that there are not substantial physical differences between polar and equatorial coronal hole jets.

Coronal Hole Front and Center

NASA Image and Video Library

2016-05-18

A substantial coronal hole had rotated so that it temporarily faced right towards Earth May, 17-19, 2016. This coronal hole area is the dark area at the top center of this image from NASA Solar Dynamics Observatory.

Simulations of Emerging Magnetic Flux. II. The Formation of Unstable Coronal Flux Ropes and the Initiation of Coronal Mass Ejections

NASA Technical Reports Server (NTRS)

Leake, James E.; Linton, Mark G.; Antiochos, Spiro K.

2014-01-01

We present results from three-dimensional magnetohydrodynamic simulations of the emergence of a twisted convection zone flux tube into a pre-existing coronal dipole field. As in previous simulations, following the partial emergence of the sub-surface flux into the corona, a combination of vortical motions and internal magnetic reconnection forms a coronal flux rope. Then, in the simulations presented here, external reconnection between the emerging field and the pre-existing dipole coronal field allows further expansion of the coronal flux rope into the corona. After sufficient expansion, internal reconnection occurs beneath the coronal flux rope axis, and the flux rope erupts up to the top boundary of the simulation domain (approximately 36 Mm above the surface).We find that the presence of a pre-existing field, orientated in a direction to facilitate reconnection with the emerging field, is vital to the fast rise of the coronal flux rope. The simulations shown in this paper are able to self-consistently create many of the surface and coronal signatures used by coronal mass ejection (CME) models. These signatures include surface shearing and rotational motions, quadrupolar geometry above the surface, central sheared arcades reconnecting with oppositely orientated overlying dipole fields, the formation of coronal flux ropes underlying potential coronal field, and internal reconnection which resembles the classical flare reconnection scenario. This suggests that proposed mechanisms for the initiation of a CME, such as "magnetic breakout," are operating during the emergence of new active regions.

Magnetic Flux Cancelation as the Trigger of Solar Coronal Jets in Coronal Holes

NASA Astrophysics Data System (ADS)

Panesar, Navdeep K.; Sterling, Alphonse C.; Moore, Ronald L.

2018-02-01

We investigate in detail the magnetic cause of minifilament eruptions that drive coronal-hole jets. We study 13 random on-disk coronal-hole jet eruptions, using high-resolution X-ray images from the Hinode/X-ray telescope(XRT), EUV images from the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA), and magnetograms from the SDO/Helioseismic and Magnetic Imager (HMI). For all 13 events, we track the evolution of the jet-base region and find that a minifilament of cool (transition-region-temperature) plasma is present prior to each jet eruption. HMI magnetograms show that the minifilaments reside along a magnetic neutral line between majority-polarity and minority-polarity magnetic flux patches. These patches converge and cancel with each other, with an average cancelation rate of ∼0.6 × 1018 Mx hr‑1 for all 13 jets. Persistent flux cancelation at the neutral line eventually destabilizes the minifilament field, which erupts outward and produces the jet spire. Thus, we find that all 13 coronal-hole-jet-driving minifilament eruptions are triggered by flux cancelation at the neutral line. These results are in agreement with our recent findings for quiet-region jets, where flux cancelation at the underlying neutral line triggers the minifilament eruption that drives each jet. Thus, from that study of quiet-Sun jets and this study of coronal-hole jets, we conclude that flux cancelation is the main candidate for triggering quiet-region and coronal-hole jets.

Computed tomography arthrography using a radial plane view for the detection of triangular fibrocartilage complex foveal tears.

PubMed

Moritomo, Hisao; Arimitsu, Sayuri; Kubo, Nobuyuki; Masatomi, Takashi; Yukioka, Masao

2015-02-01

To classify triangular fibrocartilage complex (TFCC) foveal lesions on the basis of computed tomography (CT) arthrography using a radial plane view and to correlate the CT arthrography results with surgical findings. We also tested the interobserver and intra-observer reliability of the radial plane view. A total of 33 patients with a suspected TFCC foveal tear who had undergone wrist CT arthrography and subsequent surgical exploration were enrolled. We classified the configurations of TFCC foveal lesions into 5 types on the basis of CT arthrography with the radial plane view in which the image slices rotate clockwise centered on the ulnar styloid process. Sensitivity, specificity, and positive predictive values were calculated for each type of foveal lesion in CT arthrography to detect foveal tears. We determined interobserver and intra-observer agreements using kappa statistics. We also compared accuracies with the radial plane views with those with the coronal plane views. Among the tear types on CT arthrography, type 3, a roundish defect at the fovea, and type 4, a large defect at the overall ulnar insertion, had high specificity and positive predictive value for the detection of foveal tears. Specificity and positive predictive values were 90% and 89% for type 3 and 100% and 100% for type 4, respectively, whereas sensitivity was 35% for type 3 and 22% for type 4. Interobserver and intra-observer agreement was substantial and almost perfect, respectively. The radial plane view identified foveal lesion of each palmar and dorsal radioulnar ligament separately, but accuracy results with the radial plane views were not statistically different from those with the coronal plane views. Computed tomography arthrography with a radial plane view exhibited enhanced specificity and positive predictive value when a type 3 or 4 lesion was identified in the detection of a TFCC foveal tear compared with historical controls. Diagnostic II. Copyright © 2015 American Society for

Reproducibility and repeatability of a new computerized software for sagittal spinopelvic and scoliosis curvature radiologic measurements: Keops(®).

PubMed

Maillot, C; Ferrero, E; Fort, D; Heyberger, C; Le Huec, J-C

2015-07-01

The purpose of this study was to evaluate the inter- and intra-observer variability of the computerized radiologic measurements using Keops(®) and to determine the bias between the software and the standard paper measurement. Four individuals measured all frontal and sagittal variables on the 30 X-rays randomly selected on two occasions (test and retest conditions). The Bland-Altman plot was used to determine the degree of agreement between the measurement on paper X-ray and the measurement using Keops(®) for all reviewers and for the two measures; the intraclass correlation coefficient (ICC) was calculated for each pair of analyses to assess interobserver reproducibility among the four reviewers for the same patient using either paper X-ray or Keops(®) measurement and finally, concordance correlation coefficient (rc) was calculated to assess intraobserver repeatability among the same reviewer for one patient between the two measure using the same method (paper or Keops(®)). The mean difference calculated between the two methods was minimal at -0, 4° ± 3.41° [-7.1; 6.4] for frontal measurement and 0.1° ± 3.52° [-6.7; 6.8] for sagittal measurement. Keops(®) has a better interobserver reproducibility than paper measurement for determination of the sagittal pelvic parameter (ICC = 0.9960 vs. 0.9931; p = 0.0001). It has a better intraobserver repeatability than paper for determination of Cobbs angle (rc = 0.9872 vs. 0.9808; p < 0.0001) and for pelvic parameter (rc = 0.9981 vs. 0.9953; p < 0.0001). We conclude that Keops(®) has no bias compared to the traditionally paper measurement, and moreover, the repeatability and the reproducibility of measurements with this method is much better than with similar standard radiologic measures done manually in both frontal and sagittal plane and that the use of this software can be recommended for clinical application. Diagnostic, level III.

Magnetic resonance imaging (MRI) of abnormal uterine masses.

PubMed

al-Ahwani, S; Assem, M; Belal, A; Abdel-Hamid, H

1991-01-01

Sixteen women with clinically diagnosed uterine masses were studied by magnetic resonance imaging (MRI). Pelvic study was carried out in the coronal, sagittal and axial planes. Uterine leiomyomas were detected in 12 cases, while the remaining cases were one each of uterine sarcoma, invasive molar pregnancy, cervical malignancy with pyometra and haematometra with congenital cervical stenosis. The uterine origin of the masses could be clearly detected in all patients, as well as the nature of the masses, the presence of degenerative or malignant changes and the nature of the intrauterine fluid. MRI characteristic findings of the studied masses are presented and discussed.

Solar wind and coronal structure near sunspot minimum - Pioneer and SMM observations from 1985-1987

NASA Technical Reports Server (NTRS)

Mihalov, J. D.; Barnes, A.; Hundhausen, A. J.; Smith, E. J.

1990-01-01

Changes in solar wind speed and magnetic polarity observed at the Pioneer spacecraft are discussed here in terms of the changing magnetic geometry implied by SMM coronagraph observations over the period 1985-1987. The pattern of recurrent solar wind streams, the long-term average speed, and the sector polarity of the interplanetary magnetic field all changed in a manner suggesting both a temporal variation, and a changing dependence on heliographic latitude. Coronal observations during this epoch show a systematic variation in coronal structure and the magnetic structure imposed on the expanding solar wind. These observations suggest interpretation of the solar wind speed variations in terms of the familiar model where the speed increases with distance from a nearly flat interplanetary current sheet, and where this current sheet becomes aligned with the solar equatorial plane as sunspot minimum approaches, but deviates rapidly from that orientation after minimum.

Delineation of vertebral area on the coronal plane using three-dimensional ultrasonography advanced volume contrast imaging (VCI) Omni view: intrarater reliability and agreement using standard mouse, high definition mouse, and pen-tablet.

PubMed

Araujo Júnior, Edward; Martinez, Luis Henrique; Simioni, Christiane; Martins, Wellington P; Nardozza, Luciano M; Moron, Antonio F

2012-09-01

To assess the fetal lumbosacral spine by three-dimensional (3D) ultrasonography using volume contrast imaging (VCI) omni view method and compare reproducibility and agreement between three different measurement techniques: standard mouse, high definition mouse and pen-tablet. A comparative and prospective study with 40 pregnant women between 20 and 34 + 6 weeks was realized. 3D volume datasets of the fetal spine were acquired using a convex transabdominal transducer. Starting scan plane was the coronal section of fetal lumbosacral spine by VCI-C function. Omni view manual trace was selected and a parallel plane of fetal spine was drawn including interest region. Intraclass correlation coefficient (ICC) was used for reproducibility analysis. The relative difference between three used techniques was compared by chi-square test and Fischer test. Pen-tablet showed better reliability (ICC=0.987). In the relative proportion of differences, this was significantly higher for the pen-tablet (82.14%; p<0.01). In paired comparison, the relative difference was significantly greater for the pen-tablet (p<0.01). The pen-tablet showed to be the most reproductive and concordant method in the measurement of body vertebral area of fetal lumbosacral spine by 3D ultrasonography using the VCI.

Impact of Image Filters and Observations Parameters in CBCT for Identification of Mandibular Osteolytic Lesions

PubMed Central

Monteiro, Bruna Moraes; Nobrega Filho, Denys Silveira; Lopes, Patrícia de Medeiros Loureiro; de Sales, Marcelo Augusto Oliveira

2012-01-01

The aim of this study was to analyze the influence of filters (algorithms) to improve the image of Cone Beam Computed Tomography (CBCT) in diagnosis of osteolytic lesions of the mandible, in order to establish the protocols for viewing images more suitable for CBCT diagnostics. 15 dry mandibles in which perforations were performed, simulating lesions, were submitted to CBCT examination. Two examiners analyzed the images, using filters to improve image Hard, Normal, and Very Sharp, contained in the iCAT Vision software, and protocols for assessment: axial; sagittal and coronal; and axial, sagittal and coronal planes simultaneously (MPR), on two occasions. The sensitivity and specificity (validity) of the cone beam computed tomography (CBCT) have been demonstrated as the values achieved were above 75% for sensitivity and above 85% for specificity, reaching around 95.5% of sensitivity and 99% of specificity when we used the appropriate observation protocol. It was concluded that the use of filters (algorithms) to improve the CBCT image influences the diagnosis, due to the fact that all measured values were correspondingly higher when it was used the filter Very Sharp, which justifies its use for clinical activities, followed by Hard and Normal filters, in order of decreasing values. PMID:22956955

Impact of Image Filters and Observations Parameters in CBCT for Identification of Mandibular Osteolytic Lesions.

PubMed

Monteiro, Bruna Moraes; Nobrega Filho, Denys Silveira; Lopes, Patrícia de Medeiros Loureiro; de Sales, Marcelo Augusto Oliveira

2012-01-01

The aim of this study was to analyze the influence of filters (algorithms) to improve the image of Cone Beam Computed Tomography (CBCT) in diagnosis of osteolytic lesions of the mandible, in order to establish the protocols for viewing images more suitable for CBCT diagnostics. 15 dry mandibles in which perforations were performed, simulating lesions, were submitted to CBCT examination. Two examiners analyzed the images, using filters to improve image Hard, Normal, and Very Sharp, contained in the iCAT Vision software, and protocols for assessment: axial; sagittal and coronal; and axial, sagittal and coronal planes simultaneously (MPR), on two occasions. The sensitivity and specificity (validity) of the cone beam computed tomography (CBCT) have been demonstrated as the values achieved were above 75% for sensitivity and above 85% for specificity, reaching around 95.5% of sensitivity and 99% of specificity when we used the appropriate observation protocol. It was concluded that the use of filters (algorithms) to improve the CBCT image influences the diagnosis, due to the fact that all measured values were correspondingly higher when it was used the filter Very Sharp, which justifies its use for clinical activities, followed by Hard and Normal filters, in order of decreasing values.

Coronal holes as sources of solar wind

NASA Technical Reports Server (NTRS)

Nolte, J. T.; Krieger, A. S.; Timothy, A. F.; Gold, R. E.; Roelof, E. C.; Vaiana, G.; Lazarus, A. J.; Sullivan, J. D.; Mcintosh, P. S.

1976-01-01

We investigate the association of high-speed solar wind with coronal holes during the Skylab mission by: (1) direct comparison of solar wind and coronal X-ray data; (2) comparison of near-equatorial coronal hole area with maximum solar wind velocity in the associated streams; and (3) examination of the correlation between solar and interplanetary magnetic polarities. We find that all large near-equatorial coronal holes seen during the Skylab period were associated with high-velocity solar wind streams observed at 1 AU.

Deformation and deceleration of coronal wave

NASA Astrophysics Data System (ADS)

Xue, Z. K.; Qu, Z. Q.; Yan, X. L.; Zhao, L.; Ma, L.

2013-08-01

Aims: We studied the kinematics and morphology of two coronal waves to better understand the nature and origin of coronal waves. Methods: Using multi-wavelength observations of the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) and the Extreme Ultraviolet Imager (EUVI) on board the twin spacecraft Solar-TErrestrial RElations Observatory (STEREO), we present morphological and dynamic characteristics of consecutive coronal waves on 2011 March 24. We also show the coronal magnetic field based on the potential field source surface model. Results: This event contains several interesting aspects. The first coronal wave initially appeared after a surge-like eruption. Its front was changed and deformed significantly from a convex shape to a line-shaped appearance, and then to a concave configuration during its propagation to the northwest. The initial speeds ranged from 947 km s-1 to 560 km s-1. The first wave decelerated significantly after it passed through a filament channel. After the deceleration, the final propagation speeds of the wave were from 430 km s-1 to 312 km s-1. The second wave was found to appear after the first wave in the northwest side of the filament channel. Its wave front was more diffused and the speed was around 250 km s-1, much slower than that of the first wave. Conclusions: The deformation of the first coronal wave was caused by the different speeds along different paths. The sudden deceleration implies that the refraction of the first wave took place at the boundary of the filament channel. The event provides evidence that the first coronal wave may be a coronal MHD shock wave, and the second wave may be the apparent propagation of the brightenings caused by successive stretching of the magnetic field lines.

Inter-rater Reliability of Three Musculoskeletal Physical examination Techniques Used to Assess Motion in Three Planes While Standing

PubMed Central

Prather, Heidi; Hunt, Devyani; Steger-May, Karen; Hayes, Marcie Harris; Knaus, Evan; Clohisy, John

2012-01-01

Objective The objective of the study was to measure the reliability between examiners of three basic maneuvers of the Total Body Functional Profile© physical examination test. The hypothesis was musculoskeletal health care providers of different disciplines could reliably use the three basic maneuvers as part of the musculoskeletal physical examination. Design A prospective observational study was conducted. Twenty-eight adult volunteers were measured on both the left and right side by two independent raters on a single occasion. Setting The subjects were recruited through advertisements placed by the orthopedic department at a tertiary university. Participants 28 volunteers were recruited and completed the study. The volunteers were between the ages of 18 and 51 years of age, had no symptoms in the lower extremity or spine, had no previous history of surgery or tumor involving the lower extremity, and no medical conditions that would preclude participation. Assessment On a single occasion, two examiners per one volunteer were blinded to their own and each others' measurements. Each examiner assessed the distance of frontal and sagittal plane lunge and angle of motion for transverse plane testing. Main Outcome Measurements Inter-rater agreement is expressed with intraclass correlation coefficients (ICCs) and corresponding 95% confidence intervals (CIs). The difference between raters is reported with 95% CIs. Baseline demographics, UCLA, and Harris hip questionnaires were completed by all participants. Results The UCLA and Harris hip scores showed no significant activity restrictions or pain limitations in all participants. The inter-rater reliability for sagittal, frontal, and transverse plane matrix testing was good with ICCs of 0.86 (95% CI 0.77, 0.91), 0.90 (95% CI 0.84, 0.94), and 0.85 (95% CI 0.75, 0.91) respectively. The rater reliability between disciplines for transverse, sagittal and frontal plane matrix testing was good with ICCs of 0.89 (95% CI 0.80, 0

Inter-rater reliability of three musculoskeletal physical examination techniques used to assess motion in three planes while standing.

PubMed

Prather, Heidi; Hunt, Devyani; Steger-May, Karen; Hayes, Marcie Harris; Knaus, Evan; Clohisy, John

2009-07-01

The objective of the study was to measure the reliability between examiners of 3 basic maneuvers of the Total Body Functional Profile physical examination test. The hypothesis was musculoskeletal health care providers of different disciplines could reliably use the 3 basic maneuvers as part of the musculoskeletal physical examination. A prospective observational study was conducted. Twenty-eight adult volunteers were measured on both the left and right side by 2 independent raters on a single occasion. The subjects were recruited through advertisements placed by the orthopedic department at a tertiary university. Twenty-eight volunteers were recruited and completed the study. The volunteers were between the ages of 18 and 51 years of age, had no symptoms in the lower extremity or spine, had no previous history of surgery or tumor involving the lower extremity, and no medical conditions that would preclude participation. On a single occasion, 2 examiners per 1 volunteer were blinded to their own and each others' measurements. Each examiner assessed the distance of frontal and sagittal plane lunge and angle of motion for transverse plane testing. Inter-rater agreement is expressed with intraclass correlation coefficients (ICCs) and corresponding 95% confidence intervals (CIs). The difference between raters is reported with 95% CIs. Baseline demographics, University of California Los Angeles (UCLA), and Harris hip questionnaires were completed by all participants. The UCLA and Harris hip scores showed no significant activity restrictions or pain limitations in all participants. The inter-rater reliability for sagittal, frontal, and transverse plane matrix testing was good with ICCs of 0.86 (95% CI 0.77-0.91), 0.90 (95% CI 0.84-0.94), and 0.85 (95% CI 0.75-0.91), respectively. The rater reliability between disciplines for transverse, sagittal, and frontal plane matrix testing was good with ICCs of 0.89 (95% CI 0.80-0.94), 0.88 (95% CI 0.79-0.94), and 0.90 (95% CI 0

Substantial Coronal Holes

NASA Image and Video Library

2016-10-21

A pair of large coronal holes rotated into view over the past few days (Oct. 20-21, 2016). Coronal holes appear dark in certain wavelengths of extreme ultraviolet light, such as in the wavelength used here. These holes are areas of open magnetic field that spew solar wind into space. Sometimes, when they are facing Earth, they can cause geomagnetic disturbances that generate aurora. The lines you see were drawn to represent how solar scientists are modeling the magnetic field lines. Movies are available at the Photojournal http://photojournal.jpl.nasa.gov/catalog/PIA15378

Coronal magnetohydrodynamic waves and oscillations: observations and quests.

PubMed

Aschwanden, Markus J

2006-02-15

Coronal seismology, a new field of solar physics that emerged over the last 5 years, provides unique information on basic physical properties of the solar corona. The inhomogeneous coronal plasma supports a variety of magnetohydrodynamics (MHD) wave modes, which manifest themselves as standing waves (MHD oscillations) and propagating waves. Here, we briefly review the physical properties of observed MHD oscillations and waves, including fast kink modes, fast sausage modes, slow (acoustic) modes, torsional modes, their diagnostics of the coronal magnetic field, and their physical damping mechanisms. We discuss the excitation mechanisms of coronal MHD oscillations and waves: the origin of the exciter, exciter propagation, and excitation in magnetic reconnection outflow regions. Finally, we consider the role of coronal MHD oscillations and waves for coronal heating, the detectability of various MHD wave types, and we estimate the energies carried in the observed MHD waves and oscillations: Alfvénic MHD waves could potentially provide sufficient energy to sustain coronal heating, while acoustic MHD waves fall far short of the required coronal heating rates.

Genesis Solar Wind Interstream, Coronal Hole and Coronal Mass Ejection Samples: Update on Availability and Condition

NASA Technical Reports Server (NTRS)

Allton, J. H.; Gonzalez, C. P.; Allums, K. K.

2017-01-01

Recent refinement of analysis of ACE/SWICS data (Advanced Composition Explorer/Solar Wind Ion Composition Spectrometer) and of onboard data for Genesis Discovery Mission of 3 regimes of solar wind at Earth-Sun L1 make it an appropriate time to update the availability and condition of Genesis samples specifically collected in these three regimes and currently curated at Johnson Space Center. ACE/SWICS spacecraft data indicate that solar wind flow types emanating from the interstream regions, from coronal holes and from coronal mass ejections are elementally and isotopically fractionated in different ways from the solar photosphere, and that correction of solar wind values to photosphere values is non-trivial. Returned Genesis solar wind samples captured very different kinds of information about these three regimes than spacecraft data. Samples were collected from 11/30/2001 to 4/1/2004 on the declining phase of solar cycle 23. Meshik, et al is an example of precision attainable. Earlier high precision laboratory analyses of noble gases collected in the interstream, coronal hole and coronal mass ejection regimes speak to degree of fractionation in solar wind formation and models that laboratory data support. The current availability and condition of samples captured on collector plates during interstream slow solar wind, coronal hole high speed solar wind and coronal mass ejections are de-scribed here for potential users of these samples.

Invisibility of Solar Active Region Umbra-to-Umbra Coronal Loops: New Evidence that Magnetoconvection Drives Solar-Stellar Coronal Heating

NASA Technical Reports Server (NTRS)

Tiwari, Sanjiv K.; Thalmann, Julia K.; Panesar, Navdeep K.; Moore, Ronald L.; Winebarger, Amy R.

2017-01-01

Coronal heating generally increases with increasing magnetic field strength: the EUV/X-ray corona in active regions is 10--100 times more luminous and 2--4 times hotter than that in quiet regions and coronal holes, which are heated to only about 1.5 MK, and have fields that are 10--100 times weaker than that in active regions. From a comparison of a nonlinear force-free model of the three-dimensional active region coronal field to observed extreme-ultraviolet loops, we find that (1) umbra-to-umbra coronal loops, despite being rooted in the strongest magnetic flux, are invisible, and (2) the brightest loops have one foot in an umbra or penumbra and the other foot in another sunspot's penumbra or in unipolar or mixed-polarity plage. The invisibility of umbra-to-umbra loops is new evidence that magnetoconvection drives solar-stellar coronal heating: evidently, the strong umbral field at both ends quenches the magnetoconvection and hence the heating. Our results from EUV observations and nonlinear force-free modeling of coronal magnetic field imply that, for any coronal loop on the Sun or on any other convective star, as long as the field can be braided by convection in at least one loop foot, the stronger the field in the loop, the stronger the coronal heating.

A Triumvirate: Three Coronal Holes

NASA Image and Video Library

2015-09-10

Three substantial coronal holes rotated across the face of the Sun the week of Sept. 8-10, 2015 as seen by NASA Solar Dynamics Observatory. Coronal holes are areas where the Sun magnetic field is open and a source of streaming solar wind. They appear darker in extreme ultraviolet light because there is less material in the hole areas being imaged in this specific wavelength of light. It is a little unusual to have three coronal holes at the same time, but neither is it a rare occurrence. http://photojournal.jpl.nasa.gov/catalog/PIA19950

Coronal Heating and the Increase of Coronal Luminosity with Magnetic Flux

NASA Technical Reports Server (NTRS)

Moore, R. L.; Falconer, D. A.; Porter, J. G.; Hathaway, D. H.; Six, N. Frank (Technical Monitor)

2002-01-01

We present the observed scaling of coronal luminosity with magnetic flux in a set of quiet regions. Comparison of this with the observed scaling found for active regions suggests an underlying difference between coronal heating in active regions and quiet regions. From SOHO/EIT coronal images and SOHO/MDI magnetograms of four similar large quiet regions, we measure L(sub corona) and Phi(sub total) in random subregions ranging in area from about four supergranules [(70,000 km)(exp 2)] to about 100 supergranules [(0.5 R(sub sun))(exp 2)], where L(sub corona) is the luminosity of the corona in a subregion and Phi(sub total) is the flux content of the magnetic network in the subregion. This sampling of our quiet regions yields a correlation plot of Log L(sub corona) vs Log Phi(sub total) appropriate for comparison with the corresponding plot for active regions. For our quiet regions, the mean values of L(sub corona) and Phi(sub total) both increase linearly with area (simply because each set of subregions of the same area has very nearly the same mean coronal luminosity per unit area and mean magnetic flux per unit area), and in each constant-area set the values of L(sub corona) and Phi(sub total) 'scatter' about their means for that area. This results in the linear least-squares fit to the Log ((L (sub corona)), vs Log ((Phi (sub total)) plot having a slope somewhat less than one. If active regions mimicked our quiet regions in that all large sets of same-area active regions had the same mean coronal luminosity per unit area and same mean magnetic flux per unit area, then the least-squares fit to their Log((L (sub corona)) vs Log((Phi (sub total)) plot would also have a slope of less than one. Instead, the slope for active regions is 1.2. Given the observed factor of three scatter about the least-squares linear fit, this slope is consistent with Phi(sub total) on average increasing linearly with area (A) as in quiet regions, but L(sub corona) on average increasing as

In vitro kinematic measurements of the patellar tendon in two different types of posterior-stabilized total knee arthroplasties.

PubMed

Zhu, Zhonglin; Ding, Hui; Dang, Xiao; Tang, Jing; Zhou, Yixin; Wang, Guangzhi

2010-01-01

Fixed-bearing posterior-stabilized (PS) total knee arthroplasty (TKA) has been used in Asian countries for several years, but few studies have investigated differences in the kinematic properties of the patellar tendon after standard PS TKA as compared to high-flex PS TKA. To quantify the in vitro three-dimensional (3D) kinematics of the patellar tendon during passive high flexion and full extension before and after two different types of PS TKAs. Six fresh-frozen cadaveric knees were tested under the following conditions: the unaltered state, status-post traditional PS prostheses (Simth-nephew GENESIS II) replacement, and status-post high-flexion PS prostheses replacement. The soft tissue around the knee and the quadriceps muscle were preserved, then tested under the load of a specific weight in an Oxford knee rig. We designed a specialized rigid body with four active markers fixed to each bone to track the 3D passive motion of the cadaveric knees. Flexion and extension was controlled by the knee rig and captured by an Optotrak Certus high precision optical tracking system. The attachment sites of the patellar tendon were registered as virtual markers to calculate the 3D kinematics. The patellar tendon of the unaltered knee and both TKA knees showed similar deformation. We found the length of the patellar tendon changed significantly during a motion from full extension to 30°, but there was no significant change in length while undergoing a motion from 30° to full flexion. Both the sagittal plane and coronal plane angles of the patellar tendon decreased after PS TKAs. There was no significant difference in patellar tendon kinematics between the two types of PS TKAs. We believe the changes observed in the sagittal plane and coronal plane angles of the patellar tendon after PS TKAs may influence the extensor mechanism and be an important cause of patella-femoral complications. These data may be used to assess patella-femoral complications after surgery so as to

The Influence of the Solar Coronal Radiation on Coronal Plasma Structures, I: Determination of the Incident Coronal Radiation

NASA Astrophysics Data System (ADS)

Brown, Gerrard M.; Labrosse, Nicolas

2018-02-01

Coronal structures receive radiation not only from the solar disc, but also from the corona. This height-dependent incident radiation plays a crucial role in the excitation and the ionisation of the illuminated plasma. The aim of this article is to present a method for computing the detailed incident radiation coming from the solar corona, which is perceived at a point located at an arbitrary height. The coronal radiation is calculated by integrating the radiation received at a point in the corona over all of the corona visible from this point. The emission from the corona at all wavelengths of interest is computed using atomic data provided by CHIANTI. We obtain the spectrum illuminating points located at varying heights in the corona at wavelengths between 100 and 912 Å when photons can ionise H or He atoms and ions in their ground states. As expected, individual spectral lines will contribute most at the height within the corona where the local temperature is closest to their formation temperature. As there are many spectral lines produced by many ions, the coronal intensity cannot be assumed to vary in the same way at all wavelengths and so must be calculated for each separate height that is to be considered. This code can be used to compute the spectrum from the corona illuminating a point at any given height above the solar surface. This brings a necessary improvement to models where an accurate determination of the excitation and ionisation states of coronal plasma structures is crucial.

Sagittal Plane Kinematics of the Jaw and Hyolingual Apparatus During Swallowing in Macaca mulatta

PubMed Central

Iriarte-Diaz, Jose; Arce-McShane, Fritzie; Orsbon, Courtney P.; Brown, Kevin A.; Eastment, McKenna; Avivi-Arber, Limor; Sessle, Barry J.; Inoue, Makoto; Hatsopoulos, Nicholas G.; Ross, Callum F.

2018-01-01

Studies of mechanisms of feeding behavior are important in a society where aging- and disease-related feeding disorders are increasingly prevalent. It is important to evaluate the clinical relevance of animal models of the disease and the control. Our present study quantifies macaque hyolingual and jaw kinematics around swallowing cycles to determine the extent to which macaque swallowing resembles that of humans. One female and one male adult Macaca mulatta were trained to feed in a primate chair. Videofluoroscopy was used to record kinematics in a sagittal view during natural feeding on solid food, and the kinematics of the hyoid bone, thyroid cartilage, mandibular jaw, and anterior-, middle-, and posterior-tongue. Jaw gape cycles were defined by consecutive maximum gapes, and the kinematics of the swallow cycles were compared with those of the two consecutive non-swallow cycles preceding and succeeding the swallow cycles. Although there are size differences between macaques and humans, and macaques have shorter durations of jaw gape cycles and hyoid and thyroid upward movements, there are several important similarities between our macaque data and human data reported in the literature: (1) The durations of jaw gape cycles during swallow cycles are longer than those of non-swallow cycles as a result of an increased duration of the jaw-opening phase; (2) Hyoid and thyroid upward movement is linked with a posterior tongue movement and is faster during swallow than non-swallow cycles; (3) Tongue elevation propagates from anterior to posterior during swallow and non-swallow cycles. These findings suggest that macaques can be a useful experimental model for human swallowing studies. PMID:28528492

TU-AB-BRA-10: Treatment of Gastric MALT Lymphoma Utilizing a Magnetic Resonance Image-Guided Radiation Therapy (MR-IGRT) System: Evaluation of Gating Feasibility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mazur, T; Gach, H; Chundury, A

Purpose: To evaluate the feasibility of real-time, real-anatomy tracking and gating for gastric lymphoma patients treated with magnetic resonance image-guided radiation therapy (MR-IGRT) Methods: Over the last 2 years, 8 patients with gastric lymphoma were treated with 0.3-T, Co-60 MR-IGRT. Post-treatment analysis of real-time cine imaging in the sagittal plane during each patient’s treatment revealed significant motion of the stomach. While this motion was accounted for with generous PTV margins, the system’s capability for real-time, real-anatomy tracking could be used to reduce treatment margins by gating. However, analysis was needed for the feasibility of gating using only the single availablemore » sagittal imaging plane. While any plane may be chosen, if the stomach moves differently where it is not being observed, there may potentially be a mistreatment. To that end, imaging with healthy volunteers was done to ascertain stomach motion over 2–4 min by analyzing multiple parallel sagittal and coronal planes 0.75 cm apart. The stomach was contoured on every slice, and the mean displacement between pairs of contour centroids was used to determine the amount of overall motion. Results: The mean displacement of the centroid in the image plane was 4.3 ± 0.7 mm. The greatest observed motion was more medial with respect to the patient, and less motion laterally, which implies that gating on a plane located closer to MRI isocenter will provide the more conservative scenario as it will turn the radiation delivery off when the stomach is observed to move outside a predetermined boundary. Conclusion: The stomach was observed to move relatively uniformly throughout, with maximum extent of motion closer to where most MRI systems have the best spatial integrity (near isocenter). Analysis of possible PTV margins from the healthy volunteer study (coupled with previous patient data on interfraction volumetric stomach deformation) is pending.« less

Observational Consequences of Coronal Heating Mechanisms

NASA Technical Reports Server (NTRS)

Winebarger, Amy R.; Cirtain, Jonathan C.; Golub, Leon; Kobayashi, Ken

2014-01-01

The coronal heating problem remains unsolved today, 80 years after its discovery, despite 50 years of suborbital and orbital coronal observatories. Tens of theoretical coronal heating mechanisms have been suggested, but only a few have been able to be ruled out. In this talk, we will explore the reasons for the slow progress and discuss the measurements that will be needed for potential breakthrough, including imaging the solar corona at small spatial scales, measuring the chromospheric magnetic fields, and detecting the presence of high temperature, low emission measure plasma. We will discuss three sounding rocket instruments developed to make these measurements: the High resolution Resolution Coronal Imager (Hi-C), the Chromospheric Lyman-Alpha Spectropolarimeter (CLASP), and the Marshall Grazing Incidence X-ray Spectrometer (MaGIXS).

SU-F-T-571: Objective Assessment of 3D Dosimetry for Flattened and Flattened Filter Free Stereotactic Rotational Delivery Using 729-Array Detector with Octavius 4D Phantom

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vikraman, S; Arun, C; Jain, K Sandeep

2016-06-15

Purpose: The purpose of this study was to assess the potential of 3D dosimetry for flattened and flattened filter free stereotactic rotational delivery in high definition MLC using 729-detector array with Octavius 4D phantom Methods: Twenty rapid arc plans were assessed for this study. For each patient two plans for 6X and 6FFF photon beams were generated with same prescription and critical organ constraints in Eclipse TPS version 13.0 using high definition MLC. Verification plans were generated in scanned Octavius 4D phantom in TPS. 3D dose measurements were collected from 729-ion chamber detector array in Octavius 4D phantom using verisoftmore » software v 6.0. TPS calculated dose was compared with measured 3D dose in verisoft using the following gamma analysis parameters such as 3D volumetric, 3D planar and 2D global gamma in transverse, sagittal and coronal planes for 3mm/3% and 2mm/2% distance to agreement criteria.Passing rate and arithmetic mean of global gamma were analysed for 2D and 3D global gamma in all planes. Results: The average number of dose points passing rate for 2D global gamma with 3mm/3% criteria in transverse, sagittal and coronal planes was 99.06%±2.89%, 98.8%±0.88% and 99.06%±91%, respectively. For 2mm/2% criteria 97.86%±2.26%, 94.49± 2.64% and 94.34%±2.9% was observed. In 3D planar global gamma with 3mm/3% was 99.53%±0.49%, 98.93%±1.03% and 99.29%±1.29%, for 2mm 2% criteria was 97.50%±2.24%, 94.5%±2.5% and 95.38%±4.5%. The maximum arithmetic mean gamma deviation of 0.505%±0.13% was observed in coronal plane for 2D global gamma with 2mm/2% criteria. The 3D volumetric gamma passing rate was observed as 99.61%±0.433% for 3mm /3% and 95.91%±2.51% for 2mm/2%. Conclusion: The objective assessment of 3D dosimetry have demonstrated that the rotational delivery accuracy for flattened and flattened filter free stereotactic plans can be verified by using Octavius system comprising with 729 ion chamber array and Octavius 4D phantom.« less

Lengthy Coronal Hole

NASA Image and Video Library

2017-01-09

An elongated coronal hole rotated across the face of the sun this past week so that it is now streaming solar wind towards Earth (Jan. 2-5, 2017). Coronal holes are areas of open magnetic field from which solar wind particles stream into space. In this wavelength of extreme ultraviolet light it appears as a dark area near the center and lower portion of the sun. The particle stream will likely generate aurora here on Earth. Check spaceweather.com for updates on auroral activity. Movies are available at http://photojournal.jpl.nasa.gov/catalog/PIA14093

Extensive Coronal Hole

NASA Image and Video Library

2017-09-02

A large coronal hole has been spewing solar wind particles in the general direction of Earth over the past few days (Aug. 31- Sept. 1, 2017). It is the extensive dark area that stretches from the top of the sun and angles down to the right. Coronal holes are areas of open magnetic field, which allow charge particles to escape into space. They appear dark in certain wavelengths of extreme ultraviolet light such as shown here. These clouds of particles can cause aurora to appear, particularly in higher latitude regions. Movies are available at https://photojournal.jpl.nasa.gov/catalog/PIA21942

Center of mass trajectory and orientation to ankle and knee in sagittal plane is maintained with forward lean when backpack load changes during treadmill walking.

PubMed

Caron, Robert R; Wagenaar, Robert C; Lewis, Cara L; Saltzman, Elliot; Holt, Kenneth G

2013-01-04

Maintaining the normal shape and amplitude of the vertical trajectory of the center of mass (COM) during stance has been shown to maximize the efficiency of unloaded gait. Kinematic adaptations to load carriage, such as forward lean have yet to be understood in relation to COM movement. The purpose of this study is to better understand how load impacts the vertical COM(TSYS) trajectory and to clarify the impact of forward lean as it relates to the dynamics of sagittal plane COM(TSYS) movement during stance with changing load. 17 subjects walked on treadmill at a constant preferred walking velocity while nine different loads ranging from 12.5% to 40% bodyweight were systematically added and removed from a backpack. Kinematic data were collected using an Optotrak, three-dimensional motion analysis system and used to estimate position of the COM as well as segment and COM-to-joint vector orientation angles. The shape and amplitude of the COM vertical trajectory was maintained across all loaded conditions. The orientations of COM-to-ankle and -knee vectors were maintained in all loaded conditions except the heaviest load (40% BW). Results suggest that forward lean changed linearly with changes in load to maintain the COM-to-ankle and -knee vector orientations. COM vertical trajectory was maintained by a combination of invariants including lower-limb segment angles and a constant direction of toe-off impulse vector. The kinematic invariants found suggest a simplified control mechanism by which the system limits degrees of freedom and potentially minimizes torque about lower-extremity joints with added load. Copyright © 2012 Elsevier Ltd. All rights reserved.

Ponderomotive Acceleration in Coronal Loops

NASA Astrophysics Data System (ADS)

Dahlburg, Russell B.; Laming, J. Martin; Taylor, Brian; Obenschain, Keith

2017-08-01

Ponderomotive acceleration has been asserted to be a cause of the First Ionization Potential (FIP) effect, the by now well known enhancement in abundance by a factor of 3-4 over photospheric values of elements in the solar corona with FIP less than about 10 eV. It is shown here by means of numerical simulations that ponderomotive acceleration occurs in solar coronal loops, with the appropriate magnitude and direction, as a ``byproduct'' of coronal heating. The numerical simulations are performed with the HYPERION code, which solves the fully compressible three-dimensional magnetohydrodynamic equations including nonlinear thermal conduction and optically thin radiation. Numerical simulations of a coronal loops with an axial magnetic field from 0.005 Teslas to 0.02 Teslas and lengths from 25000 km to 75000 km are presented. In the simulations the footpoints of the axial loop magnetic field are convected by random, large-scale motions. There is a continuous formation and dissipation of field-aligned current sheets which act to heat the loop. As a consequence of coronal magnetic reconnection, small scale, high speed jets form. The familiar vortex quadrupoles form at reconnection sites. Between the magnetic footpoints and the corona the reconnection flow merges with the boundary flow. It is in this region that the ponderomotive acceleration occurs. Mirroring the character of the coronal reconnection, the ponderomotive acceleration is also found to be intermittent.

Coronal Heating: Testing Models of Coronal Heating by Forward-Modeling the AIA Emission of the Ansample of Coronal Loops

NASA Astrophysics Data System (ADS)

Malanushenko, A. V.

2015-12-01

We present a systemic exploration of the properties of coronal heating, by forward-modeling the emission of the ensemble of 1D quasi-steady loops. This approximations were used in many theoretical models of the coronal heating. The latter is described in many such models in the form of power laws, relating heat flux through the photosphere or volumetric heating to the strength of the magnetic field and length of a given field line. We perform a large search in the parameter space of these power laws, amongst other variables, and compare the resulting emission of the active region to that observed by AIA. We use a recently developed magnetic field model which uses shapes of coronal loops to guide the magnetic model; the result closely resembles observed structures by design. We take advantage of this, by comparing, in individual sub-regions of the active region, the emission of the active region and its synthetic model. This study allows us to rule out many theoretical models and formulate predictions for the heating models to come.

[Fetal neurosonography using 3-dimensional multiplanar sonography].

PubMed

Chaoui, R; Heling, K S; Kainer, F; Karl, K

2012-04-01

This review focuses on the examination of the fetal brain, using three-dimensional (3D) ultrasound and the multiplanar rendering mode (MPR). The routine examination of the brain is achieved with axial planes but a dedicated fetal neurosonogram requires additional coronal and sagittal views, in order to provide a complete view of the different brain structures. Because these planes are difficult to obtain under many conditions, the present paper shows how 3D MPR allows one to obtain 1 or multiple reconstructed images from a digital volume. The display can be either as orthogonal planes, tomographic planes with parallel slices or as one single plane of the region of interest, which can be selected by the examiner. This approach allows easily the demonstration of the corpus callosum, the cerebellar vermis, the three-horn view, the foetal hippocampus and other regions. In addition, early neurosonography of the developing brain from the 7th week of pregnancy onwards can be achieved. © Georg Thieme Verlag KG Stuttgart · New York.

Assessment of Isometric Trunk Strength - The Relevance of Body Position and Relationship between Planes of Movement.

PubMed

Kocjan, Andrej; Sarabon, Nejc

2014-05-01

The aim of the study was to assess the differences in maximal isometric trunk extension and flexion strength during standing, sitting and kneeling. Additionally, we were interested in correlations between the maximal strength in sagittal, frontal and transverse plane, measured in the sitting position. Sixty healthy subjects (24 male, 36 female; age 41.3 ± 15.1 yrs; body height 1.70 ± 0.09 m; body mass 72.7 ± 13.3 kg) performed maximal voluntary isometric contractions of the trunk flexor and extensor muscles in standing, sitting and kneeling position. The subjects also performed lateral flexions and rotations in the sitting position. Each task was repeated three times and average of maximal forces was used for data analysis. RANOVA with post-hoc testing was applied to the flexion and extension data. The level of statistical significance was set to p < 0.05. Overall, in both genders together, the highest average force for trunk extension was recorded in sitting posture (910.5 ± 271.5 N), followed by kneeling (834.3 ± 242.9 N) and standing (504.0 ± 165.4 N), compared with flexion, where we observed the opposite trend (508.5 ± 213.0 N, 450.9 ± 165.7 N and 443.4 ± 153.1 N, respectively). Post-hoc tests showed significant differences in all extension positions (p < 0.0001) and between sitting/standing (p = 0.018) and kneeling/standing (p = 0.033) flexion exertions. The extension/flexion ratio for sitting was 2.1 ± 0.4, for kneeling 1.9 ± 0.4, followed by standing, where motion forward approximately equals motion backward (1.1 ± 0.6). Trunk sagittal-transverse strength showed the strongest correlation, followed by frontal-transverse and sagittal-frontal plane correlation pairs (R(2) = 0.830, 0.712 and 0.657). The baseline trunk isometric strength data provided by this study should help further strength diagnostics, more precisely, the prevention of low back disorders. Key pointsMaximal voluntary isometric force of the trunk extensors increased with the angle

Critical Magnetic Field Strengths for Unipolar Solar Coronal Plumes In Quiet Regions and Coronal Holes?

NASA Technical Reports Server (NTRS)

Avallone, Ellis; Tiwari, Sanjiv K.; Panesar, Navdeep K.; Moore, Ronald L.; Winebarger, Amy

2017-01-01

Coronal plumes are bright magnetic funnels that are found in quiet regions and coronal holes that extend high into the solar corona whose lifetimes can last from hours to days. The heating processes that make plumes bright involve the magnetic field at the base of the plume, but their intricacies remain mysterious. Raouafi et al. (2014) infer from observation that plume heating is a consequence of magnetic reconnection at the base, whereas Wang et al. (2016) infer that plume heating is a result of convergence of the magnetic flux at the plume's base, or base flux. Both papers suggest that the base flux in their plumes is of mixed polarity, but do not quantitatively measure the base flux or consider whether a critical magnetic field strength is required for plume production. To investigate the magnetic origins of plume heating, we track plume luminosity in the 171 Å wavelength as well as the abundance and strength of the base flux over the lifetimes of six unipolar coronal plumes. Of these, three are in coronal holes and three are in quiet regions. For this sample, we find that plume heating is triggered when convergence of the base flux surpasses a field strength of approximately 300 - 500 Gauss, and that the luminosity of both quiet region and coronal hole plumes respond similarly to the strength of the magnetic field in the base.

Coronal Seismology: The Search for Propagating Waves in Coronal Loops

NASA Astrophysics Data System (ADS)

Schad, Thomas A.; Seeley, D.; Keil, S. L.; Tomczyk, S.

2007-05-01

We report on Doppler observations of the solar corona obtained in the Fe XeXIII 1074.7nm coronal emission line with the HAO Coronal Multi-Channel Polarimeter (CoMP) mounted on the NSO Coronal One Shot coronagraph located in the Hilltop Facility of NSO/Sacramento Peak. The COMP is a tunable filtergraph instrument that records the entire corona from the edge of the occulting disk at approximately 1.03 Rsun out to 1.4 Rsun with a spatial resolution of about 4” x 4”. COMP can be rapidly scanned through the spectral line while recording orthogonal states of linear and circular polarization. The two dimensional spatial resolution allows us to correlate temporal fluctuations observed in one part of the corona with those seen at other locations, in particular along coronal loops. Using cross spectral analysis we find that the observations reveal upward propagating waves that are characterized by Doppler shifts with rms velocities of 0.3 km/s, peak wave power in the 3-5 mHz frequency range, and phase speeds 1-3 Mm/s. The wave trajectories are consistent with the direction of the magnetic field inferred from the linear polarization measurements. We discuss the phase and coherence of these waves as a function of height in the corona and relate our findings to previous observations. The observed waves appear to be Alfvenic in character. "Thomas Schad was supported through the National Solar Observatory Research Experiences for Undergraduate (REU) site program, which is co-funded by the Department of Defense in partnership with the National Science Foundation REU Program." Daniel Seeley was supported through the National Solar Observatory Research Experience for Teachers (RET) site program, which is funded by the National Science Foundation RET program.

Pre-flare coronal dimmings

NASA Astrophysics Data System (ADS)

Zhang, Q. M.; Su, Y. N.; Ji, H. S.

2017-02-01

Context. Coronal dimmings are regions of decreased extreme-ultravoilet (EUV) and/or X-ray (originally Skylab, then Yohkoh/SXT) intensities, which are often associated with flares and coronal mass ejections (CMEs). The large-scale impulsive dimmings have been thoroughly observed and investigated. The pre-flare dimmings before the flare impulsive phase, however, have rarely been studied in detail. Aims: We focus on the pre-flare coronal dimmings. We report our multiwavelength observations of the GOES X1.6 solar flare and the accompanying halo CME that was produced by the eruption of a sigmoidal magnetic flux rope (MFR) in NOAA active region (AR) 12158 on 2014 September 10. Methods: The eruption was observed by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory (SDO). The photospheric line-of-sight magnetograms were observed by the Helioseismic and Magnetic Imager (HMI) on board SDO. The soft X-ray (SXR) fluxes were recorded by the GOES spacecraft. The halo CME was observed by the white-light coronagraphs of the Large Angle Spectroscopic Coronagraph (LASCO) on board SOHO. Results: About 96 min before the onset of the flare/CME, narrow pre-flare coronal dimmings appeared at the two ends of the twisted MFR. They extended very slowly, with their intensities decreasing with time, while their apparent widths (8-9 Mm) continued to be nearly constant. During the impulsive and decay phases of flare, typical fan-like twin dimmings appeared and expanded, with a much larger extent and lower intensities than the pre-flare dimmings. The percentage of the 171 Å intensity decrease reaches 40%. The pre-flare dimmings are most striking in 171, 193, and 211 Å with formation temperatures of 0.6-2.5 MK. The northern part of the pre-flare dimmings could also be recognized in 131 and 335 Å. Conclusions: To our knowledge, this is the first detailed study of pre-flare coronal dimmings; they can be explained by density depletion as a result of the gradual

Deviation of landmarks in accordance with methods of establishing reference planes in three-dimensional facial CT evaluation.

PubMed

Yoon, Kaeng Won; Yoon, Suk-Ja; Kang, Byung-Cheol; Kim, Young-Hee; Kook, Min Suk; Lee, Jae-Seo; Palomo, Juan Martin

2014-09-01

This study aimed to investigate the deviation of landmarks from horizontal or midsagittal reference planes according to the methods of establishing reference planes. Computed tomography (CT) scans of 18 patients who received orthodontic and orthognathic surgical treatment were reviewed. Each CT scan was reconstructed by three methods for establishing three orthogonal reference planes (namely, the horizontal, midsagittal, and coronal reference planes). The horizontal (bilateral porions and bilateral orbitales) and midsagittal (crista galli, nasion, prechiasmatic point, opisthion, and anterior nasal spine) landmarks were identified on each CT scan. Vertical deviation of the horizontal landmarks and horizontal deviation of the midsagittal landmarks were measured. The porion and orbitale, which were not involved in establishing the horizontal reference plane, were found to deviate vertically from the horizontal reference plane in the three methods. The midsagittal landmarks, which were not used for the midsagittal reference plane, deviated horizontally from the midsagittal reference plane in the three methods. In a three-dimensional facial analysis, the vertical and horizontal deviations of the landmarks from the horizontal and midsagittal reference planes could vary depending on the methods of establishing reference planes.

Sagittal imbalance in patients with lumbar spinal stenosis and outcomes after simple decompression surgery.

PubMed

Shin, E Kyung; Kim, Chi Heon; Chung, Chun Kee; Choi, Yunhee; Yim, Dahae; Jung, Whei; Park, Sung Bae; Moon, Jung Hyeon; Heo, Won; Kim, Sung-Mi

2017-02-01

Lumbar spinal stenosis (LSS) is the most common lumbar degenerative disease, and sagittal imbalance is uncommon. Forward-bending posture, which is primarily caused by buckling of the ligamentum flavum, may be improved via simple decompression surgery. The objectives of this study were to identify the risk factors for sagittal imbalance and to describe the outcomes of simple decompression surgery. This is a retrospective nested case-control study PATIENT SAMPLE: This was a retrospective study that included 83 consecutive patients (M:F=46:37; mean age, 68.5±7.7 years) who underwent decompression surgery and a minimum of 12 months of follow-up. The primary end point was normalization of sagittal imbalance after decompression surgery. Sagittal imbalance was defined as a C7 sagittal vertical axis (SVA) ≥40 mm on a 36-inch-long lateral whole spine radiograph. Logistic regression analysis was used to identify the risk factors for sagittal imbalance. Bilateral decompression was performed via a unilateral approach with a tubular retractor. The SVA was measured on serial radiographs performed 1, 3, 6, and 12 months postoperatively. The prognostic factors for sagittal balance recovery were determined based on various clinical and radiological parameters. Sagittal imbalance was observed in 54% (45/83) of patients, and its risk factors were old age and a large mismatch between pelvic incidence and lumbar lordosis. The 1-year normalization rate was 73% after decompression surgery, and the median time to normalization was 1 to 3 months. Patients who did not experience SVA normalization exhibited low thoracic kyphosis (hazard ratio [HR], 1.04; 95% confidence interval [CI], 1.02-1.10) (p<.01) and spondylolisthesis (HR, 0.33; 95% CI, 0.17-0.61) before surgery. Sagittal imbalance was observed in more than 50% of LSS patients, but this imbalance was correctable via simple decompression surgery in 70% of patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Shoulder dislocation in patients older than 60 years of age

PubMed Central

Rapariz, Jose M.; Martin-Martin, Silvia; Pareja-Bezares, Antonio; Ortega-Klein, Jose

2010-01-01

Purpose: Recurrent anterior shoulder dislocation in elderly patients is a little studied condition. The goal of this paper is to clarify the role of associated injuries with respect to loss of function and recurrence of dislocation. Materials and Methods: We have conducted a retrospective, descriptive study on 29 patients older than 60 years at the moment they suffered their first dislocation episode. All patients were assessed clinically (Constant test) and by imaging testing (X-ray, MRI). Results: Nine (31.03%) out of 29 patients had a recurrent dislocation. Four of them required reconstructive surgery to maintain joint stability. Injury to the anterior support (anterior labrum, anterior glenoid rim) showed a statistically significant relation to the recurrence of dislocations. The occurrence or non-occurrence of a rotator cuff tear does have an impact on the shoulder function. The degree of rotator cuff involvement on the coronal plane does not significantly affect the shoulder’s functional outcome. The tear extension on the sagittal plane does cause impairment on the Constant test. Conclusions: Labrum and/or anterior glenoid involvement should be suspected in elderly patients presenting with recurrent shoulder dislocation. Recurrence is due to an injury in the anterior support or both (anterior and posterior), even though shoulder function gets impaired when a rotation cuff tear occurs with anterior extension on the sagittal plane. Evidence level: IV Case series. PMID:21655003

Determination of Coronal Magnetic Fields from Vector Magnetograms

NASA Technical Reports Server (NTRS)

Mikic, Zoran

1997-01-01

During the course of the present contract we developed an 'evolutionary technique' for the determination of force-free coronal magnetic fields from vector magnetograph observations. The method can successfully generate nonlinear force- free fields (with non-constant-a) that match vector magnetograms. We demonstrated that it is possible to determine coronal magnetic fields from photospheric measurements, and we applied it to vector magnetograms of active regions. We have also studied theoretical models of coronal fields that lead to disruptions. Specifically, we have demonstrated that the determination of force-free fields from exact boundary data is a well-posed mathematical problem, by verifying that the computed coronal field agrees with an analytic force-free field when boundary data for the analytic field are used; demonstrated that it is possible to determine active-region coronal magnetic fields from photospheric measurements, by computing the coronal field above active region 5747 on 20 October 1989, AR6919 on 15 November 1991, and AR7260 on 18 August 1992, from data taken with the Stokes Polarimeter at Mees Solar Observatory, University of Hawaii; started to analyze active region 7201 on 19 June 1992 using measurements made with the Advanced Stokes Polarimeter at NSO/Sac Peak; investigated the effects of imperfections in the photospheric data on the computed coronal magnetic field; documented the coronal field structure of AR5747 and compared it to the morphology of footpoint emission in a flare, showing that the 'high- pressure' H-alpha footpoints are connected by coronal field lines; shown that the variation of magnetic field strength along current-carrying field lines is significantly different from the variation in a potential field, and that the resulting near-constant area of elementary flux tubes is consistent with observations; begun to develop realistic models of coronal fields which can be used to study flare trigger mechanisms; demonstrated that

Coronal gas in the galaxy. II. A statistical analysis of O VI absorptions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jenkins, E.B.

Results from the survey of interstellar O VI by Jenkins and by Jenkins and Meloy are analyzed to synthesize a global description of the properties of the coronal gas. Tests for correlations of column densities or velocities with properties of the target stars showed no evidence for a circumstellar origin for the absorption lines. An overall average density n (O VI) =2.8 x 10/sup -8/ cm/sup -3/ was found in the galactic plane, with a decrease which approximately follows exp (-z/300 pc) away from the plane.Fluctuations in column densities over various lines of sight suggest that existence of six hotmore » gas regions kpc/sup -/1, randomly distributed in space, each with an O VI column density of about 10/sup 13/ cm/sup -2/. These regions account for an average density n (O VI) =2.1 x 10/sup -8/ cm/sup -3/; the remaining 7 x 10/sup -9/ cm/sup -3/ is produced by more sparsely distributed but thicker parcels of hot gas which are seen toward 10% of the stars. The statistics of radial velocity centroids and widths support the interpretation of distinct domains; each region has an internal velocity dispersion consistent with a Doppler broadening of a plasma at T> or approx. =2 x 10/sup 5/ K (near the characteristic temperature for a maximum concentration of O VI in collisional equilibrium), while the regions themselves move about with a dispersion of radial velocities equal to 26 km s/sup -1/. Systematic motions of gas away from the galactic plane could not be seen, however.Excursions from the normal O VI per unit distance have no perceptible anicorrelation with deviations in reddening by cool interstellar coulds: a fact which suggests that the average filling factor of O VI gas is less than 20% if coronal gas really displaces the cooler material and does not have large variations in density and temperature.« less

Hybrid constructs for tridimensional correction of the thoracic spine in adolescent idiopathic scoliosis: a comparative analysis of universal clamps versus hooks.

PubMed

Ilharreborde, Brice; Even, Julien; Lefevre, Yan; Fitoussi, Franck; Presedo, Ana; Penneçot, Georges-François; Mazda, Keyvan

2010-02-01

Retrospective study of prospectively collected data. Compare Universal Clamps (UCs) and hooks for the thoracic correction of adolescent idiopathic scoliosis (AIS). In scoliosis surgery, sagittal correction is as important as frontal correction due to the risk of junctional kyphosis. Compared to all-screw constructs, hybrid constructs with lumbar pedicle screws and thoracic hooks or sublaminar wires have been shown to achieve similar coronal correction while providing superior postoperative thoracic kyphosis. The authors used a novel sublaminar thoracic implant, the UC with improvements over sublaminar wires. Hybrid constructs using thoracic UCs were compared to those with thoracic hooks. This series involved 150 patients treated for AIS with hybrid constructs. A total of 75 consecutive patients operated from 2001 to 2003, who had thoracic hooks with in situ contouring, distraction, and compression (Group 1), were compared to 75 consecutive patients operated from 2004 to 2006, who had thoracic UCs with posteromedial translation (Group 2). All had intraoperative somatosensory/motor-evoked potential monitoring and at least 2-years follow-up. Except for follow-up (longer in Group 1), the 2 groups were similar before surgery. The UCs achieved better thoracic coronal correction (P < 0.001), Cincinnati index (P < 0.001), kyphosis (P = 0.02), and apical rotation (P < 0.001). In normokyphotic or hypokyphotic patients, the UC corrected thoracic kyphosis by 11.2 degrees (55%) versus 0.4 degrees (2%) achieved by hooks (P < 0.0001). These differences were stable at last follow-up. There were no intraoperative complications or changes in somatosensory/motor-evoked potentials. UC reduced operative time by 20% (60 minutes; P < 0.001) and blood loss by 23% (250 mL; P < 0.001). Although both of these hybrid constructs efficaciously corrected the coronal and axial deformities in AIS, the results of the UC technique were superior to those achieved with hooks in all 3 planes

Midline as a landmark for the position of the superior sagittal sinus on the cranial vault: An anatomical and imaging study.

PubMed

Reis, Cassius Vinicius C; Gusmão, Sebastião N S; Elhadi, Ali M; Dru, Alexander; Tazinaffo, Uédson; Zabramski, Joseph M; Spetzler, Robert F; Preul, Mark C

2015-01-01

Craniotomies involving the midline are regular practice in neurosurgery, during which injury to the superior sagittal sinus (SSS), an uncommon yet devastating event, may occur. The midline tends to be the most common landmark used to identify the position of the SSS. In this study we examined the reliability of the midline as a landmark for the SSS. We performed bilateral craniectomies on eight cadaveric heads, preserving the coronal, sagittal, and lambdoid sutures. The width of the SSS and its displacement from midline were measured on the cadaveric specimens and on 105 normal magnetic resonance images (MRIs) of the head at the following locations: halfway between nasion and bregma (NB), bregma (B), halfway between bregma and lambda (BL), lambda (L), and inion (I). In all cadaveric specimens, the SSS was partially or totally displaced toward one side of midline, usually to the right. It tended to be closer to midline in the frontal region and more displaced posteriorly. The SSS usually drained into the right-side transverse sinus. The mean width of the SSS was 4.3, 5.9, 6.9, 7.9, and 7.8 mm, and the average displacement from midline was 4.3, 6.3, 5.5, 6.9, and 6.0 mm for NB, B, BL, L, and I, respectively. These measurements were then compared with those obtained from the MRIs. The SSS was consistently displaced on either side of midline. Thus, the midline is not reliable for identifying the SSS, and caution should be used within 6-10 mm on either side of midline.

Location of radiosensitive organs inside pediatric anthropomorphic phantoms: Data required for dosimetry.

PubMed

Inkoom, Stephen; Raissaki, Maria; Perisinakis, Kostas; Maris, Thomas G; Damilakis, John

2015-12-01

The aim of this study was to determine the location of radiosensitive organs in the interior of four pediatric anthropomorphic phantoms for dosimetric purposes. Four pediatric anthropomorphic phantoms representing the average individual as newborn, 1-year-old, 5-year-old and 10-year-old child underwent head, thorax and abdomen CT scans. CT and MRI scans of all children aged 0-16 years performed during a 5-year-period in our hospital were reviewed, and 503 were found to be eligible for normal anatomy. Anterior-posterior and lateral dimensions of twelve of the above children closely matched that of the phantoms' head, thoracic and abdominal region in each four phantoms. The mid-sagittal and mid-coronal planes were drawn on selected matching axial images of patients and phantoms. Multiple points outlining large radiosensitive organs in patient images were identified at each slice level and their orthogonal distances from the mid-sagittal and mid-coronal planes were measured. In small organs, the coordinates of organs' centers were similarly determined. The outlines and centers of all radiosensitive organs were reproduced using the coordinates of each organ on corresponding phantoms' transverse images. The locations of the following radiosensitive organs in the interior of the four phantoms was determined: brain, eye lenses, salivary glands, thyroid, lungs, heart, thymus, esophagus, breasts, adrenals, liver, spleen, kidneys, stomach, gallbladder, small bowel, pancreas, colon, ovaries, bladder, prostate, uterus and rectum. The production of charts of radiosensitive organs inside pediatric anthropomorphic phantoms was feasible and may provide users reliable data for positioning of dosimeters during direct organ dose measurements. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Solar and stellar coronal plasmas

NASA Technical Reports Server (NTRS)

Golub, L.

1985-01-01

Progress made in describing and interpreting coronal plasma processes and the relationship between the solar corona and its stellar counterparts is reported. Topics covered include: stellar X-ray emission, HEAO 2 X-ray survey of the Pleiades, closed coronal structures, X-ray survey of main-sequence stars with shallow convection zones, implications of the 1400 MHz flare emission, and magnetic field stochasticity.

Assessment of Isometric Trunk Strength – The Relevance of Body Position and Relationship between Planes of Movement

PubMed Central

Kocjan, Andrej; Sarabon, Nejc

2014-01-01

The aim of the study was to assess the differences in maximal isometric trunk extension and flexion strength during standing, sitting and kneeling. Additionally, we were interested in correlations between the maximal strength in sagittal, frontal and transverse plane, measured in the sitting position. Sixty healthy subjects (24 male, 36 female; age 41.3 ± 15.1 yrs; body height 1.70 ± 0.09 m; body mass 72.7 ± 13.3 kg) performed maximal voluntary isometric contractions of the trunk flexor and extensor muscles in standing, sitting and kneeling position. The subjects also performed lateral flexions and rotations in the sitting position. Each task was repeated three times and average of maximal forces was used for data analysis. RANOVA with post-hoc testing was applied to the flexion and extension data. The level of statistical significance was set to p < 0.05. Overall, in both genders together, the highest average force for trunk extension was recorded in sitting posture (910.5 ± 271.5 N), followed by kneeling (834.3 ± 242.9 N) and standing (504.0 ± 165.4 N), compared with flexion, where we observed the opposite trend (508.5 ± 213.0 N, 450.9 ± 165.7 N and 443.4 ± 153.1 N, respectively). Post-hoc tests showed significant differences in all extension positions (p < 0.0001) and between sitting/standing (p = 0.018) and kneeling/standing (p = 0.033) flexion exertions. The extension/flexion ratio for sitting was 2.1 ± 0.4, for kneeling 1.9 ± 0.4, followed by standing, where motion forward approximately equals motion backward (1.1 ± 0.6). Trunk sagittal-transverse strength showed the strongest correlation, followed by frontal-transverse and sagittal-frontal plane correlation pairs (R2 = 0.830, 0.712 and 0.657). The baseline trunk isometric strength data provided by this study should help further strength diagnostics, more precisely, the prevention of low back disorders. Key points Maximal voluntary isometric force of the trunk extensors increased with the angle at

Solar and stellar coronal plasmas

NASA Technical Reports Server (NTRS)

Golub, Leon

1989-01-01

Progress in observational, theoretical, and radio studies of coronal plasmas is summarized. Specifically work completed in the area of solar and stellar magnetic fields, related photospheric phenomena and the relationships between magnetism, rotation, coronal and chromospheric emission in solar-like stars is described. Also outlined are theoretical studies carried out in the following areas, among others: (1) neutral beams as the dominant energy transport mechanism in two ribbon-flares; (2) magneto hydrodynamic and circuit models for filament eruptions; and (3) studies of radio emission mechanisms in transient events. Finally, radio observations designed for coronal activity studies of the sun and of solar-type coronae are described. A bibliography of publications and talks is provided along with reprints of selected articles.

First Imaging Observation of Standing Slow Wave in Coronal Fan Loops

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pant, V.; Tiwari, A.; Banerjee, D.

2017-09-20

We observe intensity oscillations along coronal fan loops associated with the active region AR 11428. The intensity oscillations were triggered by blast waves that were generated due to X-class flares in the distant active region AR 11429. To characterize the nature of oscillations, we created time–distance maps along the fan loops and noted that the intensity oscillations at two ends of the loops were out of phase. As we move along the fan loop, the amplitude of the oscillations first decreased and then increased. The out-of-phase nature together with the amplitude variation along the loop implies that these oscillations aremore » very likely to be standing waves. The period of the oscillations is estimated to be ∼27 minutes, damping time to be ∼45 minutes, and phase velocity projected in the plane of sky to be ∼65–83 km s{sup −1}. The projected phase speeds were in the range of the acoustic speed of coronal plasma at about 0.6 MK, which further indicates that these are slow waves. To the best of our knowledge, this is the first report on the existence of the standing slow waves in non-flaring fan loops.« less

Is arch form influenced by sagittal molar relationship or Bolton tooth-size discrepancy?

PubMed

Aldrees, Abdullah M; Al-Shujaa, Abdulmajeed M; Alqahtani, Mohammad A; Aljhani, Ali S

2015-06-26

Orthodontic patients show high prevalence of tooth-size discrepancy. This study investigates the possible association between arch form, clinically significant tooth-size discrepancy, and sagittal molar relationship. Pretreatment orthodontic casts of 230 Saudi patients were classified into one of three arch form types (tapered, ovoid, and square) using digitally scanned images of the mandibular arches. Bolton ratio was calculated, sagittal molar relationship was defined according to Angle classification, and correlations were analyzed using ANOVA, chi-square, and t-tests. No single arch form was significantly more common than the others. Furthermore, no association was observed between the presence of significant Bolton discrepancy and the sagittal molar relationship or arch form. Overall Bolton discrepancy is significantly more prevalent in males. Arch form in a Saudi patient group is independent of gender, sagittal molar relationship, and Bolton discrepancy.

Coronal disturbances and their terrestrial effects /Tutorial Lecture/

NASA Technical Reports Server (NTRS)

Rust, D. M.

1983-01-01

An assessment is undertaken of recent approaches to the prediction of the interplanetary consequences of coronal disturbances, with attention to the relationships of shocks and energetic particles to coronal transients, of proton events to gamma-ray and microwave bursts, of geomagnetic storms to filament eruptions, and of solar wind increases to the flare site magnetic field direction. A discussion is given concerning the novel phenomenon of transient coronal holes, which appear astride the long decay enhancements of 2-50 A X-ray emission following H-alpha filament eruptions. These voids in the corona are similar to long-lived coronal holes, which are the sources of high speed solar wind streams. The transient coronal holes may also be associated with transient solar wind speed increases.

A portable system with sample rate of 250 Hz for characterization of knee and hip angles in the sagittal plane during gait

PubMed Central

2014-01-01

Background Gait analysis and research have been developed to obtain characteristics of movement patterns of people while walking. However, traditional measuring systems present different drawbacks that reduce their use and application. Among those drawbacks one can find: high price, low sampling frequency and limiting number of steps to be analyzed. Traditional measuring gait systems carry out their measurement at frequencies oscillating between 60 to 100 Hz. It can be argued about the need of higher sampling rates for gait measurements. However small displacements of the knee or hip for example, cannot be seen with low frequencies required a more detailed sampling and higher frequency sampling. Bearing this in mind, in this paper is presented a 250 Hz system based on accelerometers for gait measurement, and the particularities of knee and hip angles during gait are highlighted. Methods The system was designed with a PCI data acquisition card instrumented with an FPGA to achieve a rate sample of 250 Hz. The accelerometers were placed in thighs and legs to calculate the joint angles of hip and knee in the sagittal plane. The angles were estimated using the acceleration polygon method without integrating the acceleration and without filters. Results The gait of thirty healthy people of Mexican phenotype was analyzed over a flat floor free of obstacles. The results showed the gait phases and particularities associated with the walking style and people's laterality; the movement patterns were similar in the thirty persons. Based on the results, the particularities as the maximum amplitude in the angles and the shape in the movement patterns were related to the anthropometry and people phenotype. Conclusions The sampling frequency was essential to record 340 samples in single gait cycle and so registering the gait cycle with its particularities. In this work were recorded an average of 8 to 10 gait cycles, and the results showed variation regarding works carried out

A portable system with sample rate of 250 Hz for characterization of knee and hip angles in the sagittal plane during gait.

PubMed

Martínez-Solís, Fermín; Claudio-Sánchez, Abraham; Rodríguez-Lelis, José M; Vergara-Limon, Sergio; Olivares-Peregrino, Víctor; Vargas-Treviño, Marciano

2014-03-31

Gait analysis and research have been developed to obtain characteristics of movement patterns of people while walking. However, traditional measuring systems present different drawbacks that reduce their use and application. Among those drawbacks one can find: high price, low sampling frequency and limiting number of steps to be analyzed. Traditional measuring gait systems carry out their measurement at frequencies oscillating between 60 to 100 Hz. It can be argued about the need of higher sampling rates for gait measurements. However small displacements of the knee or hip for example, cannot be seen with low frequencies required a more detailed sampling and higher frequency sampling. Bearing this in mind, in this paper is presented a 250 Hz system based on accelerometers for gait measurement, and the particularities of knee and hip angles during gait are highlighted. The system was designed with a PCI data acquisition card instrumented with an FPGA to achieve a rate sample of 250 Hz. The accelerometers were placed in thighs and legs to calculate the joint angles of hip and knee in the sagittal plane. The angles were estimated using the acceleration polygon method without integrating the acceleration and without filters. The gait of thirty healthy people of Mexican phenotype was analyzed over a flat floor free of obstacles. The results showed the gait phases and particularities associated with the walking style and people's laterality; the movement patterns were similar in the thirty persons. Based on the results, the particularities as the maximum amplitude in the angles and the shape in the movement patterns were related to the anthropometry and people phenotype. The sampling frequency was essential to record 340 samples in single gait cycle and so registering the gait cycle with its particularities. In this work were recorded an average of 8 to 10 gait cycles, and the results showed variation regarding works carried out in biomechanics laboratories; this

Earth-Directed Coronal Hole

NASA Image and Video Library

2016-09-21

A dark coronal hole that was facing towards Earth for several days spewed streams of solar wind in our direction (Sept. 18-21, 2016). A coronal hole is a magnetically open region. The magnetic fields have opened up allowing solar wind (comprised of charged particles) to stream into space. Gusts of solar wind can generate beautiful aurora when they reach Earth. The video clip shows the sun in a wavelength of extreme ultraviolet light. Movies are available at http://photojournal.jpl.nasa.gov/catalog/PIA21067

Coronal Heating by Magnetic Explosions

NASA Technical Reports Server (NTRS)

Moore, Ronald L.; Falconer, D. A.; Porter, Jason G.; Suess, Steven T.

1998-01-01

We build a case for the persistent strong coronal heating in active regions and the pervasive quasi-steady heating of the corona in quiet regions and coronal holes being driven in basically the same way as the intense transient heating in solar flares: by explosions of sheared magnetic fields in the cores of initially closed bipoles. We begin by summarizing the observational case for exploding sheared core fields being the drivers of a wide variety of flare events, with and without coronal mass ejections. We conclude that the arrangement of an event's flare heating, whether there is a coronal mass ejection, and the time and place of the ejection relative to the flare heating are all largely determined by four elements of the form and action the magnetic field: (1) the arrangement of the impacted, interacting bipoles participating in the event, (2) which of these bipoles are active (have sheared core fields that explode) and which are passive (are heated by injection from impacted active bipoles), (3) which core field explodes first, and (4) which core-field explosions are confined within the closed field of their bipoles and which ejectively open their bipoles.

Muscle complex saving posterior sagittal anorectoplasty.

PubMed

Zaiem, Maher; Zaiem, Feras

2017-05-01

Posterior sagittal anorectoplasty (PSARP) published by DeVries and Peña in 1982 had become the preferred surgical technique for the management of anorectal malformations (ARM). The original technique is based upon complete exposure of the anorectal region by means of a median sagittal incision that runs from the sacrum to the anal dimple, cutting through all muscle structures behind the rectum by dividing the levator muscle and the muscle complex. Then, the rectum is located in front of the levator and within the limits of the muscle complex. In this review, we described Muscle Complex Saving-Posterior Sagittal Anorectoplasty (MCS-PSARP), which is a less invasive technique that consists of keeping this funnel-shaped muscle complex completely intact and not divided, and pulling the rectum through this funnel, toward fixing the new anus to the skin. This technique aimed both to respect the lower part of the sphincter mechanism consisting of the muscle complex, and to avoid the disturbance of this important structure by dividing and resuturing it. We presented six cases of male patients who were born with anorectal malformation (ARM) and underwent MCS-PSARP. The surgical technique proved to be feasible to achieve the dissection of the rectal pouch and the division of the rectourethral fistula in all patients, by opening only the upper part of the sphincter mechanism, the levator muscle, and keeping the lower part consisting of intact muscle complex. The early results in our series are encouraging; however, long-term functional outcomes of these patients are awaited. The surgical tips were also discussed. This proposed approach in the management of anorectal malformation cases provides an opportunity to maximize preservation of the existing continence mechanisms. It preserves the muscle complex components of the levator muscle intact, allowing a better function of the continence mechanism. Copyright © 2016 Elsevier Inc. All rights reserved.

A CORONAL HOLE'S EFFECTS ON CORONAL MASS EJECTION SHOCK MORPHOLOGY IN THE INNER HELIOSPHERE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, B. E.; Wu, C.-C.; Howard, R. A.

2012-08-10

We use STEREO imagery to study the morphology of a shock driven by a fast coronal mass ejection (CME) launched from the Sun on 2011 March 7. The source region of the CME is located just to the east of a coronal hole. The CME ejecta is deflected away from the hole, in contrast with the shock, which readily expands into the fast outflow from the coronal hole. The result is a CME with ejecta not well centered within the shock surrounding it. The shock shape inferred from the imaging is compared with in situ data at 1 AU, wheremore » the shock is observed near Earth by the Wind spacecraft, and at STEREO-A. Shock normals computed from the in situ data are consistent with the shock morphology inferred from imaging.« less

Coronation Chemicals

NASA Image and Video Library

2012-08-22

This is the first laser spectrum from the ChemCam instrument on NASA Curiosity rover, sent back from Mars on Aug. 19, 2012, showing emission lines from different elements present in the target, a rock near the rover landing site dubbed Coronation.

Understanding the rotation of coronal holes

NASA Astrophysics Data System (ADS)

Wang, Y.-M.; Sheeley, N. R., Jr.

1993-09-01

In an earlier study we found that the rotation of coronal holes could be understood on the basis of a nearly current-free coronal field, with the holes representing open magnetic regions. In this paper we illustrate the model by focusing on the case of CH1, the rigidly rotating boot-shaped hole observed by Skylab. We show that the interaction between the polar fields and the flux associated with active regions produces distortions in the coronal field configuration and thus in the polar-hole boundaries; these distortions corotate with the perturbing nonaxisymmetric flux. In the case of CH1, positive-polarity field lines in the northern hemisphere 'collided' with like-polarity field lines fanning out from a decaying active region complex located just below the equator, producing a midlatitude corridor of open field lines rotating at the rate of the active region complex. Sheared coronal holes result when nonaxisymmetric flux is present at high latitudes, or equivalently, when the photospheric neutral line extends to high latitudes. We demonstrate how a small active region, rotating at the local photospheric rate, can drift through a rigidly rotating hole like CH1. Finally, we discuss the role of field-line reconnection in maintaining a quasi-potential coronal configuration.

Elongated Coronal Hole

NASA Image and Video Library

2018-03-19

Over the past week, the single, largest feature on the sun was a long coronal hole that stretched out across more than half the diameter of the sun (Mar. 13-15, 2018). Coronal holes appear dark in certain wavelengths of extreme ultraviolet light like the one you see here. They are areas of open magnetic fields from which solar wind rushes out into space. This area likely generated the beautiful aurora that were reportedly observed on March 14th in regions near Earth's poles. With the Earth set in the image to show scale, you get a good sense of just how extensive this hole is. Movies are available at https://photojournal.jpl.nasa.gov/catalog/PIA22345

Three-Dimensional Morphology of a Coronal Prominence Cavity

NASA Technical Reports Server (NTRS)

Gibson, S. E.; Kucera, T. A.; Rastawicki, D.; Dove, J.; deToma, G.; Hao, J.; Hill, S.; Hudson, H. S.; Marque, C.; McIntosh, P. S.;

Sagittal alignment after single cervical disc arthroplasty.

PubMed

Guérin, Patrick; Obeid, Ibrahim; Gille, Olivier; Bourghli, Anouar; Luc, Stéphane; Pointillart, Vincent; Vital, Jean-Marc

2012-02-01

Prospective study. To analyze the sagittal balance after single-level cervical disc replacement (CDR) and range of motion (ROM). To define clinical and radiologic parameters those have a significant correlation with segmental and overall cervical curvature after CDR. Clinical outcomes and ROM after CDR with Mobi-C (LDR, Troyes, France) prosthesis have been documented in few studies. No earlier report of this prosthesis has studied correlations between static and dynamic parameters or those between static parameters and clinical outcomes. Forty patients were evaluated. Clinical outcome was assessed using the Short Form-36 questionnaire, Neck Disability Index, and a Visual Analog Scale. Spineview software (Surgiview, Paris, France) was used to investigate sagittal balance parameters and ROM. The mean follow-up was 24.3 months (range: 12 to 36 mo). Clinical outcomes were satisfactory. There was a significant improvement of Short Form-36, Neck Disability Index, and Visual Analog Scale scores. Mean ROM was 8.3 degrees preoperatively and 11.0 degrees postoperatively (P=0.013). Mean preoperative C2C7 curvature was 12.8 and 16.0 degrees at last follow-up (P=0.001). Mean preoperative functional spinal unit (FSU) angle was 2.3 and 5.3 degrees postoperatively (P<0.0001). Mean postoperative shell angle was 5.5 degrees. There was a significant correlation between postoperative C2C7 alignment and preoperative C2C7 alignment, change of C2C7 alignment, preoperative and postoperative FSU angle, and prosthesis shell angle. There was also a significant correlation between postoperative FSU angle and preoperative C2C7 alignment, preoperative FSU angle, change of FSU angle, and prosthesis shell angle. Regression analysis showed that prosthesis shell angle and preoperative FSU angle contributed significantly to postoperative FSU angle. Moreover, preoperative C2C7 alignment, preoperative FSU angle, postoperative FSU angle, and prosthesis shell angle contributed significantly to

The addition of a sagittal image fusion improves the prostate cancer detection in a sensor-based MRI /ultrasound fusion guided targeted biopsy.

PubMed

Günzel, Karsten; Cash, Hannes; Buckendahl, John; Königbauer, Maximilian; Asbach, Patrick; Haas, Matthias; Neymeyer, Jörg; Hinz, Stefan; Miller, Kurt; Kempkensteffen, Carsten

2017-01-13

To explore the diagnostic benefit of an additional image fusion of the sagittal plane in addition to the standard axial image fusion, using a sensor-based MRI/US fusion platform. During July 2013 and September 2015, 251 patients with at least one suspicious lesion on mpMRI (rated by PI-RADS) were included into the analysis. All patients underwent MRI/US targeted biopsy (TB) in combination with a 10 core systematic prostate biopsy (SB). All biopsies were performed on a sensor-based fusion system. Group A included 162 men who received TB by an axial MRI/US image fusion. Group B comprised 89 men in whom the TB was performed with an additional sagittal image fusion. The median age in group A was 67 years (IQR 61-72) and in group B 68 years (IQR 60-71). The median PSA level in group A was 8.10 ng/ml (IQR 6.05-14) and in group B 8.59 ng/ml (IQR 5.65-12.32). In group A the proportion of patients with a suspicious digital rectal examination (DRE) (14 vs. 29%, p = 0.007) and the proportion of primary biopsies (33 vs 46%, p = 0.046) were significantly lower. The rate of PI-RADS 3 lesions were overrepresented in group A compared to group B (19 vs. 9%; p = 0.044). Classified according to PI-RADS 3, 4 and 5, the detection rates of TB were 42, 48, 75% in group A and 25, 74, 90% in group B. The rate of PCa with a Gleason score ≥7 missed by TB was 33% (18 cases) in group A and 9% (5 cases) in group B; p-value 0.072. An explorative multivariate binary logistic regression analysis revealed that PI-RADS, a suspicious DRE and performing an additional sagittal image fusion were significant predictors for PCa detection in TB. 9 PCa were only detected by TB with sagittal fusion (sTB) and sTB identified 10 additional clinically significant PCa (Gleason ≥7). Performing an additional sagittal image fusion besides the standard axial fusion appears to improve the accuracy of the sensor-based MRI/US fusion platform.

Determination of the coronal magnetic field from vector magnetograph data

NASA Technical Reports Server (NTRS)

Mikic, Zoran

1991-01-01

A new algorithm was developed, tested, and applied to determine coronal magnetic fields above solar active regions. The coronal field above NOAA active region AR5747 was successfully estimated on 20 Oct. 1989 from data taken at the Mees Solar Observatory of the Univ. of Hawaii. It was shown that observational data can be used to obtain realistic estimates of coronal magnetic fields. The model has significantly extended the realism with which the coronal magnetic field can be inferred from observations. The understanding of coronal phenomena will be greatly advanced by a reliable technique, such as the one presented, for deducing the detailed spatial structure of the coronal field. The payoff from major current and proposed NASA observational efforts is heavily dependent on the success with which the coronal field can be inferred from vector magnetograms. In particular, the present inability to reliably obtain the coronal field has been a major obstacle to the theoretical advancement of solar flare theory and prediction. The results have shown that the evolutional algorithm can be used to estimate coronal magnetic fields.

Relating magnetic reconnection to coronal heating

PubMed Central

Longcope, D. W.; Tarr, L. A.

2015-01-01

It is clear that the solar corona is being heated and that coronal magnetic fields undergo reconnection all the time. Here we attempt to show that these two facts are related—i.e. coronal reconnection generates heat. This attempt must address the fact that topological change of field lines does not automatically generate heat. We present one case of flux emergence where we have measured the rate of coronal magnetic reconnection and the rate of energy dissipation in the corona. The ratio of these two, , is a current comparable to the amount of current expected to flow along the boundary separating the emerged flux from the pre-existing flux overlying it. We can generalize this relation to the overall corona in quiet Sun or in active regions. Doing so yields estimates for the contribution to coronal heating from magnetic reconnection. These estimated rates are comparable to the amount required to maintain the corona at its observed temperature. PMID:25897089

Hybrid Stars and Coronal Evolution

NASA Technical Reports Server (NTRS)

Mushotzky, Richard (Technical Monitor); Dupree, Andrea K.

2004-01-01

This program addresses the evolution of stellar coronas by comparing a solar-like corona in the supergiant Dra (G2 Ib-IIa) to the corona in the allegedly more evolved state of a hybrid star, TrA (K2 11-111). Because the hybrid star has a massive wind, it appears likely that the corona will be cooler and less dense as the magnetic loop structures are no longer closed. By analogy with solar coronal holes, when the topology of the magnetic field is configured with open magnetic structures, both the coronal temperature and density are lower than in atmospheres dominated by closed loops. The hybrid stars assume a pivotal role in the definition of coronal evolution, atmospheric heating processes and mechanisms to drive winds of cool stars.

Coronal Hole Facing Earth

NASA Image and Video Library

2018-05-08

An extensive equatorial coronal hole has rotated so that it is now facing Earth (May 2-4, 2018). The dark coronal hole extends about halfway across the solar disk. It was observed in a wavelength of extreme ultraviolet light. This magnetically open area is streaming solar wind (i.e., a stream of charged particles released from the sun) into space. When Earth enters a solar wind stream and the stream interacts with our magnetosphere, we often experience nice displays of aurora. Videos are available at https://photojournal.jpl.nasa.gov/catalog/PIA00624

Coronal Hole Facing Earth

NASA Image and Video Library

2018-05-15

An extensive equatorial coronal hole has rotated so that it is now facing Earth (May 2-4, 2018). The dark coronal hole extends about halfway across the solar disk. It was observed in a wavelength of extreme ultraviolet light. This magnetically open area is streaming solar wind (i.e., a stream of charged particles released from the sun) into space. When Earth enters a solar wind stream and the stream interacts with our magnetosphere, we often experience nice displays of aurora. https://photojournal.jpl.nasa.gov/catalog/PIA00577

Earth-Facing Coronal Holes

NASA Image and Video Library

2016-11-09

Two good-sized coronal holes have rotated around to the center of the sun where they will be spewing solar wind towards Earth (Nov. 8-9, 2016). Coronal holes are areas of open magnetic field from which solar wind particles stream into space. In this wavelength of extreme ultraviolet light they appear as the two dark areas at the center and lower portion of the sun. The stream of particles should reach Earth in a few days and are likely to generate aurora. Videos are available at http://photojournal.jpl.nasa.gov/catalog/PIA16909

Posterior Surgery for Adolescent Idiopathic Scoliosis With Pedicle Screws and Ultrahigh-Molecular Weight Polyethylene Tape: Achieving the Ideal Thoracic Kyphosis.

PubMed

Imagama, Shiro; Ito, Zenya; Wakao, Norimitsu; Ando, Kei; Hirano, Kenichi; Tauchi, Ryoji; Muramoto, Akio; Matsui, Hiroki; Matsumoto, Tomohiro; Sakai, Yoshihito; Katayama, Yoshito; Matsuyama, Yukihiro; Ishiguro, Naoki

2016-10-01

Prospective clinical case series. To describe our surgical procedure and results for posterior correction and fusion with a hybrid approach using pedicle screws, hooks, and ultrahigh-molecular weight polyethylene tape with direct vertebral rotation (DVR) (the PSTH-DVR procedure) for treatment of adolescent idiopathic scoliosis (AIS) with satisfactory correction in the coronal and sagittal planes. Introduction of segmental pedicle screws in posterior surgery for AIS has facilitated good correction and fusion. However, procedures using only pedicle screws have risks during screw insertion, higher costs, and decreased postoperative thoracic kyphosis. We have obtained good outcomes compared with segmental pedicle screw fixation in surgery for AIS using a relatively simple operative procedure (PSTH-DVR) that uses fewer pedicle screws. The subjects were 30 consecutive patients with AIS who underwent the PSTH-DVR procedure and were followed for a minimum of 2 years. Preoperative flexibility, preoperative and postoperative Cobb angles, correction rates, loss of correction, thoracic kyphotic angles (T5-T12), coronal balance, sagittal balance, and shoulder balance were measured on plain radiographs. Rib hump, operation time, estimated blood loss, spinal cord monitoring findings, complications, and scoliosis research society (SRS)-22 scores were also examined. The mean preoperative curve of 58.0 degrees (range, 40-96 degrees) was corrected to a mean of 9.9 degrees postoperatively, and the correction rate was 83.6%. Fusion was obtained in all patients without loss of correction. In 10 cases with preoperative kyphosis angles (T5-T12) <10 degrees, the preoperative mean of 5.8 degrees improved to 20.2 degrees at the final follow-up. Rib hump and coronal, sagittal and shoulder balances were also improved, and good SRS-22 scores were achieved at final follow-up. The correction of deformity with PSTH-DVR is equivalent to that of all-pedicle screw constructs. The procedure gives

Critical Magnetic Field Strengths for Unipolar Solar Coronal Plumes in Quiet Regions and Coronal Holes?

NASA Astrophysics Data System (ADS)

Avallone, E. A.; Tiwari, S. K.; Panesar, N. K.; Moore, R. L.

2017-12-01

Coronal plumes are sporadic fountain-like structures that are bright in coronal emission. Each is a magnetic funnel rooted in a strong patch of dominant-polarity photospheric magnetic flux surrounded by a predominantly-unipolar magnetic network, either in a quiet region or a coronal hole. The heating processes that make plumes bright evidently involve the magnetic field in the base of the plume, but remain mysterious. Raouafi et al. (2014) inferred from observations that plume heating is a consequence of magnetic reconnection in the base, whereas Wang et al. (2016) showed that plume heating turns on/off from convection-driven convergence/divergence of the base flux. While both papers suggest that the base magnetic flux in their plumes is of mixed polarity, these papers provide no measurements of the abundance and strength of the evolving base flux or consider whether a critical magnetic field strength is required for a plume to become noticeably bright. To address plume production and evolution, we track the plume luminosity and the abundance and strength of the base magnetic flux over the lifetimes of six coronal plumes, using Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) 171 Å images and SDO/Helioseismic and Magnetic Imager (HMI) line-of-sight magnetograms. Three of these plumes are in coronal holes, three are in quiet regions, and each plume exhibits a unipolar base flux. We track the base magnetic flux over each plume's lifetime to affirm that its convergence and divergence respectively coincide with the appearance and disappearance of the plume in 171 Å images. We tentatively find that plume formation requires enough convergence of the base flux to surpass a field strength of ˜300-500 Gauss, and that quiet Sun and coronal-hole plumes both exhibit the same behavior in the response of their luminosity in 171 Å to the strength of the magnetic field in the base.

Feasibility study: real-time 3-D ultrasound imaging of the brain.

PubMed

Smith, Stephen W; Chu, Kengyeh; Idriss, Salim F; Ivancevich, Nikolas M; Light, Edward D; Wolf, Patrick D

2004-10-01

We tested the feasibility of real-time, 3-D ultrasound (US) imaging in the brain. The 3-D scanner uses a matrix phased-array transducer of 512 transmit channels and 256 receive channels operating at 2.5 MHz with a 15-mm diameter footprint. The real-time system scans a 65 degrees pyramid, producing up to 30 volumetric scans per second, and features up to five image planes as well as 3-D rendering, 3-D pulsed-wave and color Doppler. In a human subject, the real-time 3-D scans produced simultaneous transcranial horizontal (axial), coronal and sagittal image planes and real-time volume-rendered images of the gross anatomy of the brain. In a transcranial sheep model, we obtained real-time 3-D color flow Doppler scans and perfusion images using bolus injection of contrast agents into the internal carotid artery.

Dynamical behaviour in coronal loops

NASA Technical Reports Server (NTRS)

Haisch, Bernhard M.

1986-01-01

Rapid variability has been found in two active region coronal loops observed by the X-ray Polychromator (XRP) and the Hard X-ray Imaging Spectrometer (HXIS) onboard the Solar Maximum Mission (SMM). There appear to be surprisingly few observations of the short-time scale behavior of hot loops, and the evidence presented herein lends support to the hypothesis that coronal heating may be impulsive and driven by flaring.

Dynamical behaviour in coronal loops

NASA Astrophysics Data System (ADS)

Haisch, Bernhard M.

Rapid variability has been found in two active region coronal loops observed by the X-ray Polychromator (XRP) and the Hard X-ray Imaging Spectrometer (HXIS) onboard the Solar Maximum Mission (SMM). There appear to be surprisingly few observations of the short-time scale behavior of hot loops, and the evidence presented herein lends support to the hypothesis that coronal heating may be impulsive and driven by flaring.

Stereoscopy and Tomography of Coronal Structures

NASA Astrophysics Data System (ADS)

de Patoul, J.

2012-04-01

The hot solar corona consists of a low density plasma, which is highly structured by the magnetic field. To resolve and study the corona, several solar Ultraviolet (UV) and X-ray telescopes are operated with high spatial and temporal resolution. EUV (Extreme UV) image sequences of the lower solar corona have revealed a wide variety of structures with sizes ranging from the Sun's diameter to the limit of the angular resolution. Active regions can be observed with enhanced temperature and density, as well as 'quiet' regions, coronal holes with lower density and numerous other transient phenomena such as plumes, jets, bright points, flares, filaments, coronal mass ejections, all structured by the coronal magnetic field. In this work, we analyze polar plumes in a sequence of Solar EUV images taken nearly simultaneously by the three telescopes on board of the spacecraft STEREO/SECCHI A and B, and SOHO/EIT. Plumes appear in EUV images as elongated objects starting on the surface of the Sun extending super-radially into the corona. Their formation and contribution to the fast solar wind and other coronal phenomena are still under debate. Knowledge of the polar plume 3-D geometry can help to understand some of the physical processes in the solar corona. In this dissertation we develop new techniques for the characterization of polar plume structures in solar coronal images (Part II) then we analyze these structures using the techniques (Part III): We design a new technique capable of automatically identifying plumes in solar EUV images close to the limb at 1.01-1.39 Ro. This plume identification is based on a multi-scale Hough-wavelet analysis. We show that the method is well adapted to identifying the location, width and orientation of plumes. Starting from Hough-wavelet analysis, we elaborate on two other techniques to determine 3-D plume localization and structure: (i) tomography employing data from a single spacecraft over more than half a rotation and (ii) stereoscopy

Evaluation of the Minifilament-Eruption Scenario for Solar Coronal Jets in Polar Coronal Holes

NASA Technical Reports Server (NTRS)

Baikie, Tomi K.; Sterling, Alphonse C.; Falconer, David; Moore, Ronald L.; Savage, Sabrina L.

2016-01-01

Solar coronal jets are suspected to result from magnetic reconnection low in the Sun's atmosphere. Sterling et al. (2015) looked as 20 jets in polar coronal holes, using X-ray images from the Hinode/X-Ray Telescope (XRT) and EUV images from the Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA). They suggested that each jet was driven by the eruption of twisted closed magnetic field carrying a small-scale filament, which they call a 'minifilament', and that the jet was produced by reconnection of the erupting field with surrounding open field. In this study, we carry out a more extensive examination of polar coronal jets. From 180 hours of XRT polar coronal hole observations spread over two years (2014-2016), we identified 130 clearly-identifiable X-ray jet events and thus determined an event rate of over 17 jets per day per in the Hinode/XRT field of view. From the broader set, we selected 25 of the largest and brightest events for further study in AIA 171, 193, 211, and 304 Angstrom images. We find that at least the majority of the jets follow the minifilament-eruption scenario, although for some cases the evolution of the minifilament in the onset of its eruption is more complex than presented in the simplified schematic of Sterling et al. (2015). For all cases in which we could make a clear determination, the spire of the X-ray jet drifted laterally away from the jet-base-edge bright point; this spire drift away from the bright point is consistent with expectations of the minifilament-eruption scenario for coronal-jet production. This work was supported with funding from the NASA/MSFC Hinode Project Office, and from the NASA HGI program.

Unresolved fine-scale structure in solar coronal loop-tops

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scullion, E.; Van der Voort, L. Rouppe; Wedemeyer, S.

2014-12-10

New and advanced space-based observing facilities continue to lower the resolution limit and detect solar coronal loops in greater detail. We continue to discover even finer substructures within coronal loop cross-sections, in order to understand the nature of the solar corona. Here, we push this lower limit further to search for the finest coronal loop substructures, through taking advantage of the resolving power of the Swedish 1 m Solar Telescope/CRisp Imaging Spectro-Polarimeter (CRISP), together with co-observations from the Solar Dynamics Observatory/Atmospheric Image Assembly (AIA). High-resolution imaging of the chromospheric Hα 656.28 nm spectral line core and wings can, under certainmore » circumstances, allow one to deduce the topology of the local magnetic environment of the solar atmosphere where its observed. Here, we study post-flare coronal loops, which become filled with evaporated chromosphere that rapidly condenses into chromospheric clumps of plasma (detectable in Hα) known as a coronal rain, to investigate their fine-scale structure. We identify, through analysis of three data sets, large-scale catastrophic cooling in coronal loop-tops and the existence of multi-thermal, multi-stranded substructures. Many cool strands even extend fully intact from loop-top to footpoint. We discover that coronal loop fine-scale strands can appear bunched with as many as eight parallel strands within an AIA coronal loop cross-section. The strand number density versus cross-sectional width distribution, as detected by CRISP within AIA-defined coronal loops, most likely peaks at well below 100 km, and currently, 69% of the substructure strands are statistically unresolved in AIA coronal loops.« less

Determination of coronal magnetic fields from vector magnetograms

NASA Technical Reports Server (NTRS)

Mikic, Zoran

1992-01-01

The determination of coronal magnetic fields from vector magnetograms, including the development and application of algorithms to determine force-free coronal fields above selected observations of active regions is studied. Two additional active regions were selected and analyzed. The restriction of periodicity in the 3-D code which is used to determine the coronal field was removed giving the new code variable mesh spacing and is thus able to provide a more realistic description of coronal fields. The NOAA active region AR5747 of 20 Oct. 1989 was studied. A brief account of progress during the research performed is reported.

Constraints on active region coronal heating properties from observations and modeling of chromospheric, transition region, and coronal emission

NASA Astrophysics Data System (ADS)

Testa, P.; Polito, V.; De Pontieu, B.; Carlsson, M.; Reale, F.; Allred, J. C.; Hansteen, V. H.

2017-12-01

We investigate coronal heating properties in active region cores in non-flaring conditions, using high spatial, spectral, and temporal resolution chromospheric/transition region/coronal observations coupled with detailed modeling. We will focus, in particular, on observations with the Interface Region Imaging Spectrograph (IRIS), joint with observations with Hinode (XRT and EIS) and SDO/AIA. We will discuss how these observations and models (1D HD and 3D MHD, with the RADYN and Bifrost codes) provide useful diagnostics of the coronal heating processes and mechanisms of energy transport.

Comparison of Two Coronal Magnetic Field Models to Reconstruct a Sigmoidal Solar Active Region with Coronal Loops

NASA Astrophysics Data System (ADS)

Duan, Aiying; Jiang, Chaowei; Hu, Qiang; Zhang, Huai; Gary, G. Allen; Wu, S. T.; Cao, Jinbin

2017-06-01

Magnetic field extrapolation is an important tool to study the three-dimensional (3D) solar coronal magnetic field, which is difficult to directly measure. Various analytic models and numerical codes exist, but their results often drastically differ. Thus, a critical comparison of the modeled magnetic field lines with the observed coronal loops is strongly required to establish the credibility of the model. Here we compare two different non-potential extrapolation codes, a nonlinear force-free field code (CESE-MHD-NLFFF) and a non-force-free field (NFFF) code, in modeling a solar active region (AR) that has a sigmoidal configuration just before a major flare erupted from the region. A 2D coronal-loop tracing and fitting method is employed to study the 3D misalignment angles between the extrapolated magnetic field lines and the EUV loops as imaged by SDO/AIA. It is found that the CESE-MHD-NLFFF code with preprocessed magnetogram performs the best, outputting a field that matches the coronal loops in the AR core imaged in AIA 94 Å with a misalignment angle of ˜10°. This suggests that the CESE-MHD-NLFFF code, even without using the information of the coronal loops in constraining the magnetic field, performs as good as some coronal-loop forward-fitting models. For the loops as imaged by AIA 171 Å in the outskirts of the AR, all the codes including the potential field give comparable results of the mean misalignment angle (˜30°). Thus, further improvement of the codes is needed for a better reconstruction of the long loops enveloping the core region.

Comparison of Two Coronal Magnetic Field Models to Reconstruct a Sigmoidal Solar Active Region with Coronal Loops

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duan, Aiying; Zhang, Huai; Jiang, Chaowei

Magnetic field extrapolation is an important tool to study the three-dimensional (3D) solar coronal magnetic field, which is difficult to directly measure. Various analytic models and numerical codes exist, but their results often drastically differ. Thus, a critical comparison of the modeled magnetic field lines with the observed coronal loops is strongly required to establish the credibility of the model. Here we compare two different non-potential extrapolation codes, a nonlinear force-free field code (CESE–MHD–NLFFF) and a non-force-free field (NFFF) code, in modeling a solar active region (AR) that has a sigmoidal configuration just before a major flare erupted from themore » region. A 2D coronal-loop tracing and fitting method is employed to study the 3D misalignment angles between the extrapolated magnetic field lines and the EUV loops as imaged by SDO /AIA. It is found that the CESE–MHD–NLFFF code with preprocessed magnetogram performs the best, outputting a field that matches the coronal loops in the AR core imaged in AIA 94 Å with a misalignment angle of ∼10°. This suggests that the CESE–MHD–NLFFF code, even without using the information of the coronal loops in constraining the magnetic field, performs as good as some coronal-loop forward-fitting models. For the loops as imaged by AIA 171 Å in the outskirts of the AR, all the codes including the potential field give comparable results of the mean misalignment angle (∼30°). Thus, further improvement of the codes is needed for a better reconstruction of the long loops enveloping the core region.« less

'Lumbar Degenerative Kyphosis' Is Not Byword for Degenerative Sagittal Imbalance: Time to Replace a Misconception.

PubMed

Lee, Chang-Hyun; Chung, Chun Kee; Jang, Jee-Soo; Kim, Sung-Min; Chin, Dong-Kyu; Lee, Jung-Kil

2017-03-01

Lumbar degenerative kyphosis (LDK) is a subgroup of the flat-back syndrome and is most commonly caused by unique life styles, such as a prolonged crouched posture during agricultural work and performing activities of daily living on the floor. Unfortunately, LDK has been used as a byword for degenerative sagittal imbalance, and this sometimes causes confusion. The aim of this review was to evaluate the exact territory of LDK, and to introduce another appropriate term for degenerative sagittal deformity. Unlike what its name suggests, LDK does not only include sagittal balance disorder of the lumbar spine and kyphosis, but also sagittal balance disorder of the whole spine and little lordosis of the lumbar spine. Moreover, this disease is closely related to the occupation of female farmers and an outdated Asian life style. These reasons necessitate a change in the nomenclature of this disorder to prevent misunderstanding. We suggest the name "primary degenerative sagittal imbalance" (PDSI), which encompasses degenerative sagittal misalignments of unknown origin in the whole spine in older-age patients, and is associated with back muscle wasting. LDK may be regarded as a subgroup of PDSI related to an occupation in agriculture. Conservative treatments such as exercise and physiotherapy are recommended as first-line treatments for patients with PDSI, and surgical treatment is considered only if conservative treatments failed. The measurement of spinopelvic parameters for sagittal balance is important prior to deformity corrective surgery. LDK can be considered a subtype of PDSI that is more likely to occur in female farmers, and hence the use of LDK as a global term for all degenerative sagittal imbalance disorders is better avoided. To avoid confusion, we recommend PDSI as a newer, more accurate diagnostic term instead of LDK.

Observational Analysis of Coronal Fans

NASA Technical Reports Server (NTRS)

Talpeanu, D.-C.; Rachmeler, L; Mierla, Marilena

2017-01-01

Coronal fans (see Figure 1) are bright observational structures that extend to large distances above the solar surface and can easily be seen in EUV (174 angstrom) above the limb. They have a very long lifetime and can live up to several Carrington rotations (CR), remaining relatively stationary for many months. Note that they are not off-limb manifestation of similarly-named active region fans. The solar conditions required to create coronal fans are not well understood. The goal of this research was to find as many associations as possible of coronal fans with other solar features and to gain a better understanding of these structures. Therefore, we analyzed many fans and created an overview of their properties. We present the results of this statistical analysis and also a case study on the longest living fan.

First High-resolution Spectroscopic Observations by IRIS of a Fast, Helical Prominence Eruption Associated with a Coronal Mass Ejection

NASA Astrophysics Data System (ADS)

Liu, W.; De Pontieu, B.; Okamoto, T. J.; Vial, J. C.; Title, A. M.; Antolin, P.; Berger, T. E.; Uitenbroek, H.

2014-12-01

High-resolution spectroscopic observations of prominence eruptions and associated coronal mass ejections (CMEs) are rare but can provide valuable plasma and energy diagnostics. New opportunities have recently become available with the advent of the Interface Region Imaging Spectrograph (IRIS) mission equipped with high resolution of 0.33-0.4 arcsec in space and 1 km/s in velocity, together with the Hinode Solar Optical Telescope of 0.2 arcsec spatial resolution. We report the first result of joint IRIS-Hinode observations of a spectacular prominence eruption occurring on 2014-May-09. IRIS detected a maximum redshift of 450 km/s, which, combined with the plane-of-sky speed of 800 km/s, gives a large velocity vector of 920 km/s at 30 degrees from the sky plane. This direction agrees with the source location at 30 degrees behind the limb observed by STEREO-A and indicates a nearly vertical ejection. We found two branches of redshifts separated by 200 km/s appearing in all strong lines at chromospheric to transition-region temperatures, including Mg II k/h, C II, and Si IV, suggesting a hollow, rather than solid, cone in the velocity space of the ejected material. Opposite blue- and redshifts on the two sides of the prominence exhibit corkscrew variations both in space and time, suggestive of unwinding rotations of a left-handed helical flux rope. Some erupted material returns as nearly streamline flows, exhibiting distinctly narrow line widths (~10 km/s), about 50% of those of the nearby coronal rain at the apexes of coronal loops, where the rain material is initially formed out of cooling condensation. We estimate the mass and kinetic energy of the ejected and returning material and compare them with those of the associated CME. We will discuss the implications of these observations for CME initiation mechanisms.

Determination of coronal magnetic fields from vector magnetograms

NASA Technical Reports Server (NTRS)

Mikic, Zoran

1993-01-01

This report covers technical progress during the second year of the contract entitled 'Determination of Coronal Magnetic Fields from Vector Magnetograms,' NASW-4728, between NASA and Science Applications International Corporation, and covers the period January 1, 1993 to December 31, 1993. Under this contract SAIC has conducted research into the determination of coronal magnetic fields from vector magnetograms, including the development and application of algorithms to determine force-free coronal fields above selected observations of active regions. The contract began on June 30, 1992 and has a completion date of December 31, 1994. This contract is a continuation of work started in a previous contract, NASW-4571, which covered the period November 15, 1990 to December 14, 1991. During this second year we have concentrated on studying additional active regions and in using the estimated coronal magnetic fields to compare to coronal features inferred from observations.

Interchange Reconnection and Coronal Hole Dynamics

NASA Technical Reports Server (NTRS)

Edmondson, J. K.; Antiochos, S. K.; DeVore, C. R.; Lynch, B. J.; Zurbuchen, T. H.

2011-01-01

We investigate the effect of magnetic reconnection between open and closed field, (often referred to as "interchange" reconnection), on the dynamics and topology of coronal hole boundaries. The most important and most prevalent 3D topology of the interchange process is that of a small-scale bipolar magnetic field interacting with a large-scale background field. We determine the evolution of such a magnetic topology by numerical solution of the fully 3D MHD equations in spherical coordinates. First, we calculate the evolution of a small-scale bipole that initially is completely inside an open field region and then is driven across a coronal hole boundary by photospheric motions. Next the reverse situation is calculated in which the bipole is initially inside the closed region and driven toward the coronal hole boundary. In both cases we find that the stress imparted by the photospheric motions results in deformation of the separatrix surface between the closed field of the bipole and the background field, leading to rapid current sheet formation and to efficient reconnection. When the bipole is inside the open field region, the reconnection is of the interchange type in that it exchanges open and closed field. We examine, in detail, the topology of the field as the bipole moves across the coronal hole boundary, and find that the field remains well-connected throughout this process. Our results imply that open flux cannot penetrate deeply into the closed field region below a helmet streamer and, hence, support the quasi-steady models in which open and closed flux remain topologically distinct. Our results also support the uniqueness hypothesis for open field regions as postulated by Antiochos et al. We discuss the implications of this work for coronal observations. Subject Headings: Sun: corona Sun: magnetic fields Sun: reconnection Sun: coronal hole

Spinal alignment in surgical, multisegmental, transpedicular correction of adolescent idiopathic scoliosis

PubMed Central

Nowakowski, Andrzej; Dworak, Lechosław B.; Kubaszewski, Łukasz; Kaczmarczyk, Jacek

2012-01-01

Summary The objective of this study was to discuss the variables influencing alignment mechanisms of the spine, with particular consideration of post-surgical alignment in adolescent idiopathic scoliosis. The analysis is based on information currently available in the literature, and on the authors’ own experience, which includes surgical material from over 2200 cases of idiopathic scoliosis. Over 50% of cases of adolescent idiopathic scoliosis are decompensated before surgical treatment. Spinal alignment is most significantly influenced by the position of the pelvis. Surgical restoration of lumbar lordosis is more important than attempting to restore thoracic kyphosis in the sagittal plane. The sagittal profile has an essential impact on spinal alignment. The same curves in the coronal plane can have various 3-dimensional configurations. Clinical difficulties in the assessment of thoracic kyphosis and lumbar lordosis result from the fact that they undergo constant change with age. Thoracic hypokyphosis diagnosed before surgery is a very frequent symptom of curve progression. The presence of proximal (thoraco-thoracic) and distal (thoraco-lumbar) junctional kyphosis is very important for planning the scope of spondylodesis. The natural tendency of the spine for alignment (compensation) after surgery nowadays occurs more naturally by applying derotational forces through pedicle screws, compared to the distraction devices (eg, Harrington rod) used in the past. PMID:23229319

Optimizing Global Coronal Magnetic Field Models Using Image-Based Constraints

NASA Technical Reports Server (NTRS)

Jones-Mecholsky, Shaela I.; Davila, Joseph M.; Uritskiy, Vadim

2016-01-01

The coronal magnetic field directly or indirectly affects a majority of the phenomena studied in the heliosphere. It provides energy for coronal heating, controls the release of coronal mass ejections, and drives heliospheric and magnetospheric activity, yet the coronal magnetic field itself has proven difficult to measure. This difficulty has prompted a decades-long effort to develop accurate, timely, models of the field, an effort that continues today. We have developed a method for improving global coronal magnetic field models by incorporating the type of morphological constraints that could be derived from coronal images. Here we report promising initial tests of this approach on two theoretical problems, and discuss opportunities for application.

OPTIMIZING GLOBAL CORONAL MAGNETIC FIELD MODELS USING IMAGE-BASED CONSTRAINTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Shaela I.; Davila, Joseph M.; Uritsky, Vadim, E-mail: shaela.i.jonesmecholsky@nasa.gov

The coronal magnetic field directly or indirectly affects a majority of the phenomena studied in the heliosphere. It provides energy for coronal heating, controls the release of coronal mass ejections, and drives heliospheric and magnetospheric activity, yet the coronal magnetic field itself has proven difficult to measure. This difficulty has prompted a decades-long effort to develop accurate, timely, models of the field—an effort that continues today. We have developed a method for improving global coronal magnetic field models by incorporating the type of morphological constraints that could be derived from coronal images. Here we report promising initial tests of thismore » approach on two theoretical problems, and discuss opportunities for application.« less

Origin of Pre-Coronal-Jet Minifilaments: Flux Cancellation

NASA Technical Reports Server (NTRS)

Panesar, Navdeep K.; Sterling, Alphonse; Moore, Ronald L.

2017-01-01

Coronal jets are frequent magnetically channeled narrow eruptions. All coronal jets observed in EUV and X-ray images show a bright spire with a base brightening, also known as jet bright point (JBP). Recent studies of jets show that coronal jets are driven by small-scale filament eruptions (e.g. Hong et al. 2011, Shen et al. 2012, Adams et al. 2014, Sterling et al. 2015). We recently investigated the triggering mechanism of ten on-disk quiet-region coronal jet eruptions and found that magnetic flux cancellation at the neutral line of minifilaments is the main cause of quiet-region jet eruptions (Panesar et al.2016).

Coronal "wave": Magnetic Footprint Of A Cme?

NASA Astrophysics Data System (ADS)

Attrill, Gemma; Harra, L. K.; van Driel-Gesztelyi, L.; Demoulin, P.; Wuelser, J.

2007-05-01

We propose a new mechanism for the generation of "EUV coronal waves". This work is based on new analysis of data from SOHO/EIT, SOHO/MDI & STEREO/EUVI. Although first observed in 1997, the interpretation of coronal waves as flare-induced or CME-driven remains a debated topic. We investigate the properties of two "classical" SOHO/EIT coronal waves in detail. The source regions of the associated CMEs possess opposite helicities & the coronal waves display rotations in opposite senses. We observe deep dimmings near the flare site & also widespread diffuse dimming, accompanying the expansion of the EIT wave. We report a new property of these EIT waves, namely, that they display dual brightenings: persistent ones at the outermost edge of the core dimming regions & simultaneously diffuse brightenings constituting the leading edge of the coronal wave, surrounding the expanding diffuse dimmings. We show that such behaviour is consistent with a diffuse EIT wave being the magnetic footprint of a CME. We propose a new mechanism where driven magnetic reconnections between the skirt of the expanding CME & quiet-Sun magnetic loops generate the observed bright diffuse front. The dual brightenings & widespread diffuse dimming are identified as innate characteristics of this process. In addition we present some of the first analysis of a STEREO/EUVI limb coronal wave. We show how the evolution of the diffuse bright front & dimmings can be understood in terms of the model described above. We show that an apparently stationary part of the bright front can be understood in terms of magnetic interchange reconnections between the expanding CME & the "open" magnetic field of a low-latitude coronal hole. We use both the SOHO/EIT & STEREO/EUVI events to demonstrate that through successive reconnections, this new model provides a natural mechanism via which CMEs can become large-scale in the lower corona.

Space- and Ground-based Coronal Spectro-Polarimetry

NASA Astrophysics Data System (ADS)

Fineschi, Silvano; Bemporad, Alessandro; Rybak, Jan; Capobianco, Gerardo

This presentation gives an overview of the near-future perspectives of ultraviolet and visible-light spectro-polarimetric instrumentation for probing coronal magnetism from space-based and ground-based observatories. Spectro-polarimetric imaging of coronal emission-lines in the visible-light wavelength-band provides an important diagnostics tool of the coronal magnetism. The interpretation in terms of Hanle and Zeeman effect of the line-polarization in forbidden emission-lines yields information on the direction and strength of the coronal magnetic field. As study case, this presentation will describe the Torino Coronal Magnetograph (CorMag) for the spectro-polarimetric observation of the FeXIV, 530.3 nm, forbidden emission-line. CorMag - consisting of a Liquid Crystal (LC) Lyot filter and a LC linear polarimeter - has been recently installed on the Lomnicky Peak Observatory 20cm Zeiss coronagraph. The preliminary results from CorMag will be presented. The linear polarization by resonance scattering of coronal permitted line-emission in the ultraviolet (UV)can be modified by magnetic fields through the Hanle effect. Space-based UV spectro-polarimeters would provide an additional tool for the disgnostics of coronal magnetism. As a case study of space-borne UV spectro-polarimeters, this presentation will describe the future upgrade of the Sounding-rocket Coronagraphic Experiment (SCORE) to include the capability of imaging polarimetry of the HI Lyman-alpha, 121.6 nm. SCORE is a multi-wavelength imager for the emission-lines, HeII 30.4 nm and HI 121.6 nm, and visible-light broad-band emission of the polarized K-corona. SCORE has flown successfully in 2009. This presentation will describe how in future re-flights SCORE could observe the expected Hanle effect in corona with a HI Lyman-alpha polarimeter.

Coronal rain in magnetic bipolar weak fields

NASA Astrophysics Data System (ADS)

Xia, C.; Keppens, R.; Fang, X.

2017-07-01

Aims: We intend to investigate the underlying physics for the coronal rain phenomenon in a representative bipolar magnetic field, including the formation and the dynamics of coronal rain blobs. Methods: With the MPI-AMRVAC code, we performed three dimensional radiative magnetohydrodynamic (MHD) simulation with strong heating localized on footpoints of magnetic loops after a relaxation to quiet solar atmosphere. Results: Progressive cooling and in-situ condensation starts at the loop top due to radiative thermal instability. The first large-scale condensation on the loop top suffers Rayleigh-Taylor instability and becomes fragmented into smaller blobs. The blobs fall vertically dragging magnetic loops until they reach low-β regions and start to fall along the loops from loop top to loop footpoints. A statistic study of the coronal rain blobs finds that small blobs with masses of less than 1010 g dominate the population. When blobs fall to lower regions along the magnetic loops, they are stretched and develop a non-uniform velocity pattern with an anti-parallel shearing pattern seen to develop along the central axis of the blobs. Synthetic images of simulated coronal rain with Solar Dynamics Observatory Atmospheric Imaging Assembly well resemble real observations presenting dark falling clumps in hot channels and bright rain blobs in a cool channel. We also find density inhomogeneities during a coronal rain "shower", which reflects the observed multi-stranded nature of coronal rain. Movies associated to Figs. 3 and 7 are available at http://www.aanda.org

The Fundamental Structure of Coronal Loops

NASA Technical Reports Server (NTRS)

Winebarger, Amy; Warren, Harry; Cirtain, Jonathan; Kobayashi, Ken; Korreck, Kelly; Golub, Leon; Kuzin, Sergey; Walsh, Robert; DePontieu, Bart; Title, Alan;

Motion-plane dependency of the range of dart throw motion and the effects of tendon action due to finger extrinsic muscles during the motion.

PubMed

Mitsukane, Masahiro; Sekiya, Noboru; Kamono, Arinori; Nakabo, Tohru

2018-03-01

[Purpose] To clarify the motion-plane dependency of the range of dart throw motion and the effects of tendon action due to long finger flexors and extensors during the motion. [Subjects and Methods] Forty healthy subjects attended the experiment, and the active range of wrist motion in seven motion planes was measured with an originally designed apparatus. [Results] The reliability of the measurement was acceptable. The range of dart throw motion depended on the motion planes, with a maximum at around the motion plane of 45° from the sagittal plane (45° of pronation). The tendon action of long finger muscles was shown in dart throw motion except in 45° of pronation. [Conclusion] Motion-plane dependency of the range of dart throw motion exists in healthy subjects. The absence of tendon action due to finger extrinsic muscles in dart throw motion at 45° might be one of the causes of the advantage of dart throw motion.

Cervical vertebrae maturation index estimates on cone beam CT: 3D reconstructions vs sagittal sections.

PubMed

Bonfim, Marco A E; Costa, André L F; Fuziy, Acácio; Ximenez, Michel E L; Cotrim-Ferreira, Flávio A; Ferreira-Santos, Rívea I

2016-01-01

The aim of this study was to evaluate the performance of CBCT three-dimensional (3D) reconstructions and sagittal sections for estimates of cervical vertebrae maturation index (CVMI). The sample consisted of 72 CBCT examinations from patients aged 8-16 years (45 females and 27 males) selected from the archives of two private clinics. Two calibrated observers (kappa scores: ≥0.901) interpreted the CBCT settings twice. Intra- and interobserver agreement for both imaging exhibition modes was analyzed by kappa statistics, which was also used to analyze the agreement between 3D reconstructions and sagittal sections. Correlations between cervical vertebrae maturation estimates and chronological age, as well as between the assessments by 3D reconstructions and sagittal sections, were analyzed using gamma Goodman-Kruskal coefficients (α = 0.05). The kappa scores evidenced almost perfect agreement between the first and second assessments of the cervical vertebrae by 3D reconstructions (0.933-0.983) and sagittal sections (0.983-1.000). Similarly, the agreement between 3D reconstructions and sagittal sections was almost perfect (kappa index: 0.983). In most divergent cases, the difference between 3D reconstructions and sagittal sections was one stage of CVMI. Strongly positive correlations (>0.8, p < 0.001) were found not only between chronological age and CVMI but also between the estimates by 3D reconstructions and sagittal sections (p < 0.001). Although CBCT imaging must not be used exclusively for this purpose, it may be suitable for skeletal maturity assessments.

Cervical vertebrae maturation index estimates on cone beam CT: 3D reconstructions vs sagittal sections

PubMed Central

Bonfim, Marco A E; Costa, André L F; Ximenez, Michel E L; Cotrim-Ferreira, Flávio A; Ferreira-Santos, Rívea I

2016-01-01

Objectives: The aim of this study was to evaluate the performance of CBCT three-dimensional (3D) reconstructions and sagittal sections for estimates of cervical vertebrae maturation index (CVMI). Methods: The sample consisted of 72 CBCT examinations from patients aged 8–16 years (45 females and 27 males) selected from the archives of two private clinics. Two calibrated observers (kappa scores: ≥0.901) interpreted the CBCT settings twice. Intra- and interobserver agreement for both imaging exhibition modes was analyzed by kappa statistics, which was also used to analyze the agreement between 3D reconstructions and sagittal sections. Correlations between cervical vertebrae maturation estimates and chronological age, as well as between the assessments by 3D reconstructions and sagittal sections, were analyzed using gamma Goodman–Kruskal coefficients (α = 0.05). Results: The kappa scores evidenced almost perfect agreement between the first and second assessments of the cervical vertebrae by 3D reconstructions (0.933–0.983) and sagittal sections (0.983–1.000). Similarly, the agreement between 3D reconstructions and sagittal sections was almost perfect (kappa index: 0.983). In most divergent cases, the difference between 3D reconstructions and sagittal sections was one stage of CVMI. Strongly positive correlations (>0.8, p < 0.001) were found not only between chronological age and CVMI but also between the estimates by 3D reconstructions and sagittal sections (p < 0.001). Conclusions: Although CBCT imaging must not be used exclusively for this purpose, it may be suitable for skeletal maturity assessments. PMID:26509559

Coronal magnetic fields and the solar wind

NASA Technical Reports Server (NTRS)

Newkirk, G., Jr.

1972-01-01

Current information is presented on coronal magnetic fields as they bear on problems of the solar wind. Both steady state fields and coronal transient events are considered. A brief critique is given of the methods of calculating coronal magnetic fields including the potential (current free) models, exact solutions for the solar wind and field interaction, and source surface models. These solutions are compared with the meager quantitative observations which are available at this time. Qualitative comparisons between the shapes of calculated magnetic field lines and the forms visible in the solar corona at several recent eclipses are displayed. These suggest that: (1) coronal streamers develop above extended magnetic arcades which connect unipolar regions of opposite polarity; and (2) loops, arches, and rays in the corona correspond to preferentially filled magnetic tubes in the approximately potential field.

REVIEWS OF TOPICAL PROBLEMS: Coronal magnetic loops

NASA Astrophysics Data System (ADS)

Zaitsev, Valerii V.; Stepanov, Alexander V.

2008-11-01

The goal of this review is to outline some new ideas in the physics of coronal magnetic loops, the fundamental structural elements of the atmospheres of the Sun and flaring stars, which are involved in phenomena such as stellar coronal heating, flare energy release, charged particle acceleration, and the modulation of optical, radio, and X-ray emissions. The Alfvén-Carlqvist view of a coronal loop as an equivalent electric circuit allows a good physical understanding of loop processes. Describing coronal loops as MHD-resonators explains various ways in which flaring emissions from the Sun and stars are modulated, whereas modeling them by magnetic mirror traps allows one to describe the dynamics and emission of high-energy particles. Based on these approaches, loop plasma and fast particle parameters are obtained and models for flare energy release and stellar corona heating are developed.

Relationship of EUV Irradiance Coronal Dimming Slope and Depth to Coronal Mass Ejection Speed and Mass

NASA Technical Reports Server (NTRS)

Mason, James Paul; Woods, Thomas N.; Webb, David F.; Thompson, Barbara J.; Colaninno, Robin C.; Vourlidas, Angelos

2016-01-01

Extreme ultraviolet (EUV) coronal dimmings are often observed in response to solar eruptive events. These phenomena can be generated via several different physical processes. For space weather, the most important of these is the temporary void left behind by a coronal mass ejection (CME). Massive, fast CMEs tend to leave behind a darker void that also usually corresponds to minimum irradiance for the cooler coronal emissions. If the dimming is associated with a solar are, as is often the case, the are component of the irradiance light curve in the cooler coronal emission can be isolated and removed using simultaneous measurements of warmer coronal lines. We apply this technique to 37dimming events identified during two separate two-week periods in 2011, plus an event on 2010 August 7 analyzed in a previous paper, to parameterize dimming in terms of depth and slope. We provide statistics on which combination of wavelengths worked best for the flare-removal method, describe the fitting methods applied to the dimming light curves, and compare the dimming parameters with corresponding CME parameters of mass and speed. The best linear relationships found are nu(sub CME) [km/s] approx. equals 2.36 x 10 6 [km/%] x s(sub dim) [%/s] m(sub CME) [g] approx. equals 2.59 x 10(exp.15 [g/%] x the square root of d(sub dim) [%].These relationships could be used for space weather operations of estimating CME mass and speed using near-real-time irradiance dimming measurements.

Dynamics of Coronal Hole Boundaries

NASA Technical Reports Server (NTRS)

Higginson, A. K.; Antiochos, S. K.; DeVore, C. R.; Wyper, Peter F.; Zurbuchen, T. H.

2017-01-01

Remote and in situ observations strongly imply that the slow solar wind consists of plasma from the hot, closed-field corona that is released onto open magnetic field lines. The Separatrix Web theory for the slow wind proposesthat photospheric motions at the scale of supergranules are responsible for generating dynamics at coronal-holeboundaries, which result in the closed plasma release. We use three-dimensional magnetohydrodynamicsimulations to determine the effect of photospheric flows on the open and closed magnetic flux of a model coronawith a dipole magnetic field and an isothermal solar wind. A rotational surface motion is used to approximatephotospheric supergranular driving and is applied at the boundary between the coronal hole and helmet streamer.The resulting dynamics consist primarily of prolific and efficient interchange reconnection between open andclosed flux. The magnetic flux near the coronal-hole boundary experiences multiple interchange events, with someflux interchanging over 50 times in one day. Additionally, we find that the interchange reconnection occurs allalong the coronal-hole boundary and even produces a lasting change in magnetic-field connectivity in regions thatwere not driven by the applied motions. Our results show that these dynamics should be ubiquitous in the Sun andheliosphere. We discuss the implications of our simulations for understanding the observed properties of the slowsolar wind, with particular focus on the global-scale consequences of interchange reconnection.

Coronal hole evolution by sudden large scale changes

NASA Technical Reports Server (NTRS)

Nolte, J. T.; Gerassimenko, M.; Krieger, A. S.; Solodyna, C. V.

1978-01-01

Sudden shifts in coronal-hole boundaries observed by the S-054 X-ray telescope on Skylab between May and November, 1973, within 1 day of CMP of the holes, at latitudes not exceeding 40 deg, are compared with the long-term evolution of coronal-hole area. It is found that large-scale shifts in boundary locations can account for most if not all of the evolution of coronal holes. The temporal and spatial scales of these large-scale changes imply that they are the results of a physical process occurring in the corona. It is concluded that coronal holes evolve by magnetic-field lines' opening when the holes are growing, and by fields' closing as the holes shrink.

The longitudinal sagittal growth changes of maxilla and mandible according to quantitative cervical vertebral maturation.

PubMed

Chen, Lili; Lin, Jiuxiang; Xu, Tianmin; Long, Xiaosi

2009-04-01

To investigate the longitudinal sagittal growth changes of maxilla and mandible according to the quantitative cervical vertebral maturation (QCVM) for adolescents with normal occlusion, mixed longitudinal data were used. The samples included 87 adolescents aged from 8 to 18 y old with normal occlusion (32 males, 55 females) selected from 901 candidates. Sequential lateral cephalograms and hand-wrist films were taken once a year, lasting for 6 y. The longitudinal sagittal growth changes of maxilla and mandible according to QCVM were measured. There were some significant differences between maxilla and mandible according to QCVM. The sagittal growth change of maxilla showed a trend towards high velocity-->decelerating velocity-->completing velocity from QCVM stage I to stage IV. The sagittal growth change of mandible showed a trend towards accelerating velocity-->high velocity-->decelerating velocity-->completing velocity from QCVM stage I to stage IV. With sagittal relationship, growth magnitude was almost the same between maxilla and mandible at QCVM stage I. At stage II the growth of mandible exceeded that of maxilla and growth in mandible continued at stages III and IV, while the maxilla ceased to grow. Growth magnitude was greater and the growth duration was longer with male mandible. It is concluded that the longitudinal sagittal growth changes of maxilla and mandible on the basis of QCVM is of value in the orthodontic practice.

The green corona database and the coronal index of solar activity

NASA Astrophysics Data System (ADS)

Minarovjech, M.; Rušin, V.; Saniga, M.

2011-10-01

The green coronal line Fe XIV 530.3 nm ranks amongst the most pronounced emission lines in the visible part of the solar spectrum. Its observations outside solar eclipses started sporadically in 1939 (the Arosa coronal station), being extended, in 1946, to more coronal stations. It was found that the green corona intensities vary with solar cycle, so they are a good candidate to express solar activity in the corona. Several attempts have been made to create a single homogeneous coronal data set from different coronal stations. We will present our homogeneous coronal data set, based on the Lomnický Štít photometric scale. Also, the coronal index of solar activity as created from this database in the period 1939—2010 will be discussed.

Reliability of the xipho-pubic angle in patients with sagittal imbalance of the spine.

PubMed

Langella, Francesco; Villafañe, Jorge H; Ismael, Maryem; Buric, Josip; Piazzola, Andrea; Lamartina, Claudio; Berjano, Pedro

2018-04-01

Proximal junctional kyphosis (PJK) is a frequent complication that compromises the outcomes of spinal surgery, especially for adult deformity. To the date no single risk factor or cause has been identified that explains its occurrence. The purpose of this study was to investigate the test-retest reliability of the radiologic measurements using xipho-pubic angle (XPA) for subjects undergoing surgery for sagittal misalignment of the spine. Retrospective observational cross-sectional study of prospectively collected data. Full-spine standing lateral radiographs of 50 patients who underwent surgery for fixed sagittal imbalance (preoperative and postoperative) were evaluated. Internal consistency, reproducibility, concurrent validity, and discriminative ability of the XPA. Two physicians measured XPA on the 100 randomly sorted and anonymized radiographs on two occasions, one week apart (test and retest conditions), were calculated for inter and intraobserver agreement. Test-retest reliability of XPA measurement was excellent for pre- (ICC=0.98; P=0.001) and post-surgical (ICC=0.86; P=0.001) radiographs of subjects with sagittal imbalance of the spine. XPA was able to discriminate between preoperative and postoperative radiographs F=17.924, P<0.001) in patients undergoing surgery for fixed sagittal imbalance for both raters. There were significant differences between pre- vs. postoperative XPA, pelvic tilt, lumbar lordosis and sagittal vertical axis values (all P<0.001). Xipho-pubic angle had fair to excellent test-retest reliability, and it did possess validity to discriminate between preoperative and postoperative radiographs in patients undergoing surgery for fixed sagittal imbalance.

Free Magnetic Energy and Coronal Heating

NASA Technical Reports Server (NTRS)

Winebarger, Amy; Moore, Ron; Falconer, David

2012-01-01

Previous work has shown that the coronal X-ray luminosity of an active region increases roughly in direct proportion to the total photospheric flux of the active region's magnetic field (Fisher et al. 1998). It is also observed, however, that the coronal luminosity of active regions of nearly the same flux content can differ by an order of magnitude. In this presentation, we analyze 10 active regions with roughly the same total magnetic flux. We first determine several coronal properties, such as X-ray luminosity (calculated using Hinode XRT), peak temperature (calculated using Hinode EIS), and total Fe XVIII emission (calculated using SDO AIA). We present the dependence of these properties on a proxy of the free magnetic energy of the active region

MHD shocks in coronal mass ejections

NASA Technical Reports Server (NTRS)

Steinolfson, R. S.

1991-01-01

The primary objective of this research program is the study of the magnetohydrodynamic (MHD) shocks and nonlinear simple waves produced as a result of the interaction of ejected lower coronal plasma with the ambient corona. The types of shocks and nonlinear simple waves produced for representative coronal conditions and disturbance velocities were determined. The wave system and the interactions between the ejecta and ambient corona were studied using both analytic theory and numerical solutions of the time-dependent, nonlinear MHD equations. Observations from the SMM coronagraph/polarimeter provided both guidance and motivation and are used extensively in evaluating the results. As a natural consequence of the comparisons with the data, the simulations assisted in better understanding the physical interactions in coronal mass ejections (CME's).

A SOLAR CORONAL JET EVENT TRIGGERS A CORONAL MASS EJECTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Jiajia; Wang, Yuming; Shen, Chenglong

2015-11-10

In this paper, we present multi-point, multi-wavelength observations and analysis of a solar coronal jet and coronal mass ejection (CME) event. Employing the GCS model, we obtained the real (three-dimensional) heliocentric distance and direction of the CME and found it to propagate at a high speed of over 1000 km s{sup −1}. The jet erupted before the CME and shared the same source region. The temporal and spacial relationship between these two events lead us to the possibility that the jet triggered the CME and became its core. This scenario hold the promise of enriching our understanding of the triggeringmore » mechanism of CMEs and their relations to coronal large-scale jets. On the other hand, the magnetic field configuration of the source region observed by the Solar Dynamics Observatory (SDO)/HMI instrument along with the off-limb inverse Y-shaped configuration observed by SDO/AIA in the 171 Å passband provide the first detailed observation of the three-dimensional reconnection process of a large-scale jet as simulated in Pariat et al. The eruption process of the jet highlights the importance of filament-like material during the eruption of not only small-scale X-ray jets, but likely also of large-scale EUV jets. Based on our observations and analysis, we propose the most probable mechanism for the whole event, with a blob structure overlaying the three-dimensional structure of the jet, to describe the interaction between the jet and the CME.« less

Agreement Between Visual Assessment and 2-Dimensional Analysis During Jump Landing Among Healthy Female Athletes.

PubMed

Rabin, Alon; Einstein, Ofira; Kozol, Zvi

2018-04-01

  Altered movement patterns, including increased frontal-plane knee movement and decreased sagittal-plane hip and knee movement, have been associated with several knee disorders. Nevertheless, the ability of clinicians to visually detect such altered movement patterns during high-speed athletic tasks is relatively unknown.   To explore the association between visual assessment and 2-dimensional (2D) analysis of frontal-plane knee movement and sagittal-plane hip and knee movement during a jump-landing task among healthy female athletes.   Cross-sectional study.   Gymnasiums of participating volleyball teams.   A total of 39 healthy female volleyball players (age = 21.0 ± 5.2 years, height = 172.0 ± 8.6 cm, mass = 64.2 ± 7.2 kg) from Divisions I and II of the Israeli Volleyball Association.   Frontal-plane knee movement and sagittal-plane hip and knee movement during jump landing were visually rated as good, moderate, or poor based on previously established criteria. Frontal-plane knee excursion and sagittal-plane hip and knee excursions were measured using free motion-analysis software and compared among athletes with different visual ratings of the corresponding movements.   Participants with different visual ratings of frontal-plane knee movement displayed differences in 2D frontal-plane knee excursion ( P < .01), whereas participants with different visual ratings of sagittal-plane hip and knee movement displayed differences in 2D sagittal-plane hip and knee excursions ( P < .01).   Visual ratings of frontal-plane knee movement and sagittal-plane hip and knee movement were associated with differences in the corresponding 2D hip and knee excursions. Visual rating of these movements may serve as an initial screening tool for detecting altered movement patterns during jump landings.

A 2D threshold of the condylar-C1 interval to maximize identification of patients at high risk for atlantooccipital dislocation using computed tomography.

PubMed

Ravindra, Vijay M; Riva-Cambrin, Jay; Horn, Kevin P; Ginos, Jason; Brockmeyer, Russell; Guan, Jian; Rampton, John; Brockmeyer, Douglas L

2017-04-01

OBJECTIVE Measurement of the occipital condyle-C1 interval (CCI) is important in the evaluation of atlantooccipital dislocation (AOD) in pediatric trauma patients. The authors studied a large cohort of children with and without AOD to identify a 2D measurement threshold that maximizes the diagnostic yield of the CCI on cervical spine CT scans obtained in trauma patients. METHODS This retrospective, single-center study included all children who underwent CT of the cervical spine at Primary Children's Hospital from January 1, 2011, through December 31, 2014, for trauma evaluation. Bilateral CCI measurements in the coronal (3 measurements per side) and sagittal (4 measurements per side) planes were recorded. Using an iterative method, the authors determined optimal cutoffs for the maximal CCI in each plane in relation to AOD. The primary outcome was AOD requiring occipitocervical fusion. RESULTS A total of 597 pediatric patients underwent cervical spine CT for trauma evaluation: 578 patients without AOD and 19 patients with AOD requiring occipitocervical fusion. The authors found a statistically significant correlation between CCI and age (p < 0.001), with younger patients having higher CCIs. Using a 2D threshold requiring a sagittal CCI ≥ 2.5 mm and a coronal CCI ≥ 3.5 mm predicted AOD with a sensitivity of 95%, a specificity of 73%, positive predictive value of 10.3%, and negative predictive value of 99%. The accuracy of this 2D threshold was 84%. CONCLUSIONS In the present study population, age-dependent differences in the CCI were found on CT scans of the cervical spine in a large cohort of patients with and without AOD. A 2D CCI threshold as a screening method maximizes identification of patients at high risk for AOD while minimizing unnecessary imaging studies in children being evaluated for trauma.

High accuracy in knee alignment and implant placement in unicompartmental medial knee replacement when using patient-specific instrumentation.

PubMed

Volpi, P; Prospero, E; Bait, C; Cervellin, M; Quaglia, A; Redaelli, A; Denti, M

2015-05-01

The influence of patient-specific instrumentations on the accuracy of unicompartmental medial knee replacement remains unclear. The goal of this study was to examine the ability of patient-specific instrumentation to accurately reproduce postoperatively what the surgeon had planned preoperatively. Twenty consecutive patients (20 knees) who suffered from isolated unicompartmental medial osteoarthritis of the knee and underwent medial knee replacement using newly introduced magnetic resonance imaging-based patient-specific instrumentation were assessed. This assessment recorded the following parameters: (1) the planned and the postoperative mechanical axis acquired through long-leg AP view radiographies; (2) the planned and the postoperative tibial slope acquired by means of standard AP and lateral view radiographies; and (3) the postoperative fit of the implanted components to the bone in coronal and sagittal planes. The hypothesis of the study was that there was no statistically significant difference between postoperative results and preoperatively planned values. The study showed that (1) the difference between the postoperative mechanical axis (mean 1.9° varus ± 1.2° SD) and the planned mechanical axis (mean 1.8° varus ± 1.2° SD) was not statistically significant; (2) the difference between the postoperative tibial slope (mean 5.2° ± 0.6° SD) and the planned tibial slope (mean 5.4° ± 0.6° SD) was statistically significant (p = 0.008); and (3) the postoperative component fit to bone in the coronal and sagittal planes was accurate in all cases; nevertheless, in one knee, all components were implanted one size smaller than preoperatively planned. Moreover, in two additional cases, one size thinner and one size thicker of the polyethylene insert were used. This study suggests that overall patient-specific instrumentation was highly accurate in reproducing postoperatively what the surgeon had planned preoperatively in terms of mechanical axis, tibial

New Evidence that Magnetoconvection Drives Solar–Stellar Coronal Heating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tiwari, Sanjiv K.; Panesar, Navdeep K.; Moore, Ronald L.

2017-07-10

How magnetic energy is injected and released in the solar corona, keeping it heated to several million degrees, remains elusive. Coronal heating generally increases with increasing magnetic field strength. From a comparison of a nonlinear force-free model of the three-dimensional active region coronal field to observed extreme-ultraviolet loops, we find that (1) umbra-to-umbra coronal loops, despite being rooted in the strongest magnetic flux, are invisible, and (2) the brightest loops have one foot in an umbra or penumbra and the other foot in another sunspot’s penumbra or in unipolar or mixed-polarity plage. The invisibility of umbra-to-umbra loops is new evidencemore » that magnetoconvection drives solar-stellar coronal heating: evidently, the strong umbral field at both ends quenches the magnetoconvection and hence the heating. Broadly, our results indicate that depending on the field strength in both feet, the photospheric feet of a coronal loop on any convective star can either engender or quench coronal heating in the loop’s body.« less

‘Lumbar Degenerative Kyphosis’ Is Not Byword for Degenerative Sagittal Imbalance: Time to Replace a Misconception

PubMed Central

Lee, Chang-Hyun; Chung, Chun Kee; Jang, Jee-Soo; Kim, Sung-Min; Chin, Dong-Kyu; Lee, Jung-Kil

2017-01-01

Lumbar degenerative kyphosis (LDK) is a subgroup of the flat-back syndrome and is most commonly caused by unique life styles, such as a prolonged crouched posture during agricultural work and performing activities of daily living on the floor. Unfortunately, LDK has been used as a byword for degenerative sagittal imbalance, and this sometimes causes confusion. The aim of this review was to evaluate the exact territory of LDK, and to introduce another appropriate term for degenerative sagittal deformity. Unlike what its name suggests, LDK does not only include sagittal balance disorder of the lumbar spine and kyphosis, but also sagittal balance disorder of the whole spine and little lordosis of the lumbar spine. Moreover, this disease is closely related to the occupation of female farmers and an outdated Asian life style. These reasons necessitate a change in the nomenclature of this disorder to prevent misunderstanding. We suggest the name “primary degenerative sagittal imbalance” (PDSI), which encompasses degenerative sagittal misalignments of unknown origin in the whole spine in older-age patients, and is associated with back muscle wasting. LDK may be regarded as a subgroup of PDSI related to an occupation in agriculture. Conservative treatments such as exercise and physiotherapy are recommended as first-line treatments for patients with PDSI, and surgical treatment is considered only if conservative treatments failed. The measurement of spinopelvic parameters for sagittal balance is important prior to deformity corrective surgery. LDK can be considered a subtype of PDSI that is more likely to occur in female farmers, and hence the use of LDK as a global term for all degenerative sagittal imbalance disorders is better avoided. To avoid confusion, we recommend PDSI as a newer, more accurate diagnostic term instead of LDK. PMID:28264231

Sports Injury-Related Fingers and Thumb Deformity Due to Tendon or Ligament Rupture.

PubMed

Bai, Rong-Jie; Zhang, Hui-Bo; Zhan, Hui-Li; Qian, Zhan-Hua; Wang, Nai-Li; Liu, Yue; Li, Wen-Ting; Yin, Yu-Ming

2018-05-05

Hand injuries are very common in sports, such as skiing and ball sports. One of the major reasons causing hand and finger deformity is due to ligament and tendon injury. The aim of this study was to investigate if the high-resolution 3T magnetic resonance imaging (MRI) can demonstrate the complex anatomy of the fingers and thumb, especially the tendons and ligaments, and provide the accurate diagnosis of clinically important fingers and thumbs deformity due to ligamentous and tendinous injuries during sport activities. Sixteen fresh un-embalmed cadaveric hands were harvested from eight cadavers. A total of 20 healthy volunteers' hands and 44 patients with fingers or thumb deformity due to sports-related injuries were included in this study. All subjects had MR examination with T1-weighted images and proton density-weighted imaging with fat suppression (PD FS) in axial, coronal, and sagittal plane, respectively. Subsequently, all 16 cadaveric hands were sliced into 2-mm thick slab with a band saw (six in coronal plane, six in sagittal plane, and four in axial plane). The correlation of anatomic sections and the MRI characteristics of tendons of fingers and the ulnar collateral ligament (UCL) at the metacarpal phalangeal joint (MCPJ) of thumb between 20 healthy volunteers and 44 patients (confirmed by surgery) were analyzed. The normal ligaments and tendons in 16 cadaveric hands and 20 volunteers' hands showed uniform low-signal intensity on all the sequences of the MRI. Among 44 patients with tendinous and ligamentous injuries in the fingers or thumb, 12 cases with UCL injury at MCPJ of the thumb (Stener lesion = 8 and non-Stener lesion = 4), 6 cases with the central slip injury, 12 cases with terminal tendon injury, and 14 cases with flexor digitorum profundus injury. The ligaments and tendons disruption manifested as increased signal intensity and poor definition, discontinuity, and heterogeneous signal intensity of the involved ligaments and tendons. Sports

Spinal pedicle subtraction osteotomy for fixed sagittal imbalance patients

PubMed Central

Hyun, Seung-Jae; Kim, Yongjung J; Rhim, Seung-Chul

2013-01-01

In addressing spinal sagittal imbalance through a posterior approach, the surgeon now may choose from among a variety of osteotomy techniques. Posterior column osteotomies such as the facetectomy or Ponte or Smith-Petersen osteotomy provide the least correction, but can be used at multiple levels with minimal blood loss and a lower operative risk. Pedicle subtraction osteotomies provide nearly 3 times the per-level correction of Ponte/Smith-Petersen osteotomies; however, they carry increased technical demands, longer operative time, and greater blood loss and associated significant morbidity, including neurological injury. The literature focusing on pedicle subtraction osteotomy for fixed sagittal imbalance patients is reviewed. The long-term overall outcomes, surgical tips to reduce the complications and suggestions for their proper application are also provided. PMID:24340276

New Instruments to Isolate the Coronal Heating Mechanism

NASA Technical Reports Server (NTRS)

Winebarger, Amy

2014-01-01

The coronal heating problem remains unsolved today, 80 years after its discovery, despite 50 years of suborbital and orbital coronal observatories. Tens of theoretical coronal heating mechanisms have been suggested, but only a few have been able to be ruled out. In this talk, we will explore the reasons for the slow progress and discuss the measurements that will be needed for potential breakthrough, including imaging the solar corona at small spatial scales, measuring the chromospheric magnetic fields, and detecting the presence of high temperature, low-emission measure plasma. We will discuss three sounding rocket instruments developed to make these measurements: the High-resolution Resolution Coronal Imager (Hi-C), the Chromospheric Lyman-Alpha Spectropolarimeter (CLASP), and the Marshall Grazing Incidence X-ray Spectrometer (MaGIXS).

Photospheric magnetic field of an eroded-by-solar-wind coronal mass ejection

NASA Astrophysics Data System (ADS)

Palacios, J.; Cid, C.; Saiz, E.; Guerrero, A.

2017-10-01

We have investigated the case of a coronal mass ejection that was eroded by the fast wind of a coronal hole in the interplanetary medium. When a solar ejection takes place close to a coronal hole, the flux rope magnetic topology of the coronal mass ejection (CME) may become misshapen at 1 AU as a result of the interaction. Detailed analysis of this event reveals erosion of the interplanetary coronal mass ejection (ICME) magnetic field. In this communication, we study the photospheric magnetic roots of the coronal hole and the coronal mass ejection area with HMI/SDO magnetograms to define their magnetic characteristics.

Coronal Hole Rotating Towards Us

NASA Image and Video Library

2018-05-22

A good-sized coronal hole came around to where it is just about facing Earth (May 16-18, 2018). Coronal holes are areas of open magnetic field from which solar wind (consisting of charged particles) streams into space. The video clip covers two days and was taken in a wavelength of extreme ultraviolet light. Such streams of particles take several days to reach Earth, but they can generate aurora, particularly nearer the poles. An animation is available at https://photojournal.jpl.nasa.gov/catalog/PIA00575

The Office of the Coroner

PubMed Central

McMillan, J. Stewart

1983-01-01

Society has always been concerned about deaths which do not result from natural causes. In Canada, provincial legislatures have met this concern with legislation known as the Coroners' Act in some provinces and as the Fatality Inquiries Act in others. While these statutes are not identical, their intent is the same: to ensure that all unusual deaths are fully investigated to determine their true cause. The coroner's or medical examiner's primary responsibility is to show the public how similar deaths may be avoided. PMID:21283284

Coronal Magnetism and Forward Solarsoft Idl Package

NASA Astrophysics Data System (ADS)

Gibson, S. E.

2014-12-01

The FORWARD suite of Solar Soft IDL codes is a community resource for model-data comparison, with a particular emphasis on analyzing coronal magnetic fields. FORWARD may be used both to synthesize a broad range of coronal observables, and to access and compare to existing data. FORWARD works with numerical model datacubes, interfaces with the web-served Predictive Science Inc MAS simulation datacubes and the Solar Soft IDL Potential Field Source Surface (PFSS) package, and also includes several analytic models (more can be added). It connects to the Virtual Solar Observatory and other web-served observations to download data in a format directly comparable to model predictions. It utilizes the CHIANTI database in modeling UV/EUV lines, and links to the CLE polarimetry synthesis code for forbidden coronal lines. FORWARD enables "forward-fitting" of specific observations, and helps to build intuition into how the physical properties of coronal magnetic structures translate to observable properties.

Effect of Preoperative Molding Helmet in Patients With Sagittal Synostosis.

PubMed

Hashmi, Asra; Marupudi, Neena I; Sood, Sandeep; Rozzelle, Arlene

2017-06-01

In our practice, the authors found that molding helmet used for plagiocephaly preoperatively, in patients with sagittal synostosis, decreased bathrocephaly, forehead bossing, and improved posterior vertex, as well as Cephalic Index (CI). This prompted us to investigate the impact of preoperative molding helmet in patients with sagittal synostosis. A prospective study was performed on patients undergoing surgical correction of sagittal synostosis, over a 5-year period. Patients were categorized into 2 groups. "No Helmet group" only had surgical correction, and "Helmet group" had preoperative molding helmet, prior to surgical correction. Cephalic Index for the 2 groups was compared using t-test. There were 40 patients in the No Helmet group and 18 patients in the Helmet group. For No Helmet group, mean CI at presentation, immediately preoperative, and postoperatively was 0.70 (±0.045), 0.70 (±0.020), and 0.80 (±0.030), respectively, and for Helmet group, it was 0.69 (±0.023), 0.73 (±0.036), and 0.83 (±0.036), respectively. There was no statistically significant difference between CI of the 2 groups at presentation (P = 0.45). Comparison of postoperative CI did show a statistically significant difference between the groups (P = 0.01). For Helmet group, on comparison of CI at presentation and preoperative CI (after helmet therapy), a statistically significant improvement in CI was observed (P = 0.0004). Our results suggest that preoperative molding helmet can decrease bathrocephaly, forehead bossing, and improve posterior vertex as well as CI, prior to surgery and thus can be used as a valuable adjunct in patients with sagittal synostosis.

Dynamics of Coronal Hole Boundaries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Higginson, A. K.; Zurbuchen, T. H.; Antiochos, S. K.

Remote and in situ observations strongly imply that the slow solar wind consists of plasma from the hot, closed-field corona that is released onto open magnetic field lines. The Separatrix Web theory for the slow wind proposes that photospheric motions at the scale of supergranules are responsible for generating dynamics at coronal-hole boundaries, which result in the closed plasma release. We use three-dimensional magnetohydrodynamic simulations to determine the effect of photospheric flows on the open and closed magnetic flux of a model corona with a dipole magnetic field and an isothermal solar wind. A rotational surface motion is used tomore » approximate photospheric supergranular driving and is applied at the boundary between the coronal hole and helmet streamer. The resulting dynamics consist primarily of prolific and efficient interchange reconnection between open and closed flux. The magnetic flux near the coronal-hole boundary experiences multiple interchange events, with some flux interchanging over 50 times in one day. Additionally, we find that the interchange reconnection occurs all along the coronal-hole boundary and even produces a lasting change in magnetic-field connectivity in regions that were not driven by the applied motions. Our results show that these dynamics should be ubiquitous in the Sun and heliosphere. We discuss the implications of our simulations for understanding the observed properties of the slow solar wind, with particular focus on the global-scale consequences of interchange reconnection.« less

Features of solar wind streams on June 21-28, 2015 as a result of interactions between coronal mass ejections and recurrent streams from coronal holes

NASA Astrophysics Data System (ADS)

Shugay, Yu. S.; Slemzin, V. A.; Rod'kin, D. G.

2017-11-01

Coronal sources and parameters of solar wind streams during a strong and prolonged geomagnetic disturbance in June 2015 have been considered. Correspondence between coronal sources and solar wind streams at 1 AU has been determined using an analysis of solar images, catalogs of flares and coronal mass ejections, solar wind parameters including the ionic composition. The sources of disturbances in the considered period were a sequence of five coronal mass ejections that propagated along the recurrent solar wind streams from coronal holes. The observed differences from typical in magnetic and kinetic parameters of solar wind streams have been associated with the interactions of different types of solar wind. The ionic composition has proved to be a good additional marker for highlighting components in a mixture of solar wind streams, which can be associated with different coronal sources.

Isolated sagittal craniosynostosis: definition, classification, and surgical indications.

PubMed

Massimi, Luca; Caldarelli, Massimo; Tamburrini, Gianpiero; Paternoster, Giovanna; Di Rocco, Concezio

2012-09-01

Sagittal craniosynostosis (SC) remains the most common type of synostosis, accounting for about a half of all forms. It would result from a mesenchymal disorder involving the intramembranous ossification of the sagittal suture and leading to its early fusion. No specific data on the etiologic factors are currently available. The premature ossification of the sagittal suture can result in three main types of SC, according to the different segment prevalently involved: anterior, posterior, and complete SC. The diagnosis is easily obtained by clinical examination. However, a radiological work up (3D CT scan) may be necessary to rule out hidden venous or cranial anomalies possibly associated with most severe cases, or for the surgical planning. The most common indication for surgery is the improvement of the cosmetic appearance of the skull, since a cranial deformation may have a significant psychological impact on affected subjects. To relieve from raised intracranial pressure is a further indication to surgery. Although an increased intracranial pressure can be demonstrated in a minority of affected children at diagnosis, indeed, it can present later (usually after the second/third year of life) with chronic symptoms. The role of surgery in the preservation of cognitive functions in scaphocephalic patients does not seem to be relevant, since minor anomalies of the cerebral development associated with SC would occur independently from the cranial shape. On the other hand, the surgical correction may show a protective effect on some visual skills, like the ability to fix and follow, and the fixation shift.

The knee: Surface-coil MR imaging at 1. 5 T

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beltran, J.; Noto, A.M.; Mosure, J.C.

1986-06-01

Seven normal knees (in five volunteers) and seven injured knees (in seven patients) were examined by high-resolution magnetic resonance (MR) imaging at 1.5 T with a surface coil. Seven medial meniscal tears, three anterior cruciate ligament tears, one posterior cruciate ligament avulsion, an old osteochondral fracture, femoral condylar chondro-malacia, and one case of semimembranous tendon reinsertion were identified. MR images correlated well with recent double-contrast arthrograms or results of surgery. All tears were identified in both the sagittal and coronal planes. Because of its ability to demonstrate small meniscal lesions and ligamentous injuries readily, MR imaging with a surface coilmore » may eventually replace the more invasive arthrography.« less

Coronal Jets in Closed Magnetic Regions on the Sun

NASA Astrophysics Data System (ADS)

Wyper, Peter Fraser; DeVore, C. R.

2015-04-01

Coronal jets are dynamic, collimated structures observed in solar EUV and X-ray emission. They appear predominantly in the open field of coronal holes, but are also observed in areas of closed field, especially active regions. A common feature of coronal jets is that they originate from the field above a parasitic polarity of opposite sign to the surrounding field. Some process - such as instability onset or flux emergence - induces explosive reconnection between the closed “anemone” field and the surrounding open field that generates the jet. The lesser number of coronal jets in closed-field regions suggests a possible stabilizing effect of the closed configuration with respect to coronal jet formation. If the scale of the jet region is small compared with the background loop length, as in for example type II spicules, the nearby magnetic field may be treated as locally open. As such, one would expect that if a stabilizing effect exists it becomes most apparent as the scale of the anemone region approaches that of the background coronal loops.To investigate if coronal jets are indeed suppressed along shorter coronal loops, we performed a number of simulations of jets driven by a rotation of the parasitic polarity (as in the previous open-jet calculations by Pariat et. al 2009, 2010, 2015) embedded in a large-scale closed bipolar field. The simulations were performed with the state of the art Adaptively Refined Magnetohydrodynamics Solver. We will report here how the magnetic configuration above the anemone region determines the nature of the jet, when it is triggered, and how much of the stored magnetic energy is released. We show that regions in which the background field and the parasitic polarity region are of comparable scale naturally suppress explosive energy release. We will also show how in the post-jet relaxation phase a combination of confined MHD waves and weak current layers are generated by the jet along the background coronal loops, both of which

THE CONTRIBUTION OF CORONAL JETS TO THE SOLAR WIND

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lionello, R.; Török, T.; Titov, V. S.

Transient collimated plasma eruptions in the solar corona, commonly known as coronal (or X-ray) jets, are among the most interesting manifestations of solar activity. It has been suggested that these events contribute to the mass and energy content of the corona and solar wind, but the extent of these contributions remains uncertain. We have recently modeled the formation and evolution of coronal jets using a three-dimensional (3D) magnetohydrodynamic (MHD) code with thermodynamics in a large spherical domain that includes the solar wind. Our model is coupled to 3D MHD flux-emergence simulations, i.e., we use boundary conditions provided by such simulationsmore » to drive a time-dependent coronal evolution. The model includes parametric coronal heating, radiative losses, and thermal conduction, which enables us to simulate the dynamics and plasma properties of coronal jets in a more realistic manner than done so far. Here, we employ these simulations to calculate the amount of mass and energy transported by coronal jets into the outer corona and inner heliosphere. Based on observed jet-occurrence rates, we then estimate the total contribution of coronal jets to the mass and energy content of the solar wind to (0.4–3.0)% and (0.3–1.0)%, respectively. Our results are largely consistent with the few previous rough estimates obtained from observations, supporting the conjecture that coronal jets provide only a small amount of mass and energy to the solar wind. We emphasize, however, that more advanced observations and simulations (including parametric studies) are needed to substantiate this conjecture.« less

MACS, An Instrument and a Methodology for Simultaneous and Global Measurements of the Coronal Electron Temperature and the Solar Wind Velocity on the Solar Corona

NASA Technical Reports Server (NTRS)

Reginald, Nelson L.

2000-01-01

In Cram's theory for the formation of the K-coronal spectrum he observed the existence of temperature sensitive anti-nodes, which were separated by temperature insensitive nodes, at certain wave-lengths in the K-coronal spectrum. Cram also showed these properties were remarkably independent of altitude above the solar limb. In this thesis Cram's theory has been extended to incorporate the role of the solar wind in the formation of the K-corona, and we have identified both temperature and wind sensitive intensity ratios. The instrument, MACS, for Multi Aperture Coronal Spectrometer, a fiber optic based spectrograph, was designed for global and simultaneous measurements of the thermal electron temperature and the solar wind velocity in the solar corona. The first ever experiment of this nature was conducted in conjunction with the total solar eclipse of 11 August 1999 in Elazig, Turkey. Here twenty fiber optic tips were positioned in the focal plane of the telescope to observe simultaneously at many different latitudes and two different radial distances in the solar corona. The other ends were vertically stacked and placed at the primary focus of the spectrograph. By isolating the K-coronal spectrum from each fiber the temperature and the wind sensitive intensity ratios were calculated.

Flux Cancelation as the Trigger of Quiet-Region Coronal Jet Eruptions

NASA Technical Reports Server (NTRS)

Panesar, Navdeep K.; Sterling, Alphonse; Moore, Ronald L.

2017-01-01

Coronal jets are frequent magnetically channeled narrow eruptions. They occur in various solar environments: quiet regions, coronal holes and active regions. All coronal jets observed in EUV (Extreme UltraViolet) and X-ray images show a bright spire with a base brightening, also known as jet bright point (JBP). Recent studies show that coronal jets are driven by small-scale filament eruptions. Sterling et al. 2015 did extensive study of 20 polar coronal hole jets and found that X-ray jets are mainly driven by the eruption of minifilaments. What leads to these minifilament eruptions?

Disruption of coronal magnetic field arcades