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PubMed1986

Two-dimensional echocardiographic demonstration of restoration of normal wall motion after acute myocardial infarction.

Left ventricular wall motion was assessed by 2-dimensional (2-D) echocardiography in 17 patients admitted with a first transmural acute myocardial infarction (AMI). The left ventricular myocardium was divided into 17 segments and wall motion was scored from 1 (dyskinesia) to 6 (hyperkinesia) in each segment. Reproducibility of the wall motion scoring system when assessed separately by 2 observers was 89% and when assessed by the same observer at different times, 91%. Seven patients had anterior and 10 inferior wall AMI on the electrocardiogram. Abnormal wall motion was present in 7.3 +/- 2.8 segments (mean +/- standard deviation) on the initial 2-D echocardiogram. On follow-up echocardiograms wall motion was unchanged in 7 patients. In 5 wall motion improved by at least 2 in 2 or more contiguous segments. In 5 other patients wall motion returned to normal in all segments that had shown an abnormality on the initial echocardiogram. These 5 patients (group A), compared with the 12 patients in whom wall motion did not return to normal in all segments (group B), showed fewer involved segments (5.4 +/- 1.7 vs 8 +/- 2.8) and a higher total wall motion score (76 +/- 4 vs 63 +/- 7) (p less than 0.05) on the initial echocardiogram. Duration from the time of the AMI to return of normal wall motion in group A varied from 2 to 8 weeks. Thus, wall motion abnormalities seen on 2-D echocardiography after transmural AMI often improve and wall motion returns to normal in some patients.

Adult↗
PubMed1993

Influence of cardiac motion on Doppler measurements using in vitro and in vivo models.

OBJECTIVES: Using both in vitro and in vivo techniques, we investigated the extent to which cardiac motion alters Doppler-measured blood flow velocity and thus potentially can alter the calculation of valve areas or pressure gradients. BACKGROUND: Blood flow velocity measured by Doppler ultrasound represents the net motion of the blood relative to the transducer. It is widely assumed that the measured velocity represents the actual flow. It has been demonstrated that cardiac motion generates regularly occurring low velocity Doppler signals that are commonly treated as artifact. METHODS: We used an in vitro model that allowed us to measure and independently control the flow of a liquid through a chamber and the motion of the chamber relative to the Doppler beam. A cornstarch-water slurry was driven by a pulsatile pump through tubing to simulate the blood flow within the heart, and the tubing was cyclically moved by a piston to simulate the heart motion. We also measured cardiac motion using M-mode and two-dimensional echocardiography and compared the results with the Doppler signal derived from cardiac motion in subjects without cardiac disease. RESULTS: In the in vitro model, alteration in the motion of the tubing resulted in apparent changes in the measured maximal velocity of the fluid. The Doppler spectrum of the combined motion of the tubing and the fluid was the algebraic sum of their Doppler signals. In human subjects, the maximal slope of the M-mode tracing of the aortic annular motion and the peak Doppler signal due to cardiac motion were compared and were highly correlated. CONCLUSIONS: Cardiac motion alters the Doppler signal derived from blood flow. This effect can be demonstrated in vitro and in vivo.

Adolescent↗
PubMed1999

A demonstration of validity of 3-D video motion analysis method for measuring finger flexion and extension.

This study demonstrates the validity of using 3-D video motion analysis to measure hand motion. Several researchers have devised ingenious methods to study normal and abnormal hand movements. Although very helpful, these earlier studies are static representations of a dynamic phenomenon. Despite the many studies of hand motion using scientifically impeccable techniques, little is known about digital motion, and there are still few researchers investigating dynamic three-dimensional motion of the hand. Results from a three-camera video motion analysis system were compared to those from the "gold standard", 2-D lateral view fluoroscopy. We used these two methods to record hand motion simultaneously during unrestricted flexion and extension of the index finger of the dominant hand in 6 neurologically normal, healthy volunteers. After collection and post-processing, the waveforms of the PIP, DIP and MCP joint angles were compared using the adjusted coefficient of multiple determination (R2(a), or CMD). The mean CMD values for the MCP, PIP and DIP joint angle waveforms were 0.96, 0.98 and 0.94, respectively, suggesting a close similarity between motion of comparable joints analyzed by the 2-D and 3-D methods. This shows that the method of 3-D motion analysis is capable of accurately quantifying digital joint motion. It is anticipated that 3-D motion analysis, in addition to being used as a research tool, will also have clinical applications such as surgical planning in neuromuscular disorders and the documentation of abnormal motion in many other pathological hand conditions.

Biomechanical Phenomena↗
PubMed2001

Inter-segment foot motion and ground reaction forces over the stance phase of walking.

OBJECTIVE: To compare the magnitude and patterns of motion of the rearfoot segment relative to the leg, forefoot segment relative to the rearfoot, height change in the medial longitudinal arch and ground reaction forces of normal adult males during the stance phase of walking. BACKGROUND: Knowledge of normal motion of the rearfoot and forefoot segments and of the arch during stance phase is important in clinical management. METHODS: Motion data were obtained from surface markers, and force data from a force plate, from the right limb of participants while walking at a self-selected pace. RESULTS: Stance phase range of motion across sagittal, frontal and transverse planes was 12 degrees, 4 degrees and 10 degrees for the forefoot, compared to 22 degrees, 8 degrees and 10 degrees for the rearfoot. Most motion occurred at the beginning and end of stance phase when support was via only the rearfoot or forefoot, and when forces were maximal. Arch height decreased from heel contact and increased after heel rise to its maximum at toe-off. CONCLUSIONS: The extent of forefoot segment motion confirms the significance of midfoot joints to normal foot function. Between foot flat and heel rise, the forefoot pattern of motion is indicative of foot stability. Typical foot motion does not obey descriptions of triplanar motion such as 'pronation' and 'supination'. RELEVANCE: Typical stance phase foot motion has been described according to a forefoot:rearfoot model and rearfoot:leg model of motion, together with profiles of medial longitudinal arch height and ground reaction forces. This information can be applied in the management of foot dysfunction and should stimulate research into midfoot motion and overall control of the foot.

Adult↗
PubMed2001

Extracranial radiosurgery: immobilizing liver motion in dogs using high-frequency jet ventilation and total intravenous anesthesia.

PURPOSE: Extracranial radiosurgery requires control of organ motion. The purpose of this study is to quantitatively determine the extent of liver motion in anesthetized dogs with continuous i.v. propofol infusion with or without muscle relaxants and high-frequency jet ventilation. METHODS AND MATERIALS: Five dogs were used in the experiment. Each dog was restrained while anesthetized in the supine position using an alpha cradle. Surgical metal clips were implanted around the liver periphery so that its motion could be visualized using a fluoroscopic imaging device in a conventional simulator. Initially, two orthogonal simulation films were taken to correlate locations of implanted clips. Two orthogonal views of fluoroscopic images for each anesthetized dog were recorded on a magnetic tape and analyzed from the post-imaging data. Liver motion was documented under the following three conditions: 1) ventilated with a conventional mechanical ventilator, 2) ventilated with a high-frequency jet ventilator, and 3) ventilated with a high-frequency jet ventilator and total muscle paralysis (with vecuronium injection). The maximum liver motion for each dog was analyzed in three orthogonal directions: the inferior-to-superior direction, the anterior-to-posterior direction, and the right-to-left direction. RESULTS: When the anesthetized dogs were ventilated with a conventional mechanical ventilator, the average liver motions were 1.2 cm in the inferior-to-superior direction, 0.4 cm in the anterior-to-posterior direction, and 0.2 cm in the right-to-left direction, respectively. After the introduction of high-frequency jet ventilation, the average liver motions were reduced to 0.2 cm in the inferior-to-superior direction, 0.2 cm in the anterior-to-posterior direction, and 0.1 cm in the right-to-left direction. The maximum liver motion was dependent on ventilator settings. There was no additional measurable motion reduction with the addition of the muscle relaxant. CONCLUSION: The liver motion in each anesthetized dog was controlled under 3.0 mm in all directions with the use of high-frequency jet ventilation. No detectable advantage was identified by the injection of muscle relaxant in terms of further reducing the liver motion. The preclinical animal study indicated that the use of high-frequency jet ventilation (HFJV) would be able to limit the liver motion to an extent acceptable for the application of extracranial radiosurgery in humans. Radiosurgery for localized liver tumors warrants further investigation.

Anesthesia, Intravenous↗
PubMed2002

Intrafraction prostate motion during IMRT for prostate cancer.

PURPOSE: Although the interfraction motion of the prostate has been previously studied through the use of fiducial markers, CT scans, and ultrasound-based systems, intrafraction motion is not well documented. In this report, the B-mode, Acquisition, and Targeting (BAT) ultrasound system was used to measure intrafraction prostate motion during 200 intensity-modulated radiotherapy (IMRT) sessions for prostate cancer. METHODS AND MATERIALS: Twenty men receiving treatment with IMRT for clinically localized prostate cancer were selected for the study. Pre- and posttreatment BAT ultrasound alignment images were collected immediately before and after IMRT on 10 treatment days for a total of 400 BAT alignment procedures. Any ultrasound shifts of the prostate borders in relation to the planning CT scan were recorded in 3 dimensions: right-left (RL), anteroposterior (AP), and superior-inferior (SI). Every ultrasound procedure was evaluated for image quality and alignment according to a 3-point grading scale. RESULTS: All the BAT images were judged to be of acceptable quality and alignment. The dominant directions of intrafraction prostate motion were anteriorly and superiorly. The mean magnitude of shifts (+/-SD) was 0.01 +/- 0.4 mm, 0.2 +/- 1.3 mm, and 0.1 +/- 1.0 mm in the left, anterior, and superior directions, respectively. The maximal range of motion occurred in the AP dimension, from 6.8 mm anteriorly to 4.6 mm posteriorly. The percentage of treatments during which prostate motion was judged to be 5 mm. The extent of intrafraction motion was much smaller than that of interfraction motion. Linear regression analysis showed very little correlation between the two types of motion (r = 0.014, 0.029, and 0.191, respectively) in the RL, AP, and SI directions. CONCLUSION: Using an ultrasound-based system, intrafraction prostate motion occurred predominantly in the anterior and superior directions, but was clinically insignificant. Intrafraction motion was much smaller than interfraction motion, and the two types of movement did not correlate.

Humans↗
PubMed2002

How to detect internal motion by homonuclear NMR.

NOESY and ROESY cross-peak intensities depend on internuclear distances and internal motion. Internal motion is usually ignored, and NOESY cross-peak intensities are interpreted in terms of internuclear distances only. Off-resonance ROESY experiments measure a weighted average of NOE and ROE. The weight can be described and experimentally set by an angle theta;. For large enough molecules, NOE and ROE have opposite signs. Therefore, each cross-peak intensity becomes zero for an angle theta;(0). For any sample, the maximum angle theta;(0) is determined by the overall motion of the molecule. Smaller theta;(0) values reflect the angular component of internal motions. Because individual cross-peaks are analyzed, the method evaluates internal motions of individual H,H vectors. The reduction of theta;(0) is largest for internal motions on a time scale of 100-300 ps. The sensitivity of theta;(0) for internal motions decreases with increasing molecular weight. We estimate that detecting internal motions will be practicable for molecules up to about 15 kDa. We describe a protocol to measure theta;(0) from a series of off-resonance ROESY spectra. For such a series, we describe the choice of experimental parameters, a procedure to extract theta;(0) from the raw data, and the interpretation of theta;(0) in terms of internal motions. In the small protein BPTI, we analyzed 75 cross-peaks. The precision of theta;(0) was 0.25 degrees, as compared to typical reductions of theta;(0) of 3 degrees. We found a well-defined maximum theta;(0) for cross-peaks in rigid parts of the molecule, which reflects the overall motion of the molecule. For BPTI, also many structurally important long-range cross-peaks appear rigid. The lower theta;(0) values of long-range contacts involving methyl groups are consistent with methyl rotation on the 25-ps time scale. The lower theta;(0) values of the flexible C-terminus and of flexible side chains translate into upper limits for the angular order parameter of 0.4 and 0.5-0.8, respectively. Off-resonance ROESY can monitor internal motions of H,H contacts that are used in a structure calculation. Because no isotope labeling is needed, off-resonance ROESY can be used to detect internal motions in a wide range of natural products.

Aprotinin↗
PubMed1998

Stability of posterior spinal instrumentation and its effects on adjacent motion segments in the lumbosacral spine.

STUDY DESIGN: An in vitro biomechanical analysis of three anterior instability patterns was performed using calf lumbosacral spines. Stiffness of the constructs was compared, and segmental motion analyses were performed. OBJECTIVES: To clarify the factors that alter the stability of the spinal instrumentation and to evaluate the influence of instrumentation on the residual intact motion segments. SUMMARY OF BACKGROUND DATA: Recently, many adverse effects have been reported in fusion augmented with rigid instrumentation. Only few reports are available regarding biomechanical effects of stability provided by spinal instrumentation and its effects on residual adjacent motion segments in the lumbar-lumbosacral spine. METHODS: Eighteen calf lumbosacral spine specimens were divided into three groups according to instability patterns--one-level, two-level, and three-level disc dissections. Six constructs were cyclically tested in rotation, flexion-extension, and lateral bending of intact spines, of destabilized spine, and of spines with four segmental posterior instrumentation systems used to extend the levels of instability (Cotrel-Dubousset compression hook and three transpedicular screw fixation systems). During each test, stiffness values and segmental displacements were measured. RESULTS: The rigidity of the instrumented construct increased as the fixation range became more extensive. Although application of the instrumentation effectively reduced the segmental motion of the destabilized vertebral level, the motion at the destabilized level tended to increase as the number of unstable vertebral levels increased, and the fixation range of the instrumentation became more extensive. Instrumented constructs produced higher segmental displacement values at the upper residual intact motion segment when compared with those of the intact spine. In contrast, the instrumented constructs decreased their segmental displacement values at the lower residual intact motion segment with higher magnitude of the translational (shear) motion taking place compared with the intact spine in flexion-extension and lateral bending. These changes in the motion pattern became more distinct as the fixation range became more extensive. CONCLUSIONS: As segmental spinal instrumentation progresses from one level to three levels, the overall torsional and flexural rigidity of the system increases. However, segmental displacement at the site of simulated instability becomes more obvious. Application of segmental instrumentation changes the motion pattern of the residual intact motion segments, and the changes in the motion pattern become more distinct as the fixation range becomes more extensive and as the rigidity of the construct increases.

Animals↗
PubMed1998

The stiffness of lumbar spinal motion segments with a high-intensity zone in the anulus fibrosus.

STUDY DESIGN: Biomechanical and anatomic study of human cadaveric spinal motion segments. OBJECTIVES: To measure the stiffness of spinal motion segments by disc type and by load type (flexion, extension, axial rotation, or lateral bending). To compare stiffness in motion segments with and without a high-intensity zone or radial tear in the anulus fibrosus. SUMMARY OF BACKGROUND DATA: The high-intensity zone, that is a linear zone of high-intensity on T2-weighted magnetic resonance images corresponding to a radial tear in the anulus fibrosus, is a marker for a painful disc at discography. The high-intensity zone is hypothetically associated with diminished stiffness of the motion segment. METHODS: Human cadaveric lumbar spinal motion segments with normal disc morphology or a high-intensity zone of the anulus fibrosus were selected on the basis of magnetic resonance imaging. The motion segments were subjected to incremental flexion, extension, rotation, and lateral bending torques. Rotation was measured with a kinematic system. Torque-rotation curves and stiffness were calculated for each motion segment and for each torque. The motion segments were sectioned on a cryomicrotome to verify the disc morphology as normal or as that of a radial tear. RESULTS: In four motion segments with normal discs, stiffness was greater in axial rotation (8.4 Nm/degree) than in lateral bending (2.3 Nm/degree), flexion (1.8 Nm/degree), or extension (2.6 Nm/degree). In 16 motion segments with a high-intensity zone, stiffness was 2.4 Nm/degree in axial rotation, and less severely reduced in lateral bending, flexion, and extension. Stiffness in motion segments with a high-intensity zone was significantly less with smaller than with larger axial rotation loads. CONCLUSIONS: The presence of a high-intensity zone in the intervertebral disc is associated with reduced stiffness of motion segments. The reduction is greater in axial rotation than in other torques. The reduction is more in smaller than in larger axial torques.

Aged↗
PubMed2006

Motion-compensated and gated cone beam filtered back-projection for 3-D rotational X-ray angiography.

This paper presents a method to reconstruct moving objects from cone beam X-ray projections acquired during a single rotational run using a given motion vector field. The method is applicable to voxel driven cone-beam filtered back-projection reconstruction approaches. Here, a formulation based on the algorithm of Feldkamp, Davis, and Kress (FDK) is presented. The motion correction is applied during the back-projection step by shifting the voxel to be reconstructed according to the motion vector field. The method is applied to three-dimensional (3-D) rotational X-ray angiography. Projections from a beating coronary heart phantom are simulated. Motion-compensated reconstructions with varying accuracy of the applied motion field are carried out for a late diastolic heart phase and compared to the reconstruction obtained with the standard FDK-method from projections of the corresponding motion-free model in the same heart phase. Furthermore, gated reconstructions are calculated by weighting the projections according to their cardiac phase without using a motion vector field. Different gating window widths are applied, and the reconstructions are compared. Using the correct motion field with the motion-compensated reconstruction, the image quality of the standard reconstruction from the corresponding motion-free coronary model can almost be recovered. The reconstructed image quality stays acceptable if the accuracy of the motion field sampling points is better than 1 mm. The gated reconstructions with a window width of 15%-20% of the cardiac cycle lead to superior results compared to nearest neighbor gating, especially for histogram based visualization and analysis. The motion-compensated reconstructions provide sharp images of the coronaries far surpassing the image quality of gated reconstructions.

Algorithms↗
PubMed2001

Fluoroscopic study of tumor motion due to breathing: facilitating precise radiation therapy for lung cancer patients.

Target motion due to breathing is one of the major obstacles in dose escalation of radiation therapy to some tumors in the thoracoabdominal region. The development of beam gating or target motion tracking techniques provides a possibility to reduce normal tissue volume in a treatment field. Tumor motion monitoring in those techniques plays a crucial role, but has not yet been adequately explored. This paper reports our preliminary investigation on breath introduced tumor motion. Tumor locations and motion properties were determined from digitized fluoroscopic videos acquired during patient simulation. Image distortion due to irregularities in the imaging chain, such as the pincushion distortion, was corrected with a polynomial unwarping method. Temporal Fourier transformation of the fluoroscopic video was introduced to convert the motion information over time to a static view of a motion field, in which regions with different motion ranges can be directly measured. Patient breathing patterns vary from patient to patient and so does the kinematic behavior of individual tumors. In order to evaluate the feasibility for tracking internal target motion with nonionizing-radiation techniques, motion patterns between internal targets and external radio opaque markers placed on patient's chest during fluoroscopic video acquisition were compared. For some patients, significant motion phase discrepancies between an internal target and an external marker have been observed. Quantitative measurements are reported. These results will be useful in the design of a motion tracking or gated radiotherapy system.

Fluoroscopy↗
PubMed1999

Angle-independent motion measurement by correlation of ultrasound signals assessed with a single circular-shaped transducer.

In medicine, pulsed ultrasound is a widespread noninvasive technique that measures motion in the direction of the ultrasound beam, i.e., axial motion. The magnitude of the actual motion can be determined only if the angle between the ultrasound beam and the direction of motion (transducer-to-motion angle) is known. For blood flow measurements, current pulsed ultrasound systems assume this angle to be equal to the angle between the ultrasound beam and the longitudinal direction of the vessel, as can be estimated from a two-dimensional brightness-mode (B-mode) image that is obtained prior to the blood flow measurement. For tissue motion measurements, current pulsed ultrasound systems are mostly unable to determine the transducer-to-motion angle. Recently, a model has been derived for the correlation of(analytic) radiofrequency (rf) signals, assessed with a circular-shaped ultrasound transducer along the same line of observation. In the present paper, this model is used to derive estimators, requiring only the calculation of a few correlation coefficients, for the motion components (axial, lateral and actual) and for some of the signal parameters (center frequency, bandwidth and signal-to-noise ratio) of the assessed rf signals. The transducer-to-motion angle can be derived from the estimated motion components. For the evaluation of the estimators, rf signals were acquired with a motion-controlled experimental arrangement. The results of the evaluation study show that the transducer-to-motion angle can be estimated with a mean standard deviation of less than 2 degrees.

Algorithms↗
PubMed2000

Shank rotation: A measure of rearfoot motion during normal walking.

Motion of the shank in the transverse plane is coupled with pronation and supination of the rearfoot, and so its motion relative to the foot can be used as an indicator of the pattern of motion in the rearfoot. Compared to the more commonly used assessment of motion in the frontal plane between the heel and the shank, motion of the shank in the transverse plane relative to the foot provides a more complete measure of the pattern of motion of the rearfoot because it reflects the motion in all three joints of the rearfoot (the ankle, subtalar joint and mid-tarsal joint) not solely the ankle and subtalar components. This work aimed to provide normative data for this alternative measure of rearfoot function. Data on angular displacement, angular velocity and angular acceleration were derived from motion-analysis conducted on 25 subjects. The results suggest a difference between the pattern of angular displacement indicated when motion of the shank relative to the foot is examined and the pattern of angular displacement indicated when motion in the frontal plane between the shank and heel is examined. Specifically, the former suggests that resupination of the rearfoot after rearfoot pronation during the initial period of gait, starts at the beginning of mid-stance, while the latter suggests resupination beginning in late mid-stance. Where comparisons were possible, data on the velocity and acceleration appeared reasonable and provide further parameters with which to investigate the role of motion in the rearfoot in the development of pathologic conditions and the effects of intervention on motion in the rearfoot.

Ankle Joint↗
PubMed2004

[Effect of motion correction associated with echo train length and number of blades in propeller MRI-computer simulation].

The PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) MRI method is available with a technique for motion correction. We studied changes in correction according to differences in echo train length (ETL) and number of blades, and measured correction accuracy according to linear translation and rotation, using computer simulation. A T(2)-weighted axial image of the head taken by FSE was utilized as the basic MR image. We reconstructed other images with differences in quantity of motion, ETL, and number of blades, also using computer simulation. After motion correction was performed, we measured correction accuracy with cross-correlation to the basic image. The method of motion correction was performed by the conversion of k-space data for each blade step using 2D Fourier-transform. After motion correction of the obtained image had been carried out, the image was converted to k-space data using reverse Fourier-transform. For data of 30 pixels with horizontal translation, cross-correlation coefficients for the stationary image were 0.6 for FSE without motion correction, 0.74 for the PROPELLER (ETL 8, blades 32) image without motion correction, and 0.99 for the PROPELLER (ETL 8, blades 32) image with motion correction. For data of 24 degrees with rotation, cross-correlation coefficients were 0.38 for FSE without motion correction, 0.53 for the PROPELLER (ETL 8, blades 32) image without motion correction, and 0.93 for the PROPELLER (ETL 8, blades 32) image with motion correction. The cross-correlation coefficient of liner translation is higher than its rotation. Correction accuracy was better with larger numbers of ETL than without motion correction. The spatial resolution of the image was decreased in the corrected image more by rotation than linear translation. This study indicated that the PR method was able to inspect the imaging technique with little influence on movement.

Computer Simulation↗
PubMed2004

Multisegment foot motion during gait: proof of concept in rheumatoid arthritis.

OBJECTIVE: To test a multisegment foot model for kinematic analysis during barefoot walking in patients with well established rheumatoid arthritis (RA) and foot impairments. METHODS: Five healthy adult subjects and 11 RA patients with advanced disease were studied. Foot impairments were assessed using standardized outcomes and clinical examination techniques. A 6-camera 60 Hz video-based motion analysis system was used to measure motion of the shank, rearfoot, forefoot, and hallux segments and the vertical displacement of the navicular. Face validity and estimates of repeatability were determined. Motion patterns were calculated and comparisons were made between healthy subjects and patients with RA. Relationships between clinical impairment and abnormal motion were determined through inspection of individual RA cases. RESULTS: Across the motion variables, the within-day and between-day coefficient of multiple correlation values ranged from 0.677 to 0.982 for the healthy subjects and 0.830 to 0.981 for RA patients. Based on previous studies, motion parameters for the healthy subjects showed excellent face validity. In RA patients, there was reduced range of motion across all segments and all planes of motion, which was consistent with joint stiffness. In the RA patients, rearfoot motion was shifted towards eversion and external rotation and peak values for these variables were increased, on average, by 7 degrees and 11 degrees, respectively. Forefoot range of motion was reduced in all 3 planes (between 31% and 53%), but the maximum and minimum angles were comparable to normal. The navicular height, during full foot contact, was on average 3 mm lower in the RA patients in comparison to normal. The hallux was less extended in the RA subjects in comparison to normal (21 degrees vs 33 degrees) during the terminal stance phase. Individual cases showed abnormal patterns of motion consistent with their clinical impairments, especially those with predominant forefoot pain or pes planovalgus. CONCLUSION: In RA, multisegment foot models may provide a more complete description of foot motion abnormalities where pathology presents at multiple joints, leading to complex and varied patterns of impairment. This technique may be useful to evaluate functional changes in the foot and to help plan and assess logical, structurally based corrective interventions.

Adult↗
PubMed1984

[Mechanism of post-operative abnormal septal motion: clinical and experimental studies].

In a previous report, we showed that pericardium closure is responsible for post-operative abnormal septal motion. To elucidate this hypothesis, we performed additional clinical and experimental studies. Twenty-six patients were studied during cardiac surgery. We also studied five dogs during cardiopulmonary bypass using M-mode and two-dimensional echocardiography. M-mode echograms and short-axis views of the left ventricle were obtained before and after pericardiotomy, and before and after pericardium closure. In the clinical study, the patients were divided into three groups according to pre-operative septal motion: Group 1 included six patients with atrial septal defect showing paradoxical motion, Group 2 included thirteen patients with aortic or mitral regurgitation of hyperdynamic motion, and Group 3 consisted of seven patients with ventricular septal defects or mitral stenosis showing normal systolic motion. In Group 1, septal motion became normal after closure of atrial septal defect and then, became abnormal just after pericardium closure. Again in Group 2, septal motion became normal following surgical repair, but abnormal motion appeared immediately after pericardium closure. In Group 3, normal septal motion persisted until just prior to closure of the pericardium. Abnormal septal motion in all groups persisted following chest closure. In all dogs, paradoxical septal motion resulted from pericardium closure after cardio-pulmonary bypass. We conclude that both pericardium closure and cardio-pulmonary bypass are responsible for post-operative abnormal septal motion.

Adolescent↗
PubMed2006

Retrospective motion correction protocol for high-resolution anatomical MRI.

Modern computational brain morphology methods require that anatomical images be acquired at high resolution and with a high signal-to-noise ratio. This often translates into long acquisition times (>20 minutes) and images susceptible to head motion. In this study we tested retrospective motion correction (RMC), common for functional MRI (fMRI) and PET image motion correction, as a means to improve the quality of high-resolution 3-D anatomical MR images. RMC methods are known to be effective for correcting interscan motion; therefore, a single high-resolution 3-D MRI brain study was divided into six shorter acquisition segments to help shift intrascan motion into interscan motion. To help reduce intrascan head motion, each segment image was reviewed for motion artifacts and repeated if necessary. Interscan motion correction was done by spatially registering images to the third image and forming a single average motion-corrected image. RMC was tested on 35 subjects who were considered at high risk for head motion. Our results show that RMC provided better contrast-to-noise ratio and boundary detail when compared to nonmotion-corrected averaged images.

Adolescent↗
PubMed2002

Relationship between pain and vertebral motion in chronic low-back pain subjects.

OBJECTIVES: To investigate the relationship between intervertebral motion, intravertebral deformation and pain in chronic low-back pain patients. DESIGN: This study measured vertebral motion of the lumbar spine and associated pain in a select group of chronic low-back pain patients as they performed a standard battery of motions in all planes. BACKGROUND: Numerous studies have demonstrated that individuals with low-back pain have impaired spinal motion, yet few studies have examined the specific relationship between pain and motion parameters. Although it is accepted that the pain in mechanical low-back patients is due to specific spinal motions, no studies have related specific motions to pain measures. METHODS: Percutaneous intra-pedicle screws were placed into the right and left L4 (or L5) and S1 segments of nine chronic low-back pain patients. The external fixator frame was removed following the clinical external fixation test. The 3D locations of the pedicle screws and the level of pain were recorded as the subjects performed a battery of motions. The relationship between the pain and motion parameters was assessed using linear discriminant analysis and neural network models. RESULTS: The neural network model showed a strong relationship between observed and predicted pain (R(2)=0.997). The discriminant analysis showed a weak relationship (R(2)=0.5). CONCLUSIONS: Vertebral motion parameters are strongly predictive of pain in this select group of chronic low-back pain patients. The nature of the relationship is nonlinear and involves interactions; neural networks are able to effectively describe these relationships. RELEVANCE: Specific patterns of intervertebral motion and intravertebral deformation result in pain in chronic low-back pain patients. This substantiates the mechanical back pain aetiology.

Adult↗