scholarly journals Kyphosis index obtained in X-ray and with flexicurve assessment in children and young people

2017 ◽  
Vol 17 (1) ◽  
pp. 79-87 ◽  
Author(s):  
Rafael Paiva Ribeiro ◽  
Bárbara Vendramini Marchetti ◽  
Eduardo Bojunga de Oliveira ◽  
Claúdia Tarragô Candotti
Keyword(s):  
Young People ◽  
Cobb Angle ◽  
Concurrent Validity ◽  
Thoracic Kyphosis ◽  
Accurate Method ◽  
X Rays ◽  
Kyphosis Angle ◽  
Children And Young People ◽  
X Ray ◽  
Graph Paper

Abstract Objectives: to assess the concurrent validity of kyphosis index measured in the flexicurve from the correlation of X-rays exams, identifying its accuracy and to assess the thoracic spine in children and young people. Methods: 31 young people at an average age of 11.1±3.4 years were evaluated by digital x-rays: (1) Cobb angle (ÂngCobb), (2) Kyphosis index (KIX), and (3) KIX angle (ÂngKIX). These were measured from the flexicurve design on the millimetric graph paper: (1) Kyphosis index (KIFint), obtained from C7 the intersection of kyphosis-lordosis, (2) Kyphosis index (KIFT12), obtained between C7 and T12, and (3) Kyphosis angle (ÂngKIFint and ÂngKIFT12). Statistical analysis: Correlation to Pearson Moment-Product and t test (α<0.05). Results: the angular values (ÂngKIFint, ÂngKIFT12, ÂngKIX) were underestimated in relation to Cobb angle (p<0.05), correlating only to KIX angle and Cobb angle [r=0.698, p<0.001]. The linear values (KIFint, KIFT12, KIX) were similar ( p>0.05) among themselves, correlating only to KIX and Cobb angle [r=0.698, p<0.001] and KIX angle and KIX [r=1; p<0.001]. Conclusions: the KIX and KIX angle presented as an accurate method and valid to be used in the thoracic kyphosis assessment, although KIFint, KIFT12, KIFint angle and KIFT12 angle showed no correlation to the gold standard and not being indicated to assess the thoracic kyphosis in children and young people.

scholarly journals Problems with diagnosing early stadia of scoliosis due to discrepancies between ATR and the Cobb angle

2020 ◽  
Author(s):  
Marek Kluszczyński ◽  
Jacek Wąsik ◽  
Dorota Ortenburger
Keyword(s):  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Lumbar Lordosis ◽  
Thoracic Kyphosis ◽  
Clinical Parameters ◽  
Trunk Rotation ◽  
X Ray ◽  
False Diagnosis ◽  
Cobb Method ◽  
Threshold Rule

Abstract Background This research analysed discrepancies between the angle of trunk rotation (ATR) and the Cobb angle, in order to study if the commonly used 7° cut-off threshold for ATR helps diagnose scoliosis. In early stadia of scoliosis in children, ATR and the Cobb angle often disagree, increasing the risk of a false diagnosis: while the former does not suggest scoliosis, the latter does. Methods The study analysed ATR clinical parameters and the Cobb angle in the X-ray pictures of 117 (23 boys and 94 girls, aged 6–17 years) children who had not yet started treatment and whose X-ray pictures showed the Cobb angle of at least 10°, indicating idiopathic scoliosis. The degrees of lumbar lordosis and thoracic kyphosis were measured using the Saunders inclinometer, and back asymmetry was measured with Adam’s forward bend test using the Bunnell scoliometer. In the X-ray pictures, the curvature angle was plotted according to the Cobb method. The patients were stratified based on their age, and their ATRs and Cobb angles were compared. Results Although all the children had the Cobb angle over 10°, in 69 out of 117 (59%), ATR was below 7%. So, using the 7° cut-off threshold rule, scoliosis would not be diagnosed in those children. This shows that the two tests often disagree, suggesting that the 7° cut-off threshold or ATR is ineffective in diagnosing scoliosis. Conclusions To improve the method for diagnosing scoliosis based on ATR, consideration should be given to lowering the 7° ATR cut-off threshold.

scholarly journals Automation analysis X-ray of the spine to objectify the assessment of the severity of scoliotic deformity in idiopathic scoliosis: a preliminary report

2020 ◽  
Vol 8 (3) ◽  
pp. 317-326
Author(s):  
Grigory A. Lein ◽  
Natalia S. Nechaeva ◽  
Gulnar М. Mammadova ◽  
Andrey A. Smirnov ◽  
Maxim M. Statsenko
Keyword(s):  
Neural Network ◽  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Machine Learning Algorithms ◽  
Automated System ◽  
X Rays ◽  
X Ray ◽  
Scoliotic Deformity ◽  
Window Method ◽  
Treatment Type

Background. A large number of studies have focused on automating the process of measuring the Cobb angle. Although there is no practical tool to assist doctors with estimating the severity of the curvature of the spine and determine the best suitable treatment type. Aim. We aimed to examine the algorithms used for distinguishing vertebral column, vertebrae, and for building a tangent on the X-ray photographs. The superior algorithms should be implemented into the clinical practice as an instrument of automatic analysis of the spine X-rays in scoliosis patients. Materials and methods. A total of 300 digital X-rays of the spine of children with idiopathic scoliosis were gathered. The X-rays were manually ruled by a radiologist to determine the Cobb angle. This data was included into the main dataset used for training and validating the neural network. In addition, the Sliding Window Method algorithm was implemented and compared with the machine learning algorithms, proving it to be vastly superior in the context of this research. Results. This research can serve as the foundation for the future development of an automated system for analyzing spine X-rays. This system allows processing of a large amount of data for achieving 85% in training neural network to determine the Cobb angle. Conclusions. This research is the first step toward the development of a modern innovative product that uses artificial intelligence for distinguishing the different portions of the spine on 2D X-ray images for building the lines required to determine the Cobb angle.

scholarly journals Spinal Coronal and Sagittal Balance in 584 Healthy Individuals During Growth: Normal Plumb Line Values and Their Correlation With Radiographic Measurements

2019 ◽  
Vol 99 (12) ◽  
pp. 1712-1718
Author(s):  
Alessandra Negrini ◽  
Massimiliano Vanossi ◽  
Sabrina Donzelli ◽  
Fabio Zaina ◽  
Michele Romano ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Sagittal Balance ◽  
Thoracic Kyphosis ◽  
Plumb Line ◽  
X Rays ◽  
Healthy Individuals ◽  
X Ray ◽  
Spine Deformities ◽  
Spine Pathology ◽  
Sagittal Index

Abstract Background Plumb line distances (PDs) are widely used in conservative clinical practice to evaluate the sagittal shape of the spine. Objective The objective was to assess the normative values of PDs in a large, healthy population in an age range representative of the adolescent population with spinal deformities, and to correlate it with x-ray measurements. Design This was a cross-sectional study. Methods Participants were 584 healthy individuals (341 females) with x-rays showing no spine deformities. The whole sample (OVERALL) was divided into 5 groups: 6 to 9 years old (n = 106); &gt;10 years, Risser 0 with triradiate cartilage open (n = 129) or closed (n = 104); Risser 1 to 2 (n = 126); and Risser 3 to 5 (n = 119). PDs were taken by maintaining a tangent to the thoracic kyphosis apex at C7, T12, L3, and S2. Sagittal index (C7 + L3), and sagittal and coronal balances (C7 related to S2) were calculated. Results In OVERALL, PDs at C7, T12, L3, and S2 were 39.9 ± 16.7, 21.4 ± 15.3, 39.9 ± 15, 20.6 ± 17.0 mm, respectively. Sagittal index was 79.8 ± 26.8, sagittal balance was 19.3 ± 17 mm anterior to S2 plumb line; 13.5% had a coronal imbalance of 11.4 ± 5.4 mm to the right and 24.7% of 13.2 ± 6.0 mm to the left. C7 and L3 PDs, sagittal index, and sagittal balance were significantly lower in ages 6 to 9 compared to older patients in Risser 1 to 2 group. C7 and S2 PDs and sagittal index were significantly larger in males. Sagittal index correlated with thoracic kyphosis Cobb degrees (r = 0.47). Limitations The participants were not randomly chosen from the general population; and they had an x-ray because of spine pathology suspicion. Conclusions This study shows normative data to be used in clinical practice. Sagittal spinopelvic alignment has gained more and more importance in the last decades because of its high correlation to Health-Related Quality of Life scores in adults. 1

scholarly journals Validity and Reproducibility of the Measurements Obtained Using the Flexicurve Instrument to Evaluate the Angles of Thoracic and Lumbar Curvatures of the Spine in the Sagittal Plane

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Tatiana Scheeren de Oliveira ◽  
Cláudia Tarragô Candotti ◽  
Marcelo La Torre ◽  
Patricia Paula Tonin Pelinson ◽  
Tássia Silveira Furlanetto ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Strong Correlation ◽  
Sagittal Plane ◽  
X Rays ◽  
X Ray ◽  
Graph Paper ◽  
Spinous Processes ◽  
Significant Difference ◽  
Order Polynomial

Objective. to verify the validity and reproducibility of using the flexicurve to measure the angles of the thoracic and lumbar curvatures.Method. 47 subjects were evaluated by: (1) palpation and marking of the spinous processes using lead markers, (2) using X-rays in the sagittal plane to measure the Cobb angles, (3) molding the flexicurve to the spine, and (4) drawing the contour of the flexicurve onto graph paper. The angle of curvature was determined with the flexicurve based on a 3rd order polynomial.Results. No differences were found between the Cobb angles and the angles obtained using the flexicurve in thoracic and lumbar curvatures (). Correlations were strong and significant for the thoracic (, ) and lumbar (, ) curvatures. Excellent and significant correlations were found for both the intraevaluator and interevaluator measurements.Conclusion. The results show that there is no significant difference between the values obtained using the flexicurve and those obtained using the X-ray procedure and that there is a strong correlation between the two methods. This, together with the excellent level of inter- and intraevaluator reproducibility justifies its recommendation for use in clinical practice.

scholarly journals May bending radiographs be replaced by recumbent CT scans in patients with adolescent idiopathic scoliosis?

2021 ◽  
Author(s):  
Max Prost ◽  
Joachim Windolf ◽  
Markus Rafael Konieczny
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Strong Correlation ◽  
Ct Scans ◽  
X Rays ◽  
Exclusion Criteria ◽  
X Ray ◽  
A Minor ◽  
Main Curve

Abstract Purpose There is no data that show if it is possible to determine if a curve is structural or non-structural or to assess flexibility of an adolescent idiopathic scoliosis (AIS) by recumbent images like a CT scan (CTS) instead of bending radiographs (BR). We investigated if the results of BR may be compared to those of CTS. Methods We retrospectively analyzed prospectively collected data of patients with AIS in whom a selective spinal fusion was performed and in whom a CTS, BR, and full spine x-rays were made preoperatively. We measured the Cobb angles of the main and the minor curve in full spine x-ray, BR, and CTS. Results After applying inclusion and exclusion criteria, 39 patients were included. We found a strong correlation (r = 0.806, p < 0.01) between the Cobb angle of the main curve in BR and the Cobb angle of the main curve in the CTS and between the Cobb angle of the minor curve in BR and the Cobb angle of the minor curve in the CTS (r = 0.601, p < 0.01). All patients with a minor curve of less than 25 degrees in the BR had a Cobb angle of less than 35 degrees in the CTS. Conclusion Spinal curves showed a significant correlation between bending radiographs and recumbent images (CTS). In our group of patients, a Cobb angle of the minor curve of less than 35 degrees in the CTS indicated that this minor curve was non-structural.

Oriented Gaussian beams for high-accuracy computation with accuracy control of X-ray propagation through a multi-lens system

2019 ◽  
Vol 26 (2) ◽  
pp. 363-372
Author(s):  
P. Wojda ◽  
S. Kshevetskii
Keyword(s):  
Fine Structure ◽  
Electric Field ◽  
Focal Plane ◽  
Accurate Method ◽  
Gaussian Beams ◽  
X Rays ◽  
Accuracy Control ◽  
X Ray ◽  
Local Direction

A highly accurate method for calculating X-ray propagation is developed. Within this approach, the propagating wave is represented as a superposition of oriented Gaussian beams. The direction of wave propagation in each Gaussian beam agrees with the local direction of propagation of the X-ray wavefront. When calculating the propagation of X-ray waves through lenses, the thin lens approximation is applied. In this approximation, the wave parameters change discontinuously when the wave passes through a lens; the corresponding explicit formulae are derived. The theory is applied to highly accurate calculation of the focusing of X-rays by a system of many beryllium lenses. Fine structure of the wave electric field on the focal plane is revealed and studied. The fine structure is formed due to the diffraction of waves at the edges of the lens apertures. Tools for controlling the calculation accuracy are proposed. The amplitude of the electric field on the focal plane and the focal spot width are shown to be very sensitive to the quality of the calculation, while the best focus position can be obtained even from simple calculations.

scholarly journals Characterization of the X-ray coherence properties of an undulator beamline at the Advanced Photon Source

2018 ◽  
Vol 25 (4) ◽  
pp. 1036-1047 ◽  
Author(s):  
Guangxu Ju ◽  
Matthew J. Highland ◽  
Carol Thompson ◽  
Jeffrey A. Eastman ◽  
Paul H. Fuoss ◽  
...  
Keyword(s):  
Accurate Method ◽  
X Rays ◽  
Beam Size ◽  
Propagation Theory ◽  
X Ray ◽  
Vertical Divergence ◽  
Diffraction Patterns ◽  
Ray Methods ◽  
Photon Source

In anticipation of the increased use of coherent X-ray methods and the need to upgrade beamlines to match improved source quality, here the coherence properties of the X-rays delivered by beamline 12ID-D at the Advanced Photon Source have been characterized. The measured X-ray divergence, beam size, brightness and coherent flux at energies up to 26 keV are compared with the calculated values from the undulator source, and the effects of beamline optics such as a mirror, monochromator and compound refractive lenses are evaluated. Diffraction patterns from slits as a function of slit width are analyzed using wave propagation theory to obtain the beam divergence and thus coherence length. Imaging of the source using a compound refractive lens was found to be the most accurate method for determining the vertical divergence. While the brightness and coherent flux obtained without a monochromator (`pink beam') agree well with those calculated for the source, those measured with the monochromator were a factor of three to six lower than the source, primarily because of vertical divergence introduced by the monochromator. The methods described herein should be widely applicable for measuring the X-ray coherence properties of synchrotron beamlines.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

Chemical Species Identification in an SEM by Changes in Emitted X-Ray Energies

1974 ◽  
Vol 32 ◽  
pp. 570-571
Author(s):  
R. H. Duff
Keyword(s):  
Species Identification ◽  
Valence Electron ◽  
Chemical Species ◽  
X Rays ◽  
Chemical Bonds ◽  
Small Shift ◽  
X Ray ◽  
Electron Transitions ◽  
Peak Energy ◽  
Chemical Combination

A material irradiated with electrons emits x-rays having energies characteristic of the elements present. Chemical combination between elements results in a small shift of the peak energies of these characteristic x-rays because chemical bonds between different elements have different energies. The energy differences of the characteristic x-rays resulting from valence electron transitions can be used to identify the chemical species present and to obtain information about the chemical bond itself. Although these peak-energy shifts have been well known for a number of years, their use for chemical-species identification in small volumes of material was not realized until the development of the electron microprobe.

Influence of X-Ray Induced Fluorescence on Energy Dispersive X-Ray Analysis of Thin Foils

1977 ◽  
Vol 35 ◽  
pp. 328-329
Author(s):  
E. A. Kenik ◽  
J. Bentley
Keyword(s):  
Thin Foil ◽  
Electron Excitation ◽  
Simple Approach ◽  
Foil Thickness ◽  
X Rays ◽  
X Ray ◽  
Hole Spectrum ◽  
Illumination System ◽  
Thin Foils ◽  
Intensity Ratios

Cliff and Lorimer (1) have proposed a simple approach to thin foil x-ray analy sis based on the ratio of x-ray peak intensities. However, there are several experimental pitfalls which must be recognized in obtaining the desired x-ray intensities. Undesirable x-ray induced fluorescence of the specimen can result from various mechanisms and leads to x-ray intensities not characteristic of electron excitation and further results in incorrect intensity ratios.In measuring the x-ray intensity ratio for NiAl as a function of foil thickness, Zaluzec and Fraser (2) found the ratio was not constant for thicknesses where absorption could be neglected. They demonstrated that this effect originated from x-ray induced fluorescence by blocking the beam with lead foil. The primary x-rays arise in the illumination system and result in varying intensity ratios and a finite x-ray spectrum even when the specimen is not intercepting the electron beam, an ‘in-hole’ spectrum. We have developed a second technique for detecting x-ray induced fluorescence based on the magnitude of the ‘in-hole’ spectrum with different filament emission currents and condenser apertures.

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