The curvature of the cobb method is defined as the angle between the upper border of the upper vertebra and the lower borders of the lowest vertebra as shown in figure 3. It is used as the standard measurement to quantify and track the progression of scoliosis. Computeraided technique for the measurement of the cobb angle. Manual cobb angle determination the parameter that in. University of groningen automatic cobb angle determination. Figure 3 shows a graph of signed measurement difference between pairs of iphoneprotractor measurements for the same radiograph, versus mean cobb angle. The cobb angle of a scoliotic curve is the angle formed by the intersection of two lines, one parallel to.
As the cobb angle increases, the actual curvature of the spine becomes exponentially more severe. Background the standard for evaluating scoliosis is pa radiographs using cobb angle to measure curve magnitude. Zhang 6 proposed a cobbangle computeraided measurement algorithm based on deep neural network, which can automatically estimate the slope of the spine after manually selecting the block of interest in the upper and lower vertebrae, and automatically measure the cobb angle. The magic of the cobb angle is discovered in this video. Zhang 6 proposed a cobb angle computeraided measurement algorithm based on deep neural network, which can automatically estimate the slope of the spine after manually selecting the block of interest in the upper and lower vertebrae, and automatically measure the cobb angle. Measurement of the cobb angle on radiographs of patients. To develop a computeraided method that reduces the variability of cobb angle measurement for scoliosis assessment. Two more lines are drawn at an angle of 90 degrees to these lines, perpendicular so that they intersect. Today, the hospital is the hospital for special surgery. The highest range of manual cobb measurements on any lm has been reported as 8 degrees 6. Lines are then drawn along the endplates, and the angle between the two lines, where they intersect, measured. Several computerized cobb angle measurement techniques have been developed to improve the reliability and accuracy of measurement method till date. Although the calculation of scoliosis cobb angle is a simple technique, there has been considerable interobserver variability 6.
The cobb angle is best understood within the context of the individual patient. Cobb angle, which is a measure of spinal curvature, is the standard method for quantifying the magnitude of scoliosis, related to spinal deformity in orthopedics. Cobb angle, which is a measure of spinal curvature is the standard method for quantifying the magnitude of scoliosis related to spinal deformity in orthopedics. Cobb angle if user preference show cobb angle calculation by default in utilities tab is checked. Cobb angle measurement from digital xray image based on di. A computeraided cobb angle measurement method and its relia. The accuracy of cobb angle measurement on ct scan projection.
Specific software was developed to digitally reproduce the cobb method and calculate semiautomatically the degree of scoliotic deformity. Computerassisted algorithms improve reliability of king classification and cobb angle measurement of scoliosis ian a. Some studies say that the patient does not require any specific treatment, but just needs regular checkups to see if the curve is progressing until bone. Cobb angle measurement of scoliosis with reduced variability. In this easyangle measurement video, we demonstrate how to measure the cobb angle using the easyangle digital goniometer. Is regarded as a minimum angulation to define scoliosis. The doctor told us, at an appointment, that my daughters angles were t56 and l50.
Computeraided technique for the measurement of the cobb angle tariq abuzaghleh, buket barkana department of electrical engineering, university of bridgeport, bridgeport, ct, usa abstract cobb angle measurements give orthopedic surgeons an idea of the severity of spinal deformities. A manual cobb angle measurement was done on 36 radiographical images by 3 observers. To measure and calculate the scoliosis cobb angle by end vertebra tilt angle. He identified that only 1 in 10 scoliosis sufferers actually requires surgical treatment, and so. Scoliosis is defined by the cobbs angle of spine curvature in the coronal. Curves that are less than 10 degrees are not considered to represent scoliosis, but rather a minor spinal asymmetry. Pdf cobb angle, which is a measure of spinal curvature is the standard method for quantifying the magnitude of scoliosis related to spinal deformity. The challenging task in computerized method lies in totally automating the.
Measurement of scoliosis cobb angle by end vertebra tilt angle. Pdf use of the iphone for cobb angle measurement in. Cobb angle measurement is standard for diagnosis and followup of patients with scoliosis. Scoliosis is defined as a lateral spinal curvature with a cobb angle of 10 4. Digital goniometer scoliosis how to measure the cobb angle. This measurement is taken using a cobb angle, a measurement first illustrated decades ago in an effort to quantify scoliotic curvatures and the progression or correction thereof. Figure 2 shows all data points for both the iphone and protractor measurements plotted versus the mean cobb angle for each pair of measurements. The cobb angle helps a doctor to determine what type of treatment is necessary. The quantec spinal imaging system qsis is a raster stereography used to measure threedimensional trunk images. Cobb angle is the most widely used measurement for quantifying spine curvature. To measure and calculate the scoliosis cobb angle by end vertebra tilt angle method tilt angle method and assess its accuracy and usability. In respect of the first phase, the variation in production of the radiographs. Scoliosis is a common deformity, and its severity is usually assessed by measuring the cobb angle on the spinal xray film.
In respect of the first phase, the variation in production of the. In current clinical diagnosis, the standard curvature estimation method for assessing the curvature quantitatively is done by measuring the cobb. Computeraided technique for the measurement of the cobb. Five spinal surgeons measured the cobb angle with the use of both the manual method and the. Interexaminer consistency of cobb angle measurement has been evaluated, and a variability of 4. Although it was not clearly stated whether the classic cobb measurement method or the analytical cobb. Cobb angle measurements on digital radiographs using. Conventional methods require a higher standard of discernibility for vertebra features and suffer high variability. Study design development of a computeraided cobb measurement method and evaluation of its reliability. Reliability and reproducibility analysis of the cobb angle. While the cobb angle is the current standard for scoliosis measurement, its important to recognize three significant points. The cobb angle is the measure the frontal deformation looking from the back to the front or technically, it measures the deformation of the spine at the coronal plane on the anteriorposterior plane. Variation in cobb angle measurements in scoliosis springerlink. Measurement of the cobb angle on radiographs of patients who.
Pdf use of the iphone for cobb angle measurement in scoliosis. The cobb angle of the spinal curve was calculated automatically from the vertebral slopes predicted by the dnn. Zhang 6 proposed a cobb angle computeraided measurement algorithm based on deep neural network, which can automatically estimate the slope of the spine after manually selecting the block of. In this work, we propose a methodology to measure the magnitude of cobb angle, which appreciably reduces the variability related to its measurement compared. Cobb suggested that the angle of curvature be measured by drawing lines parallel to the upper border of the upper vertebral body and the lower border of the lowest vertebra of the structural curve, then erecting perpendiculars from these lines to cross each other, the angle between these perpendiculars being the angle of curvature. Determining the cobb angle through manual process is subject to human errors. Measurement of scoliosis cobb angle by end vertebra tilt.
Being the current golden standard, it is important to be accurately calculated and other researchers strove in finding computerised methodologies to do so as it will be presented in the main part of this work. Purpose a method for measuring spinal curvature that provides a useful analog to the cobb angle and is tolerant of degraded image quality is proposed. Feb 01, 2014 adolescent idiopathic scoliosis is the most common form of scoliosis, affecting approximately 2% to 4% of adolescents. In such a situation computerized cobb angle measurement becomes an effective tool for scoliosis evaluation and reducing the variability of cobb angle measurement. Stokes department of orthopaedics and rehabilitation, university of vermont, stafford hall 434.
John r cobb, an american orthopedic surgeon, to measure the angle of spinal curves. 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. Cobb angle measurement 10 in the frontal plane derived from standing posteroanterior radiographs is the current gold standard for scoliosis evaluation and to inform decision making for treatment. Study design development of a computeraided cobb measurement method and evaluation of its reliabi. Chest wall compliance ccw is an important determinant of lung volumes and the work of breathing. Creating a cobb angle in intellispace pacs on vimeo.
Apr 25, 2016 simply put, the cobb angle is just a way of measuring the curve of a scoliosis sufferers spine. The cobb angle measurement is the gold standard of scoliosis evaluation endorsed by scoliosis research society. Jun 30, 2017 this tutorial gives an outline of cobb angle and the geometrical basis of different basis of measuring it in scoliosis and in spinal fractures. For instance, if a 30degree cobb angle is found in a 10yearold girl who has a lot of skeletal growth left, a brace is likely to be recommended. Because it is difficult to measure vr radiographically, there exists no gold standard method for measuring vr. The cobb angle is also the preferred method of measuring posttraumatic kyphosis in a recent metaanalysis of traumatic spine fracture classifications. Measuring procedures to determine the cobb angle in idiopathic. In the measurement of a cobb angle two phases can be distinguished. Variability of cobb angle measurement from digital xray images based on different denoising techniques. Jun 14, 2019 serial xrays are needed during the followup of adolescent idiopathic scoliosis.
Measuring procedures to determine the cobb angle in. However, it is still the main standard for diagnosis, monitoring, therapeutic planning, and epidemiologic analysis of scoliosis. Reliability assessment of cobb angle measurements using. Nor was there an increase in variability in accordance with the increase in the. Cobb angle measurement of scoliosis with reduced variability raka kundu, amlan chakrabarti prasanna k. The effect of patient positioning during radiographs on. Measurement of cobb angle is the standard technique used for scoliosis assessment. In other words, a 40 degree cobb angle is more than twice as severe as a 20 degree cobb angle. Paper open access automatic measurement algorithm of. Sep 04, 2018 the measurement of the cobb angle is an important basis for selecting therapeutic methods and evaluating therapeutic effects. Cobb angle measurement we have a huge discrepancy between the doctors measurements and the official radiology report from the childrens hospital of eastern ontario cheo.
A direct relationship between cobb angle and ccw is not seen. The cobb angle is measured off the twodimensional 2d plane of a radiograph. The measurement of the cobb angle is an important basis for selecting therapeutic methods and evaluating therapeutic effects. Cobb angle measurement with a conventional convex echography. Once calibration is complete, use measurement tool to make measurement. Pdf variability of cobb angle measurement from digital x. Patients with a cobb angle of less than 50 degrees experience a minimal reduction in ccw, whereas ccw is likely to be significantly reduced if the cobb angle is greater than 100 degrees. Pdf measurement of scoliosis cobb angle by end vertebra tilt.
Measuring the cobb angle one of the most common angle used in the measure of scoliosis progression is the cobb angle. The cobb angle is important in measuring the degree of scoliosis in the coronal plane, frcs orth revision. The q angle, a coronal plane measurement generated by the quantec spinal imaging system qsis, was compared with the cobb angle in assessment of scoliosis curve magnitude. Reducing a 60 degree scoliosis by 10 degrees represents a far greater accomplishment than reducing a 20 degree scoliosis down to 10 degrees. Relationship between quantec measurement and cobb angle in p. Understanding cobb angles and what it means for scoliosis. Objectives to reduce the variability of cobb angle measurement by developing the computeraided method and to investigate if the developed method is sensitive to.
The measuring method according to cobb 1 is the standard method to quantify spinal curvature. The cobb angle is used as a standard measurement to determine and track the. New pacs systems do allow for easier cobb angle measurements without the use of goniometers. Fiftythree posteroanterior radiographs of adolescent idiopathic scoliosis patients with thoracic scoliosis were used for the standard cobb method of measurement manual set and the smartphoneaided cobb method of measurement smartphone set.
Reliability analysis of a smartphoneaided measurement. Cobb angle measurement of spine from xray images using convolutional neural network article pdf available in computational and mathematical methods in medicine 20199. The effects of patient positioning errors have not been well described in the. Computerbased methods have been developed for the precise measurement of the cobb angle 4,810. The resulting angle is measured, and the number is expressed in degrees. Use of the iphone for cobb angle measurement in scoliosis.
A deep neural network dnn was trained with vertebral patches extracted from spinal model radiographs. Pdf measurement of scoliosis cobb angle by end vertebra. Cobb angle measurement of spine from xray images using. The incidence of scoliosis is about the same in males and females.
Cobb angle and its progression are important to determine treatment. Pdf cobb angle measurement of scoliosis with reduced. On average, the difference between the measured cobb angle and the known angle was. The cobb angle of a scoliotic curve is the angle formed by the intersection of two lines, one parallel to the endplate of the superior end. Several computerized cobb angle measurement techniques have been developed to improve the reliability and accuracy of. The goal is to verify the reproducibility of the measured angles between. Figures 4 and 5 do not suggest any trend in the variability between the cobb angle measurements, either for the residents or for the specialists. Cobb angle is used worldwide to measure and quantify the magnitude of spinal deformities, especially in the case of scoliosis. To measure the cobb angle, one must first decide which vertebrae are the endvertebrae of the curve deformity the vertebra whose endplates are most tilted towards each other. Cobb angles are preferably measured while standing, since laying down decreases cobb angles by around 710. As the cobb angle is a 2d measurement of a 3d deformity, it is. However, taking radiographs has its own risks and drawbacks. Reliability analysis of a smartphoneaided measurement method. Jun 30, 2017 new pacs systems do allow for easier cobb angle measurements without the use of goniometers.
The cobb angle is named, aptly enough, after orthopedic surgeon john robert cobb who led the margaret caspary scoliosis clinic at what was, in the early 20th century, known as the hospital for ruptured and crippled in new york city. Nov 10, 2017 the cobb angle is important in measuring the degree of scoliosis in the coronal plane, frcs orth revision. Two observers are orthopedic surgeons and the other one is the. A scoliosis is defined as a lateral spinal curvature with a cobb angle of 10 or more 4. Here is a general outline of cobb angle ranges and what they could indicate in idiopathic scoliosis found in children and adolescents. Measurement of vertebral rotation from moire image for. Electronic rulers on computer screen are used to measure the cobb angle ca instead of traditional methods with rulers, protractors and pens. Original articlea original o comparison of cobb angle. The variety of software used to assess radiographs might make the ca measurements cumbersome in. Pdf cobb angle measurement of spine from xray images using.
They are done every 6 or 3 months in cases of high risk of progression. We usually use surgimapspine software to measure the cobb angle in our studies. Contour and anglefunction based scoliosis monitoring. The variations in cobb angle measurement in scoliosis have been investigated by.
Methods assumption is made that the natural representation of the spine for the purpose of scoliosis monitoring is that of a. In order to determine the reliability of the cobb angle measurement as it is used in the clinical management of scoliosis, a methodological survey was carried out. It should be noted that the specialists did not attend to the explanation of the cobb method measurement technique. Pdf the cobb technique is the universally accepted method for measuring the severity of spinal deformities. Cobb was born in 1903, and he conducted extensive research into scoliosis when relatively little was known about the condition. The cobb angle is important in measuring the degree of scoliosis in the coronal plane. Use of the iphone for cobb angle measurement in scoliosis article pdf available in european spine journal 216. Centricity ra workstation quick reference guide for tools. The cobb method is used to measure the degree of scoliosis on the posteroanterior radiograph figure 2. Pdf cobb angle measurement of scoliosis with reduced variability. Study design development of a computeraided cobb measurement method and evaluation of its reliability objectives to reduce the variability of cobb angle measurement by developing the computeraided method and to investigate if the developed method is sensitive to observer skill levels or experiences.
It is named after john robert cobb, an orthopaedic surgeon from the usa. Pdf cobb angle measurement of spine from xray images. The cobb angle is the most widely used measurement to quantify the magnitude of spinal deformities, especially in the case of scoliosis, on plain radiographs. Computeraided technique for the measurement of the cobb angle tariq abuzaghleh, buket barkana department of electrical engineering, university of bridgeport, bridgeport, ct, usa abstractcobb angle measurements give orthopedic surgeons an idea of the severity of spinal deformities. As the cobb angle is a 2d measurement of a 3d deformity, it is not the best indicator of the severity manifested in external appearance. Thanks to the advances in ultrasound techniques, deformity measurement systems free from ionizing radiations have been validated, although spinal surgeons did not use them routinely due to the need of special software. Bland and altman16 graphs were constructed with the results of the cobb angle measurements for each group of examiners according to experience, residents and specialists, in order to evaluate the concordance reproducibility of. A computeraided cobb angle measurement method and its. Aronsson, md department of orthopaedics and rehabilitation, university of vermont, correspondence.
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