Multicenter Comparison of 3D Spinal Measurements Using Surface Topography With Those From Conventional Radiography

doi:10.1016/j.jspd.2015.08.008

Spine Deformity

Volume 4, Issue 2, March 2016, Pages 98-103

https://doi.org/10.1016/j.jspd.2015.08.008 Get rights and content

Abstract

Introduction

In pediatric spinal deformity the gold standard for curve surveillance remains standing full-column radiographs, but repeated exposure to ionizing radiation motivates us to look for nonradiographic solutions. This study tests a modern system of surface topography (ST) to determine whether it is reliable and reproducible.

Methods

Patients from 6 pediatric spinal deformity clinics were recruited for enrollment. Inclusion criteria were age 8-18; diagnosis of scoliosis measuring ≥10 and <50 degrees or increased kyphosis of ≥45 degrees. Standing radiographs and ST scans (DIERS Formetric, Diers Medical Systems, Chicago, IL) were obtained on all patients and then measured and compared. A single investigator using a validated electronic measurement tool performed all radiographic measurements. Analysis of reproducibility and comparison of ST and radiographs were done.

Results

A total of 193 patients were enrolled (148 F [77%]). The mean age was 13.25 years (range 8–18). The scoliosis magnitude was as follows: thoracic average 22.7 ± 10 degrees; lumbar average 19.6 ± 9 degrees. The kyphosis magnitude was 54.0 ± 11 degrees. The reproducibility for each ST parameter for 3 repeated scans was strong (interclass correlation = 0.855–0.944). Comparison to radiographic measurements was strong in the thoracic (r = 0.7) and moderate in the lumbar curve (r = 0.5). There was an average difference of 5.8 degrees in the thoracic spine and 8.8 degrees in the lumbar spine between ST Cobb angle estimates and radiographs. Thoracic kyphosis also had a strong correlation (r = 0.8) with radiographs.

Conclusions

Although the results are intended to measure similar aspects of deformity as the traditional Cobb angle, the measurement is not intended to be an exact estimation. The utility of ST is in the reproducible quantification of deformity after the initial radiograph has been taken. This has the potential to make longitudinal assessment of change in deformity without serial radiographs.

Introduction

Adolescent idiopathic scoliosis (AIS) is a structural spinal deformity in the coronal plane that affects 1%–3% of children in the United States [1]. When the deformity is minor, less than 20°, treatment for this condition typically includes observation and surveillance to assess for curve progression [2]. Bracing and surgery are the treatments indicated for larger curves, though management in these patients also includes radiographic surveillance for evidence of a change in the deformity. The gold standard for diagnosis and subsequent curve surveillance remains standing full-column radiographs of the spine [3].

Radiographic images allows for assessment of the magnitude of the deformity in both the coronal and sagittal planes, and quantifying the spinal curvatures by deriving Cobb angle measurements. The disadvantage of radiographs, however, particularly in young patients, is that repeated exposure to ionizing radiation causes a significant increase in the risk of malignancies later in life [4], [5]. The relative risk of breast cancer, for example, is nearly four times greater in these patients [6]. Nash et al. reported in 1979 that the average teenage girl with scoliosis received 22 radiographs over 3 years of surveillance for AIS [7]. The frequency of radiographs has undoubtedly gone down since then, but there are no current studies measuring how many radiographs the average patient receives. The radiation dose for standard x-rays has also improved significantly over the years [8], but nonradiographic methods to image the spine and predict spinal deformity are still needed. Although no patient can avoid radiographs completely, there should be an effort to reduce radiation exposure whenever possible.

Surface topography (ST) has been used as an alternative to plain radiographs, beginning with the use of the inclinometer to measure the rotational deformity associated with scoliosis [9]. Many systems using surface topography have since been developed [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], but there has not yet been a system that has gained widespread acceptance, as prior research on ST has shown it to be inconsistent as a method of measuring spinal deformity [18]. The goal of this study was to test a modern system of surface topography measurement and to determine whether it was reliable and reproducible across multiple users. The correlation between ST-estimated curvature measurements and radiographic Cobb angles were compared to determine the suitability of ST as a replacement for some radiographs during AIS surveillance.

Section snippets

Methods

Patients treated for juvenile idiopathic scoliosis (JIS) or AIS from six North American institutions and one German institution were prospectively enrolled. Inclusion criteria for the analysis of the coronal plane deformity (CD) patients were as follows: age between 8 and 18 years with JIS or AIS measuring ≥10° and <50°. A second cohort of patients whose primary deformity was kyphotic (KD) were studied. Inclusion criteria for this group were defined as a sagittal Cobb angle measuring ≥45°.

Results

One hundred ninety-three patients were enrolled between 2012 and 2014. There were 170 that met the criteria for the coronal plane group (scoliosis >10 degrees), 29 that met the criteria for the sagittal plane group (kyphosis >45 degrees), and 6 that were in both groups. The demographics of each group are listed below in Table 1.

The reliability and comparison to x-ray for each ST parameter are represented in Table 2. The reproducibility for each ST parameter for 3 repeated scans was strong

Discussion

This multicenter study was conducted to test surface topography in the evaluation of spinal deformity. A similar paper by the lead author was done at a single site with a single examiner and had results that were almost identical [27]. This study utilized six different centers and multiple examiners, demonstrating the reproducibility of the Formetric surface topography scanner across many venues. The average standard deviation of repeated measurements of less than three degrees across all

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Monitoring of Curve Progression in Patients with Adolescent Idiopathic Scoliosis Using 3-D Ultrasound
2024, Ultrasound in Medicine and Biology
The aim of the work described here was to determine whether 3-D ultrasound can provide results comparable to those of conventional X-ray examination in assessing curve progression in patients with adolescent idiopathic scoliosis (AIS).
One hundred thirty-six participants with AIS (42 males and 94 females; age range: 10–18 y, mean age: 14.1 ± 1.9 y) with scoliosis of different severity (Cobb angle range: 10º– 85º, mean: of 24.3 ± 14.4º) were included. Each participant underwent biplanar low-dose X-ray EOS and 3-D ultrasound system scanning with the same posture on the same date. Participants underwent the second assessment at routine clinical follow-up. Manual measurements of scoliotic curvature on ultrasound coronal projection images and posterior–anterior radiographs were expressed as the ultrasound curve angle (UCA) and radiographic Cobb angle (RCA), respectively. RCA and UCA increments ≥5º represented a scoliosis progression detected by X-ray assessment and 3-D ultrasound assessment, respectively.
The sensitivity and specificity of UCA measurement in detecting scoliosis progression were 0.93 and 0.90, respectively. The negative likelihood ratio of the diagnostic test for scoliosis progression by the 3-D ultrasound imaging system was 0.08.
The 3-D ultrasound imaging method is a valid technique for detecting coronal curve progression as compared with conventional radiography in follow-up of AIS. Substituting conventional radiography with 3-D ultrasound is effective in reducing the radiation dose to which AIS patients are exposed during their follow-up examinations.
Automated non-contact measurement of the spine curvature at the sagittal plane using a deep neural network
2024, Clinical Biomechanics
Non-radiographical techniques have been suggested to measure the spine curvature at the sagittal plane. However, a neural network has not been used to measure the curvature.
A single video camera captured images of a standing posture at the sagittal plane from twenty healthy males. Six marker positions along the spine's contour in each image were identified for measuring inclination, thoracic kyphosis, and lumbar lordosis angles. We estimated three inflection points around the neck, hip, and between the neck and hip, followed by identifying two adjacent marker positions per inflection point to compute its tangent. The angular deviation of each tangent line from the horizontal was computed to measure inclination angles. Thoracic kyphosis and lumbar lordosis angles were computed by the angular difference between the two adjacent tangents. A deep neural network was trained with 500,000 iterations using the labeled images from 18 participants (388 and 44 images for training and test set) and then evaluated using the unseen images (2 participants, 48 images; evaluation set).
The mean total training and test errors were <2 pixels (∼ 0.6 cm). The total error in the evaluation set was qualitatively comparable (∼ 3 pixels = ∼ 0.9 cm), suggesting the model performance was maintained in the unseen data. The angle values between labeled and network-predicted marker positions were similar in the evaluation set.
The network training with a relatively small number of images was successful based on the small error values observed in the evaluation set. The model may be an affordable, automated, and non-contact measurement tool for the human spine curvature.
Consistency of vertebral motion and individual characteristics in gait sequences
2023, Human Movement Science
Vertebral motion reveals complex patterns, which are not yet understood in detail. This applies to vertebral kinematics in general but also to specific motion tasks like gait. For gait analysis, most of existing publications focus on averaging characteristics of recorded motion signals. Instead, this paper aims at analyzing intra- and inter-individual variation specifically and elaborating motion parameters, which are consistent during gait cycles of particular persons. For this purpose, a study design was utilized, which collected motion data from 11 asymptomatic test persons walking at different speed levels (2, 3, and 4 km/h). Acquisition of data was performed using surface topography. The motion signals were preprocessed in order to separate average vertebral orientations (neutral profiles) from basic gait cycles. Subsequently, a k-means clustering technique was applied to figure out, whether a discrimination of test persons was possible based on the preprocessed motion signals. The paper shows that each test sequence could be assigned to the particular test person without additional prior information. In particular, the neutral profiles appeared to be highly consistent intra-individually (across the gait cycles as well as speed levels), but substantially different between test persons. A full discrimination of test persons was achieved using the neutral profiles with respect to flexion/extension data. Based on this, these signals can be considered as individual characteristics for the particular test persons.
Scoliosis assessment tools to reduce follow-up X-rays
2023, Journal of Orthopaedic Translation
Clinical examinations of scoliosis often includes X-rays. Regular clinical monitoring is recommended in particular at young age, because of the high risk of progression during periods of rapid growth. Supplementary methods free of ionizing radiation thus could help to reduce the potential risk of ionizing radiation related health problems.
Twelve 3D scan images from female and male patients with different types and severities of spinal deformations were analysed using body scanner image analysis tools. The scan images were captured with a 3D body scanner, which used an infrared sensor and a video camera. To calculate and compare with the patient's specific spinal deformations, simulations based on finite elements methods were performed on biomechanical models of ribcage and spinal column.
The methods and parameters presented here are in good agreement with corresponding X-rays, used for comparison. High correlation coefficients of ‖ρ_s‖ ≥ 0.87 between Cobb angle and lateral deviation, as well as between Cobb angle and rotation of the vertebrae, indicate that the parameters could provide supplementary informations in the assessment of spinal deformations. So-called apex angles, in addition introduced to relate the results of the present method with Cobb angles, show strong correlations of ‖ρ_s‖ ≥ 0.68 and thus could be used for comparison in later follow-up examinations.
The user-friendly 3D body scanner image analysis tools enable orthopaedic specialists to simulate, visualize and inspect patient's specific spinal deformations. The method is intended to provide supplementary information in complement to the Cobb angle for the assessment of spinal deformations in clinical daily routine and might have the potential to reduce X-rays in follow-up examinations.
The study presents a new method, based on 3D body scanner images and biomechanical modelling, that has the potential to reduce X-rays when monitoring scoliosis especially in young patients.
CT analysis of the posterior anatomical landmarks of the scoliotic spine
2022, Clinical Radiology
Citation Excerpt :
Simony et al. described a five-times higher overall cancer rate in a Danish AIS population, as compared to age-matched controls.3 Several radiation-free imaging methods are available to measure the severity of the scoliosis, such as surface topography and ultrasound imaging.4–14 In this, surface topography has been studied for decades, but the asymmetry of the torso is influenced by spine shape, as well as the ribcage, trunk rotation, muscle volume, body fat, and posture.
To use computed tomography (CT) to assess the validity and reliability of the posterior landmarks, spinous processes (SP), transverse processes (TP), and centre of lamina (COL), as compared to the Cobb angle to assess the curve severity and progression of adolescent idiopathic scoliosis (AIS).
A consecutive series of CT examinations of severe AIS patients were included retrospectively. SP, TP, and COL angles were measured for all curves and compared to the Cobb angle.
One hundred and five patients were included. The mean Cobb versus SP, TP, and COL angles were, 54° versus 37°, 49°, and 51° in the thoracic curves and 34° versus 26°, 31°, and 34° in the (thoraco)lumbar curves. Intraclass correlation coefficient values for intra-rater measurements of the SP, TP, and COL angles were 0.93, 0.97, and 0.95 and 0.70, 0.90, and 0.88 for inter-rater measurements. The correlations between the Cobb angle and SP, TP, and COL angles in thoracic and (thoraco)lumbar curves were 0.79 and 0.66, 0.87 and 0.84, and 0.80 and 0.70.
The posterior spinal landmarks can be used for assessment of scoliosis severity in AIS; however, they show a systematic underestimation, but a strong correlation with the coronal Cobb angle. TP and COL angles had the highest validity.
Comprehensive visualization of spinal motion in gait sequences based on surface topography
2022, Human Movement Science
Analysis of spinal motion is considered to be important to assess function of the human spine. Surface topography (ST) is a method to record the vertebral orientation in 3D. Such measurements can be performed in static but also in dynamic situations like gait or other motion tasks. However, dynamic ST measurements are hard to interpret due to their complexity. The main goal of this paper is to provide comprehensive visualization tools which allow a more intuitive and comprehensive interpretation n of such measurements. In particular, juxtaposition and superimposition techniques are utilized to emphasize differences in motion characteristics. The method was applied to a test series of 12 healthy volunteers walking on a treadmill at various speed levels. It could be shown that the visualization tools are helpful to compare different motion sequences including an analysis of intra- and interindividual variation. Based on these techniques, it could be shown that the profiles of vertebral orientation remain considerable constant when one person was walking at different speed levels whereas they differed substantially between the different individuals. In contrast, the motion amplitudes contained high intra- and interindividual variation, i.e. between speed levels and different test persons. In summary, the paper demonstrates that appropriate visualization tools are helpful to interpret ST measurements and cope with the complexity of these data sets. In particular, they can be used to compare different motion sequences in a more comprehensive way

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: Author disclosures: PK (grants from DIERS Medical Systems, outside the submitted work), PS (grants from DIERS Medical Systems, outside the submitted work), BL (reports grants from DIERS Medical Systems, personal fees from DePuy Synthes, personal fees from K2M, personal fees from Spine Search, personal fees from Paradigm Spine, grants from Setting Scoliosis Straight Foundation, grants from AO Spine, grants from John and Marcella Fox Fund, grants from OREF, other from SRS Spine Deformity Journal, outside the submitted work), PC (reports grants from DIERS Medical Systems, personal fees from DePuy Synthes Spine, personal fees from Ellipse Technologies, personal fees from Globus Medical, personal fees from Medtronic, outside the submitted work), MB (grants from DIERS Medical Systems, outside the submitted work), RM (grants from DIERS Medical Systems, outside the submitted work), MK (grants from DIERS Medical Systems, outside the submitted work), LL (grants from DePuy Synthes Spine, grants from DIERS Medical Systems, outside the submitted work; a patent 6,533,787 with royalties paid, a patent 6,830,571 with royalties paid, a patent 7,655,008 with royalties paid, a patent 7,670,358 with royalties paid, a patent 7,776,072 with royalties paid, a patent 8,727,972 with royalties paid, and a patent 8,361,121 with royalties paid; consultancy fees from DePuy Synthes Spine, K2M, Medtronic; travel reimbursement, “speakers bureaus,“ included in contracts; royalties from Medtronic, Quality Medical Publishing), RB (grants from DIERS Medical Systems, other from Advanced Vertebral Solutions, grants and personal fees from DePuy Synthes Spine, personal fees from Medtronic, other from Mimedx, other from Orthobond, personal fees and other from Abyrx, personal fees and other from SpineGuard, other from Medovex, personal fees from Zimmer, outside the submitted work).

: This research project was approved by the IRB committee at Rosalind Franklin University of Medicine and Science, and then subsequently approved by cooperative agreement at each of the participating medical centers.

¹: Formerly at Shriners Hospital for Children, 3551 N Broad St, Philadelphia, PA 19140, USA.

²: Formerly at Heinrich Heine University Hospital, Moorenstraße 5, Dusseldorf, 40225, Germany.

³: Formerly at Washington University Medical Center, 4901 Forest Park Ave, St. Louis, MO 63108, USA.

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Patient EvaluationMulticenter Comparison of 3D Spinal Measurements Using Surface Topography With Those From Conventional Radiography

Abstract

Introduction

Methods

Results

Conclusions

Introduction

Section snippets

Methods

Results

Discussion

Risk factors for idiopathic scoliosis: review of a 6-year prospective study

Orthopedics

The estimated cost of school scoliosis screening

Spine (Phila Pa 1976)

Trunk distortion in adolescent idiopathic scoliosis

J Pediatr Orthop

Carcinogenesis—a synopsis of human experience with external exposure in medicine

Health Phys

Spine (Phila Pa 1976)

Cancer mortality among women frequently exposed to radiographic examinations for spinal disorders

Radiat Res

Risks of exposure to X-rays in patients undergoing long-term treatment for scoliosis

J Bone Joint Surg Am

Overview of patient dosimetry in diagnostic radiology in the USA for the past 50 years

Med Phys

Hump changes on forward flexion of the lumbar spine in patients with idiopathic scoliosis. A study using ISIS and the Scoliometer in two standard positions

Spine (Phila Pa 1976)

Measurement of body surface topography using an automated imaging system

Acta Orthop Belg

A computer vision system for diagnosing scoliosis using moiré images

Comput Biol Med

Assessing the child with scoliosis: the role of surface topography

Arch Dis Child

The effect of posture on Quantec measurements

Stud Health Technol Inform

Evaluation of a laser scanner for surface topography

Stud Health Technol Inform

Patient Evaluation
Multicenter Comparison of 3D Spinal Measurements Using Surface Topography With Those From Conventional Radiography