Lumbar disc height assessment: a comparative study between EOS and digital radiography

Lumbar disc height assessment: a comparative study between EOS and digital radiography Poster No.: C-1178 Congress: ECR 2012 Type: Scientific Paper Authors: V. Freire, M. Benhamou, F. Rannou, S. Poiraudeau, J.-L. 1 2 2 2 1 2 2 2 Drapé, A. Feydy ; Montreal, QC/CA, Paris/FR Keywords: Musculoskeletal bone, Musculoskeletal spine, Radioprotection, Digital radiography, Technology assessment DOI: 10.1594/ecr2012/C-1178 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 15

Purpose Introduction: - in recent years, a new imaging tool has been offered to clinicians and radiologists: the EOS system - EOS, an ultra low dose 2D 3D digital X-ray system, is a new imaging system developed by biospace med. The company was founded in 1989 by the 1992 winner of the Nobel Prize for Physics, Georges Charpak, for the invention of a high-energy physics gaseous particle detector. Since 2000, the detector technology has had commercial applications in preclinical imaging systems used in pharmaceutical research. Recently, with the development of EOS, biospace med has adapted Charpak's detector technology for clinical X-ray imaging. Because of the detector and product configuration, EOS allows X-ray imaging to be performed at a much lower dose, with very high contrast and without the distortion inherent in today's longer length film and digital imaging systems - EOS allows for the simultaneous acquisition of two orthogonal planar images in a vertical scanning mode. The EOS X-ray system architecture is different from usual digital radiography devices. The gantry is composed of two sets of detectors and X-ray tubes positioned orthogonally and supported by a mobile C-arm. This C-arm moves vertically using a linear scanning technique, guided by three cylindrical slide bars. The patient is positioned at the intersection of the two X-ray fan-beams which scan the patient vertically. A single scan will simultaneously produce both PA and lateral images of the patient. - the EOS system acquire simultaneously in 20 seconds an anteroposterior and lateral view in a standing patient with a radiation dose reduced 5 to 10 times - indications in the pediatric patient with scoliosis has been documented - however no clear indications in an adult population are documented - before implanting a new modality, we must prove this modality is not inferior to the standard of practice Purpose: - assess the EOS imaging system in adults with mechanical back pain, comparing it to Digital Radiographs Page 2 of 15

- evaluate if EOS is inferior or not to the actual standard of practice, Digital Radiographs - we focused on the lumbar discal height measurement Images for this section: Fig. 1: The EOS system. Page 3 of 15

Methods and Materials - we included 50 patients between 18 and 75 years old with low back pain for more than 3 months from the spinal rehabilitation department of our hospital - all patients had EOS and DR the same day - Digital Radiographs (DR) included : PA (de Seze) and lateral views of lumbar spine - EOS images included: frontal and lateral views of the entire spine - all images were reviewed by 2 readers, one senior rheumatologist and one senior MSK radiologist, assessing for: lumbar disc height of last 3 levels (mean of anterior and posterior height) - reproducibility was measured between the 2 readers and the 2 modalities with ICC and with a Bland Altman method - correlation between EOS and DR was assessed with Spearman correlation coefficient Images for this section: Page 4 of 15

Fig. 2: F49, EOS full spine AP view. Fig. 3: F49, EOS full spine lateral view. Page 5 of 15

Fig. 4: F49, EOS enlarged lateral view focused on lumbar spine. Page 6 of 15

Fig. 5: F49, EOS. Method of L4-L5 discal height measurement. Fig. 6: F49, Digital Radiography, lumbar spine PA view. Page 7 of 15

Fig. 7: F49, Digital Radiography, lumbar spine, lateral view. Page 8 of 15

Fig. 8: F49, Digital Radiography. Method of L4-L5 discal height measurement. Page 9 of 15

Results - Visual quality of EOS and DR images was assessed and compared (Fig. 9). - Figure 10 shows the results for discal height at L3-L4, L4-L5 and L5-S1 levels. Results are shown by reader and by modality. - Figure 11 shows the reproducibility results. - Figure 12 shows the correlation results. Images for this section: Fig. 9: Visual Quality of EOS and DR images (EVA). Page 10 of 15

Fig. 10: DISCAL HEIGHT Page 11 of 15

Fig. 11: REPRODUCIBILITY Page 12 of 15

Fig. 12: CORRELATIONS Page 13 of 15

Conclusion - advantages: EOS offers lower radiation doses, it produces simultaneously frontal and lateral views, without moving the patients, in a standing position - disadvantages: no angulation of XRay beam is possible, lower quality of images in obese patients with high BMI - measurements of discal height is reproducible for both modalities, however no direct comparison in the same patient is possible between the 2 modalities since there is a systematic measurement difference with higher height on DR - this difference is likely due to the absence of geometric distorsion and magnification with the EOS system - the lower radiation dose with EOS imaging favors its use in lower back pain patients assessment and follow-up References 1. 2. 3. 4. 5. 6. Charpak G. Prospects for the use in medicine of new detectors of ionizing radiation. Bull Acad Natl Med 1996;180:161-68. Kalifa G, Charpak Y, Maccia C, Fery-Lemonnier E, Bloch J, Boussard JM, Attal M, Dubousset J, Adamsbaum C. Evaluation of a new low-dose digital x-ray device: first dosimetric and clinical results in children. Pediatr Radiol 1998; 28:557-61. Dubousset J, Charpak G, Dorion I et al A new 2D and 3D imaging approach to musculoskeletal physiology and pathology with low-dose radiation and the standing position : the EOS system. Bull Acad Natl Med 2005 Feb;189(2):287-300. Dubousset J, Charpak G, Skalli W, Kalifa G, Lazennec JY. Système EOS : la radiographie de la tête aux pieds face et profil simultanés à très basses doses de radiations. Un nouveau regard pour l'orthopédie. RCO Vol 93 - N SUP6 - Octobre 2007 p. 141-143. Rillardon L, Campana S, Mitton D, Skalli W,Feydy A. Evaluation of the intervertebral disc spaces with a low dose radiographic system. J Radiol. 2005 ;86(3):311-9. Rousseau MA, Laporte S, Chavary-Bernier E, Lazennec JY, Skalli W. Reproducibility of measuring the shape and three-dimensional position of cervical vertebrae in upright position using the EOS stereoradiography system. Spine. 2007 Nov 1;32(23):2569-72. Page 14 of 15

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