J Korean Soc Spine Surg.  2018 Jun;25(2):74-80. 10.4184/jkss.2018.25.2.74.

Introduction of a New Skeletal Imaging Instrument: The Low Radiating-Dose EOS System

• Kim SB
• Heo YM
• Yi JW
• Oh BH
• Lee GS
• Jeong SJ
• Kim TG

• KMID: 2421614
• DOI: http://doi.org/10.4184/jkss.2018.25.2.74

Abstract

STUDY DESIGN: Literature review.
OBJECTIVE
The aim of this article is to introduce the EOS imaging device, with a focus on spinal and pelvic alignment. SUMMARY OF LITERATURE REVIEW: The EOS imaging device can obtain images of spinal and pelvic alignment with almost no distortion, using a low radiation dose.
MATERIALS AND METHODS
We searched for studies related to the use of EOS imaging device for spinal and pelvic alignment.
RESULTS
The EOS is not only capable of simultaneously obtaining paired anteroposterior and lateral X-ray images with a low radiation dose, but also can reconstruct the image as if it was acquired in the patient's reference plane, limiting the distortion to the patient's thickness instead of the whole distance between the source and detector. The EOS device also has the advantage of accurately measuring the sagittal alignment of the spine and pelvis and the torsional deformity of the lower limbs, as the subject can be imaged while standing upright in a weight-bearing posture.
CONCLUSIONS
EOS is a new diagnostic technique that can detect spinal and pelvic alignment and deformities of the lower limbs under weight-bearing conditions with a low radiation dose.

Keyword

Spine; Pelvis; Lower limb; Diagnostic technology; Radiation device

MeSH Terms

Congenital Abnormalities
Lower Extremity
Pelvis
Posture
Spine
Weight-Bearing

Figure

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  Fig 1. EOS is an open rectangular cage that is 2 m wide and 2.7 m tall.

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  Fig 2. An X-ray tube and a sensor installed at a 90° angle, taking images from all sides at the same time, and a safety bar and a device fixing the patient's head in place while the image is obtained.

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  Fig 3. A separated EOS station protected from the X-ray. The length and angles of the obtained images are measured and reproduced as 3-dimensional images by the EOS software at this station.

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  Fig 4. Diagrammatic representation of the amplification of the low-dose primary X-ray beam through the Charpak chamber.

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  Fig 5. EOS scans the patient's anteroposterior and lateral sides simultaneously while the patient has both hands placed on the maxillary sinus under the eyes and has paused after inhaling in a weight-bearing position.

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  Fig 6. Distortion caused by the conical projection from the center to the edges of the radiograph, increasing the scale of error for structures farther from the central region.

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  Fig 7. The cylindrical projection image corrected by the system's visualization interface, which limits distortion regardless of the patient's thickness and the distance between the object and the detector.

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  Fig 8. When a landmark is indicated on 2-dimensional images of the anteroposterior and lateral planes of the spine, the EOS imaging system provides various measures.

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