Slit-beam digital radiography system

Last revised by Andrew Murphy on 11 Apr 2024

Citation, DOI, disclosures and article data

Citation:

Botz B, Murphy A, Er A, et al. Slit-beam digital radiography system. Reference article, Radiopaedia.org (Accessed on 19 Apr 2024) https://doi.org/10.53347/rID-69259

DOI:

https://doi.org/10.53347/rID-69259

Permalink:

https://radiopaedia.org/articles/69259

rID:

69259

Article created:

4 Jul 2019, Bálint Botz ◉

Disclosures:

At the time the article was created Bálint Botz had no recorded disclosures.

View Bálint Botz's current disclosures

Last revised:

11 Apr 2024, Andrew Murphy ◉

Disclosures:

At the time the article was last revised Andrew Murphy had no financial relationships to ineligible companies to disclose.

View Andrew Murphy's current disclosures

Revisions:

8 times, by 4 contributors - see full revision history and disclosures

Sections:

Radiography

Synonyms:

EOS imaging system
EOS

EOS^® imaging system (also known as a slot-scanning device or slit-beam digital radiography system) is an x-ray technology that allows simultaneous acquisition of AP and lateral images of the entire body in a natural, erect position, and is also capable of performing three-dimensional reconstructions from these images. It is primarily used in the evaluation of scoliosis, and resultant changes in the sagittal and coronal balance ¹.

Clinical applications

The main use of the system is the assessment of scoliosis, and the resultant changes in posture (sagittal and coronal balance, pelvic tilt) ². It can also be used to evaluate degenerative changes of the spine, osteoporosis, to perform measurements of the lower limb bones and angles, and to determine implant positioning for hip or knee arthroplasty or leg length discrepancies.

Slit-beam digital radiography systems are considered favorable in some settings due to:

~5 times ³ lower patient dose compared to conventional radiography ⁴
higher detail in larger patients due to a decrease in scatter⁵
three-dimensional imaging

Physical principles

The scan is performed in a normal standing position. Unlike conventional x-ray systems, it utilizes a thin slit-beam x-ray source (eliminating the need for a grid) that moves superior-inferiorly concurrently in both planes (anterior-posterior and lateral) resulting in two acquisitions in one mechanical motion. The scan takes longer than normal radiography (10-25 s) ¹.

With a bundled dedicated software, three-dimensional reconstructions of the axial skeleton can be reconstructed, and numerous quantitative parameters for the spine and limbs can be obtained. The main advantages of the system over conventional radiography are the significant reduction of radiation dose, and the possibility of three-dimensional reconstructions ¹.

Limitations

slow image acquisition increases the risk of movement artifacts, this is quite problematic in younger populations
edge enhancement artifacts around metallic implants (algorithms have been designed to overcome this and must be implemented at the radiographer level)
severe limb deformities can influence the semi-automatic 3D reconstructions and can result in biased calculations.
concerns have been raised about the cost-effectiveness of the system ⁶