TOPLINE

Ultralow-dose CT (ULD-CT) delivered image quality sufficient for planning lower-extremity, hexapod-based deformity corrections and reduced radiation exposure by more than 30-fold compared with standard CT.

METHODOLOGY

• Researchers retrospectively analysed data from 18 patients with posttraumatic lower-extremity deformities (mean age, 48.5 years; 15 men) treated with a hexapod system at a level I trauma centre in Tübingen, Germany, between 2022 and 2024.
• All participants underwent three imaging modalities: conventional two-view radiography (anteroposterior and mediolateral views), standard CT, and ULD-CT.
• Investigators calculated the mean effective radiation dose, measured in microsieverts (µSv), separately for each modality, using recognised dosimetry frameworks.
• Two experts assessed the image quality of ULD-CT scans to determine whether cortical bone alignment was adequately visualised.

TAKEAWAY

• The mean effective dose was 150.8 µSv (range, 94.85 µSv-224.6 µSv) for standard CT, 4.61 µSv (range, 2.97 µSv-6.68 µSv) for ULD-CT, and 1.41 µSv (range, 0.66 µSv-2.53 µSv) for conventional radiography (standard CT vs radiography: mean difference, 149.4 µSv; P < .001).
• ULD-CT reduced the radiation dose by more than 30-fold compared with standard CT (mean difference, 146.2 µSv; P < .001).
• The radiation dose from ULD-CT was roughly three times higher than that from conventional radiotherapy (mean difference, 3.2 µSv; P < .001).
• Both reviewers deemed 100% of the ULD-CT scans adequate for assessing cortical alignment for treatment planning, supporting clinical applicability without compromising image quality.

IN PRACTICE

"This technology represents a promising alternative to conventional imaging approaches by combining high diagnostic accuracy with reduced radiation exposure," the authors wrote.

"Looking ahead, ULD-CT protocols may contribute to further dose optimization and expand the role of CT-based imaging in musculoskeletal diagnostics," they added.

SOURCE

The study was led jointly by Daniel Schüll and Heiko Baumgartner, University of Tübingen, Tübingen, Germany. It was published online on September 23, 2026, in Archives of Orthopaedic and Trauma Surgery.

LIMITATIONS

Image quality was assessed dichotomously rather than through objective quantitative measurement. Actual clinical outcomes such as correction accuracy, complication rates, or revision rates following ULD-CT-based planning were not assessed. The retrospective design limited the generalisability of the findings.

DISCLOSURES

No specific funding was reported for the study. The authors reported having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.