The safety and accuracy of radiation-free spinal navigation using a short, scoliosis-specific BoneMRI-protocol, compared to CT

Peter P G Lafranca; Yorck Rommelspacher; Sebastian G Walter; Sander P J Muijs; Tijl A van der Velden; Yulia M Shcherbakova; Rene M Castelein; Keita Ito; Peter R Seevinck; Tom P C Schlösser

doi:10.1007/s00586-025-09151-x

The safety and accuracy of radiation-free spinal navigation using a short, scoliosis-specific BoneMRI-protocol, compared to CT

Peter P G Lafranca^*
, Yorck Rommelspacher
, Sebastian G Walter
, Sander P J Muijs
, Tijl A van der Velden
, Yulia M Shcherbakova
, Rene M Castelein
, Keita Ito
, Peter R Seevinck
, Tom P C Schlösser^*

^*Corresponding author for this work

Regenerative Medicine and Stem Cells

Research output: Contribution to journal › Article › Academic › peer-review

Abstract

PURPOSE: Spinal navigation systems require pre- and/or intra-operative 3-D imaging, which expose young patients to harmful radiation. We assessed a scoliosis-specific MRI-protocol that provides T2-weighted MRI and AI-generated synthetic-CT (sCT) scans, through deep learning algorithms. This study aims to compare MRI-based synthetic-CT spinal navigation to CT for safety and accuracy of pedicle screw planning and placement at thoracic and lumbar levels.

METHODS: Spines of 5 cadavers were scanned with thin-slice CT and the scoliosis-specific MRI-protocol (to create sCT). Preoperatively, on both CT and sCT screw trajectories were planned. Subsequently, four spine surgeons performed surface-matched, navigated placement of 2.5 mm k-wires in all pedicles from T3 to L5. Randomization for CT/sCT, surgeon and side was performed (1:1 ratio). On postoperative CT-scans, virtual screws were simulated over k-wires. Maximum angulation, distance between planned and postoperative screw positions and medial breach rate (Gertzbein-Robbins classification) were assessed.

RESULTS: 140 k-wires were inserted, 3 were excluded. There were no pedicle breaches > 2 mm. Of sCT-guided screws, 59 were grade A and 10 grade B. For the CT-guided screws, 47 were grade A and 21 grade B (p = 0.022). Average distance (± SD) between intraoperative and postoperative screw positions was 2.3 ± 1.5 mm in sCT-guided screws, and 2.4 ± 1.8 mm for CT (p = 0.78), average maximum angulation (± SD) was 3.8 ± 2.5° for sCT and 3.9 ± 2.9° for CT (p = 0.75).

CONCLUSION: MRI-based, AI-generated synthetic-CT spinal navigation allows for safe and accurate planning and placement of thoracic and lumbar pedicle screws in a cadaveric model, without significant differences in distance and angulation between planned and postoperative screw positions compared to CT.

Original language	English
Pages (from-to)	298-304
Number of pages	7
Journal	European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society
Volume	35
Issue number	1
Early online date	21 Jul 2025
DOIs	https://doi.org/10.1007/s00586-025-09151-x
Publication status	Published - Jan 2026

Keywords

AI-generated
MRI
Navigation
Pedicle screws
Radiation-free
Synthetic CT

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The safety and accuracy of radiation-free spinal navigation using a short, scoliosis-specific BoneMRI-protocol, compared to CTFinal published version, 841 KBLicence: CC BY

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Lafranca, P. P. G., Rommelspacher, Y., Walter, S. G., Muijs, S. P. J., van der Velden, T. A., Shcherbakova, Y. M., Castelein, R. M., Ito, K., Seevinck, P. R., & Schlösser, T. P. C. (2026). The safety and accuracy of radiation-free spinal navigation using a short, scoliosis-specific BoneMRI-protocol, compared to CT. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, 35(1), 298-304. https://doi.org/10.1007/s00586-025-09151-x

Lafranca, Peter P G ; Rommelspacher, Yorck ; Walter, Sebastian G et al. / The safety and accuracy of radiation-free spinal navigation using a short, scoliosis-specific BoneMRI-protocol, compared to CT. In: European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2026 ; Vol. 35, No. 1. pp. 298-304.

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title = "The safety and accuracy of radiation-free spinal navigation using a short, scoliosis-specific BoneMRI-protocol, compared to CT",

abstract = "PURPOSE: Spinal navigation systems require pre- and/or intra-operative 3-D imaging, which expose young patients to harmful radiation. We assessed a scoliosis-specific MRI-protocol that provides T2-weighted MRI and AI-generated synthetic-CT (sCT) scans, through deep learning algorithms. This study aims to compare MRI-based synthetic-CT spinal navigation to CT for safety and accuracy of pedicle screw planning and placement at thoracic and lumbar levels.METHODS: Spines of 5 cadavers were scanned with thin-slice CT and the scoliosis-specific MRI-protocol (to create sCT). Preoperatively, on both CT and sCT screw trajectories were planned. Subsequently, four spine surgeons performed surface-matched, navigated placement of 2.5 mm k-wires in all pedicles from T3 to L5. Randomization for CT/sCT, surgeon and side was performed (1:1 ratio). On postoperative CT-scans, virtual screws were simulated over k-wires. Maximum angulation, distance between planned and postoperative screw positions and medial breach rate (Gertzbein-Robbins classification) were assessed.RESULTS: 140 k-wires were inserted, 3 were excluded. There were no pedicle breaches > 2 mm. Of sCT-guided screws, 59 were grade A and 10 grade B. For the CT-guided screws, 47 were grade A and 21 grade B (p = 0.022). Average distance (± SD) between intraoperative and postoperative screw positions was 2.3 ± 1.5 mm in sCT-guided screws, and 2.4 ± 1.8 mm for CT (p = 0.78), average maximum angulation (± SD) was 3.8 ± 2.5° for sCT and 3.9 ± 2.9° for CT (p = 0.75).CONCLUSION: MRI-based, AI-generated synthetic-CT spinal navigation allows for safe and accurate planning and placement of thoracic and lumbar pedicle screws in a cadaveric model, without significant differences in distance and angulation between planned and postoperative screw positions compared to CT.",

keywords = "AI-generated, MRI, Navigation, Pedicle screws, Radiation-free, Synthetic CT",

author = "Lafranca, \{Peter P G\} and Yorck Rommelspacher and Walter, \{Sebastian G\} and Muijs, \{Sander P J\} and \{van der Velden\}, \{Tijl A\} and Shcherbakova, \{Yulia M\} and Castelein, \{Rene M\} and Keita Ito and Seevinck, \{Peter R\} and Schl{\"o}sser, \{Tom P C\}",

note = "Publisher Copyright: {\textcopyright} The Author(s) 2025.",

year = "2026",

month = jan,

doi = "10.1007/s00586-025-09151-x",

language = "English",

volume = "35",

pages = "298--304",

journal = "European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society",

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number = "1",

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Lafranca, PPG, Rommelspacher, Y, Walter, SG, Muijs, SPJ, van der Velden, TA, Shcherbakova, YM , Castelein, RM , Ito, K , Seevinck, PR & Schlösser, TPC 2026, 'The safety and accuracy of radiation-free spinal navigation using a short, scoliosis-specific BoneMRI-protocol, compared to CT', European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, vol. 35, no. 1, pp. 298-304. https://doi.org/10.1007/s00586-025-09151-x

The safety and accuracy of radiation-free spinal navigation using a short, scoliosis-specific BoneMRI-protocol, compared to CT. / Lafranca, Peter P G; Rommelspacher, Yorck; Walter, Sebastian G et al.
In: European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, Vol. 35, No. 1, 01.2026, p. 298-304.

Research output: Contribution to journal › Article › Academic › peer-review

TY - JOUR

T1 - The safety and accuracy of radiation-free spinal navigation using a short, scoliosis-specific BoneMRI-protocol, compared to CT

AU - Lafranca, Peter P G

AU - Rommelspacher, Yorck

AU - Walter, Sebastian G

AU - Muijs, Sander P J

AU - van der Velden, Tijl A

AU - Shcherbakova, Yulia M

AU - Castelein, Rene M

AU - Ito, Keita

AU - Seevinck, Peter R

AU - Schlösser, Tom P C

PY - 2026/1

Y1 - 2026/1

N2 - PURPOSE: Spinal navigation systems require pre- and/or intra-operative 3-D imaging, which expose young patients to harmful radiation. We assessed a scoliosis-specific MRI-protocol that provides T2-weighted MRI and AI-generated synthetic-CT (sCT) scans, through deep learning algorithms. This study aims to compare MRI-based synthetic-CT spinal navigation to CT for safety and accuracy of pedicle screw planning and placement at thoracic and lumbar levels.METHODS: Spines of 5 cadavers were scanned with thin-slice CT and the scoliosis-specific MRI-protocol (to create sCT). Preoperatively, on both CT and sCT screw trajectories were planned. Subsequently, four spine surgeons performed surface-matched, navigated placement of 2.5 mm k-wires in all pedicles from T3 to L5. Randomization for CT/sCT, surgeon and side was performed (1:1 ratio). On postoperative CT-scans, virtual screws were simulated over k-wires. Maximum angulation, distance between planned and postoperative screw positions and medial breach rate (Gertzbein-Robbins classification) were assessed.RESULTS: 140 k-wires were inserted, 3 were excluded. There were no pedicle breaches > 2 mm. Of sCT-guided screws, 59 were grade A and 10 grade B. For the CT-guided screws, 47 were grade A and 21 grade B (p = 0.022). Average distance (± SD) between intraoperative and postoperative screw positions was 2.3 ± 1.5 mm in sCT-guided screws, and 2.4 ± 1.8 mm for CT (p = 0.78), average maximum angulation (± SD) was 3.8 ± 2.5° for sCT and 3.9 ± 2.9° for CT (p = 0.75).CONCLUSION: MRI-based, AI-generated synthetic-CT spinal navigation allows for safe and accurate planning and placement of thoracic and lumbar pedicle screws in a cadaveric model, without significant differences in distance and angulation between planned and postoperative screw positions compared to CT.

AB - PURPOSE: Spinal navigation systems require pre- and/or intra-operative 3-D imaging, which expose young patients to harmful radiation. We assessed a scoliosis-specific MRI-protocol that provides T2-weighted MRI and AI-generated synthetic-CT (sCT) scans, through deep learning algorithms. This study aims to compare MRI-based synthetic-CT spinal navigation to CT for safety and accuracy of pedicle screw planning and placement at thoracic and lumbar levels.METHODS: Spines of 5 cadavers were scanned with thin-slice CT and the scoliosis-specific MRI-protocol (to create sCT). Preoperatively, on both CT and sCT screw trajectories were planned. Subsequently, four spine surgeons performed surface-matched, navigated placement of 2.5 mm k-wires in all pedicles from T3 to L5. Randomization for CT/sCT, surgeon and side was performed (1:1 ratio). On postoperative CT-scans, virtual screws were simulated over k-wires. Maximum angulation, distance between planned and postoperative screw positions and medial breach rate (Gertzbein-Robbins classification) were assessed.RESULTS: 140 k-wires were inserted, 3 were excluded. There were no pedicle breaches > 2 mm. Of sCT-guided screws, 59 were grade A and 10 grade B. For the CT-guided screws, 47 were grade A and 21 grade B (p = 0.022). Average distance (± SD) between intraoperative and postoperative screw positions was 2.3 ± 1.5 mm in sCT-guided screws, and 2.4 ± 1.8 mm for CT (p = 0.78), average maximum angulation (± SD) was 3.8 ± 2.5° for sCT and 3.9 ± 2.9° for CT (p = 0.75).CONCLUSION: MRI-based, AI-generated synthetic-CT spinal navigation allows for safe and accurate planning and placement of thoracic and lumbar pedicle screws in a cadaveric model, without significant differences in distance and angulation between planned and postoperative screw positions compared to CT.

KW - AI-generated

KW - MRI

KW - Navigation

KW - Pedicle screws

KW - Radiation-free

KW - Synthetic CT

UR - https://www.scopus.com/pages/publications/105011168409

U2 - 10.1007/s00586-025-09151-x

DO - 10.1007/s00586-025-09151-x

M3 - Article

C2 - 40691585

SN - 0940-6719

VL - 35

SP - 298

EP - 304

JO - European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society

JF - European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society

IS - 1

ER -

Lafranca PPG, Rommelspacher Y, Walter SG, Muijs SPJ, van der Velden TA, Shcherbakova YM et al. The safety and accuracy of radiation-free spinal navigation using a short, scoliosis-specific BoneMRI-protocol, compared to CT. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2026 Jan;35(1):298-304. Epub 2025 Jul 21. doi: 10.1007/s00586-025-09151-x

The safety and accuracy of radiation-free spinal navigation using a short, scoliosis-specific BoneMRI-protocol, compared to CT

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Keywords

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Answer to the letter to the editor of E. Mohebi, et al. concerning "The safety and accuracy of radiation-free spinal navigation using a short, scoliosis-specific BoneMRI-protocol, compared to CT" by P.P.G. Lafranca, et al. (Eur spine J [2025]; doi:10.1007/s00586-025-09151-x)

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