Lafranca Peter P G, Rommelspacher Yorck, Walter Sebastian G, Muijs Sander P J, van der Velden Tijl A, Shcherbakova Yulia M, Castelein Rene M, Ito Keita, Seevinck Peter R, Schlösser Tom P C
Department of Orthopedic Surgery, University Medical Center Utrecht, Utrecht, The Netherlands.
Department of Spine Surgery, Krankenhaus der Augustinerinnen, Cologne, Germany.
Eur Spine J. 2025 Jul 21. doi: 10.1007/s00586-025-09151-x.
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.
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.
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).
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.
脊柱导航系统需要术前和/或术中三维成像，这会使年轻患者暴露于有害辐射中。我们评估了一种针对脊柱侧弯的MRI协议，该协议通过深度学习算法提供T2加权MRI和人工智能生成的合成CT（sCT）扫描。本研究旨在比较基于MRI的合成CT脊柱导航与CT在胸椎和腰椎椎弓根螺钉规划和置入的安全性和准确性。
对5具尸体的脊柱进行薄层CT扫描和针对脊柱侧弯的MRI协议扫描（以创建sCT）。术前，在CT和sCT上规划螺钉轨迹。随后，四位脊柱外科医生在T3至L5的所有椎弓根中进行表面匹配、导航置入2.5毫米克氏针。对CT/sCT、外科医生和侧别进行随机分组（1:1比例）。在术后CT扫描上，在克氏针上模拟虚拟螺钉。评估最大成角、计划和术后螺钉位置之间的距离以及内侧穿破率（Gertzbein-Robbins分类）。
共置入140根克氏针，3根被排除。没有椎弓根穿破超过2毫米的情况。在sCT引导的螺钉中，59根为A级，10根为B级。对于CT引导的螺钉，47根为A级，21根为B级（p = 0.022）。sCT引导的螺钉术中与术后螺钉位置之间的平均距离（±标准差）为2.3±1.5毫米，CT引导的为2.4±1.8毫米（p = 0.78），sCT的平均最大成角（±标准差）为3.8±2.5°，CT的为3.9±2.9°（p = 0.75）。
基于MRI的、人工智能生成的合成CT脊柱导航在尸体模型中能够安全、准确地规划和置入胸椎和腰椎椎弓根螺钉，与CT相比，计划和术后螺钉位置之间的距离和成角没有显著差异。
