光子计数CT在颈椎前路融合术后的金属伪影减少与骨融合评估
结果显示VMI120+iMAR减伪影最强，尤其钛笼附近，但可能因重建相关伪影妨碍骨融合判断。
要点
- VMI120+iMAR对钛笼周围金属伪影抑制最强，可作为评估骨-金属界面的首选重建。
- PEEK-钽笼用T3DiMAR即可获得与VMI120+iMAR相当的减伪影效果，可避免过度重建。
- 评估植骨区内外骨融合时应以标准T3D图像为主，iMAR类重建的假性骨溶解可能模拟假关节形成。
核心结论
- 锡滤过PCD-CT的VMI120+iMAR在ACDF术后金属伪影减少最强，并改善骨-金属界面清晰度，尤以钛笼周围显著。
- iMAR类重建可产生假性骨溶解，可能模拟假关节形成；白色带伪影可能模拟假性骨桥，具有材料和kVp依赖性。
- 临床评估ACDF患者应采用重建特异性策略，在金属伪影减少与骨融合诊断可靠性之间权衡。
研究设计与样本
- 其中23例为PEEK-钽笼，21例为钛笼；比较T3D、T3DiMAR、VMI120及VMI120+iMAR四种重建。
- 定量分析包括低密度和高密度伪影衰减值及校正噪声；三名肌肉骨骼放射科医师独立评分。
关键影像表现/征象
- VMI120+iMAR使低密度伪影从-362.5 HU降至-38 HU，高密度伪影从218.5 HU降至83.5 HU，均优于T3D（P<0.001）。
- 骨-金属界面清晰度在VMI120和VMI120+iMAR重建中显著改善（P≤0.01）。
- iMAR类重建产生假性骨溶解（20.5%–38.6%）和白色带伪影（50%–56.8%），暗区和剪影伪影较少见（4.5%–6.8%）。
- 白色带伪影在140 kVp时比100 kVp更常见（P<0.05），暗区和剪影伪影仅在100 kVp下观察到。
- 标准T3D图像对植骨区内外骨融合可见度评分最高（中位3–4），VMI120+iMAR评分最低（中位2–3，P≤0.01）。
诊断标准与关键数值
- T3DiMAR在PEEK-钽笼中伪影减少效果与VMI120+iMAR相当（P=0.55–0.83），但在钛笼中伪影减少效果较差（P<0.001）。
- 观察者间一致性为substantial至almost perfect（κ=0.62–0.94）。
临床应用与阅片要点
- 评估骨-金属界面时优先选择VMI120或VMI120+iMAR重建，尤其钛笼周围。
- 判断植骨区内外骨融合时应以标准T3D图像为主要依据，避免仅凭iMAR重建诊断假关节。
- 看到iMAR重建中的透亮区需考虑假性骨溶解可能，不要直接报骨不连或假关节形成。
- 白色带伪影可模拟骨桥形成，阅片时需与真实融合鉴别，尤其在140 kVp采集时更常见。
局限性
- 本研究为回顾性设计，存在选择偏倚可能。
以上解读依据论文摘要（全文未开放获取或许可不允许翻译转载）。
英文原文（摘要）· 点击展开
OBJECTIVE: To evaluate the impact of tin-filtered photon-counting detector (PCD) computed tomography (CT) in combination with high-energy virtual monoenergetic imaging (VMI) and iterative metal artifact reduction (iMAR) on metal artifact reduction, image quality, and assessment of intragraft and extragraft bone fusion, in patients after anterior cervical discectomy and fusion (ACDF).
MATERIALS AND METHODS: Patients who underwent ACDF and postoperative tin-filtered PCD-CT between 2023 and 2026 were retrospectively analyzed. Metal artifacts were quantitatively and qualitatively assessed in standard polychromatic (T3D), iMAR (T3DiMAR), VMI at 120 keV (VMI120), and combined VMI120 + iMAR (VMI120+iMAR) reconstructions. Quantitative analysis included measurement of hypodense and hyperdense artifact attenuation and corrected noise. Three musculoskeletal radiologists independently scored 5 imaging features on 4-point Likert scales and assessed the presence of secondary artifacts. Subgroup analyses were performed for polyetheretherketone (PEEK)-tantalum versus titanium cages and for 140 versus 100 kVp acquisitions.
RESULTS: Forty-four patients (23 with PEEK-tantalum cages, 21 with titanium cages) were included. VMI120+iMAR achieved the strongest metal artifact reduction with hypodense artifacts from -362.5 Hounsfield Units (HU) to -38 HU and hyperdense artifacts from 218.5 to 83.5 HU, as well as significant noise improvements compared with T3D (all P<0.001); effects were most pronounced near titanium cages. T3DiMAR provided comparable artifact reduction to VMI120+iMAR in PEEK-tantalum cages (P=0.55 to 0.83) but inferior artifact reduction in titanium cages (P<0.001). Bone-metal interface conspicuity improved significantly with VMI120 and VMI120+iMAR (P≤0.01). Intragraft and extragraft bone fusion visibility was rated highest with standard T3D images (median 3 to 4), whereas the most pronounced impairments were observed for VMI120+iMAR (median 2 to 3, P≤0.01). iMAR-based techniques introduced secondary artifacts, including pseudo-osteolysis (20.5% to 38.6%), and white zone artifacts (50% to 56.8%), while dark zone and silhouette artifacts were less common (4.5% to 6.8%). White zone artifacts were significantly more frequent at 140 versus 100 kVp (P<0.05), while dark zone and silhouette artifacts were exclusively observed at 100 kVp. Inter-reader agreement was substantial to almost perfect (κ=0.62 to 0.94).
CONCLUSIONS: Tin-filtered PCD-CT with VMI120+iMAR offers the most effective metal artifact reduction after ACDF and improves bone-metal interface conspicuity, particularly near titanium cages, followed by T3DiMAR. However, these advanced reconstructions may impair diagnostic accuracy for bone fusion assessment due to reconstruction-induced artifacts. iMAR-based reconstructions introduced pseudo-osteolysis that may simulate pseudoarthrosis, as well as white zone artifacts that may mimic false bony bridging in a material-dependent and kVp-dependent manner. Therefore, a reconstruction-specific approach is recommended for the clinical evaluation of ACDF patients, balancing metal artifact reduction against diagnostic reliability for bone fusion.
引用
- Abel, Curti, Marth, et al. Photon-counting CT in Anterior Cervical Discectomy and Fusion: Improved Metal Artifact Reduction and Impact on Bone Fusion Assessment. Invest Radiol. 2026. PMID: 42226485. doi:10.1097/RLI.0000000000001298
供执业医师工作参考，不替代临床判断；数值与分级以指南原文为准。