Schiettecatte Eva, Vereecke Elke, Jaremko Jacob L, Morbée Lieve, Vande Walle Caroline, Jans Lennart, Herregods Nele
Department of Radiology and Nuclear Medicine, Ghent University Hospital, Corneel Heymanslaan 10, 9000, Ghent, Belgium.
Department of Radiology, University of Alberta Hospital, 8440-112 Street, Edmonton, Alberta, T6G 2B7, Canada.
Insights Imaging. 2024 Feb 18;15(1):53. doi: 10.1186/s13244-023-01603-6.
The purpose of this study is to assess the equivalency of MRI-based synthetic CT (sCT) to conventional CT for sacroiliac joint bony morphology assessment in children.
A prospective study was performed. Children who had (PET-)CT-scan underwent additional MRI. sCT-CT image quality was analyzed by two readers subjectively overall, semi-quantitatively in terms of cortical delineation, joint facet defects, growth plate fusion, ossified nuclei, lumbosacral transitional anomaly, and bony bridges, and quantitatively for disc space height, spinal canal width, and sacral vertebrae width and height. Cohen's kappa and equivalence analyses with Bland-Altman plots were calculated for categorical and continuous measures respectively.
Ten patients were included (6 boys; aged 9-16 years; mean age 14 years). Overall sCT image quality was rated good. Semi-quantitative assessment of cortical delineation of sacroiliac joints, bony bridges, and joint facet defects on the right iliac and sacral sides showed perfect agreement. Correlation was good to excellent (kappa 0.615-1) for the presence of lumbosacral transitional anomaly, fusion of sacral growth plates, joint facet defect, and presence of ossified nuclei. sCT-CT measurements were statistically equivalent and within the equivalence margins (-1-1 mm) for intervertebral disc space height and spinal canal width. Intra- and inter-reader reliability was excellent for quantitative assessment (0.806 < ICC < 0.998). For categorical scoring, kappa ranged from substantial to excellent (0.615-1).
sCT appears to be visually equivalent to CT for the assessment of pediatric sacroiliac joints. sCT may aid in visualizing sacroiliac joints compared to conventional MRI, with the benefit that no ionizing radiation is used, especially important in children.
MRI-based synthetic CT, a new technique that generates CT-like images without ionizing radiation, appears to be visually equivalent to CT for assessment of normal pediatric sacroiliac joints and can potentially assess structural damage as it clearly depicts bony cortex.
• MRI-based sCT is a new image technique that can generate CT-like images. • We found that sCT performs similarly to CT in displaying bony structures of pediatric sacroiliac joints. • sCT has already been clinically validated in the sacroiliac joints in adults. • sCT can potentially assess structural damage from erosions or ankylosis as it clearly depicts bony cortex.
本研究旨在评估基于磁共振成像（MRI）的合成CT（sCT）与传统CT在评估儿童骶髂关节骨形态方面的等效性。
进行了一项前瞻性研究。已接受（PET-）CT扫描的儿童额外接受了MRI检查。两位阅片者对sCT-CT图像质量进行主观总体分析，对皮质轮廓、关节面缺损、生长板融合、骨化核、腰骶移行异常和骨桥进行半定量分析，并对椎间盘高度、椎管宽度以及骶椎宽度和高度进行定量分析。分别针对分类指标和连续指标计算Cohen's kappa系数以及采用Bland-Altman图进行等效性分析。
纳入10例患者（6名男孩；年龄9 - 16岁；平均年龄14岁）。总体sCT图像质量评级为良好。对骶髂关节右侧髂骨和骶骨侧的皮质轮廓、骨桥和关节面缺损进行半定量评估显示完全一致。对于腰骶移行异常、骶骨生长板融合、关节面缺损和骨化核的存在情况，相关性良好至极佳（kappa值为0.615 - 1）。sCT-CT测量在椎间盘高度和椎管宽度方面在统计学上等效且在等效界限（-1 - 1毫米）内。阅片者内和阅片者间可靠性在定量评估方面极佳（0.806 < ICC < 0.998）。对于分类评分，kappa值范围从高度一致到极佳（0.615 - 1）。
在评估儿童骶髂关节方面，sCT在视觉上似乎与CT等效。与传统MRI相比，sCT可能有助于显示骶髂关节，其优点是不使用电离辐射，这在儿童中尤为重要。
基于MRI的合成CT是一种无需电离辐射即可生成类似CT图像的新技术，在评估正常儿童骶髂关节方面在视觉上似乎与CT等效，并且由于能清晰描绘骨皮质，有可能评估结构损伤。
• 基于MRI的sCT是一种可生成类似CT图像的新成像技术。• 我们发现sCT在显示儿童骶髂关节的骨结构方面与CT表现相似。• sCT已在成人骶髂关节中得到临床验证。• 由于sCT能清晰描绘骨皮质，有可能评估侵蚀或强直导致的结构损伤。
