Department of Radiology and Nuclear Medicine, Amsterdam UMC, Location AMC, Amsterdam Movement Sciences, Amsterdam, the Netherlands.
Ospedale Maggiore della Carità di Novara, Istituto di Radiodiagnostica ed Interventistica, Università del Piemonte Orientale, Novara, Italy.
Eur J Radiol. 2021 May;138:109674. doi: 10.1016/j.ejrad.2021.109674. Epub 2021 Mar 20.
We hypothesize that three-dimensional (3D) geometric analyses in weight bearing CT-images of the foot and ankle are more reproducible compared to two-dimensional (2D) analyses. Therefore, we compared 2D and 3D analyses on bones of weight-bearing and non weight-bearing cone-beam CT images of healthy volunteers.
Twenty healthy volunteers (10 male, 10 female, mean age 37.5 years) underwent weight-bearing and non weight-bearing cone-beam CT imaging of both feet. Clinically relevant height and angle measurements were performed in 2D and 3D (for example: cuboid height, calcaneal pitch, talo-calcaneal angle, Meary's angle, intermetatarsal angle). Three-dimensional measurements were obtained using automated software. Intra-observer and inter-observer agreement were evaluated for all 2D measurements.
Overall intraclass correlation coefficients (ICC's) were higher than 0.750 for most 2D measurements, ranging from 0.352 to 0.995. Calcaneal pitch, angle between the first metatarsal (MT1) and proximal phalange 1, between the fifth metatarsal (MT5) and the calcaneus and heights of the sesamoid bones, navicular, cuboid and talus decreased during weight-bearing in both 2D and 3D results (p < 0.01). Meary's angle was not statistically different in 2D (p = 0.627) and 3D (p = 0.765). Higher coefficients of variation in 2D geometric analysis parameters (0.27 versus 0.16) indicate that 3D analyses are more precise compared to 2D (p < 0.01). Results of left and right feet are comparable for 2D and 3D analyses.
Although 2D and 3D geometrical analyses are fundamentally different, automated 3D analyses are more reproducible and precise compared to 2D analyses. In addition, 3D evaluation better demonstrates differences in bone configurations between weight-bearing and non weight-bearing conditions, which may be of value to demonstrate pathology.
我们假设，与二维（2D）分析相比，三维（3D）几何分析在足部和踝关节负重 CT 图像中更具可重复性。因此，我们比较了健康志愿者负重和非负重锥形束 CT 图像的 2D 和 3D 分析。
20 名健康志愿者（10 名男性，10 名女性，平均年龄 37.5 岁）接受了双脚负重和非负重锥形束 CT 成像。在 2D 和 3D 中进行了临床相关的高度和角度测量（例如：骰骨高度、跟骨倾斜角、距跟骨角、Meary 角、跖骨间角）。使用自动软件获得 3D 测量值。评估了所有 2D 测量的观察者内和观察者间一致性。
大多数 2D 测量的总体组内相关系数（ICC）均高于 0.750，范围为 0.352 至 0.995。在 2D 和 3D 结果中，跟骨倾斜角、第一跖骨（MT1）和第一近节趾骨之间的角度、第五跖骨（MT5）和跟骨之间的角度以及籽骨、舟骨、骰骨和距骨的高度在负重时均降低（p<0.01）。Meary 角在 2D （p=0.627）和 3D （p=0.765）中无统计学差异。2D 几何分析参数的变异系数较高（0.27 比 0.16），表明 3D 分析比 2D 分析更精确（p<0.01）。2D 和 3D 分析的左右脚结果具有可比性。
尽管 2D 和 3D 几何分析在原理上有所不同，但与 2D 分析相比，自动 3D 分析更具可重复性和精确性。此外，3D 评估更好地显示了负重和非负重条件下骨结构之间的差异，这可能有助于显示病理学。
