基于多视角融合的CBCT图像牙齿实例分割算法
Tooth Instance Segmentation Algorithm Based on Multi-View Fusion in CBCT Images
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摘要: 在牙科治疗中,准确、快速地从锥形束CT图像(CBCT)分割出单颗牙齿具有重要意义.为了解决咬合面难以处理和CBCT图像分辨率较低的问题,提出一种基于多视角融合的CBCT图像牙齿实例分割算法.首先,将CBCT数据转化为水平面和矢状面2个视角的序列切片;其次,结合不同视图的数据特点,使水平面分割结果为矢状面分割提供分割指导和实例标签信息;最后,基于矢状面图像的实例分割结果还原CBTC数据,得到高精度的牙齿实例分割结果.以基于Test29构造的CBCT数据集为例,以平均Dice系数为评价指标,所提算法在牙齿和咬合面的平均Dice系数分别达到89.74%和93.56%,与CGDNet等算法相比,平均提升0.82~3.45个百分点;同时,平均分割速度为9.2 s,实现短时间内完成CBCT数据高精度实例分割.Abstract: Accurate and rapid segmentation of individual teeth from cone beam computed tomography (CBCT) images is of great significance in dental treatment. In order to solve the problems of difficult processing of occlusal surface and low resolution of CBCT image, a multi-view fusion-based algorithm for tooth instance segmentation in CBCT images is proposed in this paper. First, the CBCT data is transformed into sequential slices in both the axial and sagittal views. Second, by leveraging the characteristics of data from different views, the segmentation results from the axial view provide guidance and instance label information for the sagittal view segmentation. Finally, the instance segmentation results from the sagittal view images are used to reconstruct the CBCT data, yielding high-precision tooth instance segmentation results. Based on Test29 structure of CBCT dataset for example, with average Dice coefficient as evaluation indicators, the experimental results show that the average Dice coefficients of teeth and occlusal surfaces are 89.74% and 93.56%, respectively, which representing an improvement of 0.82 to 3.45 percentage points compared to algorithms such as CGDNet; additionally, the average segmentation speed is 9.2 s, which realizes the task of high-precision instance segmentation of CBCT data in a short time.