North Carolina State University, College of Veterinary Medicine, Department of Clinical Sciences, 1060 William Moore Drive, Raleigh, NC 27607, USA.
Vet J. 2013 Sep;197(3):625-30. doi: 10.1016/j.tvjl.2013.04.005. Epub 2013 May 9.
Assessment of equine foot conformation is often based on linear and angular measurements performed on lateral digital photographs. However, quantification of external foot conformation requires more comprehensive assessments to capture the shape of the entire foot. Volumetric measurements of the hoof capsule represent a summary measure quantifying foot shape. The aim of this study was to develop a method for computation of virtual foot models from digital foot images allowing precise and accurate volumetric measurements. This photogrammetric technique was then assessed for the characterization of foot volume changes associated with foot trimming. Using the technique, three different photographers imaged feet from 18 cadavers at different time points and one analyst processed their images to generate virtual computer models. Volumetric measurements were obtained from these models to determine their precision in the context of 'Photographer', 'Time' and the effect of 'Trimming'. Computed tomographic (CT) imaging was used to assess the accuracy of the photogrammetric method. Pre-trim photogrammetric measurements showed excellent precision and accuracy and the results did not depend on the person acquiring the images. The accuracy of post-trim photogrammetric measurements deteriorated in comparison with the average differences measured by CT imaging (19 cm(3)). Precise volumetric measurements were obtained using the photogrammetric method, but average differences in foot volume after trimming as measured by CT imaging are likely too small to be detected with confidence.
马的足部形态评估通常基于对侧位数码照片进行的线性和角度测量。然而，对外足部形态的量化需要更全面的评估，以捕捉整个足部的形状。蹄壳的容积测量代表了一种综合的测量方法，可量化足部的形状。本研究的目的是开发一种从数字足部图像计算虚拟足部模型的方法，以实现精确和准确的容积测量。然后，评估了这种摄影测量技术在描述与蹄部修剪相关的足部容积变化方面的特征。使用该技术，三名不同的摄影师在不同的时间点拍摄了 18 具尸体的足部图像，然后由一名分析员对其图像进行处理，生成虚拟计算机模型。从这些模型中获取容积测量值，以确定其在“摄影师”、“时间”和“修剪”影响下的精确性。计算机断层扫描（CT）成像用于评估摄影测量方法的准确性。修剪前的摄影测量测量显示出极好的精度和准确性，且结果不依赖于获取图像的人员。与 CT 成像测量的平均差异相比，修剪后摄影测量测量的准确性降低（19cm3）。使用摄影测量方法可以获得精确的容积测量值，但 CT 成像测量的修剪后足部容积的平均差异可能太小，无法有把握地检测到。
