Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:…on k-space (Basu et al., 2006), local neighborhood pattern analysis (Manjón et al., 2008), high-order partial differential equations (Bai and Feng, 2007; Moraschi et al., 2010), diffusion tensor
Keywords Anomalous diffusion, Image enhancement, Diffusion Tensor Imaging, Spatial filtering.
Category: