Comparing line detection methods for medical images

In medical image analysis there are various examples where the detection of linear structures can provide important information. These include mammography, blood vessel detection and the extraction of trabecular structure from bone images. There are several generic techniques which can be used to obtain linear structure information at a pixel level. Several of these techniques are compared on the basis of their performance in detecting line strength and orientation. In addition we comment on the possibility of using the same techniques in a multi-scale approach to also obtain line scale information. The methods discussed include those based on simple orientation bins, a multidirectional line operator, directional second order Gaussian derivatives, directional morphology, curvilinear structures detection and directional Fourier space.