how to create data set for neural network and how to check outputs

i m working on project in which i have to recognize certain shapes in ct images,should i give direct images as input to neural network?how to feed images as input to neural network?i have also extracted some feature vectors can i give both feature vectors and images to input? how do i check if outputs are correct in nntoolbox?can u specify how to feed inputs by nnstart(how to create datasets) please help...