This paper describes the participation of the Bioingenium re- search group of Universidad Nacional de Colombia in the ImageCLEF2012 Medical Retrieval challenge, specically in the ad-hoc image-based re- trieval task. The methods used for solving textual and visual queries with which we submitted uni-modal runs are described. They were ranked 1st and 3rd respectively. These results have been obtained by using our own implementation of Okapi-BM25 weighting scheme for text retrieval, and by adding spatial layouts to the CEDD descriptors for visual retrieval. We also used these uni-modal features to learn multimodal representa- tions using matrix factorization for solving visual queries. Despite the potential of multimodal indexes to improve the quality of visual queries, these experiments were not as successful as uni-modal indexes. We dis- cuss the main ndings of all these experiments.