SiNC: Saliency-injected neural codes for representation and efficient retrieval of medical radiographs

• Published in: PloS one Vol. 12; no. 8; p. e0181707
• Main Authors: Ahmad, Jamil, Sajjad, Muhammad, Mehmood, Irfan, Baik, Sung Wook
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 03-08-2017; Public Library of Science (PLoS)
• Subjects: Artificial intelligence; Artificial neural networks; Binary codes; Biology and Life Sciences; Computer science; Databases, Factual; Diagnosis; Disease detection; Feature extraction; Fractures; Humans; Image management; Image Processing, Computer-Assisted - methods; Image retrieval; Indexing; Information processing; International conferences; Medical imaging; Medical imaging equipment; Medical radiography; Medicine and Health Sciences; Methods; Neural networks; Neural Networks, Computer; Pattern recognition; People and Places; Radiographs; Radiography; Radiology; Repositories; Research and Analysis Methods; Retrieval; Semantics; Social Sciences; Spots; Tomography; Tumors; Visual perception; South Korea
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0181707

Medical image collections contain a wealth of information which can assist radiologists and medical experts in diagnosis and disease detection for making well-informed decisions. However, this objective can only be realized if efficient access is provided to semantically relevant cases from the ever-growing medical image repositories. In this paper, we present an efficient method for representing medical images by incorporating visual saliency and deep features obtained from a fine-tuned convolutional neural network (CNN) pre-trained on natural images. Saliency detector is employed to automatically identify regions of interest like tumors, fractures, and calcified spots in images prior to feature extraction. Neuronal activation features termed as neural codes from different CNN layers are comprehensively studied to identify most appropriate features for representing radiographs. This study revealed that neural codes from the last fully connected layer of the fine-tuned CNN are found to be the most suitable for representing medical images. The neural codes extracted from the entire image and salient part of the image are fused to obtain the saliency-injected neural codes (SiNC) descriptor which is used for indexing and retrieval. Finally, locality sensitive hashing techniques are applied on the SiNC descriptor to acquire short binary codes for allowing efficient retrieval in large scale image collections. Comprehensive experimental evaluations on the radiology images dataset reveal that the proposed framework achieves high retrieval accuracy and efficiency for scalable image retrieval applications and compares favorably with existing approaches.