ITK-SNAP is an interactive software application that allows users to navigate three-dimensional medical images, manually delineate anatomical regions of interest, and perform automatic image segmentation. The software was designed with the audience of clinical and basic science researchers in mind, and emphasis has been placed on having a user-friendly interface and maintaining a limited feature set to prevent feature creep. ITK-SNAP is most frequently used to work with magnetic resonance imaging (MRI), cone-beam computed tomography (CBCT) and computed tomography (CT) data sets.
Features
The purpose of the tool is to make it easy for researchers to delineate anatomical structures and regions of interest in imaging data. The set of features is kept to a minimum. The main features of the program are
Image navigation
three orthogonal cut planes through the image volume are shown at all times. The cut planes are linked by a common cursor, so that moving the cursor in one cut plane updates the other cut planes. The cursor is moved by dragging the mouse over the cut planes, making for smooth navigation. The linked cursor also works across ITK-SNAP sessions, making it possible to navigate multimodality imaging data (e.g., two MRI scans of a subject from a single session).
Manual segmentation
ITK-SNAP provides tools for manual delineation of anatomical structures in images. Labeling can take place in all three orthogonal cut planes and results can be visualized as a three-dimensional rendering. This makes it easier to ensure that the segmentation maintains reasonable shape in 3D.
Automatic segmentation
ITK-SNAP provides automatic functionality segmentation using the level-set method. This makes it possible to segment structures that appear somewhat homogeneous in medical images using very little human interaction. For example, the lateral ventricles in MRI can be segmented reliably, as can some types of tumors in CT and MRI.
^Kauke, Martin (February 2018). "Volumetric analysis of keratocystic odontogenic tumors and non-neoplastic jaw cysts – Comparison and its clinical relevance". Journal of Cranio-Maxillofacial Surgery. 46 (2): 257–263. doi:10.1016/j.jcms.2017.11.012. PMID29233700.
^Safi, Ali-Farid (2018). "Does volumetric measurement serve as an imaging biomarker for tumor aggressiveness of ameloblastomas?". Oral Oncology. 78 (March 2018): 16–24. doi:10.1016/j.oraloncology.2018.01.002. PMID29496045.
^Rizzi, S.H.; Banerjee, P. P.; Luciano, C. J. (2007). "Automating the Extraction of 3D Models from Medical Images for Virtual Reality and Haptic Simulations". Automation Science and Engineering, 2007. CASE 2007. IEEE International Conference on. pp. 152–157. doi:10.1109/COASE.2007.4341748.
^Krishnan, S.; Slavin, M. J.; Tran, T. T.; Doraiswamy, P. M.; Petrella, J. R. (2006). "Accuracy of spatial normalization of the hippocampus: implications for fMRI research in memory disorders". NeuroImage. 31 (2): 560–571. doi:10.1016/j.neuroimage.2005.12.061. PMID16513371. S2CID5554390.