One or more techniques and/or systems are described for automatically generating a transformation matrix for correlating images from an ultrasound modality with images from another modality (or with ultrasound images acquired at a different point in time). Ultrasound volumetric data and volumetric data yielded from another image modality are examined to identify and/or extract features. The transformation matrix is automatically generated, or populated, based at least in part upon common features that are identified in both the ultrasound volumetric data and the volumetric data yielded from the other image modality. The transformation matrix can then be used to correlate images from the different modalities (e.g., to display a CT image of an object next to an ultrasound image of the object, where the images are substantially similar to one another even though they were acquired using different modalities).