1. An apparatus that collects and processes physical space data while performing an image-guided procedure on an anatomical area of interest, the apparatus comprising: (a) a calibration system that collects physical space data, the physical space data providing three-dimensional (3D) coordinates; (b) a tracked ultrasonic probe that outputs ultrasonic image data; (c) a tracking device that tracks the ultrasonic probe in space; (d) an image data processor comprising a non-transitory computer-readable medium holding computer-executable instructions including: (i) based on the physical space data collected by the calibration system, determining registrations used to indicate position in both image space and physical space; (ii) using the registrations to map into image space, image data describing the physical space of the tracked ultrasonic probe used to perform the image-guided procedure and the anatomical area of interest; and (iii) constructing a 3D volume based on the ultrasonic image data on a periodic basis; and (e) a storage medium that stores a plurality of 3D volumes acquired by the image data processor.