1. A system for imaging a volume of tissue, comprising: an array of ultrasound emitters configured to surround the volume of tissue and emit acoustic waveforms toward the volume of tissue; an array of ultrasound receivers configured to surround the volume of tissue and to receive acoustic waveforms scattered by the volume of tissue, each acoustic waveform corresponding to a respective emitter-receiver pair; and a processor that: determines an observed differential time-of-flight data set based on relative observed time-of-flights of adjacent scattered acoustic waveforms corresponding to adjacent emitter-receiver pairs; determines a calculated differential time-of-flight data set; and generates an acoustic speed rendering of the volume of tissue at least partially based on the difference between the observed differential time-of-flight data set and the calculated differential time-of-flight data set.