A system for ablation zone detection, the system comprising: an ablation device configured to deliver microwave energy to tissue at a treatment location; a computing device including a processor and a memory storing instructions which, when executed by the processor, cause the computing device to: receive a plurality of ultrasound return signals from an ultrasound device , wherein the ultrasound device is configured to deliver ultrasound energy to tissue and receive, from a plurality of respective portions of the tissue, the plurality of ultrasound return signals that are based on the delivered ultrasound energy, detect, in the plurality of ultrasound return signals, a plurality of respective Doppler shifts that are based on the microwave energy delivered to the tissue, determine an ablation zone characteristic based on the plurality of Doppler shifts, and cause a display device to display, by way of a graphical user interface , an image representing at least a portion of the tissue and a representation of the ablation zone characteristic, the computing device being further configured to display on the display device, based on the plurality of Doppler shifts, an indication of the size and shape of the ablation zone on an ultrasound image. an ablation device configured to deliver microwave energy to tissue at a treatment location; a computing device including a processor and a memory storing instructions which, when executed by the processor, cause the computing device to: receive a plurality of ultrasound return signals from an ultrasound device , wherein the ultrasound device is configured to deliver ultrasound energy to tissue and receive, from a plurality of respective portions of the tissue, the plurality of ultrasound return signals that are based on the delivered ultrasound energy, detect, in the plurality of ultrasound return signals, a plurality of respective Doppler shifts that are based on the microwave energy delivered to the tissue, determine an ablation zone characteristic based on the plurality of Doppler shifts, and cause a display device to display, by way of a graphical user interface , an image representing at least a portion of the tissue and a representation of the ablation zone characteristic, the computing device being further configured to display on the display device, based on the plurality of Doppler shifts, an indication of the size and shape of the ablation zone on an ultrasound image. receive a plurality of ultrasound return signals from an ultrasound device , wherein the ultrasound device is configured to deliver ultrasound energy to tissue and receive, from a plurality of respective portions of the tissue, the plurality of ultrasound return signals that are based on the delivered ultrasound energy, detect, in the plurality of ultrasound return signals, a plurality of respective Doppler shifts that are based on the microwave energy delivered to the tissue, determine an ablation zone characteristic based on the plurality of Doppler shifts, and cause a display device to display, by way of a graphical user interface , an image representing at least a portion of the tissue and a representation of the ablation zone characteristic, the computing device being further configured to display on the display device, based on the plurality of Doppler shifts, an indication of the size and shape of the ablation zone on an ultrasound image. <EOS>