A medical image-processing apparatus of embodiments includes processing circuitry. The processing circuitry extracts plural regions corresponding to at least one of a lobe and a subsegment forming a lung from three-dimensional medical-image data that is acquired by imaging in temporal order. The processing circuitry calculates a physical index relating to respiratory activity for each of the extracted regions. The processing circuitry detects an abnormal region having an abnormality relating to the respiratory activity out of the regions by comparing temporal changes of the physical index of the respective regions. The processing circuitry outputs information indicating about the abnormal region.
