A scanner of a blood flow measurement apparatus of an embodiment alternately performs first scan and second scan for first and second cross sections both intersecting an interested blood vessel. An image forming unit forms one or more images of the first cross section including a phase image of the first cross section and an image of the second cross section. A blood vessel region specification unit specifies a first blood vessel region in any of the one or more images of the first cross section and a second blood vessel region in the image of the second cross section. A gradient calculation unit calculates a gradient of the interested blood vessel at the first cross section based on the first and second blood vessel regions. A blood flow information generation unit generates blood flow information based on the phase image and the gradient.
