Brain US, short for Brain Ultrasound, is an image dataset about brain anatomical segmentation, containing 1,629 vivo B-mode US images from 20 subjects, of which 1,300 were used for training and 329 for testing. The ventricles and septum pellecudi of each image were manually segmented by ultrasound experts, and the image size was 512 X 512. These subjects were treated between 2010 and 2016, and the age difference of the subjects was less than one year. Some of the subjects had IVH, and the other subjects were at risk of IVH. US scans were collected using a Philips US machine with a C8-5 broadband curved array transducer, using coronal and sagittal scanning planes.