An angle guidance device includes a base, which can be flexible and self-adhesive; a connector piece, including a rotatable connection, which is tiltable to a left or right side, and right and left connector plates, each including center and protractor cutouts; and a guidance piece, including an insert or protractor piece, and v-shaped needle guide, such that the v-shaped needle guide can be adjusted to a predetermined device inclination angle relative to the base. Optionally included are longitudinal and lateral level components, a bullseye level, a laser pointer, a screen, and an angle-guidance control unit, including a processor, a non-transitory memory, an input/output, a CT controller, an angle sensor, an angle viewer, a 3-axis accelerometer, and a data bus. Also disclosed is an angle-guidance method, including obtaining CT images, measuring angle and depth, setting biopsy angle, marking entry point, positioning angle-guidance device, marking position, inserting procedure needle.