According to one embodiment, the present technique provides a phantom for testing imaging device. The exemplary phantom includes a first portion having groups of vessels, which are filled with a radiographically opaque substance (i.e., a contrast agent). The each group of vessels may extend from a central region of the first portion to the periphery of the central portion. The phantom may also include a second portion having a testing region. By way of example, the testing region may comprise a series of rings, each ring being configured to attenuate X-ray radiation differently. Adventurously, each ring may comprise materials configured to emulate different types and amounts of human tissue. For example, the exemplary phantom may include a ring, which emulates bone tissue, and a second ring, which emulates soft tissue. Moreover, each ring may be configured to emulate different amounts of tissue. That is to say, the certain rings in the phantom may include a first amount of a first material configured to emulate one kind of human tissue and a second amount of a second material configured to emulate a second kind of human tissue.