The portion of radiographic contrast caused by variations in anatomy or pathology is called?

• A. Radiographic contrast
• B. Anatomic contrast
• C. Pathologic contrast
• D. Subject contrast

Answer: (D)

Subject contrast is the differences in X-ray attenuation that come from the patient’s own tissues and any pathology. As X-rays pass through the body, bones, soft tissue, air, and abnormal masses absorb or transmit photons to different extents. Those intrinsic differences create brightness variations on the radiograph—the image’s contrast that arises from the patient itself. This portion of contrast is inherent to the subject, independent of how the image is acquired, although the final appearance also depends on imaging factors and processing. For example, the distinct brightness between bone and surrounding soft tissue is a result of subject contrast.