What does hypodense mean?

• A. Radiolucent
• B. Radiopaque
• C. Hypodense
• D. Isodense

Answer: (A)

Hypodense describes tissue that is less dense than its surroundings, so it attenuates fewer X-rays and appears darker on the image. On plain radiographs, that darker, more translucent area is called radiolucent. In contrast, radiopaque areas block more X-rays and appear white, while isodense areas have similar density to surrounding tissue. So, hypodense corresponds to radiolucent, which is why radiolucent is the correct description.