Hounsfield

Hounsfield units (HU) are a scale used in medical imaging, specifically CT scans, to measure how much different tissues absorb X-ray radiation. Each type of tissue—like bone, muscle, or fat—has a characteristic HU value based on its density. For example, air has a very low HU (around -1000), water is set at 0, and dense bone can be over +1000. This scale helps radiologists distinguish between various tissues, identify abnormalities, and diagnose conditions accurately by providing a standardized way to interpret X-ray attenuation within the body.