Hounsfieldyksiköissä

Hounsfieldyksiköissä, often abbreviated as HU, is a relative measurement unit used in computed tomography (CT) imaging. It quantifies the radiodensity of a material within a CT scan. The scale is defined by assigning a value of 0 HU to pure water and 1000 HU to compact bone. Air is assigned a value of -1000 HU.

Different tissues and substances within the body are assigned specific HU values based on their density and the attenuation of X-rays they cause. For example, soft tissues like muscle typically fall within a range of 40-60 HU, while fat is around -40 to -100 HU. Blood has a value of approximately 50-60 HU, and cerebrospinal fluid is around 10-15 HU. Pathological conditions can alter these values; for instance, calcifications might appear as very high HU values, while edema might show lower values than surrounding healthy tissue.

The Hounsfield scale is named after Sir Godfrey Hounsfield, one of the inventors of the CT scanner. This standardized unit allows for consistent interpretation of CT images across different scanners and institutions, facilitating accurate diagnosis and monitoring of disease progression. It is a crucial tool for radiologists and clinicians to differentiate between various tissues and identify abnormalities.