CAMRT Radiography Practice Exam

What is the average CT number for muscle?

1. 25

2. 35

3. 50

4. 75

The correct answer is: 50

The average CT number for muscle is typically around 40 to 60 Hounsfield units (HU), depending on various factors such as the patient's condition and the specific scanning parameters used. Among the provided options, the choice of 50 Hounsfield units is the closest approximation to the average CT number for muscle. CT numbers, measured in Hounsfield units, reflect the radiodensity of tissues. Muscle has a relatively high density compared to fat, which tends to have lower CT numbers (usually below zero). In addition to muscle, other soft tissues like water and organs also have distinct CT numbers but fall within a similar range. Given this knowledge, a CT number of 50 makes sense as it falls within the expected spectrum for muscle density when using standard CT imaging techniques.