What type of blood is associated with a poor MRI signal?

Deoxygenated blood is associated with a poor MRI signal due to its paramagnetic properties. In MRI, the contrast in images comes from differences in the magnetic environment of various tissues and substances. Oxygenated blood contains oxyhemoglobin, which has a different magnetic susceptibility than deoxygenated blood, or deoxyhemoglobin.

Deoxygenated blood has fewer interactions with the magnetic field due to the presence of unpaired electrons in its molecular structure, causing a loss of signal during imaging. This leads to lower signal intensity in MRI scans when deoxygenated blood is present compared to oxygenated blood. Understanding this distinction is crucial for interpreting MRI results, especially in clinical contexts where blood oxygen levels might indicate various health conditions or the effectiveness of treatments.