In the context of liver imaging, what does the equilibrium phase refer to?

The equilibrium phase in liver imaging is characterized by a balanced concentration of contrast agent within the liver and adjacent structures. This phase typically occurs a few minutes after the contrast injection, approximately 2-3 minutes in this context. During the equilibrium phase, the contrast medium diffuses into the interstitial spaces, allowing for the visualization of both vascular and parenchymal structures without the intense enhancement seen during the arterial or venous phases. This is crucial for assessing liver lesions or masses, as it provides better contrast and detail for diagnostic purposes.

Understanding the timing of this phase is essential for interpreting liver scans effectively. The ability to identify and differentiate between the various phases of contrast enhancement helps radiologists make more accurate diagnoses, so knowing when the equilibrium phase occurs is vital for accurate imaging analysis.