During which phase does most routine (non-angiographic) imaging with contrast typically take place?

In the context of imaging with contrast, most routine (non-angiographic) imaging typically occurs during the non-equilibrium phase. This phase is characterized by a significant amount of contrast media present within the tissue, allowing for clear visualization of structures without the rapid changes seen in other phases.

During the non-equilibrium phase, the contrast agent has distributed throughout the tissues but has not yet reached the equilibrium state where it saturates both the vessels and the interstitial spaces evenly. This allows imaging to highlight the differences between various tissues based on their perfusion and vascularization, which is particularly useful for diagnosing a range of conditions.

The other phases each serve distinct purposes: the equilibrium phase indicates where the distribution of contrast is balanced throughout the vascular and extravascular compartments, while the washout phase refers to the time after peak concentration when the contrast begins to leave the tissues. The arterial phase captures images when the contrast is primarily located within the arteries, emphasizing vascular structures but not necessarily providing the breadth of information needed for routine imaging.

Thus, focusing on the non-equilibrium phase aligns with standard practices for conducting routine imaging with contrast, enabling effective assessment without the specific vascular emphasis of angiographic studies.