COMT Practice Exam 2025 – Complete Resource for Exam Prep

Abnormal hypofluorescence in imaging typically indicates areas where the fluorescein dye is not showing up as expected in the scan. This can occur when there is an impediment to the normal flow of fluorescein through the vasculature or if there is a blockage within the structures being imaged.

The presence of blood can cause hypofluorescence because blood has the ability to absorb and scatter the fluorescein dye, preventing it from adequately illuminating the area being observed. In scenarios where there is hemorrhage or leakage of blood into the tissues, the fluorescein signal can be diminished, leading to an area of abnormal hypofluorescence on images. This phenomenon is crucial in diagnosing various ocular conditions as well as retinal diseases.

While blocked vessels can also cause abnormal hypofluorescence, the presence of blood is more directly involved in affecting the fluorescein signal in imaging studies. Therefore, focusing on the presence of blood as a main cause provides insights into the dynamics of fluorescein distribution and visualization in clinical imaging contexts.