Final answer:
Contrast agents are not used in Spin Echo True T2 imaging. They are typically used in pre- and post-administration for T1 spin echo images to enhance contrast.
Step-by-step explanation:
In Spin Echo (SE) or Conventional Spin Echo (CSE) True T2 imaging, contrast agents are not typically used. These imaging techniques rely on the intrinsic relaxation properties of the tissues being imaged.
Pre-and post-administration of contrast agents is commonly utilized in T1 spin echo imaging. Contrast agents are substances that can alter the relaxation properties of tissues and enhance the contrast of the images. Before the administration of the contrast agent, the T1 spin echo images show the natural relaxation properties of the tissues. After the administration of the contrast agent, some tissues will exhibit a higher signal intensity, while others may show a decrease in signal intensity, resulting in improved visualization and differentiation between tissues.