For T1 weighted images, why is contrast enhancement used to rule out metastatic lesions of the spinal cord?

In T1 weighted images, the use of contrast enhancement is particularly effective for distinguishing metastatic lesions in the spinal cord due to the different enhancement patterns observed between lesions and normal tissue. Metastatic lesions typically exhibit an increase in vascularity and breakdown of the blood-spinal cord barrier, allowing the contrast agent to accumulate more significantly in these areas. As a result, metastatic lesions appear hyperintense (or brighter) on T1 weighted images after contrast administration.

In contrast, normal spinal cord tissue does not typically enhance in the same manner because it maintains intact blood barriers and lacks the abnormal vascular features associated with lesions. Thus, the enhanced visibility of metastatic lesions compared to the normal cord helps radiologists and clinicians effectively identify and rule out malignancies, aiding in accurate diagnosis and treatment planning.