What MRI characteristic is associated with fluid-filled masses like a ganglion cyst?

Fluid-filled masses, such as a ganglion cyst, typically demonstrate certain MRI characteristics that can help in their identification. These masses are usually filled with synovial fluid, which has specific magnetic properties.

When imaged with MRI, fluid is characterized by low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. The low T1 signal is due to the high water content of the fluid, which reduces the T1 relaxation time. In contrast, on T2-weighted images, the high signal intensity occurs because T2 relaxation time is prolonged in fluid, making it appear bright.

This distinctive imaging characteristic—low T1 signal and high T2 signal—is essential for radiologists and clinicians to accurately diagnose and differentiate ganglion cysts from other types of soft tissue masses or lesions. Recognizing this pattern is critical for diagnosis, as it can influence the management and treatment plan for the patient.

The other options suggest various combinations of T1 and T2 signal intensities that do not accurately represent the typical MRI findings for fluid-filled structures.