Magnetic resonance imaging of fluid levels in an aneurysmal bone cyst and in anticoagulated human blood.

Magnetic resonance imaging (MRI) demonstrated a fluid level within an aneurysmal bone cyst (ABC). Since the ABC contained gross blood at operation, an anticoagulated human blood sample was studied by MRI also, and a fluid level was again clearly visible. MRI pulse sequences emphasizing T1 contrast showed the fluid levels most clearly in both the ABC and the blood. Sequences emphasizing T2 contrast showed homogeneous, bright signals in the ABC and in the blood, with no visible fluid level in the ABC and a nearly invisible one in the blood. In the blood sample, the calculated plasma T1 value was 1585 ms, and that of the red cells was 794 ms.