Fig. 3.

Case of occult sacral fractures. Top row: These are axial CT cuts of an 80-year-old man who presented with low back pain. The CT scan does not demonstrate any obvious sacral fractures. Middle row: A lumbar MRI was performed on the same day as the aforementioned CT and revealed evidence of fracture lines/signal change (blue arrows). Bottom row: These are similar axial cuts from a subsequent CT obtained several days later, which demonstrate displacement of fracture lines (red arrows). CT computed tomography, MRI magnetic resonance imaging.