What space is the abnormality in?
Spinal epidural space.
What is the lesion in the T3 vertebral body?
Demonstrating high T1 and high T2 signal, almost certainly representing a vertebral haemangioma.
Extensive, acute epidural haematoma extending from C3 to T4 compressing the spinal cord. There is increased T2 signal within the cord, likely reflecting cord oedema.