Diaphragm apertures: spinal levels
Anatomy   Wikipedia  
 Mnemonic:
Aortic hiatus = 12 letters = T12
Oesophagus = 10 letters = T10
Vena cava = 8 letters = T8
I ate 10 eggs at 12:
I = IVC ate = T8
Eggs = Esophagus T10
At = Aorta T12