Explanation

Magnetic Resonance Imaging (MRI) technique was developed by Felix Block and Edward M Purcell. This technique relies on the Nuclear Magnetic Resonance (NMR). MRI detects water because it focuses on the behaviour of hydrogen atoms in water molecule. It is especially useful in studying brain and spinal cord. Scapula and canine are osteocytic structures with negligible water content so, they do not appear in MRI