This imaging test is the most specific and detailed way to look at the body.
ct scan
pet scan
mri
nuclear medicine test

The imaging test that is the most specific and detailed way to look at the body would be a MRI scan. MRI scan give us the best spatial resolution and enable us to best view any part of the body, depending on which one we need. 

Nail fungus, which can cause the nails to crack, peel and change color and texture.