Occult is used in radiology to refer to pathology that cannot be seen on more or more modalities. Most commonly it is used to refer to occult fractures on plain radiography, which are easy to see on MRI.
Examples of occult phenomena
Several disease entities have been commonly described as "occult", however this sobriquet can actually be used for any pathology that is concealed on one or more forms of imaging.
- occult cancer
- occult filum terminale syndrome
- occult fractures
- occult pneumomediastinum
- occult pneumothorax
Separately the term occult is also used to refer to a form of spinal dysraphism, in which no neural tissue is visible on physical examination.
History and etymology
The word occult is derived from the Latin term 'occultus', meaning 'hidden', itself the past participle of the verb 'occulere' meaning 'to hide' 1,2.