Article Type : Short commentary
Authors : Abdulwahab F Alahmari
Keywords : Pareidolia; Assessing radiographs; Radiology imaging
Pareidolia is the tendency for perception to ascribe a meaningful interpretation to an ambiguous stimuli, typically visual, such that one perceives an object, pattern, or meaning when none exists.
Pareidolia is the
tendency for perception to ascribe a meaningful interpretation to an ambiguous
stimuli, typically visual, such that one perceives an object, pattern, or
meaning when none exists. Pareidolia and patternicity are two techniques that
medical educators occasionally instruct medical students and resident
physicians (doctors-in-training) to utilize to learn to identify human anatomy
on radiology imaging examinations. Assessing radiographs (X-ray radiographs) of
the human vertebral spine is one example. Pareidolia is utilized to teach
medical trainees how to check for spinal fractures and spinal malignancies. According
to Patrick Foye, M.D., professor of physical medicine and rehabilitation at
Rutgers University, New Jersey Medical School (cancers). Normal bony anatomic
landmarks on spinal radiographs resemble an owl's face, (The spinous process
and spinal pedicles resemble an owl's beak and eyes, respectively). However,
the radiographic image alters so that the owl's eye now seems to be missing or
closed, which is known as the "winking owl sign," when malignancy
erodes the bony spinal pedicle. On a spinal x-ray, the "Scottie dog
sign" is another typical pattern. In a paper titled "Baby Yoda:
Pareidolia and Patternicity in Sacral MRI and CT Scans" from a medical
journal, Foye once more made a contribution to the existing knowledge on this
subject in 2021. He described a novel technique for viewing the sacrum on CT
and MRI scans. He observed that in some imaging slices, the human sacral
anatomy resembles the face of "Baby Yoda," a made-up character from
the television series “The Mandalorian” (also known as Grogu). The sacral canal
resembles the Baby Yoda's mouth, while the sacral foramina, which are sacral
holes for leaving nerves, resemble the baby Yoda's eyes. There is a published
book called Neuroradiology Signs by Dr. Ho which mainly focus on signs in neuroradiology
scans which basically another word for pareidolia and patternicity [1]. All
different signs like molar tooth sign of midbrain affected by joubert syndrome,
moose head sign of corpus callosum affected by dysgenesis, racing car sign of
corpus callosum affected by agenesis, etc. Pareidolia makes it easy for a
radiology resident to know how to different diseases appearances by using these
signs. There are many occasions where these signs do not follow the classic
pareidolia and patternicity. For example, a published paper did not show the
classic Mount Fuji sign of pneumocephalus [2].
The classic sign did not appear like in the classical way. Patterns and
pareidolia could lead to a wrong diagnosis, for inexperienced medical
professionals. Human nature can lead to illusion and started imagining patterns
that do not exist due to the tendency of humans to make a pattern from a random
stimuli. This method of teaching metaphorical signs can make the interpreter
see patterns that do not exist. This is like medical student syndrome when the
medical student start studying different disease then start applying it on
him/herself. Similarly, if you read about a rare medical condition that appears
in a certain way on radiology examinations and you became really interested in
this condition and you started looking in all your patients scans to find this
condition, your brain might trick you to imagine that disease appearance in all
of your patient in hope you find one which will lead you to the wrong diagnosis
certainly. For example, if you read a paper about eagle syndrome which is
calcified stylohyoid ligament, then when you see a long styloid process you
might think that’s it! This case must be an eagle syndrome patient! But the
measurements and the criteria differ by stating that the styloid process must
be above 3.2 cm and less than that is a normal length, not an elongated
process. The whole thing started by the interpreter obsession with a medical
condition and the interpreter wish (wishful thinking) to find this condition in
his/her patients. Pareidolia in such cases, will make it worse for sure! In a
study that was done to assess the usefulness of radiology signs in teaching.
Both groups were tested by showing them radiology scans. One group were taught
radiology metaphorical signs and the other group were not taught any radiology
metaphorical signs. It showed that the group who did not tough radiology signs
scored a 9% less correct answers than the group whom were taught the radiology
metaphorical signs. The issue is that 9% of the group whom did not taught the
metaphorical signs already mentioned the radiology signs in their answers for
some of the radiology scans which used to evaluate the ability of each group.
So the study result is not accurate [3].
Pareidolia can lead to
subjective opinions and lack of a well-established criteria for diagnoses. The
huge amount of radiology signs could lead to confusion rather than a good
approach of teaching and learning. Many classical signs do not appear in their
classical appearance in many patients. Therefore; the student need to be
informed that sometimes the signs maybe look in the same way, a little bit
different, or totally opposite to the classical sign.