Radiological Pareidolia: Christmas signs in x-rays

snowcap signFig 1 (Wiles et al., 2013). Snowcap sign.

BMJ is at it again with another festive Christmas article: We wish you a merry x-ray-mas: Christmas signs in radiology (Wiles et al., 2013). The abstract tells us that…

Radiological signs act as memory aids for clinicians and radiologists when attempting to recognise and recall how a particular radiological appearance relates to a condition. These signs are often associated with well known objects and several are related to Christmas. This article describes some familiar and more unusual Christmas related radiological signs that might be useful for trainees revising for examinations, as well as practising clinicians and radiologists.

But are the authors reading a little too much into these x-mas signs? Pareidolia is the phenomenon of perceiving a meaningful stimulus (such as the Virgin Mary) in random everyday objects or sounds. Let’s take a look at a few more images, and you can decide for yourself.

holly leaf signFig 4 (Wiles et al., 2013). Holly leaf sign.

And then things start to escalate…

snowman signFig 2 (Wiles et al., 2013). Snowman sign.


Christmas tree bladderFig 6 (Wiles et al., 2013). Christmas tree bladder.

A little silly, no?

Finally, I’ve saved the brain for last.

ivy signFig 5 (Wiles et al., 2013). Ivy sign. Selected coronal images of the brain. (A) Fluid attenuated inversion recovery and (B) T1 weighted image after administration of intravenous gadolinium. These images show increased signal intensity in the meninges, particularly overlying the right cerebral hemisphere. This is likened to the appearance of the ivy plant creeping over stones and walls (C)

I just don’t see it…


Further Reading


Elvis in potato chip neuroscience

The case of the haunted scrotum

Rorschach inkblots and the neuroscientific basis for pareidolia


witch dust extractor
The 14 July 14 1906 issue of the highly esteemed medical journal, The Lancet, had a review of a vacuum cleaner called theĀ “WITCH” DUST EXTRACTOR:

THE removal of dust from carpets, hangings, and furniture by means of the broom or brush is opposed to sanitary ideals. Such a method merely effects at its best the dislodgment of dust from one place only to fall upon another. In short, the carpet may be cleaned and may look brighter for the process, but the dust is only scattered and sooner or later appears elsewhere, as, for example, upon the mantelpiece, bookshelves, or pictures in the room. Moreover, the broom by no means removes the dust perfectly even from the carpet to which it is assiduously applied. At any rate, when suction is applied to the swept carpet a good deal more dust is seen to be extracted. This is very well illustrated in the application of the simple dust extractor known as the “Witch,” a model of which has recently been submitted to us for trial by the Witch Dust Extractor Co. of Temple Row, Birmingham.

At the time, there was a section of the journal called New Inventions.

New Inventions

The review continues, explaining the mechanism of action (it’s not electric) :

The way in which this appliance works will be readily understood from an inspection of the accompanying illustration. It consists of a pair of exhaust bellows worked by foot to which is attached a length of hose and in its turn an “extractor” shaped like a flattened out speaking-tube. On working the bellows a strong suction takes place at the mouth of the extractor which rapidly withdraws the dust from the carpet over which the extractor travels. Some idea of the force of the suction may be gathered from the fact that ordinary pins find their way into the receptacle for the dust which is contained in the exhaust chest of the apparatus.

Servants will love it!

Of course, the machine cannot be worked without expending some energy upon it but in practice it is said that servants prefer this kind of labour to the use of the broom and the result is much more satisfactory and decidedly cleaner in its application.

And finally, it’s scientific!

This system threatens to do away with the unscientific and clumsy method of sweeping the carpet, and those who have any care at all for the application of sanitary measures in the house will express no regret that such is the case.

witch_on_broom_04Free Clipart of Halloween Silhouette