Test your Knowledge

ECR 2023 will see the return of the popular session for general radiologists and residents at the end of their training looking for a simple update on subjects outside of their usual field.

The Case-Based Diagnosis Training session will offer an interactive way to test your knowledge in a range of subspecialty areas.

If you have any questions, please contact [email protected].

Imaging signs related to mnemonics

The term mnemonic is based on ancient Greek and stands for "memory aid". According to Wikipedia mnemonics are memory devices, which help to retain and retrieve information by establishing mental associations to existing knowledge. These connections can be visual, spatial, semantic or acoustic. By mentally linking items of a grocery list to well-known places in one’s bedroom, the brain finds it easier to recall, what needs to be bought. Successive pairs of items can be matched to a chain of images or stories to facilitate remembering them. Linking nouns to rhymes can also be a great way to encode engramming. By assigning a person, action or object to an item, which one would like to memorize, one can create a story line.

In Latin pons asinorum and German Eselsbrücke, this technique can also be called "donkey’s bridge". This is based on the fact that donkeys won’t cross a brook or river. Due to the reflection of the water, they can’t judge its depth and the ongoing journey will definitely be considerably faster, if the travellers won’t waste time pulling and pushing the donkey, but set to work to build a little bridge for the stubborn donkey to cross. By building mental bridges, we also help our stubborn brain to store memories, which it might be reluctant to keep. 

Ancient, medieval and baroque poets loved acrostics, where the first letters or syllables in each line of a poem transported a new meaning.

We radiologists are less sophisticated, but often use a composition of letters, which individually stand for the first letter of a series of differential diagnoses or anatomical descriptions. "I’m slow" is an appropriate means to bear in mind that thyroid orbitopathy affects medial, superior, lateral rectus and the oblique muscles in descending frequency (Fig. 1).

Numerical rules may aid in categorizing radiological findings. The 1-2-3 rule classifies ovarian anechoic structures: < 1 cm follicle, 1 - 2 cm dominant follicle, > 3 cm cyst. The 3-6-9 rule assists in judging normal bowel diameter (small bowel, large bowel, cecum).

"TTTL" in a retrosternal mass stands for "Thymoma, Thyroid, Teratoma and Lymphoma; "CROHNS" summarizes "Cobblestone appearance of mucosa, Rose-thorn ulcers, Obstruction of bowels, Hyperplasia of mesenteric lymph nodes, Narrowing of intestinal lumen and Skip lesions".

There is a long list of mnemonics for all sorts of pathologic findings both in general and subspecialized radiology, which probably not all of us know by heart.

Fig. 1


Figure 1.: Coronal fat suppressed 3 T T2 of a patient with thyroid orbitopathy predominantly affecting his left inferior, but to a lesser extent also his left medial rectus muscle. 

Help us to boost our mental associations by sending us your didactically most instructive mnemonics illustrated with pathognomonic images. We will open for submissions in October and keep it open until December 11th, 2022.

Come and join us and maybe you will win the award for your excellent work-up. Before and after the Interlude, you can try to solve clinical cases from ten different fields in radiology, where specialists then help to highlight typical characteristics and differential diagnostic entities.