One of the more disquieting feelings one has while listening to trainees present cases, or for that matter when reading radiology reports, is not knowing what the speaker is going to eventually say the preferred diagnosis is. Now let me be clear about this; I don’t think you should be saying what the diagnosis is in your description, and in fact I think in most instances there are very good reasons for not doing this. What you should ensure is that your description contains all the relevant positive and negative findings (see secret art of relevant negatives) presented in a way that makes your eventual conclusion inevitable.
"Montmorency vs. Collins" Date: 24 Feb. 1897, Photographer: Frederick Lyonde
A perhaps somewhat stretched analogy is that each case you present is a criminal trial, and you are the prosecuting attorney. Your mission is to convince the jury of the guilt of the accused. Every piece of evidence you present should, from the very start, be seen to obviously fit into a an overall narrative. There is no point in presenting a jumble of seemingly random facts and only trying to tie it all together at the end. By the time you get to you closing arguments, the jury should know exactly what you are going to say. They should believe you and feel that they would have come to the same conclusions, given the obvious facts you have presented.
Similarly if you present the findings of a radiology case in this way (both when presenting orally or dictating a report), the examiner/reader can sit back and relax. They soon know where you are going, they feel that you are safe and that not only do you understand this case but also have a sound approach to all similar cases. When you conclude and give you preferred diagnosis, this only confirms what they have thought all along. Perfect. Next.
In contrast a poorly structured or worded description, with vague or inappropriate terminology results in examiner-anxiety (not yet recognized in the DSM). They sit wondering what you are going to say, and at the end, even if you come up with the correct diagnosis it feels a little accidental.
Contrast these two descriptions of the same lesion picture above (from this case):
In the left occipital lobe is a periventricular peripherally enhancing cystic or centrally necrotic mass surrounded by high T2 signal. It has curvilinear peripheral areas of low T2 signal and high signal on diffusion weighted imaging. No enlarged flow voids are seen, although I would review an MRA. The overlying cortex is not thickened, and the white matter elsewhere appears normal.
In the left occipital lobe a ring enhancing lesion is present with abundant surrounding vasogenic edema. The enhancement is relatively thin without nodularity with a slightly irregular outer border. It is thinner on the ventricular border which it is approaching, without evidence of ependymal enhancement or intraventricular debris or abnormal signal. The rim of this lesion also demonstrates a complete ring of low T2 signal. Centrally the non-enhancing component demonstrates vivid restricted diffusion.
Both are essentially describing the same features, but they differ markedly in what they are implying the lesion is. The first uses some imprecise terminology, and drops in some irrelevant negatives which would make an examiner wonder exactly what they were thinking. In the second description it should be obvious that the speaker thinks that this is a cerebral abscess (which it is).
Being able to generate the second version on the fly during a stressful exam does not just magically happen, and is not a merely a natural offshoot of reading numerous textbooks and memorizing cubic meters of knowledge. It requires practice (see effectively practicing without wasting time and practicing your oral technique in the shower) and focused attention on the words you are using.
Achieving this zen like state of awesomeness will mean that the handful of cases you present will convey to your examiners that you are knowledgable and have a good grasp of the topic, rather than floundering from one finding to the next. As always, never forget: improving your technique improves your performance on every single case, so it is well worth the effort. Not only that, but the same skills you develop here will directly translate in to written reports, which you will be generating for the rest of your professional life.
NB: Opinions expressed are those of the author alone, and are not those of his employer, or of Radiopaedia.org.