Radiopaedia Blog: Exam

28th Jun 2016 07:25 UTC

How much do I need to study?

"How much do I need to study to pass?" is a question asked by almost every radiology trainee as they approach their fellowship/board examinations. I recently passed the RANZCR part 2 examination series and thought I would share my experience. 


Procrastination and distraction are the trainee's nemesis, but there are two techniques I used that are useful to maximize efficiency:

  • pomodoro technique
    • 25 minute study blocks (same length as the viva examination) with 5-10 minute breaks in between
    • procrastinate and complete non study tasks in breaks
    • set a minimum number per day, easy to fit into the day (e.g. one before work, one at lunch (or work), and two after work = 100 minutes of study per day)
  • active recall with spaced repetition: essentially reading and then self-testing knowledge at intervals

These two techniques were the key to keeping on track, keeping study guilt under control, and feeling like I could get on with life. Active recall is difficult, it requires much more effort than passive study (such as note taking) but the results are much much better. 

Further viva techniques are discussed in Frank's blog "How to prepare for radiology oral exams: essential techniques".


I kept track of of how many minutes I studied, tutorials and lectures attended, and practice viva exams performed for the 258 days (approximately 8.5 months) in the lead up to my fellowship exams (although I "started" studying 8 months prior to this, just not effectively):

  • 430 hours solo study (not including tutorials, lectures, courses, etc)
    • average 166 minutes/day leading up to the written exams
    • average 74 minutes/day in the 10 weeks between the written and viva exams
  • 25 lectures
  • 114 film tutorials
  • 34 practice viva examinations (individual and in series)

I hope this gives some outline to what is needed. If you've done your fellowship/board examinations add your estimate or tracked time in the comments below, it'd be interesting to know!


Dr Henry Knipe is a radiology registrar at The Royal Melbourne Hospital in Australia, and is a managing editor at Twitter: @DrHenryK.

 NB: Opinions expressed are those of the author alone, and are not    those of his employer nor of


12th May 2014 01:09 UTC

Never surprise your examiner


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):

Version 1

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.

Version 2

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. 



Dr Frank Gaillard is a neuroradiologist at the Royal Melbourne Hospital, Melbourne, Australia, and is the Founder and Editor of

NB: Opinions expressed are those of the author alone, and are not those of his employer, or of


The term relevant negatives gets trotted out a fair bit. It should, as judicious use of actually relevant negatives is a crucial part of a quality report or oral description of a case. The problem is often the negatives given are irrelevant, or in some cases not only irrelevant but also imply that the speaker has no idea what he or she is talking about.

So what exactly is a relevant negative?

The “negative” component is fairly easy although there is confusion here also. A negative is the absence of a specific finding. It is not the same as a statement of normality. In other words “No hydrocephalus” is a negative. “Ventricles are of normal caliber” is not. The difference is important, as the use of a negative implies that a particular finding is specifically being sought and has not been found.

Now for the tricky bit; what does the “relevant” mean? Relevant to what? This is where most candidates get hopelessly confused and start muddying the waters by introducing irrelevant negatives. A relevant negative is the absence of a finding which would help in narrowing the differential diagnosis or would be important in management of the patient.


Crafting good relevant negatives

This is most easily explained with an example. Take the following posterior fossa mass (full case can be viewed here) and let's work out what are the relevant negatives are.

The trick is to first work out what the differential diagnosis for it is. Fortunately for this mass in a 60 year old female the likely differential is quite short: metastasis (common primaries include breast, lung, melanoma, RCC and GIT), hemangioblastoma and possibly a meningioma. We are not going to even consider an acoustic schwannoma or epidermoid as these are easily excluded by location and appearance.

Additionally as the patient is 60 years of age first presentation of von Hippel Lindau syndrome would be unusual, and it is probably safe to not dwell on it too much, lest you give the impression you do not know this.


Next you need to know which features are going to help you distinguish between them. They include:

  • large flow voids are common in hemangioblastomas
  • hemorrhage is common is RCC and melanoma metastases
  • broad dural base / dural tail are common in meningiomas (although can be seen in dural metastases e.g. breast cancer)
  • multiple lesions would favor metastases, or hemangioblastoma in the setting of von Hippel Lindau syndrome (unlikely in this age group).

You also need to think about management issues, the main one in this case is distortion of the fourth ventricle.


Relevant negatives in action

So here is how I would try and present his case. Relevant negatives are in bold.

  • Within the right cerebellar hemisphere is a rounded vividly enhancing mass with surrounding vasogenic edema. It exerts significant local mass effect, distorting the fourth ventricle but at this stage is not associated with obstructive hydrocephalus. The mass does not abut the dura, appearing intra-axial. It does not have prominent flow voids nor is there evidence of hemorrhage. No other similar lesions are seen either in the posterior fossa or elsewhere.

Then you can throw in some statements of normality if you really feel like it, although in this instance you have covered most things. You could go on and add:

  • The remainder of the scan is unremarkable for age.

Your next step would be your conclusion (or interpretation) and your reader / examiner won’t be at all surprised when you state:

  • Findings in this patient favor a solitary metastasis, and a lung or breast primary are most likely.

You don’t even need to go into why at this stage, because you have, by virtue of your description and judicious use of relevant negatives, already implied that you know the differential diagnosis and the important features of each.

It is important to note that sometimes a relevant negative does not preclude discussing a particular aspect of the case, and it would be prudent in this case to also add:

  • Despite no current obstructive hydrocephalus, urgent referral to a neurosurgeon is prudent and I would contact the treating physician to inform them of these findings.


Why is this so often done badly?

The problem with using relevant negatives well in the setting of an oral exam is that it requires you to have a differential very early on in the case, before you have described andy very much. This is usually the case by the time you get to your exam, but is usually not the case when you are starting out. So if have not been effectively practicing without wasting time or practicing your oral technique in the shower from the very start, you will not have been practicing the secret art of relevant negatives. The end result is that your descriptions will be longer, baggier, filled with seemingly random negatives and your examiner will be unsure of what you are going to say in your conclusion.

So, go back and practice. Look at your reports and the way you present cases and look for ways of introducing relevant negatives and removing irrelevant ones. This will have an enormous impact on how well you convey knowledge during an oral exam (see islands of knowledge vs puddles of ignorance) as well as allow you to create well crafted reports for the rest of your professional career.

Read next: Never surprise your examiner


Dr Frank Gaillard is a neuroradiologist at the Royal Melbourne Hospital, Melbourne, Australia, and is the Founder and Editor of

NB: Opinions expressed are those of the author alone, and are not those of his employer, or of



How do examiners, or for that matter your referrers or colleagues, form an opinion of your competence? This may seem like a glib question, but stop and consider.

An examiners duty, at a fundamental level, is to decide if you know enough about everything relevant to the practice of radiology to be unleashed on an unsuspecting and largely trusting public. How do they try and accomplish this daunting task? Well, they show you a handful of cases. Statistically this is not a very sound method, after all, even if you consider knowledge in a very superficial way, there are thousands upon thousands of individual facts, and during an exam only a tiny fraction of this knowledge can be directly examined.

So what do they do? They judge you based on a few answers and extrapolate from there to the totality of your possible knowledge. If that worries you, it should, but only if your technique is lousy.

A candidate with good technique will convince the examiner that each correct answer represents merely an example of a vast amount of untested knowledge, whereas each incorrect answer is an unfortunate fluke,  just happening to land in a tiny puddle of ignorance.

Poor technique, on the other hand, will convince the examiner of the opposite. Each correct answer represents a chanced up inconsequential island of knowledge stranded in a vast ocean of ignorance. Each incorrect answer on the other hand, merely confirms how little that candidate knows.


Thus, with exactly the same mix of correct and incorrect answers, your technique can give very different impressions, and in many cases be the difference between passing and failing.

So where does that leave you? Time to pack it in and go home and cuddle up to a large tumbler of single malt on the couch while watching The Wire for the third time (this is a fairly good plan at the best of times; The Wire is after all the best TV ever made)? Well, perhaps, but not because of the unfairness of exams. There is a relatively simple solution; stop studying and start thinking and practicing. It is my day to day experience that trainees have absorbed great quantities of factual knowledge but have not taken the time to tie all of it together, and that as a result in an exam setting, or when speaking to clinicians, they come across far more ignorant than they actually are. Now you need to take the time to work out how all these facts and disparate conditions fit together in the context of cases, and be able to articulate this quickly and clearly in an oral setting.

I have already covered some aspects of how to effectively practice without wasting time and how to practice your oral technique in the shower in previous posts, and in future posts I hope to also go into how to use cases as the starting point for study, the secret art of relevant negatives and why you should never surprise your examiner, but for now if you are in sight of your exams, let me leave you with this advice: you are better off practicing cases until you are limited by your knowledge and not your technique. Then and only then, hit the books again. 


Next: The secret art of relevant negatives


Dr Frank Gaillard is a neuroradiologist at the Royal Melbourne Hospital, Melbourne, Australia, and is the Founder and Editor of

NB: Opinions expressed are those of the author alone, and are not those of his employer, or of



Ok so this is nowhere near as lurid (or entertaining) as it sounds. One of the cornerstones to developing a successful oral technique for radiology exams is practice. The majority of this practice, as I discussed in the previous post on how to effectively practice for oral radiology exams, and not waste time should be on your own where you have the opportunity to work on each film, breaking down an oral exam into individual types of films. You can however take a step even further back by practicing the phrasing and choosing the words you want to use without the distraction of an actual film.

This might sound silly, but the last thing you want to be struggling over is how to phrase your discussion on the day of your exam. During your viva your mouth should be on autopilot, freeing your mind (what's left of it) to think about the case. To get to this point you must have developed a consistent presentation style. This acts as scaffolding upon which you hang stock phrases. The best way to do this (although this is not very time effective) is just to report thousands and thousands of films in your day to day work; this is of course something you should all be doing. Unfortunately exam cases are a different subset of real life cases. 

One way to create a polished style is to visualize a case and start talking, paying attention to the words and not the particulars of the case. A great place to do this is the shower, but of course you can do this anywhere else you are alone with some time to kill, and free from too many distractions.

No known copyright restrictions:

The sort of questions you should ask yourself during this exercise are:

  • does what I am saying make sense?

  • am I implying something I do not wish to imply? (e.g. if you use the term “cystic” when describing a necrotic glioma, the examiner may well wonder if you are thinking about low grade tumor, and later wonder if you understand what the word “cyst” means)

  • is my terminology precise? (e.g. one of my pet hates is the use of the word "density" rather than "intensity" when describing the appearance on MRI)

  • are my descriptions clear and concise? (e.g. when describing a mass, logically work your way through its macroscopic appearance, imaging features, relations to surrounding structures etc… 

  • am I clearly separating my description from discussion? Nothing creates the sense of confusion than jumping between findings and interpretation. 

  • am I including relevant negatives but not too many irrelevant ones? Think ahead of the differential you are going to entertain and make sure you touch upon the features of each. 

By practicing in this way, in or out of the shower, you should find that your presentation will be more polished and as a result you will be able to articulate the knowledge you have better.

Remember... (this is important, so pay attention): spending a few hours improving your technique will improve every single case you every get shown in your exam. Spending the same amount of time reading about a specific topic will probably result in no improvement, as you are unlikely to be asked about that particular condition. So unless you technique is awesome and much better than your knowledge, you should be spending more time in the shower. 


Next: Islands of knowledge or puddles of ignorance


Dr Frank Gaillard is a neuroradiologist at the Royal Melbourne Hospital, Melbourne, Australia, and is the Founder and Editor of

NB: Opinions expressed are those of the author alone, and are not those of his employer, or of


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