Radiopaedia Blog: Report

Everyone knows that radiology is a discipline of images. Perfectly penetrated chest radiographs, speckled T2 hyperintensities in the liver parenchyma, subtle fat stranding around the appendix on a noncontrast CT... these images are the domain of the radiologist.

But there is another domain of radiology that doesn't always receive enough attention: the words of imaging. One could even think of the duties of the radiologist as threefold:

  1. to obtain a high quality image
  2. to medically interpret the image
  3. to express the image and interpretation in words

Each is important.

When I listed the imaging findings above, your mind probably pictured them immediately. The words were a mediator between your mind and the image. Although the language of radiology is highly mimetic (representational of an "objective" reality, rather than creative), it is inevitable that the way in which we structure a report will change the way our reader looks at an image. A report is not a shadow of an image (a shadow of a shadow), but a lens through which an image is read. The way a report is structured can either obscure an image or shed light on it.  

Since this is the case, attention to the language of radiology is not optional. Words must be used carefully and deliberately in order to achieve the effect we want.

Active vs. passive voice

One effect that should be deliberately chosen is when to use the active voice and when to use the passive voice when writing a report.

The active voice is the more common way of constructing an English sentence:

  • "I dictated the report" (subject - verb - object)

The passive voice often implies the subject:

  • "The report was dictated" ("object" - verb)

This passive construction raises the question: "by whom"?  The report was dictated... by whom?

The passive construction is endemic to much scientific writing and by extension, to radiology reports. Take these common radiology phrases as examples:

  • ... was seen / can be seen (by whom?)
  • ... is/was noted (by whom?)
  • ... is shown  (by whom?)

Passive constructions often contain a form of "to be": is, was, been, were, etc. But the way to determine if a sentence is passive is to see what part of the sentence is being acted upon. If the subject is acting ("I am reading a study"), then the sentence is active. If the object of the action is the important part of the sentence ("The study is being read by me"), then the sentence is passive. For example, a report I read today contained the sentence:

  • "No discrete parenchymal mass delineated."

This is a passive construction (and an incomplete sentence).

So why do radiologists use passive forms so often?

It probably partly arises from good intentions. In medical writing, we try to remove the "I" as much as possible to achieve a (somewhat illusory) semblance of objectivity. There's probably some humility involved as well, not wishing to grandstand one's interpreting self to the reader again and again and again.

Probably the most important reason it's so pervasive is because it's unconscious. Most of us were trained that way. We absorb it by reading other reports. It's now a habit.

So why is there anything wrong with the passive voice?

The problem is that it gently tortures the English language. Sentences containing passive constructions are more grammatically complex and constant repetition of the passive tense becomes difficult for a reader to wade through. 

The passive voice also connotes a lack of confidence and adds "hedginess" to a report by artificially disassociating oneself from it.

Furthermore, some may subconsciously use this awkward construction to promote an illusion of complexity and academic erudition.

Compare these two examples:

  • "a 1.8 cm para-aortic lymph node is seen" (passive)


  • "there is a 1.8 cm para-aortic lymph node"


  • "in the ascending colon, a fat-containing submucosal lesion is noted" (passive)


  • "there is a fat-containing submucosal lesion in the ascending colon"

The first construction (the passive construction) is unnecessarily complex. Seen by whom? Even though the sentences contain the same number of words, one has to read the first sentence more slowly... the grammar is implying something, leaving behind some faint residue of mystery. The second sentence (the more active existential "There is..." construction) is simple and declarative. One can read it at top speed. There is no grammatical mystery.

There is no situation in which a passive voice is more clear and concise than an active voice.

So, active voice vs. passive voice... why should you as radiologist care?

You should care because over the remainder of your career you will probably craft thousands (or tens of thousands) of these important little text objects we call radiology reports.

If you're going to spend a good part of your life putting these things together, it's important to be conscious in your choice of voice. The active voice is easier on the reader. The active voice is often shorter, saving you valuable time over thousands of reports. The passive voice may seem nobly objective, but it's a strain on grammar and it could be abused as a subtle (and eventually habitual) way to avoid committing to the second duty of the radiologist, to medically interpret the image. 

Try experimenting with your reports by eliminating the passive voice (for instance, see the next blog post "Staying active: an exercise in reporting").  Your readers will thank you ("you will be thanked by your readers"?). You may even find that you prefer it, too.


Thanks to Tim Luijkx and Eric A. Blair.

When reporting follow-up studies the usual practice is to compare to the most recent previous study. Although generally this is a safe thing to do, with increased frequency of follow up exams in many disciplines, one runs the risk of not detecting subtle growth. If this occurs repeatedly then a tumor that may have significantly increased over time will have a series of reports all of which state “no change”.

As an example (Fig 1) look at 4 studies in a patient with a partially excised low grade glioma. Each study (A to D) is approximately 6 months apart. Note how hard it is to discern a change between adjacent pairs.

We simply cannot reliably detect subtle change. How much is below our change threshold will depend on many factors, such as the size and shape of the lesion, scan parameters and partial volume effect, slice position and patient position etc… Regardless, there is an amount below which we simply won’t be convinced that any actual change has taken place. This is obvious if you consider what would happen if you were to scan a patient every day. Even the fasted growing mass would look unaltered on sequential scans.

So what is the solution?

Look at older scans and consider what you expect the biological behavior of the process you are looking at to be; the more indolent the process the longer interval you need between scan pairs to detect change.

In the same patient as before, see how easy it is to see that there has been change when comparing scans 2 years apart (Fig 2).


My practice when assessing gliomas for example, is to look at the most recent scan, and then at the oldest valid comparison; one which does not have intervening surgery, and is not in the  immediate postoperative period.

You are then left with three possible outcomes from such a comparison:

  1. change is obvious even when just compared to the most recent scan
  2. no change when compared to the recent scan but some change when compared to the oldest scan
  3. no change when compared to both the recent and oldest scan

In the setting of obvious change, there is no problem, and in fact there is no need to look at older scans.

If there is, however, no change compared to the recent study but change is evident when compared to the older scan, I usually pull up a few of the intervening scans, to try and assess whether growth is gradual, or something has changed in the behavior of this tumor, suggesting dedifferentiation into a higher grade. After all a tumor that had been stable for years but suddenly starts to grow needs, at the very least, closer follow-up and probably also needs to be considered for a change in management. My conclusion then reflects this distinction; e.g. “Although there is little discernable change when compared to the most recent study, when compared to multiple previous studies dating back 4 years, slow steady growth is evident.”

Only if there is no change when compared to the most recent scan, and no change when compared to the oldest scan does my conclusion read “Stable”, and then I append the time period over which I am claiming no change to have occurred; e.g. “Stable, with no appreciable growth over the past 24 months”.

This approach is valid to all comparison studies, regardless of system or underlying pathology. I hope this approach is useful to you, and will stop you from merely concluding with “stable”.

Deciding what to include in the conclusion of a report is one of the most difficult but important challenges faced by a radiologist. It will come as no surprise to you that clinicians love a conclusion, so much so that it is often the first and only thing they read. And so here's my list of the...

1. Not having a conclusion

If your report is longer than three or four sentences then it really should have a conclusion. In my experience, radiologists most often omit a conclusion when they are unsure how to interpret the findings. Unfortunately this is precisely when a conclusion is most valuable, as it's likely the clinician will find the case difficult too.

Solution: Don’t be afraid to admit when you are uncertain.  Write your conclusion as if you are talking face to face to the referring clinician.

e.g. The parenchymal appearances in the lung bases are of uncertain significance and not clearly pathological. Comparison with previous imaging or a follow-up study may be helpful.


2. Repetition

Repeating your findings and descriptions such that the conclusion is almost as long as the body of the report defeats the whole purpose!  Often I find it is the radiologists who are insecure about the significance of their many findings that are most tempted to repeat them all in the conclusion.

Solution: Restrict your conclusion to short relevant descriptions only and never have a whole sentence without an interpretation.

e.g. Right anterior cranial fossa mass with appearances characteristic of a meningioma.


3. Not answering the question

Good clinicians almost always ask one or more specific questions in their referral. Ignoring or failing to address a question is a sure-fire way to alienate a referrer and may stop them ever sending a patient to you again!

Solution: Explicitly address the clinician's question in your conclusion.

​e.g. Normal study, with no evidence of appendicitis.

4. Irrelevant incidental findings

Including irrelevant incidental findings in a conclusion makes the important points harder to find. When the study is otherwise normal then it might be permissible to add one irrelevant incidental finding to the conclusion but even this is a questionable practice.

Solution: Only include an incidental finding in the conclusion if it warrants its own follow-up or management (e.g. Bosniak 2F renal cyst) or if it impacts the management of the primary condition (e.g. deviated nasal septum in a patient undergoing transsphenoidal surgery).


5. Guess what I am thinking

Many conclusions I read never actually state what the author thinks is going on. A statement of facts can mean nothing to a clinician without an encompassing impression.  For example, “Gallstones. Dilated common bile duct.” is nowhere near as useful as “Gallstones. Although choledocholithiasis is not definitely seen, given the common bile duct is dilated, a small distal stone is suspected.”

Solution: Always assume the clinician reading your report is tired, rushed and not familiar with the condition. Don't hide your diagnosis or the patient may be managed incorrectly.  


So that rounds out the top 5 mistakes made in radiology report conclusions. Hopefully now you can successfully avoid these pitfalls in your next reporting session. If you think of other important ones to add to these five then please leave a comment below.

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