Honestly I think as a whole radiologists do a great job. Hell, I think doctors of all ilks do a great job. Obviously there are bad ones. I hope I didn’t come across as trying to single any group out. It merely seemed like evidence for an opportunity to improve and be aware is all. Of course from the still somewhat naive POV of a lowly 4th year med student, for whatever that is worth.

@ccbowers:

In the latest SGU Dr. Novella discusses this and states that the scan was a normal sequential CT scan with a gradual increase in opacity of the gorilla over successive slides. I do agree, however, that the potential significant confounder I see here (which neuroradjacks implied) was that the radiologists knew they were in a study, were told to look for nodules, and were singularly focused on doing that rather than a “normal” read. I can’t imagine that the study would have been so flawed as to explicitly set up that sort of failure, but it could have happened anyways.

Indeed I continue to find it puzzling that radiologists would “look at” but not “see” the gorilla. I agree this may have to do with the task-specific attention that Dr. Novella suspects. I still think they would have stopped looking for anything else if/when they identified the nodule in the other lung. I very seriously doubt that anybody would identify the gorilla and simply choose to ignore it.

I happen to be one of those radiologists who mentions every little thing . And I agree it should be standardized. At least in my practice we encourage all readers to use similar format and verbiage so the ordering clinicians can expect some consistency in our reporting.

In your patient’s case, given the history of chest pain and lack of prior films for comparison, a radiologist should have identified and described vertebral compression fractures. If there are comparison radiographs and the fractures are not new, and if, for example, the patient just had a chest xray days before, I might not mention the fractures again. Given the additional details of your anecdote, it does seem more likely that the radiologist just didn’t look or didn’t see the fractures.

As for the surgical clip question, it is not an issue of acuity or chronicity in this case. Patients are often poor historians and do not report prior surgeries. It can be helpful to document evidence of prior surgeries for this reason. I cannot tell you how often I’ve received requests to perform an ultrasound specifically to evaluate the gallbladder on patients who have had a cholecystectomy.

I agree with Dr. Novella that recognizing bias and understanding how our eyes and brains process information will help at least identify if not prevent the potential for error. For now, I have raised my index of suspicion for unexpected safari animals on all imaging studies.

Indeed, I believe it was clear that I noted there may have been something to set up the failure, but it seems that the study actually tracked eye movements and found that the radiologists did actually look at that part of the screen. I can indeed understand not mentioning a compression fracture (we do use “crush” colloquially in my institution – perhaps it is because part of my education was in Australia?) if the radiologist thought it was chronic and not the point of the study. But not mentioning a gorilla? That still seems odd to me. I mean at the very least I would imagine it should register and make the radiologist laugh and realize immediately what the point of the study they were partaking was.

As for the compression fractures and the interobserver variability – indeed I think you are at least partially correct. My patient was admitted for suspected pneumonia but in the study order “chest pain” was specifically noted. To me that would indicate noting the fractures. And even then, I’ve seen plenty of reads where obviously old findings are mentioned. If you have a patient with surgical clips in place on an abdominal scan those are (at least in my experience – perhaps you can tell me different?) pretty much always noted even though they are obviously not acute and we know exactly what they are and why they are there. By the same token that the compression fractures were omitted due to assumed chronicity shouldn’t surgical clips be omitted from the report? (That is a genuine question – perhaps there is some legitimate reason to note the latter and not the former and I don’t know about it since I am not even graduated from medical school quite yet).

The differences in reporting styles almost certainly account for much of the interobserver variability. The question I would have then is wouldn’t it make sense to standardize the reporting and include chronic findings such that they can then be tracked and thus have more confidence in the read as well as confidence that there is no acute on chronic process? I know in certain cases comparison to old films is done and it is noted that there are or aren’t interval changes in chronic radiological findings – perhaps this is simply too time consuming and low yield to do routinely? (Once again, genuine question).

In any event, thank you for your comments. I really am not expert in the nuances involved, but as I said above it seems to me that if a radiologist is actually looking at the gorilla (which the eye tracking data seems to indicate) then it should have been noted – after all I doubt chronic gorillas is a mundane finding to be omitted from reports It just seems to me that the take home message from this is that anyone can become a little too focused on finding specific things to the exclusion of other findings. I seriously doubt it is horribly bad like many of the popular article titles imply or state outright, but something to be cognizant of and engender action to boost accuracy.

Anyways, my rambling thoughts over coffee before heading off to clinic.

After my reply, my friend sent me the link to a BBC article about this study. I confess, I was really surprised that such a huge percentage of radiologists missed this “finding.” It makes me wonder, too, whether there was something to the study design that set the radiologists up to fail. I also wonder if most radiologists identified the pulmonary nodule and assumed that was the finding they were meant to identify. We in the field call this “satisfaction of search.”

@SARA
Radiologists do use a checklist of sorts. In my practice, we have templates for our reports that remind us to look at certain structures.

@nybgrus
We all have anecdotes about missed findings. I myself have missed my share of abnormalities. That said, much of the interobserver variability in radiology reports probably has more to do with style. Some radiologists mention every little thing. Others choose only to mention things they think are important. In the case of your patient’s “crush” fractures (assuming you mean compression fractures) if the patient did not have back pain it may have been assumed that these were chronic and therefore not clinically important.

@petrucio
I am sorry to hear about your father. It is true that an 8 mm nodule should be identified by a radiologist (btw, they are called nodules not nodes. Nodes are usually lymph nodes). We have looked into getting CAD for chest CT because it can in fact be very tedious to look for tiny little nodules all over the place. We have a similar program in use for detection of small calcifications in mammography. That said, your characterization of radiologists and their compensation is unfair at best. In my practice the radiologists are compensated based on the number of days worked without regard for productivity. I do not know a single radiologist who rushes through cases to make more money. In real practice, there are many, many interruptions (e.g., from ordering doctors, technologists, phone calls) throughout the day. These interruptions are likely a real contributor to missed findings.

Forgive the rambling, I rarely comment. Thank you Dr. Novella!

Yes, this is a key distinction and I agree with the statements that follow.

“I thought the same the first time I saw the gorilla video; I didn’t see the gorilla then either.”

The gorilla in the video was very obvious to my eyes (and brain), and I find it strange that people often don’t see it. I have watched a lot of basketball in my life, which likely impacts the results because counting the passes does not require as much attention. The gorilla in the scan took me a while, despite the hint in the title.

I don’t disagree at all, except that I think it is very possible that those who see the gorilla are not “better” at their craft. More relevant to that issue is if they can identify unusual or atypical, but clinically relevant abnormalities.

I agree. And indeed there may be a very real possibility that the gorilla missing has nothing to do with actually missing pathology and could be utterly unrelated or even correlated by not causational and be pure coincidence.

However, what this tells me is that either the radiologists didn’t see the gorilla at all (which means they didn’t actually look at that part of the CT scan) or that they saw it and subconsciously discounted it as irrelevant.

In the former, I think we can agree that pathology could have existed there that they did not see.

In the latter, it seems a failure on my part that they could see something as obviously out of the ordinary and discount it as irrelevant without it even crossing concsious thought.

No matter how you slice it, without further data to suss out the potential confounders here, it seems reasonable to conclude that this is an example of genuinely missing something that shouldn’t be missed