Stop asking radiologists to rule out disease

When you get frustrated with my interpreting a chest x-ray as “atelectasis at the right lung base, pneumonia can’t be excluded,” trust me, I don’t enjoy it. But when you ask me to rule out pneumonia you leave me no choice but to tell you that pneumonia can’t be ruled out.

To rule out a disease a test must have a sensitivity of 100%, meaning there should be no false negatives. No imaging modality has a perfect sensitivity but the chest x-ray is nowhere near that perfection.

There are often blobs at the bottom of the lungs on a radiograph. In the vast majority these are areas of atelectasis, closure of parts of the lungs. Nearly all patients admitted in hospital have atelectasis. Here is the problem: it looks just like pneumonia. If I call one pneumonia I must call all pneumonia. This would mean that some patient somewhere is going to be put on Imipenem unnecessarily, develop pseudomembranous colitis all because of my interpretation. To reduce that possibility, I throw the ball back in your court by asking you to clinically correlate.

This is not good medicine. We can do better. You can tell me what you are actually thinking and I can tell you what I am actually seeing. Because when you tell me you really suspect pneumonia and I see that blob at the lung base, I will call it pneumonia, because I trust your clinical acumen.

When you don’t really think your patient has pneumonia, but just want to be extra sure because the patient’s temperature has marginally straddled beyond a threshold, and you want to feel you’ve done something by ordering a chest x-ray, be honest. Again, I trust your clinical judgment. I will call that patch atelectasis and won’t disclaim.

Better still, don’t order the test. Yes, you heard that right, don’t order a chest radiograph when you don’t really think the patient has pneumonia: fewer chances of a false positive. This would also mean that whenever you do order a chest x-ray or a CT scan a bulb will light in my frontal cortex, because I trust your clinical reasoning, and I know you are not the type to order tests frivolously.

But when you cry wolf, well you’ve heard the fable. But it won’t be you or I that will suffer, but the patient.

I am in the business of ruling in disease not ruling out disease. I am an adjunct to your clinical reasoning, not a substitute for it. I should mostly confirm your clinical suspicions, occasionally challenge them.

I am only as smart as the appropriateness of your imaging request. A diagnostic test is only as good as you make it. If you ask me to “rule out pulmonary embolism and aortic dissection, and whilst you are can you make sure he doesn’t have bowel ischemia and arterial clot,” my interpretation will read as if transcribed by a decerebrate pigeon. This is because I don’t know what you are thinking or not thinking. I have to assume the worst. My sensitivity rises, and specificity falls, and false positives abound.

Imaging findings are not binary: they are seldom all or none. They are a spectrum. There are shades of gray. Some of those shades are shared by both normal and diseased individuals. If I am forced to rule out disease I will either give lots of normal people disease or have to disclaim.

Help me help you by telling me truthfully your clinical reasoning. United we can be cleverer than Sherlock. By being divided and second guessing each other, we will lead to waste, over testing and poorer quality care.

Saurabh Jha is a radiologist.


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  • NewMexicoRam

    Maybe it would also be helpful of the radiologist would step out of the darkened room, examine the patient like they used to in med school, and help the clinician make the clinical correlation.

    • saurabh jha

      The equation is quite simple. Rubbish in, equals rubbish out. ALL sides need to improve their clinical acumen and resist fishing in ponds of impossibilities. It’s about prior probability. Simple Bayesian logic.

      • NewMexicoRam

        Yes, all sides need to do better at communication
        But your article does not indicate that.

        • Elmo

          Completely agree. I have not used the dreaded “r/o” phrase in at least a decade and no radiology dept I work with would complete the test with that phrase, rather a description of signs/symptoms. Perhaps Dr Jha, you should take this up with your radiology/hospital administrator as opposed to a rant on a website?

          • saurabh jha

            I applaud and admire you for your clinical acumen and restraint.

            But over testing is a national problem which leads to poorer quality care and waste. Of that there is little doubt.

            I have highlighted one etiology: fishing for improbabilities, a function of diminished clinical acumen. This is a recursive problem. A vicious cycle. Radiologists all over the country, indeed the world, will attest.

            There are no doubt others. And no doubt radiology needs to bolster its side.

            But not acknowledging a problem facing the aggregate because it may upset some good doctors is not really the way to solve the healthcare’s woes.

            So develop a thicker hide & keep up your good work. The nation’s healthcare is more important than our sensitivities.

            And Merry Christmas (or Happy Holiday or Happy New Year)!

          • NewMexicoRam

            You still have not adressed my point:
            Why doesn’t the radiologist examine the patient?
            It’s the only specialty I know of where the consultant does not place a hand on the patient, in most situations.

          • saurabh jha

            It might come to that if utilization is not managed, or they may be yet another party that interposes between the referring physician and the radiologist. Both scenarios would be rather regrettable, as it would mean that the work of a highly skilled professional is needlessly repeated and rendered redundant. A far better and more intelligent solution for all would be more judicious and contextual use of imaging that is mindful of prior probability of disease; would you not agree?

          • NewMexicoRam

            No, I don’t agree.
            Every other specialist who sees my patient EXAMINES the patient. Why do we expect any less from the radiologist?

          • saurabh jha

            Even pathologists examining excisions for tumor margins? Not to mess with semantics too much but an examination of your patient’s CT of the abdomen and pelvis is an examination of your patient. If the physical examination has declined it is not because radiologists are not physically examining patients (which is what I suspect your lamentation is about) it is because imaging is so easily available physical examination is rendered useless.

            On another note, 86 % of the diagnosis is afforded by history alone, as I am sure you are aware.

          • NewMexicoRam

            Pathologists don’t usually report “cannot rule out…..”

          • saurabh jha

            Oh yes they do. But at least we both agree that examination has a more expansive meaning than whispering pectoriloquy.

  • John C. Key MD

    There’s blame enough to go around. For decades I’ve not used the dreaded “rule out” phrase, and in fact radiology techs at my institution are instructed not to take a film if a succinct but relevant history is not completed on the request.

    So it is doubly frustrating to fill out the succinct, accurate, and to-the-point request, only to have the report returned clearly demonstrating that the radiologist has completely ignored said history and the clinical implications thereof…

    A plague on both our houses.

  • saurabh jha

    I am sure there is an element of truth in what you are saying.

    Emphasis on efficiency and output has pushed radiologists further away from the clinical context.

  • buzzkillerjsmith

    Most rads do the best they can with what they got, just like the rest of us.

    Question: Is there any movement on have x-rays read by machine, as ekgs are? With human over-reading of course.

  • saurabh jha

    You make an excellent point. There are many instances when the picture says a thousand words and an interpretation is noise rather than signal. I agree that there should be more “diagnostic consultations” which might sometimes lead to imaging being foregone.

  • saurabh jha

    Very mature attitude and I am confident that you will be diagnostically sensitive without compromising specificity with the emphasis on clinical context that you have recognized.

  • saurabh jha

    Quite correct. They should not be asking for serum creatinine in hypotensive and trauma patients. Also, d-dimers should not be in the panel of tests that all patients get for any presentation. False positive d-dimers can wreak havoc. Clinical context is everything and it seems you recognize that. Oh, and if you insist that PE is ruled out you will end up with a whole lot of sub-segmental emboli versus mixing artifact. Limitation of the test, I am afraid.

  • ClinicalPosters

    Patients are caught in the middle of the unwillingness of doctor or radiologist to commit. It prolongs diagnosis and increases expense. I recently underwent three different imaging technologies that led to seven medical conclusions. Eventually, excisional biopsy was required to try and make sense of the confusion.

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