Please Correlate Clinically

Clinicians hate this phrase in a radiology report. I’ve heard fellow clinicians say “this means nothing” or “radiology doesn’t want to take any responsibility” or “that can mean anything”.

I used to be like that. But since I’ve had the opportunity to delve deeper into clinical decision making, I’ve changed my mind.

What this dreaded phrase means is that the radiology findings can mean different things under different circumstances. Radiology is not giving us the answer, radiology is giving us another piece of the puzzle. We as clinicians still have to put the pieces of that puzzle together. We have to see how this new data fits into the big picture, and try to make the oftentimes scattered data into a cohesive picture of useful information.

Let’s use an example that uses the exact same concept, but without the words “Please correlate clinically” attached. You order a CBC and the white blood cell count result returns at16,000. We know 16,000 is above normal and that’s about it from this single data point. We as clinicians have to put this data into a clinical context to give us some useful information.

Can this mean the patient is acutely sick?

If a patient chronically has this white blood cell count, then no.

Can it mean the patient is getting worse?

If the patient had a white blood cell count of 13,000 yesterday, then it indicates that the patient is getting worse.

Can it mean the patient is getting better?

If the white blood cell count yesterday was 22,000, the it indicates the patient is getting better.

Does it mean the patient has a serious infection?

If the patient has no symptoms of infection and has been on corticosteroids for an asthma attack for 3 days, then it points away from infection.

The same data can have different meanings depending on context.

Most clinicians won’t get frustrated and say “why didn’t the lab just tell me what the patient has?”. We’ll take the white blood cell count of 16,000, put it in it place in the clinical context, take a step back, and use that information to help figure out what’s going on with our patient. Basically, we correlate clinically and it’s no big deal.

A radiology reading gives us data just the same as the white blood cell count. We should treat it just the same. We should put all pieces of data about our patient together into the puzzle that is our patient. Our job as clinicians is to put those pieces together in a sensible, cohesive way to achieve our diagnosis.

Let’s see a couple radiology examples:

We have a chest x-ray with an ill defined, left lower lobe opacity. Radiology tells us, “Please correlate clinically”.

In one scenario, the patient has 3 days of fever, worsening productive cough, pleuritic chest pain, and a white blood cell count of 14. Sounds like the patient’s got pneumonia.

In another scenario, the patient has 3 months of weight loss, generalized weakness, and a scant, productive cough that is occasionally tinged with a small amount of blood. Here it Sounds like the patient’s got cancer.

Let’s see yet another example:

The patient had a CT of the abdomen. The small intestine shows an area of bowel wall thickening that could be consistent with inflammatory bowel or poor distension due to incomplete filling with oral contrast. Radiology tell us, “Correlate clinically”.

In one scenario, the patient has a week of worsening diarrhea, nausea, low grade fever, diffuse abdominal tenderness on repeat exams, and a white blood cell count of 15. Sounds like inflammatory bowel disease.

In another scenario, the patient has vomiting and diarrhea that started yesterday resolved just prior to arrival to the ER, has decreasing tenderness on repeat examinations despite only receiving fluids, feels hungry, and has a normal WBC. Sounds more like incomplete filling.

The take home message here is that “correlate clinically” just means you should put the pieces of the puzzle into place, and make the decision on the patient’s diagnosis as a clinician. Most of the time, you should be making the diagnosis, not the radiologist. The radiologist is there to help you make the decision, with one piece of the picture… not the whole picture. Sometimes radiology’s piece of the picture will be bigger, sometimes it will be smaller, but it will rarely be the whole puzzle.

So the next time the radiologist writes, “Please correlate clinically”, take this as a gentle reminder that you’re the one putting the puzzle together.

If you’re interested in learning more about clinical decision making (either a student, resident, faculty, or lifelong intern), please keep an eye out for my upcoming book tentatively titled A Guide To Making Clinical Decisions.

You may also be interested in my book on medical charting for clarity and medicolegal defensibility: The Handbook of Medical Charting