Pitfalls: Introduction

Introduction to the Pitfalls Course

Welcome to the Pitfalls course.

I don't think you'll find a lot of other courses like this around the country.

I've had a number of comments from people saying, I'm glad you're doing this, because this issue of pitfalls and errors in radiology and how to avoid them is obviously of great importance to radiologists.

And there have been a lot of new insights into how to detect and prevent these errors.

And we'll be addressing those in this meeting.

I'm Mike Federally. I'm the organizer of the meeting.

It's sponsored by IAME, as you know.

Importance of Pitfalls and Errors in Radiology

I believe that pitfalls and errors in radiology are relatively common and certainly important.

They lead to unnecessary morbidity, mortality and expense.

It's a common source of malpractice claims and it's under close scrutiny by government, by payers, and by licensing agencies.

And you can't pick up medical journals or the New York Times or anything else without being aware of that, I think.

I'm just by way of introduction, and I think Giles Boland who follows me here will be addressing some of these as well.

Sources of Misdiagnoses

What are the sources of these misdiagnoses?

One of the ones we're always taught in radiology residency is satisfaction of search.

You see an abnormality and then your brain kind of goes soft and you don't recognize additional abnormalities on the study.

Misinterpretation of imaging is a more complex issue, one that can only be addressed by reading and training and practice poor or incorrect technique or protocol.

And that's something you can find a lot about in the literature.

But I don't think it's done optimally in many cases, failure to review multiplanar reformations.

This is something that's increasingly taking an important role in my own practice.

Satisfaction of Search: Definition and Examples

Satisfaction of search, premature termination of your search after identification of one abnormality resulting in missed findings.

It was a nice letter to the AJR by Dr. Chu and colleagues.

And I'm gonna show some images with proper accreditation from that article.

Really very brief article that just highlighted a personal experience with this, with four cases that occurred in a four month period at a single institution.

And I think it was actually kind of brave of these doctors to say, look, we screwed up on these things.

We learned from them and maybe you can learn from our bad experience as well.

So a 55-year-old woman with endometrial carcinoma and they saw and correctly described and staged the carcinoma and so forth.

And what they didn't note was a lesion in the spinal canal.

And I think that would be easy enough to miss, I think in this case, on the sagittal view, and maybe some of us only are looking at the vertebral column, the spinal cord tumor is quite evident.

Of course, all these things are more evident in retrospect.

I think this might be an example of where multiplanar reformations are useful, but also it's a good example of the satisfaction of search issue.

This went on to be a diagnosis in Appendamoma and led to caught Aquinas syndrome.

But the diagnosis wasn't made till five months after that initial study from the same brief communication.

An older woman who presents with renal colic and they correctly identify the ureteral stone.

Again, easy enough to miss a subtle little mesenteric mass with calcification.

And this is a classic satisfaction of search thing.

And that went on to be recognized much later as a carcinoid tumor.

The mask gets bigger, liver metastases and so forth, rectal cancer correctly staged, recognized all the rest.

In this case, they recognized the dilated pancreatic duct and they attributed it to chronic pancreatitis.

Now, actually, in my estimation, I wouldn't call that as a satisfaction of search.

I think that's a misinterpretation 'cause they actually saw the finding but misinterpreted the significance.

This went on to be correctly recognized much later as an IPMN intraductal, papillary, mucinous neoplasm.

And that had a bad outcome as well with malignant degeneration and so forth.

Articles on Types and Sources of Errors

There are many articles, especially over the last few years that have been addressing the types and sources of errors.

Here's another one. And they talk about poor image interpretation, false negatives, exceeding false positives.

And the ones that they came up with more often than others were bowel and pancreatic tumors, pulmonary emboli, vascular lesions such as occlusions, aneurysms, dissections, bone lesions, and a mental and peritoneal disease.

And I'll tell you, I've done a lot of medical legal consulting over the last 30 years, and I would've come up with the same list of cases that keep coming up over and over again as missed lesions or misinterpreted lesions in body imaging.

Miscellaneous the wrong diagnoses, 62% were on CT scans.

And I think that just matches the prevalence of CT in all of our practices and the fact that if you've got this permanent record on CT of essentially every organ system that's in the field of imaging and there's almost an infinite number of potential abnormalities that could be detected or mist, the value of routine use of coronal and sagal reformations has been addressed in specific articles and there is a statistically significant additional information available in on those reformations.

Value of Multiplanar Reformations

Sagal images in my experience, are especially important for recognizing abnormalities of the abdominal vessels, the spine in the kidneys.

For instance, I have several times seen renal masses that extend off the upper or lower pole of the kidney that on axial images alone are difficult to attribute to a mass and may actually just be misinterpreted as a portion of the kidney.

The coronal images in my anecdotal experience routinely show much more evident mesenteric lymphadenopathy and are important for tracing bowel abnormalities and correctly localizing them.

Missed Lesions and Protocol Errors in Oncologic CT

Missed lesions on oncologic CT protocol errors.

This is a big, big issue.

You really need specific protocols tailored to specific tumors.

So using one contrast enhanced technique for all of your cancer patients just doesn't cut the mustard.

So primary endocrine tumors, when you're searching for hepatocellular carcinoma in a cirrhosis surveillance protocol, you absolutely need multiphasic imaging for detecting renal masses and characterizing them.

You need multiphasic imaging interpretive errors, inadequate search pattern, failure to use optimal window settings in reformations.

Again, and these are just other things we've already talked about.

Blind Spots and the Role of PET/CT

Blind spots, subcutaneous tissues, paraspinal muscle breast.

I've included lectures by one of my former colleagues, Todd Blott in this meeting specifically on PET ct.

And we were able to have experience with the first clinical PET in Pittsburgh when I worked there.

And when I started interpreting PET ct, it was amazing to me how many blind spots I realized I had been missing by just interpreting CT scans alone.

So PET can really make one a better interpreter of routine ct.

A radiologist accustomed to reading PET CT scans can become a better interpreter.

And that's definitely been my experience.

Blind spots, especially bone metastases, muscle metastases, subcutaneous metastases, et cetera.

Specific and Common Errors

Specific and common errors, lymphadenopathy, inconsistent size criteria, mistaking these run a pacified blood vessels or bowel steatosis.

I'm going to address that specifically in my liver. Talk.

Easy to mistake for tumor positive or false positive or negative unfamiliarity with newer principles.

For instance, you've got somebody who has a GI stromal tumor, a gist, you got imaging study at baseline, then the patient goes on treatment and on the next study the lesion is increased in diameter and you say, well increase in diameter.

The patient's doing badly, not necessarily.

If the lesion has now become devascularized, no longer enhances that patient, that may actually be a very good response.

So we need to be familiar with some newer concepts.

Value of Delayed Phase Imaging

Value of delayed phase imaging.

Some of my colleagues have written this up.

So for geneal urinary work, we always produce or add in a delayed phase of imaging.

So it helps with renal cell carcinomas as well as transitional cell renal sinus cyst.

Not a big deal, but you can easily mistake a renal sinus cyst for hydro nephrosis.

You probably know if you don't get delayed imaging.

The adrenal mass protocol for distinguishing, especially a lipid poor adenoma.

It's the best means of diagnosing lipid. Poor adenoma is much better than non-contrast CT or Mr.

Examples in Vascular, Hepatobiliary, and Trauma Imaging

Vascular imaging in trauma and in evaluation of patients with aortic stent grafts, hepatobilliary, again, you need multiphasic imaging if you are going to adequately characterize most hepatic masses.

Typical HCC hepatocellular carcinoma, hard to see on the non-contrast, easy to see on the arterial phase imaging and then it washes out.

In this case, it washes out to being hypodense to the liver, which is really the definition of washout with those criteria.

That is such a specific set of findings that this is as good as a biopsy.

So when we do our weekly liver transplant tumor board, this patient does not get biopsied.

This patient goes on to therapy based on the imaging findings alone.

Cholangiocarcinoma, which can also occur in patients with chronic liver disease, has a very different set of findings.

You've got capsular retraction, it does enhance.

But unlike the washout on delayed phase imaging here, it's quite the contrary.

There's actually delayed persistent enhancement of the mass, again, essentially diagnostic of the peripheral or intrahepatic cholangiocarcinoma in the setting of trauma.

It's useful to have an early and a later phase of imaging.

In this case. The later phase more clearly shows active extravasation, which is the most important criterion determining management of somebody with abdominal traumatic injuries.

Aortic stent grafts, no leak noted on the initial phase of imaging.

On the later phase, we see an obvious endo leak, clearly an important finding.

Summary and Faculty Introduction

So in summary, pitfalls and errors in radiology are common.

We all know that. And this course is meant to review the many types and of errors in different organ systems and in different modalities.

And importantly, how to avoid them helping in this endeavor.

I'm pleased to say we've really put together an outstanding faculty in my humble opinion.

Jen Bennett is from NYU, where she's an assistant professor of radiology and O-B-G-Y-N, by the way, I've heard all of these speakers give talks on these topics and they are outstanding.

Todd Blot, you'll be seeing tomorrow, who is the president of FRG Molecular Imaging, specializing in PET ct Giles Bolen, who will follow me to the podium, associate professor and vice chair at Harvard, mass General Hospital,

Jaffe Lipson, who's one of my colleagues at Stanford in the mammography women's imaging section, Nancy Major, who many of you have probably heard since she's a common speaker at continuing education meetings, director of Imaging and Orthopedic Associates, Ali Kota, I'll be introducing in more detail later this morning.

Professor at uc, Irvine Rick Webb, one of my former colleagues at UCSF and I am at Stanford as well.

With that, thank you.

Welcome to the course, and we'll move on now to the first of our formal talks.