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WWWTP #24 Answer…

July 1, 2015

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Trauma patient came in to the ED:

CXR 1

What’s Wrong With This Picture?

The patient’s chest tube is not inserted far enough.  It is also a bit high residing between ribs 3-4.

Chest tubes have a side port and a distal port for suctioning fluids, air from the pleural space.  There is a radiopaque line seen on the tube that is interrupted at the side port (see magnified image).  In this case the radiograph shows that the side port is subcutaneous and not inserted all the way into the pleural space.  The chest tube needs to be replaced!

Author:  Russell Jones, MD

Image Contributor:  David Barnes, MD

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What’s Wrong With This Picture #24 (WWWTP?)

June 26, 2015

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Trauma patient came in to the ED:

CXR 1

What’s Wrong With This Picture?

Author:  Russell Jones, MD

Image Contributor:  David Barnes, MD

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Student Corner: Air Everywhere

May 19, 2015

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This time, we have an interesting CXR to examine. There are three distinct places in the image below where air is in places it shouldn’t be. Can you identify them?

sp EGD 1

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Need a refresher on how to read a CXR? This post will help you out.

Scroll down further for the answer.

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PTX, SubQ, Pneumoperitoneum post EGD

Image Key: Blue arrows–supraclavicular subcutaneous emphysema; Purple arrows–pneumothorax; Red arrows = pneumoperitoneum

Pneumothorax: air in the pleural space

On an upright CXR, a pneumothorax is one of the more easily identifiable pathologies in the thoracic cavity. The presence of air separates the parietal pleura and visceral pleura, resulting in the lung tissue being pushed towards midline. This results in the edge of the lung tissue being easily identifiable (purple arrows). The rest of the cavity is devoid of lung markings.

It is important to note that the size of a pneumothorax can vary greatly. Therefore even if the absence of lung markings isn’t as striking as it is in this picture, the edges of the thoracic cavity should always be closely examined to see if there is any evidence of air. On the other extreme is a tension pneumothorax, which is defined as an expanding pocket of air in the thoracic cavity, which causes half of the lung to completely collapse and shift the mediastinal structures in the contralateral direction.

Pneumoperitoneum: air in the abdominal cavity

The presence of air in the abdominal cavity comes from two major sources: outside the body or the GI tract. Air from outside the body enters into the abdominal cavity through either iatrogenic (surgery, peritoneal dialysis) or traumatic (penetrating wound) routes. Air from the GI tract enters if any segment of the bowel is perforated (most commonly secondary to a duodenal ulcer). On an upright CXR, as is shown above, the air rises to the level of the diaphragm and can be identified.

Even though the subdiaphragmatic air in this picture is clearly evident, CXR’s are not the gold standard diagnostic test for pneumoperitoneum. Abdominal CT scans can pick up much smaller amounts of air that may be difficult to visualize on a plain film.

Subcutaneous Emphysema: air in subcutaneous tissue planes

The image above has distinct areas of radiolucency in the supraclavicular area as a result of air tracking in the subcutaneous tissue, which is defined as subcutaneous emphysema. The area is patchy from the infiltration of air into soft tissues.

Similarly to pneumomediastinum, the air comes from either inside the body (secondary to pneumothorax, pneumomediastinum) or outside the body (penetrating trauma, chest tube insertion site). The air travels along fascial planes between the dermal and muscular layers. Another, more serious, cause is necrotizing fasciitis. In this case, however, it is likely that the air entered into the subcutaneous tissues as a result of trauma, which also resulted in a pneumothorax.

Author: Jaymin Patel

Image Contributor: Katren Tyler, M.D.

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Rare arm fracture…

April 21, 2015

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Elbow GF1 Elbow GF2 Wrist GF 1 Wrist GF2

This patient presented with arm pain after a fall.  The radiographs obtained showed a distal radius fracture along with a radial head fracture (irregularity and bone fragment seen at the radial head).

I haven’t seen this fracture pattern before.  I’m not sure if it can be classified as an Essex-Lopresti fracture (radial head fracture accompanied by dislocation of the radioulnar joint).  In looking at the radiographs I believe the radioulnar joint is still intact.  However, I’m wondering if the clinical principle of the Essex-Lopresti fracture is maintained:  is there a disruption of the interosseous membrane between the radius and ulna.  This disruption can lead to serious long-term disability including pain, loss of pronation, supination and extension range-of-motion (1).

Has someone out there seen this before?  Any pearls of wisdom regarding this fracture pattern?

Author:  Russell Jones, MD

Imaging Contributor:  Joe Barton, MD

 

References

1.  Essex Lopresti Fracture.  Wheelessonline.com.  Accessed 4/2015.

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WWWTP #23 (What’s Wrong With This Picture?) Answer

March 12, 2015

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Patient presented with cough, fevers.  This Chest Xray was obtained:

WWWTP 21 1

One finding on this Xray is very concerning.  The Xray showed free air under the diaphragm.

A further diagnostic study was obtained (CT abdomen/pelvis):

WWWTP 21 2 WWWTP 21 3

Turns out this patient has pneumatosis cystoides intestinalis.  He has a history of this disorder and has had a prior laparoscopy showing multiple cystic structures in the intestinal walls.

Findings on imaging:

1.  Chest Xray:  Concern for free air underneath the diaphragm.  He also has a tracheostomy, pacemaker, scoliosis, and a right lower lung infiltrate.

2.  CT abdomen/pelvis:  The coronal imaging shows multiple cystic structures full of free air in the cecal area.  The cross-sectional imaging above shows a large amount of pneumoperitoneum.

Luckily this patient has a history of pneumatosis cystoides intestinalis.  He has had multiple abdominal CT’s showing similar findings.  Clinically he had no abdominal tenderness.  Keep this rare diagnosis in mind for the patient presenting with free air in the abdomen!  Information about pneumatosis cystoides intestinalis:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3235639/

Author:  Russell Jones, MD

Image Contributor:  Mary Bing, MD

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Rice bodies…

January 15, 2015

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Elderly gentleman came to the ED because he was wandering around the neighborhood.  A bystandard called 911.  He was pleasantly confused, had a mental status consistent with dementia.  The only other pertinent physical exam finding was some erythema, cellulitic appearance to his ankle.  We obtained a tibia and fibula xray looking for gas in the setting of cellulitis and this is what we found:


Rice bodies 2Rice bodies 1

 

The densities in the soft tissue of his legs are “Rice bodies.”  They are sometimes seen in systemic cysticercosis.  These bodies are calcified dead cysts from the organism Taenia Solium.  Typically this tapeworm is found in pork.  Taenia Solium is rare in the U.S., it is more prevalent in underdeveloped countries especially with a diet that has potential to include raw or undercooked pork.  This should also be on your differential with new onset seizures (1).

 

Multiple calcifications 1

 

He also had rice bodies on head CT.  Possibly the cause of his dementia?

Author:  Russell Jones, MD

References

(1) Parasites – Taeniasis.  http://www.cdc.gov/parasites/taeniasis/.  Accessed 1/2015.

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Student Corner: A Cavitary Lesion

January 6, 2015

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Cavitary lesions in the lungs are gas or fluid filled compartments in an area of pathology, such as a consolidation or a mass. Interestingly, a specific set of pathologies are known to cause this specific finding. Cavitary lesions can be detected on a chest x-ray, as is shown below.

cavitary-mass with IDCavitary masscavitary mass lateral with IDCavitary mass 2

Legend: Red Ellipse–cavity (with margins), Blue Ellipse–air-fluid level

The lesion practically jumps out of the picture on the AP view, but the colored circles are there just to point out the entire area of pathology (blue) and the cavity within (red). The pathology is a bit harder to see on lateral view, but the cavity has an air-fluid level that is easily identified as a vertical line separating a lighter fluid filled portion from an air filled portion. This air-fluid interface is often called a meniscus. You might remember being in chemistry class and measuring water out of tall beakers where the water stuck to the sides of the glass creating a concave meniscus. The surface tension of water allows it to stick to both itself and surrounding surfaces. If you look close enough, you’ll notice that the air-fluid level in the image above, best visualized in the AP view, has a slightly concave shape because the liquid at the bottom is sticking to the solid sides of the cavity.

The underlying pathophysiology is an interesting concept to understand when discussing cavitary lesions. A cavity can form in lung tissue for various reasons, but infection is the major underlying cause. Abscesses are localized collections of pathogens, fluid and immune system components that are walled off from the surrounding tissue, therefore creating a fluid-filled cavity. Tuberculosis is a disease process that involves caseous necrosis, which results in coagulation of cell proteins and liquefaction of cellular components. Eventually, the liquid portion drains out through the lymph system or through the bronchi, leaving air pockets behind. Necrotizing pneumonia and non-infectious processes such as ischemia and neoplasm can also cause a similar picture. Rheumatologic diseases such as granulomatosis with polyangitis and sarcoidosis also cause cavitary lesions by causing localized inflammation, which in turn leads to an area of increased mass, which then in turn can cavitate once the inflammatory reaction recruits fluid to the area. In other words, most of these processes, even if they aren’t inherently related to one another, all converge on the same mechanism of causing a localized area of inflammation.

With such a wide array of categories to choose from, it is perhaps more important than usual to contextualize the radiographic image with information about the patient.

This particular patient is a 30 year old male who presents with a cough.  He has been traveling around the world to multiple continents including Sub-Saharan Africa.  The extensive travel history, including to continents with rare infectious diseases leaves infection at the top of the differential. Things like Staphylococcal pneumonia, fungal infections and even amebiasis are possible because of the patient’s travel history. For a complete list of the infectious causes of a cavitary lesion, check the first two references at the bottom of the page.

References/resources:

Gadkowski LB, Stout JE. Cavitary Pulmonary Disease. Clinical Microbiology Reviews 2008;21(2):305-333. doi:10.1128/CMR.00060-07. (LINK)

Ryu, Jay H. et al. Cystic and Cavitary Lung Diseases: Focal and Diffuse. Mayo Clinic Proceedings , Volume 78 , Issue 6 , 744 – 752. (LINK)

Good pathologic image of caseous necrosis with resulting cavitation

Image Contributor:  James Luz, MD

Author:  Jaymin Patel

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What valve has been replaced?

December 16, 2014

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Here is a patient with a cardiac valve…he did not know which valve was replaced.  Which one is it?

Valve AP Valve Lat

RadDaily.com helps with this dilemma:

http://www.raddaily.com/whitepaperarticle.php?articleTitle=Cardiac+Valves:+Assessment+and+Identification

If we apply the rules from RadDaily.com to our patient, it appears he has an aortic valve:

Valve Lat EditedValve Lat

Valve AP editValve AP

AV = Aortic Valve*

TV = Tricuspid Valve*

MV = Mitral Valve*

PV = Pulmonic Valve*

*These are anticipated locations.  The locations could be altered if the patient has anatomic variations such as chamber enlargement, cardiac rotation, etc.

RadDaily also has additional information using flow directional clues from the shape of the valves.  Check it out!

Author:  Russell Jones, MD

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What valve has been replaced?

December 10, 2014

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Here is a patient with a prosthetic cardiac valve…he did not know which valve was replaced.  Which one is it?

Valve AP Valve Lat

Answer to follow.

Author:  Russell Jones, MD

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Student Corner: Ottawa Ankle Rules

October 14, 2014

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The Ottawa Ankle Rules are a set of criteria that are designed to help clinicians identify which patients that present with acute ankle injuries require imaging. The 1992 paper which outlined the criteria (PMID:1554175) consisted of a prospective study of 750 patients who came into the Ottawa Civic and Ottawa General hospitals with acute ankle injuries. The study was designed to record each patient’s particular presentation (area of tenderness, amount of swelling, ecchymoses, etc) and see if any aspect of their presentation correlated with a fracture identified on subsequent imaging (i.e. if a patient has pain over the medial malleolus, how likely are images of that ankle to show a fracture?).

MD Calc has a good summary picture of the criteria here. I’ll summarize it below as well:

A series of ankle x-rays is necessary if:

There is tenderness in the malleolar zone (lateral or medial) AND bony tenderness at the posterior edge of the medial malleolus OR bony tenderness at the posterior edge of the lateral malleolus OR an inability to bear weight immediately and in the ED

OR

There is tenderness in the midfoot zone AND bony tenderness at the base of the 5th metatarsal OR bony tenderness at the navicular OR an inability to bear weight immediately and in the ED

The picture on the link above is probably more helpful to visualize the algorithm. They note that 102 patients out of the 750 cohort had “significant” fractures and these criteria would have led to imaging on all of those cases. Also, they report that this criteria would have led to a 32.3% decrease in the number of radiographs ordered. The algorithm’s sensitivity was 100% and specificity was 40% for identifying fractures that were later confirmed by imaging. In other words, it was touted as a great screening tool since it was highly sensitive in picking up an ankle fracture.

(Note: The original criteria included an age stipulation, so that every patient with ankle pain [but not midfoot pain] over the age of 55 was recommended to get imaging. Additional research and subsequent modification of the algorithm proved that age was actually not a predictive variable. [PMID: 8433468])

Now on to a case:

Homeless male, in his 50’s, with ankle and foot pain after falling 10 feet. Walked into the E.D. with some pain, but had the ability to bear weight. Pt had swelling on exam, but no tenderness at the lateral malleolus, medial malleolus, mid foot or lateral foot.

The question is, do you get imaging on this patient?

Oh, look, it turns out we have criteria for that! And, in short, if you follow the Ottawa Ankle Criteria, the answer is no. The patient can bear weight and has no tenderness at any of the 4 areas that the criteria specifies, therefore according to the algorithm, imaging should not be ordered.

But we have a twist! This patient did indeed get ankle x-rays.

Ottawa Ankle 1

Why did this patient end up getting ankle x-rays despite not having met the Ottowa Ankle criteria?

Dr. Jones plays “devil’s advocate” in arguing against the use of the Ottowa Ankle Rules:

“Despite high negative likelihood ratio’s found on creation and validation of the Ottowa Ankle Rules, ED physicians are still ordering x-rays for most traumatic ankle complaints.  Why?  Because they are immediately available, low cost, and low radiation.  Many of our radiology decision rules pertain to expensive tests that are 10-100 times the amount of radiation (CT head, CT c-spine) and/or may not be readily available.  It is less practical to try and decrease a test that has little downside…such as an ankle radiograph.  

There is usually significant comorbidity associated with many different types of ankle fractures including calcaneal and talar fractures (I mention these because in my experience these are the two fracture patterns that are missed by the Ottowa Ankle Rules despite their reported 100% sensitivity…see the case above).  In our medicolegal environment in the United States, it is very difficult to defend missing an ankle fracture when you have a low cost, low radiation, readily available test at your disposal.  One must take into account that it is nearly impossible to recreate an exam with our current medical documentation.  A radiograph is an objective picture of a non-fractured ankle while a nicely worded exam is not so defendable in the eyes of a layman jury.  You open yourself up to legal problems if you miss a high-morbitidy injury because you used a rule that “decreases medical costs and increases efficiency” (these are the main benefits of the Ottowa Ankle Rules).  Courts are more patient-centered, they don’t care about our waiting room times!

We practice medicine taking into account more than just evidence-based medicine.  Until the “standard of care” we are held up to in court is in line with evidence-based medicine, we will always have to take into account the burden of the medicolegal consequences.  Be careful utilizing any clinical decision rules until they are universally accepted as standard of care among all ED physicians.  

I personally use “shared decision making” with most of my decision rule utilization.  My practice pattern using Ottowa Ankle Rules involves (1) A medical record documenting negative Ottowa Ankle Rules AND (2) a patient that understands the decision not to x-ray AND (3) the patient agrees.  This situation is rare but I will sometimes not x-ray if all the above parameters are met.  This is easier to defend if you happen to miss something by not getting an x-ray.  

The above statement is of course my own opinion and practice pattern.  Please utilize the Ottowa Ankle Rules as you feel fit and I appreciate any comments for and against their use in the ED.    

Russell Jones, MD”

So, there you have it. As is the case with many different areas of medicine, real-life practice varies from guidelines, rules and algorithms (even if they are backed up by multiple research studies) for various different reasons which include, but are not limited to differences in: availability of testing methods, medical setting, hospital policies, patient needs, legal considerations and the physician’s own interpretation of all of the above factors and the medical research/literature.

For students, this means that you’ll have to soon adapt yourself to an environment and way of thinking that takes multiple variables into account when it comes to decision making. Almost every patient is a different shade of grey, not black and white. After all, medicine is both art and science.

But, I digress from the patient. Can you spot the fracture in the above image? Answer below:

Calcaneal fracture with arrow

 

There is indeed a fracture of the calcaneus right around the inferior edge of the bone. Good thing this patient got imaging, right?

Author: Jaymin Patel

References:

Stiell IG, Greenberg GH, McKnight RD, Nair RC, McDowell I, Worthington JR. A study to develop clinical decision rules for the use of radiography in acute ankle injuries. Ann Emerg Med. 1992 Apr;21(4):384-90. PubMed PMID: 1554175

Stiell IG, Greenberg GH, McKnight RD, Nair RC, McDowell I, Reardon M, Stewart JP, Maloney J. Decision rules for the use of radiography in acute ankle injuries. Refinement and prospective validation. JAMA. 1993 Mar 3;269(9):1127-32. PubMed PMID: 8433468.

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