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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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Lunate dislocation…

September 30, 2014

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This patient presented with wrist pain after a fall:

 

Lunate 1Lunate edits

This is an example of a lunate dislocation.  The lunate can be seen on the lateral view (blue arrow).  It is dislocated quite a far distance.  Also note that the lunate is not in its usual location on the AP view.

The above radiographs are not subtle.  Keep in mind that lunate dislocation is sometimes not so obvious.  We visited lunate and perilunate dislocation on a prior post (lunate).  Stay tuned in the future for tips on reading wrist radiographs to avoid missing any subtle injuries.

Author:  Russell Jones, MD

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How to identify a cardiac rhythm device with CXR…

September 25, 2014

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How many times have you had trouble with figuring out what type of cardiac device (e.g. pacemaker/defibrillator) a patient has implanted?  A patient presented to our ED with chest pain, palpitations.  He did not have his device card with them, no prior visits to our ED, and did not know the manufacturer of the device.  How do you decide which company to call for interrogation?

Here is an article I found with radiologic characteristics of devices that can help identify which company produced the device.  It has a great identification algorithm they coined the CaRDIA-X algorithm:

http://www.ianchristoph.com/physician-resources-2/device_id.pdf

There are 5 major manufacturers currently:  Medtronic, Boston Scientific, St. Jude, Biotronik, and Sorin Group.  Each device manufactured by these companies have certain differentiating characteristics of can shape, battery shape, alphanumeric codes, capacitor shadows, coil types, etc.  Turns out you can identify the manufacturer using the device characteristics on chest X-ray relatively easily.

In the case I was describing above the patient had an easily identifiable Medtronic device and we were able to get it interrogated.  Our ED now has the algorithm posted at our doctor’s station so we can utilize it for device identification.

Author:  Russell Jones, MD

References

Jacob S et al.  Cardiac Rhythm Device Identification Algorithm Using X-Rays: CaRDIA-X.  Heart Rhythm 2011; 8(6): 915-922.

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Acromioclavicular separation…

September 15, 2014

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This person fell from bike and won’t move their shoulder:

AC separation 1 AC separation 2

On initial evaluation we actually thought this person had a shoulder dislocation (glenohumeral dislocation) because of the significant deformity visible externally.  They had the classic anterior “divot” on the shoulder and wouldn’t perform shoulder range of motion.  We were somewhat surprised when we found an acromioclavicular (AC) separation instead.

This case is a good argument as to why often it is appropriate to obtain pre-reduction X-rays for possible shoulder (glenohumeral) dislocations.  Unless the patient will allow a good exam, sometimes it is very hard to differentiate AC separation from glenohumeral dislocation without imaging.   In this case, if we went directly to attempted “reduction”  it would have been very difficult to “reduce” the shoulder!  Hence the need for an X-ray.

There are six different types/degrees of AC separation that are summed up well on the following LearningRadiology.com webpage:

AC Separation Types

 

Author:  Russell Jones, MD

References

1.  Acromio-clavicular separation.  www.LearningRadiology.com

 

 

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Student Corner: How to Read a Chest X-Ray Follow Up

September 1, 2014

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Here is the same CXR from last time.

 

CXR UL pna

Here’s some further information about the case:

Pt is a 52 y/o man with a history of smoking, atrial fibrillation, and HTN that presents to the ED today with a 2-3 day history of fatigue, weakness, fever, generalized body pains, drenching night sweats, increased urinary frequency, L ear discomfort, throat discomfort and blurry vision in the morning. The symptoms came on suddenly and have been constant since the beginning of the episode. The fatigue and weakness cause the patient to want to “drop into a hole” and sleep. His nightly sleep patterns have been disrupted by his night sweats and his increased urinary frequency. The night sweats are drenching and he often wakes up in the middle of the night with his shirt completely soaked. Around 8-9 AM in the morning he reports being cold and getting chills. He also has some lower sternal chest pain that occurs mostly with deep breathing. The pain does not radiate. The pt has a 30-35 year history of smoking cigarettes and drinking 15-20 alcoholic drinks/week. The pt stopped smoking yesterday with the intent to quit.

The pt has no change in appetite or weight, no new masses or lumps anywhere on his body and no syncope or LOC. The pt denies any history of similar symptoms. The pt denies any family history of these symptoms. The pt denies any sick contacts. The pt’s wife does not have similar symptoms. The patient has no N/V or history of recent travel. The pt was routinely tested for tuberculosis 2 years ago as part of an employment physical and the test was negative.

Vitals: BP 142/106 | Pulse 105 | Temp(Src) 100.6 °F (38.1 °C) (Oral) | Wt 228 lb (103.42 kg) | BMI 31.36 kg/m2 | SpO2 99%

Physical Exam: 

General appearance – alert, well appearing, and in no distress; slightly pale

Eyes – PERRLA, EOMI

Ears – bilateral TM’s and external ear canals normal

Mouth – mucous membranes moist, pharynx normal without lesions

Neck – supple, no significant adenopathy

Lymphatics – no palpable lymphadenopathy, no hepatosplenomegaly

Chest – clear to auscultation, no wheezes, rales or rhonchi, symmetric air entry

Heart – normal rate, regular rhythm, normal S1, S2, no murmurs, rubs, clicks or gallops, no pericardial rub on auscultation with patient leaning forward

Abdomen – mild suprapubic ttp without rebound/guarding

Neurological – alert, oriented, normal speech, no focal findings or movement disorder noted, CN 2-12 grossly intact

Skin – normal coloration and turgor, no rashes, no suspicious skin lesions noted

With all of that in mind, let’s take a look at the x-ray again. The last post went through the ABCDE methodology to review the image and the A through D aspect was pretty well outlined there. The airway is patent, there is no obstruction and it lines up with the cervical spinous processes. The bones have no step-offs or other evidence of fractures and there are 10 ribs visible. The cardiac silhouette is not enlarged (in other words, not more than twice the width of the chest cavity) and the AP window sits between the aortic arch and pulmonary artery. The diaphragm has normal contour and the costo-vertebral angle is sharp.

The E is where things get interesting. One of the ways I like to do it is to try and look for asymmetry in the lung fields. And I think I see something!

CXREXoriginal-finalread

The blue circle seems like a focal area of consolidation (either liquid or solid). That same “opacity” is not present on the corresponding place on the L lung field.  I think its important to note that this finding has a large differential diagnosis attached to it, even if you put the finding on the x-ray in context with the case presentation. Most of the diagnoses on the list would be infectious, like TB or pneumonia, but other possibilities include lung cancer, edema, hemorrhage and systemic inflammatory conditions like sarcoidosis.

The radiologist read that image as most likely a case of lobar pneumonia. There was some hedging by the radiologist on the read because the lateral film was taken from L to R, therefore the opacity in the R lung field was very hard to see (that’s why I didn’t include a lateral view as well, but we can save that particular x-ray type for another post). In general, you want to get two views on any pathology on x-ray because it’s important to try and construct a 3D image in your head about where the pathology is located.

In any case, his patient presented with fever, cough, loss of energy, chills and body aches, with all of those symptoms having an acute onset. This makes an infectious process more likely (I say “more likely” because as everyone in medicine learns at some point or another, it is very dangerous to talk and think in absolutes). He was treated empirically with antibiotics for pneumonia.

Hopefully this example helps you to have a system in place when you look at any chest x-ray. If you have any questions, feel free to drop them in the comments and I’ll do my best to answer them.  Also, if you have any requests for certain types of images you would like to see for the next post, also let me know in the comments. Until next time!

Author: Jaymin Patel

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