Tag Archives: Pneumonia

How to you tell its a right middle lobe infiltrate?

January 30, 2013

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This patient presented with a cough, fever, and dyspnea.  Here is her Chest Xray:

PNA RML

This is a great example of a right middle lobe (RML) pneumonia.  Some features that help distinguish the lobe include:

The right diaphragm is visible.  The lobe overlying the diaphragm is the lower lobe and a RML will sometimes not “silhouette” the right diaphragm.  “Silhouette” is when a radiographically dense material such as fluid comes into contact with another radiodense thoracic structure such as the diaphragm.  Silhouetting can be seen with the right heart border.  Thus, this fluid on the xray is touching the right heart border but not the diaphragm.  The lobe that corresponds with this is the RML.

A lateral radiograph can also help you identify which lobe is involved (not provided here).

Author:  Russell Jones, MD

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Its RSV season again!

January 24, 2013

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Don’t you love working Jan and Feb in the Peds ED?  Or as I like to refer to it as the Mucus ED.

What findings on Chest Xray are consistent with viral pneumonia?

Viral CXR 2Viral CXR

Viral respiratory infections commonly cause an “interstitial” pattern on Chest XR.   Interstitial patterns can also be found in atypical bacterial pneumonia from organisms such as Bordatella pertussis, Chlamydia pneumonia, and Mycoplasma.  Findings include peribronchial cuffing, perihilar infiltrates or “haze”.  Peribronchial cuffing can be seen on the XR above:

PB Cuffing

Other findings in interstitial patterns can include fluid in fissures, bands of atelectasis.

Bronchioles are usually very difficult, if not impossible to identify in cross-section on a Chest XR.  They look like a small clear circle with a thin wall.  However, when they are inflammed and have surrounding edema peribronchial cuffing occurs.  Basically you see a dense fluid around an air-filled bronchiole.  This can be seen in asthma, viral illnesses, heart failure, pertussis, and other pathology (1).  Here is a link to a good web image of peribronchial cuffing close up and on crossection:

http://www.torontonotes.ca/interstitial-disease/peribronchial-cuffing

It is important to note that the Chest XR can support your diagnosis of viral respiratory infection but it is not 100%.  Keep in mind the atypical organisms and prescribe antibiotics if highly suspicious.  Prescribing antibiotics in respiratory infections is a controversial topic with many different thoughts and practice patterns.  I’m not going to poke that sleeping bear…

Author:  Russell Jones, MD

References

1.  Broder JS.  Diagnostic Imaging for the Emergency Physician.  Elsevier 2011.  Pg. 241.

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Cough and fever

January 1, 2013

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Here is a good Chest XR showing an infiltrate which shows up on the lateral projection.  On the AP you can get a hint of infiltrate along the L cardiac border but it isn’t very impressive.  However on the lateral you can really see the infiltrate as you get into the diaphragmatic recess.  Normally on the lateral projection the vertebral bodies will become more lucent (darker) as you approach the diaphragm.  One of the signs of a left lower lobe pneumonia is loss of the vertebral lucency on the lateral projection (as in this case).  Other signs can be silhouetting of the diaphragm (the diaphragm will be obscured by infiltrate).

PNA Lateral 2PNA lateral 1

Author:  Russell Jones, MD

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