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Pulmonary Embolism

Posted Sun, 04/27/2008 - 12:29 by Vikram Dogra
Images

Figure 1

Figure 2

Figure 3


Clinical History:

Pulmonary embolism in a 46 y/o female with chest pain and shortness of breath 


Findings:

 

Figure 1: Coronal reformatted CT showing prominent intra-arterial thrombus occluding a left lower lobe pulmonary artery.

Figure 2: CT image showing intra-arterial thrombus occluding a left lower lobe pulmonary artery.

 

Figure 3: CT image showing wedge shaped hyperattenuation with linear lung parenchymal bands and focal pleural effusion consistent with Hampton’s hump ( Pulmonary infarct) 


Diagnosis:

Acute Pulmonary Embolism. (Left lower lobe pulmonary embolism with small left pleural effusion and wedge shaped area of hyperattenuation consistent with pulmonary infarction.) 


Discussion:

 

Pulmonary embolism is a very common, serious, and notoriously difficult to diagnose clinical entity. In the United States, approximately 175,000 to 250,000 cases of PE are diagnosed each year with 50,000 deaths. Even with PE diagnosis, three-month mortality approaches 18%. There are numerous diagnostic modalities for pulmonary embolism, but CT angiography is the most widely available, fastest, most sensitive (83%-94%) and specific (94%-100%) non-invasive diagnostic tool available. Further, advantages over ventilation-perfusion scanning include very low number of non-diagnostic examinations (6%-7% compared to 39% with VQ scans) the ability to diagnose the other common causes of chest pain and shortness of breath in the thorax including pericarditis, myocardial infarction, aortic dissection, esophagitis, esophageal rupture, pneumonia, carcinoma, pleural disease and rib abnormailities. Risks of CT angiography include increased radiation doses, contrast induced renal failure, and contrast reactions.

 

I will refer the reader to the very well written and frequently sighted article by Saad & Saad for details regarding the diagnostic findings of PE on CT angiography. Below is a table describing some of the �classic� findings of PE on CT angiography. 

 

Acute Pulmonary Embolus CTPA

Findings

  1. Pulmonary arterial occlusion with enlarged pulmonary artery caliber
  2. Partial filling defect with acute angles with pulmonary artery wall
  3. Extra-pulmonary artery findings: 
    • Wedge shaped infiltrate
    • Linear parenchymal bands
    • Pleural effusion

Right heart strain:

  • RV dilation (RV > LV)
  • Deviation of IVS towards the LV
  • Reflux of contrast into hepatic veins

 

Chronic Pulmonary Embolus CTPA Findings

  1. Pulmonary arterial occlusion with diminished pulmonary artery caliber
  2. Partial filling defect with obtuse angles with pulmonary artery wall
  3. Extra-pulmonary artery findings:
    • Mosaic perfusion pattern
    •  Prominent bronchial collaterals

Pulmonary hypertension:

  • MPA diameter > 33 millimeters
  • Pericardial effusion
  • Pruning of the pulmonary vasculature

RV: Right ventricle, LV: Left ventricle, IVS: Intra-ventricular septum, MPA: Main pulmonary artery ( This table is reproduced from Reference 1)

 


References / Suggested Reading:
  1.  Saad W, Saad N. Computer Tomography for Venous Thromboembolic Disease. Radiol Clin N Am 45 (2007) 423-445.

Author

Andrew Tompkins, Chuck Hubeny and Vikram S Dogra,MD

Professor of Radiology

University of Rochester, NY

Sat, 01/29/2011 - 12:23
#1
anshu mahajan
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Very much informative case

Very much informative case with excellent description . Thanks for sharing SIR  !

anshu mahajan

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Mon, 04/28/2008 - 01:05
#2
drrajeshsharma
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Good quality informative images especially coronal reformation and Relevant discussion covering important imaging findings of PE is included in this case report.
I just want to add that classical triad of hemoptysis, pleural friction rub and thrombophlebitis is only seen in one third of the patients, and false positive clinical diagnosis of PE is made in about two third of patients, So Radiologist plays the most important role in the diagnosis of PE.
Radiologists should be aware of the fact that not on a an average PE has been found to be occulusive in only 40% of cases. Also cases of PE without infarction(40-90%) usually outnumber cases of PE with infarction(10-60%).

Dr.Rajesh Sharma MD, DMRD, Department of Radiodiagnosis, Government Medical College, Jammu (J&K) India

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Mon, 04/28/2008 - 05:28
#3
aliko76
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Joined: 04/10/2008

It's a demonstrative case. I want to learn that we can always assume Hampton's hump as pulmonary infarct or not?

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Mon, 04/28/2008 - 17:15
#4
Vikram Dogra
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Joined: 12/09/2007

If the area of consolidation falls in tha area of the artery with thrombus you can presume it to be Hampton's hump.

Vikram Dogra,MD

Vikram Dogra, MD Professor of Radiology,Urology & BME University of Rochester, NY

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