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Pulmonary Embolism Diagnosis : What Else The Radiologist Must Report!

Introduction

Pulmonary embolism is a potentially life-threatening condition and is the third most cardiovascular condition causing death, following myocardial infarction and stroke. Clinical symptoms and risk factors for pulmonary embolism are discussed in detail elsewhere, we shall discuss the imaging features. An essay writer is a person whose job is to create articles and this important topic will also be highlighted in an essay format.

Radiographs:

  • Not reliable for pulmonary embolism diagnosis, owing to poor sensitivity and specificity.
  • Help to rule out other causes of chest pain like pneumothorax and pneumonia.
  • Important from an academic reason as few examiners still like to ask named signs of pulmonary embolism (WHY!). I have mentioned a few mnemonics for remembering these.  
    • Hampton hump: peripheral wedge-shaped opacity corresponding to infarct
    • Fleischner sign: Prominent pulmonary artery (FLUSHED pulmonary artery).
    • Westermark sign: Regional oligaemia  (reduced marks).
    • Palla sign: Enlarged right descending pulmonary artery (PA prominent).

The writer assigned to write essay for me task about radiology topic is qualified to the same academic level or higher than your writing requirements.

Conventional Pulmonary Angiography:

  • Highly sensitive and specific.
  • Not feasible in all patients.
  • Reserved in patients where endovascular treatment is planned.

 

MRA:

  • Technically difficult.
  • Low sensitivity.
  • Can be difficult to perform in the acute setting.
  • Has similar results to that of CT pulmonary angiography if images have been acquired optimally and interpreted with expertise.

 

Nuclear Medicine: Ventilation-perfusion scanning

  • Ventilation-perfusion scanning is preferred in younger patients and in pregnant patients as it is associated with less radiation exposure than CTPA.
  • Lower sensitivity and specificity as compared to CTPA.
  • Detailed description for V/Q scanning.

 

CT pulmonary angiography:

Has replaced conventional pulmonary angiography as the reference standard for pulmonary embolism diagnosis because of its ease of performing and high sensitivity and specificity. The writer assigned to write my essay request related to radiology topic is qualified to the same academic level or higher than your writing requirements.

Additional screening for lower limb DVT can be performed as well.

Offers alternative diagnosis when pulmonary embolism is absent.

CT pulmonary angiography protocol:

Multidetector CT is preferred (at least 16 slices)

Caudal-cranial direction: Most emboli are located in the lower lobes and, if the patient breathes during image acquisition, there is more excursion of the lower lobes compared with the upper lobes.

IV access: 18- or 20-gauge catheter is preferred.

Pulmonary embolism-specific window: Window width, 700; window level, 100 

Detailed protocols can be accessed in this AJR article and here.

Diagnosis is straightforward in most cases.

Acute Pulmonary Embolism

Arterial lumen occlusion with failure to enhance with/without dilatation of the artery.

MIP images are good for diagnosis and documentation, especially coronal views (refer image below).

Partial filling defects:

“polo mint” sign: transverse view

“railway track” sign: longitudinal view.

Lung parenchyma findings

Peripheral wedge-shaped hyperdense areas and linear bands.

Chronic Pulmonary Embolism

Complete occlusion of a vessel that is smaller in caliber than adjacent patent vessels

A peripheral, crescent-shaped intraluminal defect that forms obtuse angles with the vessel wall

Thickened smaller caliber arteries due to recanalization

Secondary signs

Extensive collateral vessels

Mosaic perfusion pattern

Calcification within eccentric vessel thickening

Ancillary findings:

Pulmonary arterial hypertension: PAD diameter > 33mm or more than the adjacent ascending aorta.

Pericardial effusion.

 

Conclusion:

Pulmonary embolism diagnosis on CT pulmonary angiography is quite straightforward. An essay typer is a person whose job is to create articles and this important topic will also be highlighted in an essay format. Radiologists should also report additional findings that help prognosis, including the presence of right heart strain. It is essential to be a CLINICAL radiologist ourselves than writing “Clinical correlation is suggested”.