Transient interruption of contrast

Transient interruption of contrast (TIC) is a common flow artefact seen in CT pulmonary angiography (CTPA) studies. The artifact is a result of an increase in the flow of unopacified blood from the inferior vena cava (IVC) to the right side of the heart, often during deep inspiration 1. This results in suboptimal pulmonary artery contrast enhancement despite optimal contrast administration 2. Optimal pulmonary artery opacification is essential to the diagnostic quality of a CTPA study 2. A short interruption in vascular opacification can lead to an indeterminate study or be misinterpreted as a pulmonary embolus 3.   

Transient interruption of contrast incidence is more common in pregnant women due to increased intra-abdominal pressure and becomes less common as patient age increases 2.

CTPA protocols vary slightly between radiology departments. Inspiratory breath-holding techniques are commonly used, however, there is debate in the literature regarding the influence of breathing and breath-holding on image quality in CTPA 2.

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rID: 73690
Synonyms or Alternate Spellings:
  • transient contrast interruption

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