UMEM Educational Pearls

Title: Gadolinium - To Use or Not Use?

Category: Neurology

Keywords: MRA, MRV, non-contrast, contrast-enhanced, gadolinium, time-of-flight, TOF (PubMed Search)

Posted: 6/8/2016 by WanTsu Wendy Chang, MD
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Gadolinium - To Use or Not Use?

  • One advantage of MR imaging is the option between non-contrast vs. contrast-enhanced MR angiography (MRA) and venography (MRV)
  • How do they work and when should you use which?

Non-Contrast MRA/MRV Contrast-Enhanced MRA/MRV
How Does It Work?

* Time-of-flight (TOF) is a commonly used sequence

* Relies on flow of blood into imaging plane

* Difference between signal of blood and suppressed background tissue

* Similar to CT angiography/venography

* Higher intravascular signal purely from gadolinium-based contrast, not dependent on flow

Pros

* Does not require contrast

* Generally better image quality

* Shorter acquisition time

Cons

* Slow, turbulent, or retrograde flow may result in signal loss

* Over-estimates stenosis

* Longer acquisition time

* RIsks associated with contrast use

* Timing of image acquisition important

Applications

* Patients with allergy to gadolinium, renal dysfunction, pregnancy

* Evaluation of intracranial vessels and cerebral venous system

* Evaluation of stenoses and occlusions of the neck vessels and their origins at the aortic arch

References

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