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Blood flow in coronary artery bypass vein grafts: volume versus velocity at cardiovascular MR imaging

Liesbeth P Salm1, Susan E Langerak, Hubert W Vliegen

  • 1Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands. l.p.salm@lumc.nl

Radiology
|July 27, 2004
PubMed

Insights

Cardiovascular magnetic resonance (MR) imaging effectively assesses bypass grafts after surgery. Velocity analysis offers similar diagnostic accuracy to volume flow analysis but is quicker, making it the preferred method for detecting significant stenoses.

Area of Science:

  • Cardiovascular imaging
  • Medical diagnostics
  • Biomedical engineering

Background:

  • Bypass surgery is a common procedure for coronary artery disease.
  • Monitoring the patency of bypass grafts is crucial for patient outcomes.
  • Cardiovascular magnetic resonance (MR) imaging offers a non-invasive method for graft assessment.

Purpose of the Study:

  • To compare the diagnostic accuracy of volume flow and velocity analyses using cardiovascular MR imaging for evaluating single-vein bypass grafts.
  • To determine the preferred MR imaging analysis method for detecting significant graft stenoses.

Main Methods:

  • Forty-nine patients with prior bypass surgery were included.
  • Coronary angiography and cardiovascular MR imaging of single-vein bypass grafts were performed.
  • Volume flow and velocity analyses were conducted and compared using Bland-Altman analysis and receiver operating characteristic curves.

Main Results:

  • Bland-Altman analysis indicated close agreement between volume flow and velocity analyses.
  • No significant differences were found in detecting stenoses of 70% or greater between the two methods.
  • Diagnostic accuracy for volume flow and velocity parameters was high (92% and 93%, respectively).

Conclusions:

  • Cardiovascular MR imaging is accurate for assessing bypass grafts.
  • Velocity analysis is a time-efficient alternative to volume flow analysis with comparable diagnostic accuracy.
  • Velocity analysis is recommended as the preferred method for evaluating bypass graft stenosis.

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