In vitro model of arterial stenosis: correlation of MR signal dephasing and trans-stenotic pressure gradients

Magn Reson Imaging. 1998 Apr;16(3):301-10. doi: 10.1016/s0730-725x(97)00304-4.


Purpose: Turbulent flow just distal to stenoses causes signal loss (dephasing) on magnetic resonance angiography (MRA). This study correlates dephasing with trans-stenotic pressure gradients in an in vitro model of arterial stenosis.

Materials and methods: Three-dimensional (3D) phase contrast, 2D time-of-flight, and 3D spoiled gradient echo MRA with/without gadolinium and varied echo time were performed for a system consisting of a peristaltic perfusion pump and a silastic vessel with stenoses of varying caliber. Length and diameter of dephasing jets were measured, and volumes calculated at varying pressure gradients and echo times, then correlated with percentage cross-sectional area stenosis as measured by conventional angiography.

Results: Dephasing occurred in all sequences at pressure gradients of > or =4 mmHg (1 mmHg = 133 Pa) and stenoses of greater than 70%, and varied directly with pressure gradient. The dephasing was greatest for 3D phase contrast (PC). Gadolinium did not diminish dephasing.

Conclusions: MRA signal dephasing at stenoses varies directly with pressure gradient. MRA may provide a non-invasive means for determining the hemodynamic significance of arterial stenoses.

MeSH terms

  • Arterial Occlusive Diseases / diagnosis*
  • Arterial Occlusive Diseases / physiopathology
  • Blood Flow Velocity / physiology
  • Blood Pressure / physiology
  • Contrast Media
  • Hemodynamics / physiology*
  • Humans
  • Image Enhancement / instrumentation
  • Image Processing, Computer-Assisted / instrumentation*
  • In Vitro Techniques
  • Magnetic Resonance Angiography / instrumentation*
  • Models, Cardiovascular*
  • Phantoms, Imaging*
  • Sensitivity and Specificity


  • Contrast Media