Accuracy and precision of MR velocity mapping in measurement of stenotic cross-sectional area, flow rate, and pressure gradient.
J Magn Reson Imaging
; 3(2): 433-7, 1993.
Article
in En
| MEDLINE
| ID: mdl-8448407
ABSTRACT
Reliability of magnetic resonance (MR) velocity mapping to assess severity of stenosis was assessed in vitro. Steady flow at different flow rates through five stenoses with a central orifice area ranging from 17 to 176 mm2 was measured with velocity mapping performed perpendicular to the stenotic jet. Besides determination of the stenotic cross-sectional area and flow rate, the pressure gradient was calculated with the modified Bernoulli equation and compared with manometer measurements. Cross-sectional areas were measured with an accuracy of > or = 76%, a precision of > or = 91%, and an error of < or = 19 mm2. Flow rates had an accuracy of > or = 72%, a precision of > or = 94%, and an error of < or = 1.4 L/min. The modification of the Bernoulli equation limited its reliability to stenoses with areas of 35-113 mm2. Pressure gradients were calculated with an accuracy of > or = 80%, a precision of > or = 88%, and an error of < or = 15 mm Hg. The method was applied in a single patient with aortic stenosis and gave estimates that agreed with those obtained by heart catheterization.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Aortic Valve Stenosis
/
Blood Flow Velocity
/
Magnetic Resonance Imaging
Type of study:
Diagnostic_studies
/
Prevalence_studies
/
Prognostic_studies
Limits:
Humans
Language:
En
Journal:
J Magn Reson Imaging
Journal subject:
DIAGNOSTICO POR IMAGEM
Year:
1993
Document type:
Article