MRI for diagnosing aortic valve stenosis : a comparison study of MRI and ultrasound

In cases when Doppler ultrasound examinations are not reliable for determining the severity of aortic valve stenosis, patients undergo a catheterisation. Cardiac magnetic resonance imaging (MRI) is a promising tool for the determination of this disease. Aim. We investigated the value of MRI as a substitute for catheterisation in such circumstances, by comparing MRI measurements with Doppler ultrasound measurements. Methods. Five volunteers and ten patients entered this study, which was approved by the Institutional Ethics Committee. A 1.0T MRI scanner was used for cardiac MRI. On the same day, a Doppler ultrasound examination was performed. The maximum velocity and the orifice area of the aortic valve (called orifice) were compared. Results. A good correlation was observed between the maximum velocity measured with MRI and that measured with ultrasound (r2=0.95) and between the orifice determined by MRI and by ultrasound (r2=0.94); however, the orifice determined by MRI is consistently larger than the orifice determined by ultrasound. Conclusion. MRI measurements of velocity and orifice of the aortic valve correlate well with Doppler ultrasound measurement. MRI is a useful diagnostic tool and can be a good substitute for catheterisation, in particular because it allows simultaneous acquisition of anatomical and functional information.