Prabhakar Rajiah MBBS, Presenter: Nothing to Disclose

Randolph Setser, Abstract Co-Author: Nothing to Disclose

Scott Daniel Flamm MD, Abstract Co-Author: Research grant, Koninklijke Philips Electronics NV Research grant, Siemens AG Medical Advisory Board, Vital Images, Inc

To determine if there is correlation between regurgitation grades measured in MRI by velocity-encoded phase-contrast imaging and echocardiographic assessment. In addition, qualitative grading of regurgitant jets using two different MRI (Flow sensitive echoplanar Imaging (EPI) and relatively flow insensitive Steady-State Free-precession (SSFP) sequences were also correlated with echocardiography.

62 consecutive patients were scanned at 1.5 T (Philips Achieva) for evaluation of aortic valve. Aortic regurgitant jets were assessed qualitatively with SSFP and EPI sequences and  graded as: 0, 1(lasting <1/3 diastolic fames,remaining near the valve), 2 (<1/3rd diastole, extending into LV), 3(>1/3rd diastole),  4 (throughout diastole). The regurgitant fractions (1 <15%, 2 16-25%, 3 26-48%, and 4 >48%) and volumes were calculated using a  velocity-encoded (200 cm/sec) phase-contrast image at the mid-ascending aorta. Regurgitant jet severity by echocardiography was obtained within 30 days of MRI and graded: 0 None, 1 mild, 2 moderate, 3 mod-severe, 4 severe. Kappa coefficients and regression analysis were used for detecting agreements and correlation between the different sequences and with echocardiography.

On qualitative analysis of the regurgitant jet, there was a good agreement between the EPI sequences and SSFP (R² 0.75, kappa 0.7), with the jet grade generally higher in the EPI than the SSFP group. There was better correlation between EPI and quantitative MRI than between SSFP and quantitative MRI (R² - 0.52 vs 0.29). Similar comparison of qualitative jet grade with echocardiographic grade shows similarly better agreement between EPI and echocardiography than between SSFP and echocardiography (R²-0.72 vs 0.49). There was good correlation between the MRI regurgitant fraction and echocardiographic regurgitant fraction (R²= 0.7, MR grade = 0.75 + 0.59*echo grade).

For qualitative analysis of aortic regurgitant jet, the EPI sequence is superior to  SSFP, with improved correlation of MRI and echocardiographic regurgitant grades. There was good agreement between quantitative MRI and echocardiographic grades, with MRI grades slightly lower than echocardiography.

EPI sequence  grades aortic valvular dysfunction similar to MRI regurgitation fraction, and enhances the value of MRI as a tool for comprehensive tool for assessment of valve dysfunction.

Rajiah, P, Setser, R, Flamm, S, MRI Evaluation of Aortic Regurgitation by Quantitative and Multiple Qualitative Techniques with Comparison to Echocardiography.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8012869.html