Functional parameters of the left ventricle determined by MRI.

Purpose: To prove the accuracy of MR methods in the determination of left v entricular (LV) functional parametes and anatomy. Materials and Methods: At 1.5T, 20 healthy volunteers and 22 patients with aortic valvular disease ( stenosis n = 15, regurgitation n = 7) were examined. Functional parameters like cardiac output, ejection fraction, end-diastolic volume, aortic flow m aximum, and time interval from the R-wave to maximum flow were obtained usi ng a velocity encoding 2D FLASH sequence (T-R 24 ms, T-E 5 ms, venc 250 cm/ sec) and segmented breath-hold cine FLASH 2D technique (T-R 100 ms, T-E 4.8 ms, flip angle 25 degrees, temporal resolution 50 ms). Invasive measuremen ts (Fick principle) served as gold standard, intra- and interobserver varia bility were determined. Results: Differences of functional parameters betwe en normal volunteers and patients were detectable at a high level of signif icance (p < 0.0001). For cardiac output a superior correlation with the gol d standard was found using flow measurements (r = 0.66, p < 0.0007) compare d to volumetric calculations from cine studies (r = 0.47, p < 0.02). Intero bserver variability was 2.5 +/-2.7%/4.5 +/-6.9% (flow quantification/calcul ations from cine studies), intraobserver variability was 1.7 +/-1.6 %/3.3 /-2.2%. Conclusions: MRI is an appropriate tool for determining LV function al parameters and anatomy. Differences between normal volunteers and patien ts with aortic valvular disease can be detected reliably. Flow measurements turned out to be more accurate than calculations from cine images. Therefo re, flow quantification techniques should be preferred for clinical use.