Comparative Study Between Phase Contrast,Modified Simpson Rule and Myocardial Strain Analysis Methods of Cardiac MRI in Assessment of Estimated Corrected Ejection Fraction in Valvular Heart Disease.

Valvular heart diseases are common cardiovascular conditions that account for 10% to 20% of all cardiac surgical procedures.

In routine clinical practice,left ventricular performance is one of the most important prognostic factors in valvular heart diseases,whether treated medically or surgically.It gives valuable information that may be useful in the selection of therapy or determination of the optimal time for intervention.

Cardiovascular MR has grown to be a widely used clinical tool for evaluating cardiovascular disease,it is designed to assess cardiovascular morphology,ventricular function,myocardial perfusion,tissue characterization,flow quantification and coronary artery disease.Utilization of CMR for evaluation of valvular regurgitation has recently been recognized as part of the American Society of Echocardiography (ASE) and the Society of Cardiovascular Magnetic Resonance (SCMR) recommendations. In previous guidelines,CMR was only advocated in valvular disease in situations where echocardiographic evaluation was insufficient or inconclusive.However,with excellent spatial and temporal resolution,CMR may provide added benefits for valvular evaluation,including visualization of valve structure, direct measurements of flow,assessment of ventricular volumes, and quantification of regurgitant volumes and fractions .Among CMR techniques are:

• Phase-contrast MRI a technique with which flow can be measured accurately with flexible spatial and temporal resolution .The severity of valvular disease can be assessed and quantified with Phase contrast MRI providing the ability to quantify peak velocities and flow across the valves.
• Simpson rule a method to calculate cardiac global function parameters out of multiple single slices,quantifying volumetric indices of the heart directly from the 3 dimensional dataset; an ability that sets it apart from other modalities. End-Diastolic Volume,End-Systolic Volume,Stroke Volume,Ejection Fraction and Ventricular Mass can be obtained using Simpson rule making it able to determine these measurements in the right side as well as the left.
• Myocardial Strain Analysis provides higher spatial resolution than echocardiography and is useful for the quantitative assessment of cardiac function.Measurement of left ventricular volume parameters such as ejection fraction, end diastolic volume, end systolic volume, stroke volume , cardiac output ,cardiac index and contractile function are possible in analysis using MRI.