TRANSLATIONAL CARDIAC MR RESEARCH CENTER

The diagnosis and management of cardiac disease requires a precise assessment of the parameters of cardiac morphology and function. CMRI is recognized as the gold standard for the assessment of left and right ventricular volume and mass in vivo. Assessment of GLOBAL FUNCTION of the heart requires the measurement of the chamber volumes at different points in the cardiac cycle. Quantification of volumetric dimensions requires segmentation of the acquired MR images to isolate the blood pool of the ventricle in multiple slices. Resulted measurements of the global heart function include:

  • Left ventricular volume at end systole (ESV)
  • Left ventricular volume at end diastole (EDV)
  • Left ventricular mass (LV mass): 1.05 x sum of slice volumes x slice thickness
  • Stroke volume (SV): EDV - ESV
  • Cardiac output (CO): SV x HR (heart rate)
  • Ejection fraction (EF): (EDV – ESV / EDV) x100%
  • Maximum ejection rate and maximum filling rate.

Assessment of the REGIONAL FUNCTION of the heart include:

  • Left ventricular wall thickness.
  • LV wall thickening, a relative difference in LV wall thickness in end-systole and end-diastole.
  • Myocardial strain (assessment of local tissue deformation).
  • Wall stress (WS) = SVP x 3 (1 + (3 x ESV/MV)), where SVP = systolic ventricular pressure, ESV = end systolic volume, and MV = myocardial volume.

VENTRICULAR REMODELING occurs after myocardial infarction in many species, including humans, and is typically characterized by progressive ventricular dilatation, eccentric hypertrophy, and contractile dysfunction. CMRI is a valuable method for assessment of interventions affecting remodeling of the left ventricle.

  • LV mass and wall thickness taken together allow an exact quantification of LV hypertrophy.
  • EDV is used for assessment of the heart ventricle dilatation.

CINE multislice images of the non-human primate's heart