ABSTRACT
Our objective was to establish normal ranges of left and right ventricular mass and function with cine magnetic resonance imaging (MRI) and to determine gender differences. Seventy-five healthy subjects (age range 8-55, mean 28 yr) were studied with cine MRI. Ten dogs were imaged for autopsy validation with a mean difference between actual and MRI-determined mass of 0.2 A +/- 8.4 g. Intraobserver and interobserver variability and interstudy variability were 5-6%. All parameters were significantly different between males and females except ejection fraction and the left ventricular mass to end-diastolic volume ratio. Agreement with published autopsy series, including gender differences, was excellent. This study presents normative MRI data that can be used for comparing individual patients and for further study of right and left ventricular interaction.
Subject(s)
Magnetic Resonance Imaging, Cine , Ventricular Function, Left/physiology , Ventricular Function, Right/physiology , Adolescent , Adult , Animals , Cardiac Volume , Child , Dogs , Female , Humans , Image Processing, Computer-Assisted , Linear Models , Male , Middle Aged , Observer Variation , Reference Values , Sex Characteristics , Systole/physiologyABSTRACT
As the importance of the right ventricle in many diseases and conditions has been realized, the need for quantitative assessment of the motion and contraction of the right ventricular free wall (RVFW) has become apparent. This study applied the myocardial tagging magnetic resonance imaging (MRI) technique to the normal RVFW to elucidate normal heterogeneity in RV motion and contractile patterns. The RVFW was divided into three segments (inferior, mid and superior) in each of three slices (apical, mid and basal) to allow for a detailed analysis of the motion and contraction. Percent segmental shortening (PSS) was used to measure the amount of contraction, and a vector analysis was used to quantitate the trajectory of the RVFW through systole. PSS increased monotonically through time to an average across all segments of 12% in the basal slice, 14% in the mid-ventricular slice, and 16% in the apical slice of the heart. The trajectory of the RVFW was characterized by a wave of motion toward the septum and outflow tract. The data provided in this study provide a better understanding of normal RV kinematics and can serve as a comparison for disease states.
