%0 Journal Article
%T The Transaxial Orientation Is Superior to Both the Short Axis and Horizontal Long Axis Orientations for Determining Right Ventricular Volume and Ejection Fraction Using Simpson's Method with Cardiac Magnetic Resonance
%A Michael K. Atalay
%A Kevin J. Chang
%A David J. Grand
%A Shawn Haji-Momenian
%A Jason T. Machan
%A Florence H. Sheehan
%J ISRN Cardiology
%D 2013
%R 10.1155/2013/268697
%X We sought to determine which of the three orientations is the most reliable and accurate for quantifying right ventricular (RV) volume and ejection fraction (EF) by cardiac magnetic resonance using Simpson¡¯s method. We studied 20 patients using short axis (SA), transaxial (TA), and horizontal long axis (HLA) orientations. Three readers independently traced RV endocardial contours at end-diastole and end-systole for each orientation. End-diastolic volumes (EDVs), end-systolic volumes (ESVs), and EF were calculated and compared with the 3D piecewise smooth subdivision surface (PSSS) method. The intraclass correlation coefficients among the 3 readers for EDV, ESV, and EF were 0.92, 0.82, and 0.42, respectively, for SA, 0.95, 0.92, and 0.67 for TA, and 0.85, 0.93, and 0.69 for HLA. For mean data there was no significant difference between TA and PSSS for EDV (£¿2.6%, 95% CI: £¿8.2 to 3.3%), ESV (£¿5.9%, £¿15.2 to 4.5%), and EF (1.7%, £¿1.5 to 4.9%). HLA was accurate for ESV (£¿8.9%, £¿18.5 to 1.8%) and EF (£¿0.7%, £¿3.8 to 2.5%) but significantly underestimated EDV (£¿9.8, £¿16.6 to £¿2.4%). SA was accurate for EDV (0.5%, £¿6.0 to 7.5%) but overestimated ESV (10.5%, 0.1 to 21.9%) and had poor interrater reliability for EF. Conclusions. The TA orientation provides the most reliable and accurate measures of EDV, ESV, and EF. 1. Introduction Right ventricular (RV) dysfunction can occur in several congenital and acquired disease states, and the importance of evaluating RV size and function has become increasingly evident [1, 2]. Two-dimensional echocardiography and nuclear techniques are used in clinical practice to qualitatively survey RV size and function [3, 4]. Due chiefly to the complex shape, thin wall, and substernal location of the RV, these methods are limited in their ability to accurately assess morphology and function. It has become generally accepted that MRI, with its high temporal, spatial, and contrast resolution, provides the most comprehensive and robust assessment of the RV [5¨C7]. However, because of its complex shape and associated problems with contour delineation and partial volume averaging, there is no clearly preferred axis for RV volumetric analysis using Simpson¡¯s method of slice summation. Although stacked short axis (SA) slices obtained for LV evaluation are routinely available in clinical cardiac magnetic resonance (CMR) and can be used to calculate RV volumes and ejection fraction (EF) [7, 8], it has recently been suggested that quantitative assessment of RV chamber volumes is more reliable using the transaxial (TA) orientation [9, 10]. A
%U http://www.hindawi.com/journals/isrn.cardiology/2013/268697/