http://repub.eur.nl/res/aut/38302/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/27478/ 2010-06-01T00:00:00Z The right ventricular (RV) volume is commonly measured from magnetic resonance images using Simpson's method from the stack of short-axis images acquired for analysis of the left ventricle. We compared the RV volume measured using Simpson's method to the RV volume measured using 3-dimensional reconstruction and the piecewise smooth subdivision surface (PSSS) method. We studied 6 normal subjects and 18 patients whose right ventricles carried a systemic pressure load, 1/2 with dexto-transposition of the great arteries repaired with an atrial baffle and 1/2 with levo-transposition of the great arteries. The right ventricle was reconstructed from manually traced borders from the short- and long-axis views using the PSSS method. Simpson's analysis was performed on short-axis views alone. The RV volumes were smaller when analyzed using Simpson's method than using the PSSS method. The underestimation averaged 12 ± 19 ml (7 ± 12% of PSSS volume; p <0.001), without a significant difference between the groups. The ejection fraction was similar using both methods in patients with transposition of the great arteries and was overestimated in normal subjects. Image review revealed that the volume underestimation using Simpson's method was more frequently due to difficulty in interpreting the basal short-axis images than the apical images. In conclusion, to obtain accurate analysis of the short-axis views for RV volume measurement, it would be helpful to incorporate information from additional images, such as the long-axis views, to assist in delineating this chamber's complex anatomy. http://repub.eur.nl/res/pub/27628/ 2010-04-01T00:00:00Z We tested the accuracy and reproducibility of knowledge-based reconstruction (KBR) for measuring right ventricular (RV) volume and function. KBR enables rapid assessment of the right ventricle from sparse user input by referencing a database. KBR generates a 3-dimensional surface to fit points that the user enters at anatomic landmarks. We measured the RV volume using KBR from magnetic resonance images in 20 patients with repaired tetralogy of Fallot at end-diastole and end-systole. We entered points in the long- and short-axis and/or oblique views. The true volume was computed by manually tracing the RV borders for 3-dimensional reconstruction using the piecewise smooth subdivision surface method. The reference database included 54 patients with tetralogy of Fallot patients. The KBR values agreed closely with the true values for the end-diastolic volume (r = 0.993), end-systolic volume (r = 0.992), and ejection fraction (EF; r = 0.930). KBR slightly overestimated the end-diastolic volume (4 ± 10 ml, p = NS), end-systolic volume (1 ± 9 ml, p = NS), and EF (4 ± 3%, p = NS). No bias in the error was found by Bland-Altman analysis (p = NS for end-diastolic and end-systolic volume and EF). The KBR volumes had approached the true volumes (235 ± 93 vs 243 ± 93, p = 0.012, r = 0.978 for end-diastolic and end-systolic volumes combined) already after the first run and the entry of 19 ± 3 points. In conclusion, KBR provided accurate measurement of the RV volume and EF with minimal user input. KBR is a clinically feasible alternative to full manual tracing of the heart borders from imaging data.