Richard Takx

Publications of Richard Takx

• Reproducibility of left and right ventricular mass measurements with cardiac CT.

  Authors: Florian Schwarz, Richard Takx, U Joseph Schoepf, Yeong Shyan Lee, Balazs Ruzsics, Eva Maria Gassner, Salvatore Chiaramida, Thomas Henzler

  Journal of cardiovascular computed tomography. 08/2011; 5(5):317-24.

  Cardiac CT provides volumetric data that enables characterization of the myocardium. We evaluated intraobserver, interobserver, and interstudy reproducibility of left ventricular (LV) and rightCardiac CT provides volumetric data that enables characterization of the myocardium. We evaluated intraobserver, interobserver, and interstudy reproducibility of left ventricular (LV) and right ventricular (RV) mass quantification with cardiac CT. Thirty-eight patients who underwent cardiac CT twice within 365 days were included in this analysis. Functional reconstructions in 10% steps throughout the R-R interval and axial 1.5-mm sections were used. Semiautomatic contour detection was used to trace epicardial and endocardial borders in all cardiac phases for calculation of LV and RV ejection fraction, end-diastolic volume, end-systolic volume, cardiac output, stroke volume, and ventricular mass. For each study 2 observers measured LV and RV mass twice. LV mass parameters derived from semiautomatic contour detection algorithm had excellent intraobserver (r = 1.00), interobserver (r = 0.99), and interstudy (r = 0.99) reproducibility (P < 0.0001). Average end-diastolic LV mass was 146.2 ± 42.9 g at the first CT study and 146.8 ± 44.4 g at the second study. For measuring RV mass, reproducibility was good on all levels (r = 0.78, r = 0.78, and r = 0.68, respectively, with an average end-diastolic mass of 25.7 ± 5.8 g at the first study and 24.4 ± 4.8 g at the second study. Quantification of LV mass at cardiac CT with the threshold-based, region-growing semiautomatic segmentation analysis software evaluated here is highly observer independent and reproducible. This largely holds true for the estimation of RV mass as well; however, further improvements are needed to optimize reproducibility for RV mass quantification.

• Recurrent subaortic membrane causing subvalvular aortic stenosis 13 years after primary surgical resection.

  Authors: Richard Takx, U Joseph Schoepf, Brad Friedman, Anthony M Hlavacek, Thomas Henzler

  Journal of cardiovascular computed tomography. 01/2011; 5(2):127-8.

  This case demonstrates the use of cardiac CT angiography as part of the preoperative evaluation of a recurrent subaortic membrane in a 23-year-old women. A subaortic membrane is a rare finding onThis case demonstrates the use of cardiac CT angiography as part of the preoperative evaluation of a recurrent subaortic membrane in a 23-year-old women. A subaortic membrane is a rare finding on coronary CT angiography and typically consists of a thin fibrous membrane in the left ventricular outflow tract (LVOT). The resulting turbulent flow may lead to LVOT obstruction and aortic insufficiency.