Regurgitation Quantification Using 3D PISA in Volume Echocardiography Leo Grady 1 , Saurabh Datta 2 , Oliver Kutter 1 , Christophe Duong 2 , Wolfgang Wein 3 , Stephen H. Little 4 , Stephen R. Igo 4 , Shizhen Liu 5 , and Mani Vannan 5 1 Siemens Corporate Research, Princeton, NJ, USA 2 Siemens Healthcare, Ultrasound Business Unit, Mountain View, CA, USA 3 White Lion Technologies AG, Munich, Germany 4 Methodist DeBakey Heart and Vascular Center, Houston, TX, USA 5 Ohio State University, Columbus OH, USA Abstract. We present the first system for measurement of proximal isovelocity surface area (PISA) on a 3D ultrasound acquisition using modified ultrasound hardware, volumetric image segmentation and a simple efficient workflow. Accurate measurement of the PISA in 3D flow through a valve is an emerging method for quantitatively assessing car- diac valve regurgitation and function. Current state of the art protocols for assessing regurgitant flow require laborious and time consuming user interaction with the data, where a precise execution is crucial for an ac- curate diagnosis. We propose a new improved 3D PISA workflow that is initialized interactively with two points, followed by fully automatic seg- mentation of the valve annulus and isovelocity surface area computation. Our system is first validated against several in vitro phantoms to verify the calculations of surface area, orifice area and regurgitant flow. Finally, we use our system to compare orifice area calculations obtained from in vivo patient imaging measurements to an independent measurement and then use our system to successfully classify patients into mild-moderate regurgitation and moderate-severe regurgitation categories. 1 Introduction Valvular heart diseases are a major cause of death in developed countries, which are estimated to affect 2.5% of the population and are the underlying cause of over 43700 deaths and 93000 hospital discharges in 2006 in the US. Pooled data from multiple studies suggest that the prevalence increases with age from 0.7% in par- ticipants 18–44 years of age to 13.3% in participants ≥ 75 years of age. The cause of these diseases can be congenital or acquired and, depending on the severity, treatment might involve medication, surgical valve repair or replacement. Timely diagnosis and accurate assessment of regurgitation severity is important for ap- propriate clinical decision making and optimal patient outcome [3]. Doppler ultrasound is routinely used to non-invasively evaluate intracardiac blood flow and detect regurgitant lesions for all cardiac valves. Several indexes G. Fichtinger, A. Martel, and T. Peters (Eds.): MICCAI 2011, Part III, LNCS 6893, pp. 512–519, 2011. c  Springer-Verlag Berlin Heidelberg 2011