This technology includes a versatile intravascular 3D intracardiac echocardiography (ICE) catheter that can operate under conventional X-ray and MRI for use during interventional cardiac procedures. The 3D MRICE and custom, GPU-based, real-time imaging system are also included. Structural heart disease affects more than 2.9% of the US population, and common interventional procedures can be difficult because of limitations in catheter devices and inadequate image guidance. Miniaturization of ultrasound probes to provide uninterrupted real-time full-volume intra-procedural 3D en-face depiction of cardiac pathology and catheter devices would represent a dramatic advance in image-guided intervention. A 3D ICE probe that can operate safely during MRI and conventional X-ray would revolutionize the capabilities of transcatheter therapy by enabling radiation-free, non-surgical catheter navigation. This invention describes such a catheter, the 3D MRICE. This catheter uses CMUT-on-CMOS technology and massive parallel RF data multiplexing to implement an ultraminiature, single chip volumetric ultrasound imaging system.