NEW AND FUTURE-DEVELOPMENTS IN CEREBROVASCULAR ULTRASOUND, MAGNETIC-RESONANCE ANGIOGRAPHY, AND RELATED TECHNIQUES

Four-dimensional (4D) analysis of atherosclerotic plaque and wall moti on, the application of 4D ultrasound to the study of atherogenesis, an d the incorporation of ultrasound data into flow models for simulation of cerebrovascular hemodynamics are new frontiers in diagnostic ultra sound that use computer vision and optical flow techniques to exploit the full potential of real-time imaging and Doppler studies. New appro aches to improve blood vessel delineation with ultrasound include appl ication of contrast agents, harmonic imaging, and red blood cell densi ty imaging. An assessment of the potential clinical utility of these n ew developments in cerebrovascular ultrasound requires an analysis of comparable trends in magnetic resonance (MR) technology, eg, rapid adv ances in the fields of MR angiography, dynamic contrast-enhanced MR, a nd MR diffusion imaging. Likewise, the value of ultrasound techniques for the measurement of blood flow to evaluate cerebrovascular hemodyna mics must be compared to related methods in magnetic resonance, such a s dynamic MR inflow tracking. This article addresses several new and f uture developments in cerebrovascular ultrasound and discusses their r elative merits in terms of ongoing research in the field of magnetic r esonance angiography, imaging, and related techniques. (C) 1995 John W iley and Sons, Inc.