Abstract
Purpose :
All prior color-flow Doppler ultrasound studies of the eye has been performed with non-commercial units that exceed U.S. Food and Drug Administration (FDA) permissible ultrasonic energy limits when applied to the eye. Our aim is to study normal vascular anatomy and vascular malformations in the orbit using a novel ultrafast compound coherent plane-wave ultrasound (CCPU) device to produce power Doppler images that complies with FDA guidelines.
Methods :
Using a Versonics (Verasonics, Inc., Kirkland, WA) Vantage 128 ultrasound engine and a user-developed MATLAB (The MathWorks, Inc., Natick, MA) program with a 5 MHz linear-array probe, CCPU data were collected on patients with vascular malformations and normal orbits. Real-time color-flow Doppler visualized orbital blood flow. Power Doppler images were produced by post-processing CCPU images acquired continuously for 2-seconds.
Results :
CCPU was performed on seven orbits (2 normal, 2 venolymphatic malformations, 1 arterio-venous malformation, 1 cavernous hemangioma, 1 orbital varix). The power Doppler images corresponding to MRI imaging from four of the cases are highlighted (Figures 1-4). Preliminary results demonstrate that CCPU produces higher-resolution depiction of orbital blood flow compared to conventional color-Doppler technology for normal vascular anatomy and orbital vascular malformations. There is also increased sensitivity to slow flow. In addition, CCPU produces much higher resolution of vascular malformations, dilated vessels and areas of abnormal blood flow when compared to standard MRI imaging.
Conclusions :
CCPU is unfocused on emission; instead, focusing is performed on received echo data. Consequently, the ultrasound intensity is substantially lower than in conventionally focused ultrasound linear array systems and it falls well within FDA guidelines. CCPU offers a new modality to better understand normal ocular vascular anatomy and complex vascular malformations. Information regarding blood flow in orbital lesions is a valuable aid to treatment planning.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.