High frequency, high frame-rate ultrasound imaging

Abstract

A system for producing an ultrasound image comprises a scan head having a transducer capable of generating ultrasound energy at a frequency of at least 20 megahertz (MHz), and a processor for receiving ultrasound energy and for generating an ultrasound image at a frame rate of at least 15 frames per second (fps).

1 . A scanhead for use with an ultrasound imaging system, comprising: 
 a transducer assembly comprising a single element ultrasonic transducer that is configured to generate ultrasound at a frequency of at least 20 megahertz (20 MHz), to transmit at least a portion of the generated ultrasound into a subject and to receive ultrasound energy from the subject;    an elongate member having a proximal end, wherein the elongate member is configured to pivot about a pivot axis spaced from the proximal end, and wherein the transducer assembly is non-rotatably coupled to the proximal end of the elongate member;    a means for oscillating the transducer along a reciprocating convex arcuate path at a frequency of at least 7.5 Hz, wherein a portion of the means for oscillating is fixed relative to the elongate member and moves along a reciprocating arcuate route remote from the reciprocating arcuate path of the transducer such that movement of the portion of the means for oscillating causes a complementary and opposite movement of the transducer, and wherein the reciprocating arcuate path of the transducer is co-planer to the reciprocating arcuate route of the portion of the means for oscillating; and    a means for sensing the spatial position of a proximal end of the portion of the means for oscillating along the reciprocating actuate route to determine the position of the transducer along its arcuate path.    
   
   
       2 . The scanhead of  claim 1 , wherein the transducer is a broadband transducer.  
   
   
       3 . The scanhead of  claim 1 , wherein the transducer assembly and at least a portion of the elongate member are located within an enclosed volume, and wherein the enclosed volume is at least partially filled with a fluid.  
   
   
       4 . The scanhead of  claim 3 , wherein the enclosed volume is partially defined by an acoustically penetrable membrane and wherein the acoustically penetrable membrane is positioned such that at least a portion of the generated ultrasound can pass therethrough the membrane before being transmitted into the subject.  
   
   
       5 . The scanhead of  claim 4 , wherein the acoustically penetrable membrane comprises a material selected from the group consisting of: polyester, polycarbonate, acrylic, thermoplastic elastomer, silicone elastomer, latex elastomer, Surlyn® ionomer, Surlyn® 8940, Kapton®, polymethyl pentene, TPX® MX-002, TPX® 95, MX-004; Teflon®, Mylar®, polyethylene, polytetrafluoroethylene, polycarbonate, polypropylene, and polyurethane films.  
   
   
       6 . The scanhead of  claim 1 , further comprising a position encoder configured to determine the position of the transducer along its reciprocating arcuate path.  
   
   
       7 . The scanhead of  claim 6 , wherein the position encoder is configured such that the position of the transducer can be accurately tracked along the reciprocating arcuate path to within about 1.0 micron (μm) of the actual transducer position.  
   
   
       8 . The scanhead of  claim 1 , wherein the means for oscillating comprises a limited angle motor.  
   
   
       9 . An ultrasound imaging system, comprising: 
 the scanhead of  claim 1;  and    a processor configured to process the received ultrasound to provide an image having a frame rate of at least 15 frames per second (fps).    
   
   
       10 . The system of  claim 9 , wherein the processor is further configured to produce an ultrasound image having a spatial resolution of less than about 100 microns (μm).  
   
   
       11 . The system of  claim 10 , wherein the processor is further configured to produce an ultrasound image having a spatial resolution of about and between 75-100 microns (μm).  
   
   
       12 . The system of  claim 10 , wherein the processor is further configured to produce an ultrasound image having a spatial resolution of about and between 30-100 microns (μm).  
   
   
       13 . The system of  claim 9 , wherein the transducer can be oscillated along the reciprocating arcuate path at a frequency of at least 15 Hz, and wherein the processor is configured to provide an image having a frame rate of at least 30 fps and a spatial resolution of less than about 100 microns (μm).  
   
   
       14 . An ultrasound imaging system, comprising: 
 the scanhead of  claim 1;     a processor configured to process the received ultrasound to provide an image having a frame rate of at least 15 frames per second (fps); and    a means for positioning the transducer to within about 1 micron (μm) of a predetermined location along the reciprocating arcuate path.    
   
   
       15 . The ultrasound imaging system of  claim 14 , wherein the processor is further configured to provide a pulsed-wave Doppler image.  
   
   
       16 . The ultrasound imaging system of  claim 14 , wherein the processor is further configured to provide an M-Mode image.