Ultrasonic diagnosis apparatus

Abstract

An ultrasonic diagnosis apparatus comprises an ultrasound probe, a transmitter (including a transmitting pulse generator and a transmitting beamformer), a receiver (including a preamplifier and a receiving beamformer), a CFM processor (including a moving-element signal extractor and a velocity corrector), a tomographic image processor, and a display unit. The apparatus scans a desired section of a subject by transmitting and receiving an ultrasound pulse to and from the subject, and displays images obtained by the scanning. The velocity corrector comprises a pulsation-characterizing-velocity (velocities of a moving element) calculator, a representative velocity (reference velocity) calculator, and a corrector to correct the velocities of the moving element based on the standard velocity. The corrected velocity data is visualized on display unit. The ultrasonic diagnosis apparatus makes it possible to display the pulsatility of blood vessels in an easier and useful way.

1 . An ultrasonic diagnosis apparatus comprising: 
 scanning means for scanning a subject to be examined while transmitting and receiving an ultrasound pulse to and from the subject;    means for obtaining in sequence a plurality of velocities of a moving element within the subject based on reception signals acquired by the scanning performed by the scanning means;    processing means for computing a reference velocity based on the plurality of velocities obtained from during a predetermined period of time and correcting each of the velocities of the moving element using the reference velocity so that data of the corrected velocities is obtained; and    displaying means for displaying the data so that the data is updated a plurality of times during the predetermined period of time.    
   
   
       2 . The ultrasonic diagnosis apparatus according to  claim 1 , wherein the reference velocity is at least one selected from 
 1) a mean of velocities acquired during a predetermined period of time or an absolute value of the mean thereof,    2) a mean of absolute values of velocities acquired during a predetermined period of time,    3) an RMS (Root Mean Squire Value) value of velocities acquired during a predetermined period of time,    4) a value or an absolute value thereof, which is calculated by applying any one of an FIR (Finite Impulse Response) filter, IIR (Infinite Impulse Response) filer, and a non-linear filter to velocities acquired during a predetermined period of time or absolute values of the velocities, and    5) a vectorial mean of velocities acquired from a predetermined period of time or an absolute value of the mean.    
   
   
       3 . The ultrasonic diagnosis apparatus according to  claim 1 , wherein the processing means comprises at least one of 
 1) means for dividing the velocities of the moving element by the reference velocity, and    2) means for converting the velocities of the moving element to values relative to the reference velocity.    
   
   
       4 . An ultrasonic diagnosis apparatus comprising: 
 scanning means for scanning a subject to be examined while transmitting and receiving an ultrasound pulse to and from the subject;    means for obtaining velocity information about a moving element within the subject based on reception signals acquired by the scanning performed by the scanning means;    display image producing means for producing an image to be displayed indicative of a state of pulsation on the basis of the velocity information; and    means for controlling the display image producing means so that display of the pulsation is switched on or off on the basis of the velocity information.    
   
   
       5 . The ultrasonic diagnosis apparatus according to  claim 1 , wherein the processing means has at least one of means for correcting aliasing resultant from a sampling theorem for the velocities and means for moderating temporal changes in the data obtained by the processing means.  
   
   
       6 . The ultrasonic diagnosis apparatus according to  claim 1 , wherein the scanning means is configured to scan one section of the subject at the number of frames larger than a value indicated by an inverse number of a period of time corresponding to an ejection period of cardiac pulsation.  
   
   
       7 . The ultrasonic diagnosis apparatus according to  claim 1 , wherein the display means is configured to display a two-dimensional image of the data obtained by the processing means.  
   
   
       8 . An ultrasonic diagnosis apparatus comprising: 
 scanning means for three-dimensionally scanning one section of a subject to be examined a plurality of times corresponding to one heartbeat while transmitting and receiving an ultrasound pulse to and from the subject;    means for obtaining in sequence velocities of a moving element within the subject based on reception signals obtained three-dimensionally by the scanning means;    processing means for computing a reference velocity based on the plurality of velocities obtained from during a predetermined period of time and correcting each of the velocities of the moving element using the reference velocity so that data of the corrected velocities is obtained; and    displaying means for displaying at least a three-dimensional image based on the data so that the image is updated a plurality of times during the predetermined period of time.    
   
   
       9 . The ultrasonic diagnosis apparatus according to  claim 8 , wherein the scanning means is configured to three-dimensionally scan the subject through an electrical scan by means of a two-dimensional array type of transducer, the velocities of the moving element are set to a maximum velocity during a predetermined period of time, and the reference velocity is information that is unchangeable over cardiac time phases of the subject.  
   
   
       10 . The ultrasonic diagnosis apparatus according to claim  8 , further comprising means for obtaining a tomographic image of the section, 
 wherein the display means has at least one of means for displaying on the same monitor the tomographic image and the image of data obtained by the processing means and means for displaying on the tomographic image the image of data obtained by the processing means in a superposition manner, the tomographic image being a two-dimensional image and a three-dimensional image.    
   
   
       11 . The ultrasonic diagnosis apparatus according to either of  claim 1  or  8 , further comprising at least one of 
 means for displaying in colors the image of data obtained by the processing means,    means for displaying pieces of information formed by combining the data obtained by the processing means and power information of scattering echoes from the moving element within the subject,    means for displaying a color bar mapped not only by a hue indicative of a lower velocity when magnitudes of the data obtained by the processing means are nearly equal to or less than the reference velocity but also by other hues indicative of higher velocities as the magnitude of the data obtained by the processing means becomes larger than a value nearly equal to the reference velocity, and    means for displaying together both of the data obtained by the processing means and an aliasing velocity.    
   
   
       12 . The ultrasonic diagnosis apparatus according to either of  claim 1  or  8 , wherein the processing means includes means for obtaining the velocities of the moving element within the subject pixel by pixel, the apparatus further comprising means for displaying together both of a graph showing temporal changes in the velocities at one or more of the pixels and the image of the data obtained by the processing means.  
   
   
       13 . The ultrasonic diagnosis apparatus according to  claim 8 , wherein the processing means comprises processing means for obtaining factors including a pulsatility index (PI) and a resistivity index (RI).  
   
   
       14 . The ultrasonic diagnosis apparatus according to either of  claim 1  or  8 , further comprising at least one of 
 means for displaying by mixture the image of the data obtained by the processing means and an information of power information of scattering echoes from the moving element within the subject,    means for displaying by mixture an image of the power information and an image of information formed by combining the data obtained by the processing means and the power information,    means for displaying together both of a color bar for the data obtained by the processing means and another color bar for the power information,    means for displaying together both of a color bar indicative of a combination of the data obtained by the processing means and the power information and another color bar for the power information,    means for setting an upper limit and a lower limit on the color bar for the data obtained by the processing means, and    means for displaying at least one of an upper limit, a lower limit, and an aliasing velocity on the color bar for the data obtained by the processing means.    
   
   
       15 . The ultrasonic diagnosis apparatus according to claim  2 , further comprising means for re-averaging velocities of the moving element which are equal to or smaller than a value produced by multiplying the average by “1+α” (α≧0) after the average and for setting to the reference velocity another mean obtained by the re-averaging.